JPH0796949A - Easy-to-open gas-barrier wrapping bag - Google Patents

Abstract

PURPOSE:To align a stretching direction with a tearing direction to improve tearableness by making a cut in a direction equal to a stretching direction of a high polymer resin layer having transparency which is layered on a high polymer material base having transparency. CONSTITUTION:On a surface of a base material of a resin film having transparency which has been uniaxially stretched in a certain direction, evaporated film laminate with a thin film layer comprising an evaporated film of metal oxide formed is overlaid. A sealing bag maker is used to heat-fuse four sides by a heat-sealing method or the like to from a seal 41 to obtain a wrapping bag 1. A cut of a notch 42 of a part of the seal 41 is formed in line by a razor- like cutter blade after heat fusion during a bag making process thereby affording an easy-to-open wrapping bag.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier packaging bag comprising a vapor deposition film laminate having a vapor deposition film layer of a metal oxide having transparency and gas barrier properties, and particularly a gas barrier packaging bag which can be easily opened. Regarding

[0002]

2. Description of the Related Art In recent years, packaging materials used for packaging foods, pharmaceuticals, precision electronic parts, etc. suppress deterioration of contents, particularly oxidation and deterioration of proteins, fats and oils in foods, and further improve taste and freshness. In order to hold the product, in pharmaceutical products that require aseptic handling, it suppresses the deterioration of the active ingredient and maintains its efficacy, and in precision electronic components, it also prevents corrosion and poor insulation of metal parts. In order to
It is necessary to prevent the influence of oxygen, water vapor, and other gases that change the contents of the packaging material, and it is required to have a gas barrier property of blocking these gases.

Therefore, polymer resin compositions such as polypropylene (KOP) coated with vinylidene chloride resin, polyethylene terephthalate (KPET) or ethylene vinyl alcohol copolymer (EVOH), which are generally said to have a relatively high gas barrier property, have been conventionally used. The packaging film used as a gas barrier material, a metal foil made of a metal such as Al, a suitable polymer resin composition (alone, even a resin that does not have a high gas barrier property)
A packaging film using a metal deposition film obtained by depositing a metal or a metal compound as a packaging material has been generally used.

However, the packaging film using only the above-mentioned polymer resin composition is inferior in gas barrier property as compared with a foil using a metal or a metal compound such as Al or a metal vapor deposition film formed with a vapor deposition film. However, it is susceptible to temperature and humidity, and the gas barrier property may be further deteriorated depending on the change. On the other hand, a foil using a metal or a metal compound such as Al or a metal vapor deposition film on which a vapor deposition film is formed is less affected by temperature and humidity and has excellent gas barrier properties, but the contents of the package can be seen through. However, it has a drawback that it must be treated as an incombustible material when it is discarded after use, which cannot be confirmed.

Therefore, as a packaging material that overcomes these disadvantages, for example, US Pat.
A metal oxide such as magnesium oxide, silicon oxide, aluminum oxide or tin oxide as described in JP-A-3-28017 is formed on a polymer film by a vapor deposition method or a sputtering method to form a vapor deposition film. Formed films are being developed. This film is known to have transparency and gas barrier properties such as oxygen and water vapor,
It is suitable as a packaging material having both transparency and gas barrier properties that cannot be obtained by a metal vapor deposition film.

By the way, even a vapor-deposited film suitable for the above-mentioned packaging material is rarely used as a vapor-deposited film alone, and is post-processed after vapor deposition as a packaging container or a packaging material. To make this a packaging bag,
It is laminated with other base materials to form a laminate that can be processed into a packaging bag, and then processed into a bag shape through a bag manufacturing process. That is, the heat seal layer made of a thermoplastic resin layer is provided while sufficiently maintaining the transparency and gas barrier properties specific to the vapor deposition film, and the heat seal layers are heat-sealed by the heat seal method.

[Problems to be Solved by the Invention]

However, the packaging bag used for packaging foods, pharmaceuticals, precision electronic parts, etc. is required to be easily opened by ordinary consumers without using scissors, knives, cutters, etc., except in special cases. However, the packaging bag made from the above vapor-deposited film laminate is generally made of a polymer material that is biaxially stretched from the viewpoint of vapor deposition suitability for a substrate to be vapor-deposited. A packaging bag using a base material that is difficult to tear itself has a problem that it is difficult to open and cannot be easily opened.Also, even if a notch or other notch is made on the edge of the packaging bag to improve the opening property, Since it is stretched in the axial direction, the tearing direction is not fixed, and although it can be opened to some extent, there is a problem that the packaging bag cannot be opened neatly with a small force.

Therefore, an object of the present invention is to provide a packaging bag which is colorless and transparent, has excellent transparency, has a high gas barrier property, and has excellent bag opening property, that is, tearing property.

[0009]

The present invention has been made to solve the above problems, and the invention according to claim 1 is a substrate made of a polymer material having uniaxial stretching in one direction and having transparency. Metal oxide thin film layer, a heat-sealing layer consisting of a thermoplastic resin is sequentially laminated on both end surfaces or a plurality of laminates, to form a sealing portion by heat fusion of the heat-sealing layer surfaces, and, A gas barrier packaging bag having an easy-open property, characterized in that a cut is provided in an edge of the sealing portion in the same direction as the stretching direction of the base material.

According to the second aspect of the present invention, a metal oxide thin film layer is formed on a substrate made of a transparent polymer material uniaxially stretched in one direction, and the metal oxide thin film layer side is stretched. A resin layer made of a polymer material having transparency is sequentially laminated, and both end surfaces or a plurality of sheets of a laminate obtained by laminating a heat seal layer made of a thermoplastic resin on one of the surfaces are laminated, and the heat seal is formed. A gas barrier packaging bag having an easy-opening property, characterized in that a sealing portion is formed by heat-sealing layer surfaces, and a cut is provided in an edge of the sealing portion in the same direction as the stretching direction of the base material. is there.

According to the third aspect of the present invention, a metal oxide thin film layer is provided on a base material made of a polymer material having transparency, and transparency is obtained by uniaxially stretching the metal oxide thin film layer side in one direction. Sequentially laminating a resin layer made of a polymer material, and laminating a heat-sealing layer made of a thermoplastic resin on either side of the laminated body at both end faces or a plurality of layers, and heat-sealing the heat-sealing layer faces. A gas barrier packaging bag having an easy-opening property, characterized in that a sealing part is formed by fusion bonding, and a cut is provided in an edge of the sealing part in the same direction as the stretching direction of the base material.

The invention described in claim 4 is a gas barrier packaging bag having an easy-open property, wherein the metal oxide thin film layer is magnesium oxide, silicon oxide, aluminum oxide, or tin oxide.

According to a fifth aspect of the present invention, there is provided a gas barrier packaging bag having an easy-open property, characterized in that a heat-sealing layer is formed on at least a part of both surfaces of the laminate.

[0014]

The gas barrier packaging bag having an easy-open property according to the present invention has a transparency which is laminated on a base material made of a polymer material having transparency or a base material made of a polymer material having transparency. By providing a notch in the same direction as the stretching direction of the resin layer made of polymer material, the tearing direction matches the stretching direction, improving tearability and high light transmission and lowering gas passing through the thin film. Can be suppressed.

[0015]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a vapor-deposited film laminate that constitutes a gas barrier packaging bag having an easy-open property of the first invention, and FIG. 2 shows a gas barrier packaging bag having an easy-open property of the second invention. It is sectional drawing explaining the vapor deposition film laminated body which comprises, FIG. 3 is sectional drawing explaining the vapor deposition film laminated body which comprises the gas barrier packaging bag which has the easy opening property of 3rd invention, and FIG. 4 is this. It is a front view of a gas barrier packaging bag having an easy-open property of the invention.

First, the structure of the vapor-deposited film laminate 11 constituting the gas barrier packaging bag 1 having the easy-opening property of the first invention will be described with reference to FIG. Reference numeral 11 is a vapor deposition film laminate, and a thin film layer 13 made of a vapor deposition film of a metal oxide is formed on the surface of a base material 12. This thin film layer 13
May be formed on both sides of the substrate 12, or may be formed in multiple layers. Further, a heat seal layer 14 is formed on the thin film layer 13.

The base material 12 is a polymer material having transparency, and is particularly colorless and transparent, and in order to improve the unsealing property of the packaging bag after bag making, it is arranged in a certain direction, for example, in the horizontal direction or the vertical direction. Any uniaxially stretched resin film may be used, and those usually used as packaging materials are preferable. For example, uniaxially stretched polyethylene terephthalate (PE
T), polyester films such as polyethylene naphthalate, polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polyvinyl chloride films, polycarbonate films, polyacrylonitrile films, polyimide films, etc. are used, and mechanical strength and dimensional stability are used. Those having properties are preferable. These are processed into a film and used. Further, a film having excellent smoothness and a small amount of additives is preferable. In addition, in order to improve the adhesion of the thin film on the surface of the base material 12, corona treatment as pretreatment,
It may be subjected to a low temperature plasma treatment, an ion bombardment treatment, a chemical treatment, a solvent treatment or the like.

The thickness of the base material 12 is not particularly limited, but considering the suitability as a packaging material, the case where other layers are laminated, and the workability when the thin film layer 3 is formed, In practice, it can be said that it is preferably in the range of 3 to 200 μm, and 6 to 30 μm depending on the application.

In consideration of mass productivity, it is desirable to use a long film so that a thin film can be continuously formed.

When a transparent polymer material used for the substrate 12 is laminated as a resin layer, a film made of the above resin is subjected to a dry laminating method, a non-solvent laminating method, or the above resin is melted by heating to form a curtain. Lamination can be performed by a known method such as an extrusion laminating method in which extrusion and laminating are performed.

The thin film layer 13 is made of a vapor deposition film of a metal oxide such as magnesium oxide, silicon oxide, aluminum oxide, tin oxide, etc., as long as it is transparent and has a gas barrier property against oxygen, water vapor and the like. . Particularly, magnesium oxide is excellent in transparency and gas barrier property. However, the thin film layer 3 of the present invention is not limited to metal oxides of magnesium oxide, silicon oxide, and aluminum oxide, and any material that meets the above conditions can be used.

The thickness of the thin film layer 13 varies depending on the type and composition of the metal oxide used, but it is generally desirable to be in the range of 400 to 3000 Å, and the value is appropriately selected. . However, if the film thickness is less than 400 Å, the entire surface of the base material 2 may not be a film or the film thickness may not be sufficient, and it may not be possible to sufficiently fulfill the function as a gas barrier material. In addition, the film thickness is 3000
If it exceeds Å, the thin film cannot maintain flexibility, and the thin film may be cracked due to external factors such as bending and pulling after the film formation.

The substrate 12 is provided with a thin film layer 13 made of a metal oxide.
There are various methods of forming on the above, it can be formed by a usual vacuum deposition method such as resistance heating method, high frequency induction heating method, electron beam heating method, electron impact heating method, flash vapor deposition method, laser vapor deposition method, Ion beam sputtering is another thin film forming method. A sputtering method such as magnetron sputtering or an ion plating method can be used. However, if productivity is taken into consideration, the vacuum deposition method is currently the best. It is preferable that the heating means of the vacuum vapor deposition apparatus by the vacuum vapor deposition method is an electron beam heating method, and a plasma assist method or an ion beam assist method is used to improve the adhesion between the thin film and the substrate and the denseness of the thin film. Is also possible.

Next, the heat seal layer 14 is made of a thermoplastic resin such as polyethylene, unstretched polypropylene, ionomer, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer and Those metal crosslinked products and the like can be used, and are appropriately selected from these. The thickness is determined depending on the purpose, but is generally in the range of 15 to 200 μm. As a forming method, a known method such as a dry laminating method of laminating a film made of the above resin by a non-solvent laminating method, an extrusion laminating method in which the above resin is melted by heating and extruded in a curtain shape and pasted is laminated. can do.

The above vapor-deposited film laminates 11 are stacked as shown in FIG. 4, and the sealing bag 41 is formed on all four sides by heat-sealing such as heat-sealing with a sealing bag-making machine to obtain the packaging bag 1. You can Then, a notch 42 or the like may be formed in a part of the sealing portion 41 in-line with a razor blade-shaped cutter blade after heat fusion in the bag making process. The heat-sealing layer 14 can be provided at a necessary place so that pillow packaging and gusset packaging can be performed, and a bag making process such as a vertical pillow bag making machine or a gusset bag making machine is selected according to the packaging purpose, and the same process is performed. As a result, a packaging bag having an easy opening property can be obtained.

Next, the structure of the vapor-deposited film laminate 21 constituting the gas barrier packaging bag 1 having the easy-opening property of the second invention will be described with reference to FIG. Reference numeral 21 denotes a vapor deposition film laminate, and a thin film layer 23 made of a vapor deposition film of metal oxide is formed on the surface of a base material 22. The thin film layer 23 may be formed on both sides of the base material 22, or may be formed in multiple layers. Further, a resin layer 25 is laminated on the thin film layer 23, and a heat seal layer 24 is formed on the other surface of the base material 22.

The substrate 22 is the substrate 12, the thin film layer 23 is the thin film layer 23, and the heat seal layer 24 is the heat seal layer 1.
Same as 4.

A resin layer 2 formed on the side of the metal oxide thin film layer 23 and made of a stretched and transparent polymer material.
The film used for 5 is a general packaging film such as a biaxially oriented polyester film or a biaxially oriented polypropylene film, and the thickness is practically 5 to 50 μm.
The range is good. Further, a printing layer such as back printing may be provided on the laminated side of the films. As a method of forming the resin layer 25,
A method of laminating a film-like thing made of the above resin by a dry laminating method or a non-solvent laminating method,
The resin can be laminated by a known method such as an extrusion lamination method in which the resin is heated and melted, extruded in a curtain shape, and laminated.

Similarly, the above vapor deposition film laminate 21 is formed.
4, the four sides are sealed by a seal bag-making machine to form the sealing portion 41 by heat fusion such as a heat sealing method to obtain a packaging bag. Then, a notch 42 or the like may be formed in a part of the sealing portion 41 in-line with a razor blade-shaped cutter blade after heat fusion in the bag making process. The heat-sealing layer 14 can be provided at a necessary place so that pillow packaging and gusset packaging can be performed, and a bag making process such as a vertical pillow bag making machine or a gusset bag making machine is selected according to the packaging purpose, and the same process is performed. As a result, a packaging bag having an easy opening property can be obtained.

Next, the structure of the vapor-deposited film laminate 31 constituting the gas barrier packaging bag 1 having the easy-opening property of the third invention will be described with reference to FIG. Reference numeral 31 is a vapor deposition film laminate, and a thin film layer 23 made of a vapor deposition film of metal oxide is formed on the surface of a base material 32. The thin film layer 33 may be formed on both sides of the base material 32, or may be formed in multiple layers. Further, a resin layer 35 is laminated on the thin film layer 33, and a heat seal layer 34 is formed on the other surface of the base material 32.

The thin film layer 23 is the thin film layer 23, the heat seal layer 24 is the heat seal layer 14, and the resin layer 35 is the substrate 12.
Is the same as.

Substrate 3 made of a polymer material having transparency
2 is, for example, a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a biaxially oriented polypropylene film, a biaxially oriented nylon film or the like having mechanical strength and dimensional stability, and the thickness is practically The range may be 5 to 50 μm.

Similarly, the above vapor deposition film laminate 21 is formed.
4, the sealing bag 41 is formed on the four sides by a heat-sealing method such as a heat-sealing method using a sealing bag-making machine to obtain the packaging bag 1. Then, a notch 42 or the like may be formed in a part of the sealing portion 41 in-line with a razor blade-shaped cutter blade after heat fusion in the bag making process. The heat-sealing layer 14 can be provided at a necessary place so that pillow packaging and gusset packaging can be performed, and a bag making process such as a vertical pillow bag making machine or a gusset bag making machine is selected according to the packaging purpose, and the same process is performed. As a result, a packaging bag having an easy opening property can be obtained.

The packaging bag of the present invention will be described with reference to specific examples.

[Example 1] A substrate 12 having a film thickness of 12 μm
On one surface of the transparent laterally stretched polypropylene film of No. 3, magnesium oxide was vapor-deposited to a thickness of about 500 Å by a vacuum vapor deposition apparatus by an electron beam heating method (not shown) to form a thin film layer 13, and a heat seal layer 14 having a thickness of 30 μm An unstretched polypropylene film was laminated with a two-component curing type urethane adhesive by a dry lamination method to obtain a vapor deposition film laminate.

Next, the vapor-deposited film laminate 11 is bag-formed by a four-side seal bag-making machine, and at the same time, a notch or other notch is formed in a part of the sealing portion by heat sealing to form a gas barrier packaging bag having an easy-opening property. It was made.

Example 2 As in Example 1, the substrate 22 was made of a transparent laterally stretched polypropylene film, and one surface of the substrate 22 was filled with magnesium oxide to a thickness of about 500 Å by an electron beam heating type vacuum deposition apparatus. A thin film layer 23 is formed by vapor deposition, and a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm is laminated on the thin film layer 23 side as a resin layer 25 by a dry lamination method via a two-component curing type urethane adhesive and further heat sealed. As the layer 24, an unstretched polypropylene film having a thickness of 25 μm was laminated simultaneously with a polyethylene resin having a thickness of 20 μm by an extrusion lamination method to obtain a vapor deposition film laminate 21.

Next, the vapor-deposited film laminate 21 is bag-made by a four-side seal bag-making machine, and at the same time, a notch or other notch is made in a part of the sealing portion by heat sealing to form a gas-barrier packaging bag having an easy-opening property. It was made.

[Example 3] Instead of the magnesium oxide thin film of the thin film layer 3 of Example 1, a 400 Å-thick silicon oxide thin film was formed by a resistance heating method, and otherwise the vapor deposition film laminate 11 was formed in the same manner. Then, a gas barrier packaging bag was produced.

[Embodiment 4] The substrate 32 has a film thickness of 12 μm.
On one surface of the transparent biaxially stretched polyethylene terephthalate film of No. 1, magnesium oxide is vapor-deposited to a thickness of about 500 Å by a vacuum vapor deposition apparatus using an electron beam heating method (not shown) to form a thin film layer 33, and a thickness of 20 μm on the thin film layer 33 side.
Of the laterally stretched polyethylene film as a resin layer 35 is laminated by a dry lamination method via a two-component curing type urethane adhesive, and a heat seal layer 34 having a thickness of 30 is formed.
An unstretched polypropylene film having a thickness of 20 μm was laminated simultaneously with a polyethylene resin having a thickness of 20 μm by an extrusion laminating method to obtain a vapor deposition film laminate 31.

Next, the vapor-deposited film laminate 31 is made into a bag by a four-side sealing bag making machine, and at the same time, a notch or the like is cut in a part of the sealing portion by heat sealing to form a gas barrier packaging bag having an easy-opening property. It was made.

[Embodiment 5] Instead of the magnesium oxide thin film of the thin film layer 3 of Embodiment 1, an aluminum oxide thin film having a thickness of 500 Å is formed by an electron beam heating method. Then, a gas barrier packaging bag was produced.

Example 6 Instead of the magnesium oxide thin film of the thin film layer 3 of Example 1, a tin oxide thin film having a thickness of 500Å was formed by an electron beam heating method, and otherwise the vapor deposition film laminate 11 was formed in the same manner. Then, a gas barrier packaging bag was produced.

Comparative Example 1 Instead of the laterally stretched polypropylene film of the substrate 12 of Example 1, a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm was used.
Except for this, the vapor deposition film laminate was obtained in the same manner to produce a gas barrier packaging bag.

Comparative Example 2 Instead of the magnesium oxide thin film in Comparative Example 1, a 400 Å-thick silicon oxide thin film was formed by a resistance heating method, and otherwise the vapor deposition film laminate was obtained in the same manner to obtain a gas barrier property. A packaging bag was produced.

[Comparative Example 3] A gas barrier packaging bag was produced in the same manner as in Comparative Example 2, except that notches such as notches were not provided during the bag manufacturing process.

[Comparative Example 4] As a comparative product having another structure, a packaging bag formed by laminating an aluminum foil on a substrate was produced.

As described above, the openability, transparency, and incineration of each packaging bag
And further evaluate the gas barrier property of the packaging bag.
Therefore, the oxygen permeability (cc) of the laminate forming the packaging bag is
/ M ²Table 1 shows the results of measurement and evaluation of
It was

[0049]

[Table 1]

In contrast to the examples, the comparative examples are provided with the above-mentioned conditions for use as a package, and are transparent enough to directly look at the contents themselves, and the gas that affects the contents is blocked. Although it has a high gas barrier property, it can be said that the unsealing property is inferior.

[0051]

As described above, according to the present invention, a transparent polymer material is laminated on a substrate made of a transparent polymer material or a substrate made of a transparent polymer material. By providing a notch in the same direction as the stretching direction of the resin layer made of, the tearing direction matches the stretching direction, so that the packaging bag can be neatly torn and opened with a small force. In addition, since the contents can be seen from the outside of the packaging bag and the gas that permeates the thin film can be kept low, the transparency and gas barrier properties originally possessed by the metal oxide thin film are preserved so that the contents can be stored without deterioration. It is possible to maintain the above and sufficiently demonstrate practicality.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a vapor deposition film laminate that constitutes a gas barrier packaging bag having an easy-open property according to the first invention.

FIG. 2 is a cross-sectional view illustrating a vapor deposition film laminate that constitutes a gas barrier packaging bag having an easily openable property of the second invention.

FIG. 3 is a cross-sectional view illustrating a vapor deposition film laminate that constitutes a gas barrier packaging bag having an easy-open property according to a third aspect of the invention.

FIG. 4 is a front view of a gas barrier packaging bag having an easy-open property according to the present invention.

[Explanation of symbols]

 1 Gas Barrier Packaging Bag 11 Vapor Deposition Film Laminate 12 Base Material 13 Thin Film Layer 14 Heat Seal Layer 21 Vapor Deposition Film Laminate 22 Base Material 23 Thin Film Layer 24 Heat Seal Layer 25 Resin Layer 31 Vapor Deposition Film Laminate 32 Base Material 33 Thin Film Layer 34 Heat seal layer 35 Resin layer 41 Sealing part 42 Notch

Claims (5)

[Claims] 1. Both end faces of a laminate obtained by sequentially laminating a metal oxide thin film layer and a heat-sealing layer made of a thermoplastic resin on a base material made of a transparent polymer material uniaxially stretched in one direction, or It is characterized in that a plurality of sheets are stacked, a sealing portion is formed by heat-sealing the heat seal layer surfaces, and a cut is provided at an edge of the sealing portion in the same direction as the stretching direction of the base material. A gas barrier packaging bag having openability. 2. A metal oxide thin film layer on a base material made of a transparent polymer material uniaxially stretched in one direction, and a transparent polymer material stretched to the metal oxide thin film layer side. Resin layers are sequentially laminated, and either end surface or a plurality of sheets of a laminate obtained by laminating a heat seal layer made of a thermoplastic resin on one of the surfaces are stacked, and the heat seal layer surfaces are sealed by heat fusion. A gas barrier packaging bag having an easy-opening property, characterized in that a cut portion is formed and a cut is provided in an edge of the sealing portion in the same direction as the stretching direction of the base material. 3. A metal oxide thin film layer on a substrate made of a polymer material having transparency, and a resin layer made of a polymer material having transparency which is uniaxially stretched in one direction on the metal oxide thin film layer side. Are sequentially laminated, and either end surface or a plurality of laminates formed by laminating a heat-sealing layer made of a thermoplastic resin on one of the surfaces are laminated, and a sealing portion is formed by heat-sealing the heat-sealing layer surfaces. A gas barrier packaging bag having an easy-open property, characterized in that a cut is provided in the edge of the sealing portion in the same direction as the stretching direction of the base material. 4. The easy-opening gas barrier packaging bag according to claim 1, wherein the metal oxide thin film layer is made of magnesium oxide, silicon oxide, aluminum oxide or tin oxide. 5. The gas barrier packaging bag having an easy-open property according to claim 1, wherein a heat seal layer is formed on at least a part of both surfaces of the laminate.