JP2024071059A - Self-supporting packaging bag - Google Patents

Abstract

[Problem] To provide a self-supporting packaging bag made of a mono-material, capable of improving drop impact resistance without changing the appearance, without requiring a separate member for reinforcement or an excessive material configuration, and without impairing the self-supporting property.
[Solution] A self-supporting packaging bag comprising a pair of main body portions and a bottom tape, wherein the base material layer and the sealant are made of the same resin material, wherein the ratio a/L of the minimum width a of the bottom seal portion to the distance L from the bottom edge of the main body portion to the mountain fold portion is 0.15 or more and 0.50 or less, wherein when the boundary line between the bottom seal portion and the unsealed portion is defined as the bottom seal line, the angle α between the mountain fold portion and the bottom seal line at the point where the mountain fold portion and the bottom seal line intersect is 20° or more and 45° or less, wherein when the elastic modulus of the sealant used in the main body portion is A and the elastic modulus of the sealant used in the bottom tape is B, B < 800 MPa and A ≧ B.
[Selected Figure] Figure 1

Description

The present invention relates to a packaging bag using a plastic film as a base material. In particular, the present invention relates to a self-supporting packaging bag in which the main body is composed of a front main body portion and a rear main body portion, and an expandable base material is disposed below the main body portion.

Packaging bags, a type of packaging material, are widely used and are made of a single film with a plastic film base or a laminate with a plastic film base. They come in a variety of shapes and are used for a wide range of purposes, making them an indispensable part of modern people's lives.

In other words, by selecting the plastic film or plastic material that makes up the laminate depending on the application of the packaging bag, it becomes possible to finely design the materials to meet the required quality.

For example, due to the excellent water resistance of plastic film, packaging bags are also used as liquid containers, and are widely used in the food industry, such as for beverage containers and retort foods, as well as in the field of daily necessities and toiletries, with a variety of products lining the shelves of supermarkets, drugstores, and convenience stores. In addition, a variety of other applications are being developed, mainly as liquid containers.

The advantages of packaging bags are that they are cheaper than containers such as cans and bottles, that materials can be designed according to the required quality, and that they are lightweight and space-saving before being filled with the contents and during distribution and storage. Packaging bags can also be said to be environmentally friendly from the perspective of reducing waste.

In addition, high-resolution printing on the layer visible from the surface of the packaging bag can improve the product's image and display information about the contents, and printed barcodes and other items can also serve as a source of product distribution and marketing information.

Some packaging bags have been commercialized with a base material placed under the main body to allow them to stand on their own, and are generally called standing pouches. Giving the packaging bag the ability to stand on its own not only has the advantage of making it easier to display as a product as a self-supporting packaging bag, but also makes it more convenient when cooking the contents in a microwave oven or removing the contents.

For this type of self-supporting packaging bag, a laminate having a plastic film as a base material and a sealant layer is stacked with the sealant layers facing each other to form a main body, and a base material is inserted between the front and back main bodies in a mountain fold with the sealant layer on the outside, and then sealed to form the bottom, completing the packaging bag.

On the other hand, due to the growing awareness of environmental issues in recent years, technology is being considered to make the plastic film and sealant layer that make up the packaging bag out of the same material, so that the packaging bag can be reused as a single material. This is called mono-materialization of packaging bags.

As mentioned above, conventional packaging bags are designed to be laminated by combining a variety of different materials, and have responded to various quality requirements, including resistance to drop impact.

For example, to prevent bags from breaking due to the impact of being dropped, laminates that combine polyolefin film with polyester film, polyamide film, etc. have been used.

The packaging bags described in Patent Documents 1 and 2 attempt to solve problems such as bag breakage due to impact from being dropped by selecting the material composition and thickness of the laminate, but they attempt to improve strength by combining polyethylene terephthalate film, polyamide film, and polyolefin film, which is incompatible with mono-materialization. Furthermore, increasing the bag breakage strength can affect other properties, and at the same time, it is inevitable that the quality will be excessive.

However, with mono-material packaging bags, the freedom of material selection is limited, and for example, if a packaging bag filled with contents is dropped and subjected to an impact, there is a risk that the bag may tear at the sealed area of the base material.

In particular, when the laminate is made of all-polyolefin materials such as all-polyethylene or all-polypropylene, there is a risk of the bag breaking due to the impact of being dropped. This is particularly noticeable when the temperature of the packaging bag is low.

On the other hand, environmental problems caused by plastic materials are becoming more serious, so a material composition that allows for thorough recycling as a mono-material packaging material is to be welcomed, and even in the case of material compositions that are all-polyolefin, such as all-polyethylene or all-polypropylene, there is a strong demand for improved performance.

Japanese Patent Application Laid-Open No. 7-237281 Japanese Patent Application Laid-Open No. 7-241967

The present invention was made in consideration of such circumstances, and aims to provide a self-supporting mono-material packaging bag that can improve drop impact resistance without changing the appearance, without requiring additional reinforcement members or excessive material configuration, and without compromising the self-supporting properties.

As a means for solving the above problems, one aspect of the present disclosure is to
A self-supporting packaging bag formed by heat-sealing a pair of main body portions each including a base layer and a sealant layer, and a bottom tape including the base layer and the sealant layer and having a mountain fold,
A pair of side seal portions that bond the pair of main body portions to each other in the vertical direction of the self-supporting packaging bag;
a bottom seal portion that bonds the pair of main body portions and the bottom tape in the lateral direction of the self-supporting packaging bag,
the base layer and the sealant are made of the same resin material,
a ratio a/L of a minimum width a of the bottom seal portion to a distance L from a bottom side of the main body portion to the mountain fold is 0.15 or more and 0.50 or less;
When the boundary between the bottom sealed portion and the unsealed portion is defined as a bottom seal line, an angle α between the mountain fold portion and the bottom seal line at a point where the mountain fold portion and the bottom seal line intersect is 20° or more and 45° or less;
When the elastic modulus of the sealant used in the main body is A and the elastic modulus of the sealant used in the bottom tape is B,
It is a self-supporting packaging bag, wherein B<800 MPa and A≧B.

Another aspect of the present disclosure is
The self-supporting packaging bag has an angle α of 25° or more and less than 30°.

Yet another aspect of the present disclosure is a method for producing a method for manufacturing a semiconductor device comprising the steps of:
The self-supporting packaging bag has an angle α of 40° or more and 45° or less.

Yet another aspect of the present disclosure is a method for producing a method for manufacturing a semiconductor device comprising the steps of:
When the elastic modulus of the sealant used in the body portion is A and the elastic modulus of the sealant used in the bottom tape is B, the self-supporting packaging bag has an elastic modulus B≦600 MPa.

Yet another aspect of the present disclosure is a method for producing a method for manufacturing a semiconductor device comprising the steps of:
A self-supporting packaging bag that satisfies the condition expressed by the following inequality (1): 0.4≦W/2L≦0.8... (1)
(In the formula, the opening width of the self-supporting packaging bag is indicated by W, and the distance from the bottom side of the main body portion to the mountain fold is indicated by the bottom height L.)
It is.

Yet another aspect of the present disclosure is a method for producing a method for manufacturing a semiconductor device comprising the steps of:
By providing a cutout portion on each side of the bottom tape,
The pair of main body portions are bonded to each other through the cutout portions,
Between the bottom side of the main body and the mountain fold,
With respect to the area S1 of the region R1 up to a vertical distance of 10 mm from the side edge of the main body,
The self-supporting packaging bag has a ratio S2/S1 of the area S2 of the joint portion of 0.35 or more and 0.60 or less.

Yet another aspect of the present disclosure is a method for producing a method for manufacturing a semiconductor device comprising the steps of:
The pair of main body portions and the bottom tape form a self-supporting packaging bag further including a gas barrier layer.

Yet another aspect of the present disclosure is a method for producing a method for manufacturing a semiconductor device comprising the steps of:
This is a self-supporting packaging bag used for applications requiring heat treatment at 80°C or higher.

According to the present disclosure, it is possible to provide a packaging bag that has a bottom tape and is self-supporting, and that can improve drop impact resistance without using excessive material for reinforcement and without compromising the self-supporting properties.

The self-supporting packaging bag is formed by heat sealing a pair of main body parts each including a base layer and a sealant layer, and a bottom tape including a base layer and a sealant layer and having a mountain fold. When the contents are filled, the bottom tape opens up into a boat shape under its own weight and expands to form a bottom surface, allowing the packaging bag to stand on its own.

The left and right sides of the periphery of the main body are sealed with side seal sections, and the inner edge of these side seal sections is the boundary line between them and the unsealed section, and is called the side seal line.

In addition, at the bottom of the main body, the bottom tape is folded in a mountain fold with the sealant layer of the laminate on the outside, sandwiched horizontally between the two laminates of the main body and sealed with the bottom seal portion to form the bottom, so that the unsealed portion between the front main body and the rear main body can form a space that can be filled with contents. This boundary line is called the bottom seal line.

At the intersection of the side seal line and the bottom seal line, the angle α between the downwardly curved convex bottom seal line and the horizontal ridge of the folded portion of the bottom tape is 20°≦angle α≦45°, making it possible to provide a packaging bag that can improve drop impact resistance without using excessive material for reinforcement or compromising self-supporting properties.

Also, even in the case of self-supporting packaging bags made of mono-material packaging materials that have relatively low drop impact resistance, such as polyethylene or polyolefin alone, it is possible to make self-supporting packaging bags that have improved drop impact resistance without using excessive material for reinforcement, which is the issue, and without compromising the self-supporting properties. In this case, it is also effective for the purpose of promoting thorough recycling.

In addition, an angle α of 25° or greater and less than 30° is more effective in improving drop impact resistance.

In addition, the angle α should be between 40° and 45°, which is effective in maintaining the stability of the frame and improving resistance to shock from being dropped.

In addition, the elastic modulus of the sealant of the laminate constituting the main body is A, and the elastic modulus of the sealant layer of the laminate constituting the bottom tape is B.
B≦600MPa
This makes it possible for the sealant to have high flexibility and contain a large amount of rubber components that can act as shock absorbers.

In addition, when the width of the opening at the front and rear of the bottom surface of the self-supporting packaging bag is W and the distance from the bottom side of the main body to the mountain fold is L,
0.4≦W/2L≦0.8
That is, the smaller the opening width relative to the height of the bottom, the less the load on the bottom when dropped, which makes it possible to improve the drop impact resistance.

In addition, a cutout is provided on both sides of the bottom tape, and the main body portion consisting of the front main body portion and the rear main body portion has a joint portion that is directly bonded at the cutout portion, and the joint portion is located between the bottom side of the main body portion and the height of the horizontal ridge line of the mountain fold, and the ratio of the area S2 of the joint portion to the area S1 of the region up to a vertical distance of 10 mm from both ends of the main body portion is:
0.35≦S2/S1≦0.6
This is effective in improving drop impact resistance.

In other words, generally, when the bottom of the bag touches the ground, the joints are likely to cause the bag to break. However, by keeping the surface area ratio of the joints within the specified range, the joints are less likely to break and the seal at the bottom remains self-supporting, which is effective in mitigating impacts on the bottom.

Furthermore, if the specified range is exceeded, the area of the joint will be excessively large compared to the area of the bottom film, making bag production difficult. Conversely, if the specified range is exceeded, the joint will be easily damaged by the impact of a drop, resulting in little improvement in drop impact resistance.

In addition, the laminate that forms the front body portion, rear body portion, and bottom tape that forms the bottom surface of the packaging bag further includes a gas barrier layer, which can prevent the contents from changing or deteriorating due to environmental influences and improve storage stability. Alternatively, it can prevent the components and odors of the contents from leaking out of the packaging bag.

The packaging bag can also be used for applications that require heat treatment at 80°C or higher, allowing the contents to be heated in a hot water bath or cooked in a microwave oven, for example.

FIG. 1 is a schematic cross-sectional view of a self-supporting packaging bag according to one embodiment of the present disclosure, taken along a vertical line, for illustrating the components thereof. FIG. 2 is a schematic plan view (partially see-through) for explaining one embodiment of a self-supporting packaging bag according to the present disclosure. FIG. 3 is a schematic plan view (partially see-through) illustrating another embodiment of the self-supporting packaging bag according to the present disclosure, particularly the bottom portion. FIG. 4 is a perspective (partially see-through) schematic diagram for explaining a state in which one embodiment of the self-supporting packaging bag according to the present disclosure stands on its own.

The present disclosure will be described in more detail below with reference to Figures 1 to 4. However, the present disclosure is not limited to the examples shown here. The present disclosure is defined by the claims.

Figure 1 is a schematic cross-sectional view of a self-supporting packaging bag cut vertically to illustrate the components of one embodiment of the self-supporting packaging bag according to the present disclosure.

The self-supporting packaging bag (100) according to the present disclosure is a packaging bag made of a laminate having a plastic film as a base material and a sealant layer. The schematic cross-sectional view shown in FIG. 1 is a schematic cross-sectional view of the self-supporting packaging bag (100) cut vertically at the center of the main body.

However, the schematic cross-sectional view shown in FIG. 1 is intended to be used to explain the components of the self-supporting packaging bag (100), and does not show the sealed portion involved in the bag making process.

The self-supporting packaging bag (100) is composed of a main body portion composed of a front main body portion (10) and a rear main body portion (20), and a bottom tape (30) disposed on the bottom portion (40). As described above, these are laminates having a sealant layer with a plastic film as a base material, and are made of the same type of plastic material. In addition, these laminates can further be provided with a gas barrier layer.

The front body portion (10) and the rear body portion (20) are laminates of the same configuration, and are formed by stacking the sealant layers (12) facing each other and sealing both the left and right ends vertically with side seal portions to form a bag, but the sealed portions are not visible in the schematic cross-sectional view shown in Figure 1, as they are located at the front and back of Figure 1. In addition, the plastic film (11) is located on the outside of the self-supporting packaging bag (100) in both the front body portion (10) and the rear body portion (20).

The bottom tape (30) of the bottom (40) is disposed between the front body part (10) and the rear body part (20) at the bottom of the body part. The bottom tape (30) is also a laminate having a plastic film (31) as a base material and a sealant layer (32).

The bottom tape (30) is folded horizontally between the two laminates of the main body with the sealant layer (32) of the laminate facing outward, and is sealed at the bottom seal portion to form the bottom (40). The self-supporting packaging bag (100) is sealed at the bottom seal portion and can stand on its own thanks to the bottom surface that can be formed by expanding the bottom tape (30). This self-supporting state will be described later with reference to Figure 4.

Figure 2 is a schematic plan view (partially see-through) illustrating one embodiment of a self-supporting packaging bag according to the present disclosure.

In the present disclosure, the self-supporting packaging bag (100) is made by stacking the sealant layers of the laminated body of the front body part (10) and the rear body part (20) facing each other, and sealing both the left and right ends vertically with the side seal parts (1).

The inner edge of this side seal portion (1) is the boundary line between the unsealed portion, and this boundary line is defined as the side seal line (2). The contents can be stored inside this side seal line (2) and the bottom seal line (4) described below.

The width of the side seal portion (1) can be, for example, 3 mm to 18 mm, or 5 mm to 15 mm. Having a width of 3 mm to 18 mm has the advantage of providing sufficient seal strength and making it easier to ensure the content volume.

The bottom (40) is formed by sandwiching the bottom tape (30) horizontally between a pair of laminates in the lower part of the main body, with the sealant layer (32) of the laminate facing outwards, and sealing the bottom (40) with the bottom seal part (3).

The self-supporting packaging bag (100) is sealed by the bottom seal portion (3) and can stand on its own thanks to the bottom surface that can be formed by expanding the bottom tape (30). The bottom tape (30), which is initially folded in a mountain shape, can also expand due to the weight of the contents when they are filled inside the packaging bag.

At the bottom (40), when the bottom tape (30) is in a flat, mountain-folded state before expansion, the inner edge of the bottom seal portion (3) is the boundary line between it and the unsealed portion, forming a downwardly curved convex edge, and this boundary line is defined as the bottom seal line (4).

In order to provide a self-supporting packaging bag (100) capable of improving resistance to a drop impact, which is the subject of the present disclosure, we have been conducting detailed studies focusing on the causes of bag breakage.

In other words, when a packaging bag is dropped, it breaks due to impact with the ground and the flow of the contents. At this time, the bottom part (40) is thought to bear the most weight, and the body part is also subjected to a rebound shock.

Because these loads are thought to cause cracks in the sealant layer, especially inside it, we focused on the impact resistance of the sealant layer and selected the optimal one. We also considered improving the shape of the bottom seal part (3), and achieved good results by improving the overall drop impact resistance.

In the present disclosure, the ratio a/L of the minimum width a of the bottom seal portion to the distance L from the bottom side of the main body portion to the mountain fold of the bottom tape is:
0.15≦a/L≦0.50
In the course of intensive investigation into the present disclosure, we have found that when a/L is in this range, drop impact resistance is effectively improved.

In other words, by setting a/L within this range, when the self-supporting packaging bag (100) is dropped and hits the ground, the bottom tape (30) is less likely to come into direct contact with the ground, which reduces deformation of the contents and the associated impact on the bottom (40), while at the same time making it possible to produce a packaging bag with excellent self-supporting properties.

From the viewpoint of drop impact resistance, a/L is preferably 0.2 or more, and more preferably 0.3 or more. Also, in consideration of self-supporting ability, a/L is preferably 0.45 or less, and more preferably 0.40 or less.

In the present disclosure, when the angle between the downwardly curved convex bottom seal line (4) and the horizontal ridge line (33) of the mountain fold of the bottom tape (30) at the intersection of the side seal line (2) and the bottom seal line (4) is α,
20°≦angle α≦45°
In the course of diligent investigation into the present disclosure, we have found that when the angle α is in this range, it is effective in improving drop impact resistance.

Incidentally, angle α is defined as the angle between the horizontal ridge line (33) of the mountain fold of the bottom tape (30) and the tangent to the bottom seal line (4) at the point where the ridge line (33) intersects with the bottom seal line (4).

On the other hand, we assume that the angle α is 20°≦angle α≦45°.
We found that it was also effective in improving independence when
Further, the angle α is more preferably equal to or greater than 25° and less than 30°, or equal to or greater than 40° and less than 45°.

Self-supporting refers to the fact that the self-supporting packaging bag (100) can stand on its own when placed on a horizontal surface, and that it can maintain its independence even if the surface on which it is based has a certain degree of inclination.

As mentioned above, we have focused on drop impact resistance, because when a packaging bag is dropped, it collides with the ground and the contents flow and impacts, which can cause the bag to break. It is believed that the bottom part (40) bears the most weight at this time, and the body part is also subjected to a rebound impact. Since these loads are believed to cause cracks in the sealant layer, especially inside it, we have focused on the elasticity of the sealant layer and have chosen one with low elasticity to absorb the impact.

Specifically, they found that when the elastic modulus is 800 MPa or more, the sealant layer tends to be weak against impacts, and that when the elastic modulus of the sealant layer is lower in the bottom portion (40) than in the main body portion, the sealant layer is resistant to impacts immediately after touching the ground.

That is, in the present disclosure, assuming that the elastic modulus of the sealant layer (12) of the laminate constituting the main body is A and the elastic modulus of the sealant layer (32) of the laminate constituting the bottom tape (30) is B,
B < 800 MPa and A ≥ B
In the course of diligent investigation into the present disclosure, we have found that when the elastic modulus A and the elastic modulus B are in this range and have this relationship, it is effective in improving drop impact resistance.

Furthermore, assuming that the elastic modulus of the sealant of the laminate constituting the main body is A and the elastic modulus of the sealant layer of the laminate constituting the bottom tape is B,
B≦600MPa
In general, when the elastic modulus of the sealant layer is 600 MPa or less, this indicates that the flexibility of the sealant layer is high, for example, when the sealant layer contains a large amount of a rubber component that plays a role in shock absorption.

As the material for the sealant layer, polyolefin-based resins, which are among the thermoplastic resins, are generally used. Specifically, ethylene-based resins such as low-density polyethylene resin (LDPE), medium-density polyethylene resin (MDPE), linear low-density polyethylene resin (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-methacrylic acid resin copolymer, as well as blends of polyethylene and polybutene, and polypropylene-based resins such as homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α-olefin copolymer can be used.

The objective of this disclosure is to improve the drop impact resistance of a mono-material self-supporting packaging bag without changing its appearance, without requiring additional reinforcement members or excessive material configurations, and without impairing its self-supporting properties. Therefore, when a polyolefin resin is used for the sealant layer, the base film is also polyolefin-based.

In addition, from the viewpoint of recyclability, the content of polyolefin resin is preferably 70% by mass or more of the entire packaging bag, more preferably 92% by mass or more, and even more preferably 95% by mass or more.

One of these resins may be used, or different resins may be used in combination for each layer of the laminate. Alternatively, the laminate may be made up of a single layer or multiple layers.

To form the sealant layer, a film of molten resin can be formed using an extruder or the like to form a layer on the laminate. Alternatively, a sealant layer can be formed on the surface of the laminate by laminating a material that has already been formed into a film.

Methods for constructing a laminate by lamination include, for example, lamination by adhesive and lamination by heat treatment.

As a lamination method using an adhesive, known lamination methods such as dry lamination, wet lamination, and non-solvent lamination can be used. Examples of adhesives used in these lamination methods include polyurethane resins in which an isocyanate compound having two or more functional groups is reacted with a base material such as polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol. These polyols can be used alone or in combination of two or more.

Lamination methods using heat treatment can be broadly classified into the following methods.
(1) A method of extruding an adhesive resin between each layer and laminating them.
(2) A method in which the laminate substrate obtained by the method (1) above is further heated and pressed with a roll to bond the substrate.
(3) The laminate substrate obtained by the method (1) above is further stored in a high-temperature atmosphere, or passed through a drying/baking furnace in a high-temperature atmosphere.

Examples of adhesive resins used in lamination methods using heat treatment include acid-modified polyolefins.

An adhesive primer (anchor coat) can be applied between each layer, and materials that can be used include polyester, polyurethane, polyallylamine, polyethyleneimine, polybutadiene, ethylene-vinyl acetate copolymer, and chlorine-vinyl acetate. If necessary, various hardeners and additives that can be used as adhesives can be blended into the adhesive primer.

In the present disclosure, a cutout portion can be provided on both sides of the bottom tape (30). The cutout portion may also be referred to as a punch hole depending on the method of formation. In this case, the main body portion consisting of the front main body portion (10) and the rear main body portion (20) has a joint portion (34) that is directly bonded at the cutout portion, and the joint portion (34) is located between the bottom side (21) of the main body portion and the height of the horizontal ridge line (33) of the mountain fold, and is determined by dividing the area S1 of the area up to 10 mm vertically from both ends of the main body portion by the following ratio:
The ratio of the area S2 of the joint (34) is
0.35≦S2/S1≦0.6
It can be said that:

We have found that this improves drop impact resistance, and the reasons for this are as follows.
If the device is dropped and the bottom (40) hits the ground, the joint (34) will break, thereby absorbing and mitigating the impact.
By specifying the range of the area ratio of the joint (34), the self-supporting property of the packaging bag is maintained and the impact on the bottom (40) is mitigated. In addition, if the position of the joint (34) is above the upper limit, it becomes difficult to manufacture the bag, and if it is below the lower limit, the joint (34) is easily torn and does not lead to improvement of drop impact resistance.

As described above, the laminate forming the front body portion (10), the rear body portion (20), and the bottom tape (30) forming the bottom surface of the self-supporting packaging bag (100) according to the present disclosure may further include a gas barrier layer.

That is, by including a gas barrier layer in the laminate, it is possible to prevent the contents from being altered or deteriorated due to the influence of the environment, thereby improving the preservability, or to prevent the components or odors of the contents from leaking out of the packaging bag.

Metal foils such as aluminum are also effective as gas barrier layers, but they are opaque and are unsuitable when transparency is required. Applications in which it is inappropriate to use metals should also be avoided. These can be used appropriately depending on the application and required quality.

For example, cooking in a microwave oven is unsuitable because of the high frequency waves that can cause sparks. Instead, a gas barrier film with an inorganic compound layer on the surface can be used.

The plastic film used in the gas barrier film is a film made of a polymer resin composition, such as polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polyimide, etc., and is selected appropriately depending on the application. In particular, when polypropylene is used as the plastic film substrate, it is more preferable from the viewpoint of film strength and price, as well as from the viewpoint of mono-material.

In the case of gas barrier films, the gas barrier layer can be composed of a vapor deposition layer and a coating layer of an inorganic compound, and after providing an anchor coat on the plastic film, the vapor deposition layer and the coating layer are provided in that order.

For example, urethane acrylate can be used for the anchor coat layer of the gas barrier film. The anchor coat layer can be formed by applying a coating method that applies a printing technique such as gravure coating with a paint in which a resin is dissolved in a solvent, or by using a commonly known coating method to form a coating film.

The deposition layer can be formed by coating an inorganic compound such as SiO or AlO onto a plastic film with an anchor coat layer using a vacuum deposition method, forming an inorganic compound layer by the vacuum deposition method. The thickness of the deposition layer should be 15 nm to 30 nm.

The coating layer can be formed by applying a coating agent, the main component of which is an aqueous solution or a water/alcohol mixed aqueous solution containing at least one of a water-soluble polymer and one or more alkoxides or their hydrolysates, or both, or tin chloride, onto the film, and then heating and drying to form an inorganic compound layer by the coating method. In this case, the coating agent can be added with a silane monomer to improve adhesion with the anchor coat layer.

The inorganic compound layer has gas barrier properties even when it is only a coating film formed by vacuum deposition, but a gas barrier layer can also be formed by overlaying a coating layer, which is an inorganic compound layer formed by a coating method, on a deposition layer, which is an inorganic compound layer formed by vacuum deposition.

By combining these two layers, a reaction layer between the inorganic compound layer formed by vacuum deposition and the inorganic compound layer formed by coating is generated at the interface between the two layers, or the inorganic compound layer formed by coating fills and reinforces defects or micropores such as pinholes, cracks, and grain boundaries that occur in the inorganic compound layer formed by vacuum deposition, forming a dense structure.

Therefore, the gas barrier film can achieve high gas barrier properties, moisture resistance, and water resistance, and has flexibility that allows it to withstand deformation due to external forces, making it suitable for use as a packaging material.

When, for example, _SiOx is used as the gas barrier layer, the coating is transparent, so that the contents can be seen from the outside of the packaging bag. The gas barrier film can be laminated so that the gas barrier layer faces either the outside or the inside of the packaging bag.

If necessary, a printed layer can be provided on the layer of the laminate based on a plastic film that is visible from the outside of the packaging bag in order to improve the product's image, display necessary information about the contents, and improve the design. The printed layer may be provided on the outermost layer of the packaging bag.

The printed layer may be provided on a part of the packaging bag, or may be provided over the entire surface of the packaging bag. Alternatively, a display portion may be provided without using a printed layer, for example by attaching a printed sticker to the surface of the packaging bag.

There are no particular restrictions on the printing method and printing ink, but any known printing method may be appropriately selected, taking into consideration printability on plastic films, design such as color tone, adhesion, and safety as a food container.

For example, a printing method can be selected from known printing methods such as gravure printing, offset printing, gravure offset printing, flexographic printing, silk screen printing, and inkjet printing. Among them, gravure printing is preferred for its productivity, suitability for printing on plastic films, and high definition of the image.

Figure 3 is a schematic plan view (partially see-through) illustrating another embodiment of the self-supporting packaging bag according to the present disclosure, particularly the bottom portion.

In this disclosure, at the bottom (4) of the self-supporting packaging bag (100), the inner edge of the bottom seal portion (3) is the boundary line between the unsealed portion and forms a downwardly curved convex edge, and this boundary line is defined as the bottom seal line (4). However, the bottom seal line does not have to be an arc shape as shown in FIG. 2. For example, as long as it is a downwardly curved convex edge, the shape and angle of the bottom seal portion (3) can be within the range specified in this disclosure, as in the example shown in FIG. 3. In the example shown in FIG. 3, the distance from the bottom edge (21) of the main body portion to the bottom seal line (4) is indicated by an arrow in FIG. 3 as the minimum width a of the bottom seal portion.

Figure 4 is a perspective (partially see-through) schematic diagram illustrating the self-supporting appearance of one embodiment of the self-supporting packaging bag according to the present disclosure.

The example shown in FIG. 4 shows a self-supporting packaging bag (100) filled with contents (50) and in a state in which the packaging bag stands on its own due to the formation of the bottom surface.

The example shown in FIG. 4 is an example in which a spout (60) for removing the liquid contents (50) is attached to the upper corner of the packaging bag, but the packaging bag may be of a type in which the contents (50) can be removed by opening the bag by cutting a part of it without providing a spout (60). In addition, the top edge of the packaging bag is sealed with the top edge seal part (8) after filling with the contents (50).

The bottom tape (30) is pushed out by the weight of the contents (50) of the packaging bag, forming a boat-shaped bottom surface. At this time, the width W of the bottom surface from front to back is indicated by the dashed arrow in FIG.
When the width of the bottom opening from front to back of the self-supporting packaging bag (100) is W, and the distance from the horizontal ridge line (31) of the mountain fold of the bottom tape to the bottom side (21) of the main body is L,
0.4≦W/2L≦0.8
When W/2L is within this range, the impact on the bottom portion (40) when the bag is dropped is reduced, and drop impact resistance is improved.

If the angle exceeds the upper limit, particularly if the angle α is 35° or more, the impact on the bottom (40) will be large, resulting in poor resistance to drop impacts. If the angle does not reach the lower limit, the opening width of the bottom (40) will be small, resulting in poor self-supporting ability and reduced capacity.

The self-supporting packaging bag (100) according to the present disclosure can be used, for example, as a packaging bag for food. For example, it can be used for liquids such as soup, solids such as vegetables, or solid-liquid mixtures of liquids and solids such as curry. These can be cooked by subjecting them to a heat treatment of 80°C or higher. It can also be suitably used for applications requiring retort sterilization at a temperature of 125°C or higher.

In this way, according to the present disclosure, it is possible to provide a self-supporting packaging bag made of a mono-material that can improve drop impact resistance without changing the appearance, without requiring additional reinforcement members or excessive material configuration, and without compromising the self-supporting properties.

The present disclosure will be explained in more detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the examples shown here. The present disclosure is defined by the claims.

A self-supporting packaging bag was produced and evaluated.
1. External dimensions of packaging bag: Width: 140mm x Height: 180mm
2. Configuration of the laminate constituting the packaging bag From the outside of the packaging bag,
Stretched polypropylene film 1 (thickness 20 μm) / Stretched polypropylene film 2 (
Thickness 20 μm) / Non-oriented polypropylene (sealant layer thickness 60 μm)
3. Material composition ・Stretched polypropylene film 1: Futamura FOR
・ Stretched polypropylene film 2: (gas barrier film) Stretched polypropylene film with inorganic compound deposition layer ・ Unstretched polypropylene: A A'; Not disclosed (only physical properties disclosed),
B: Toray ZK207,
C: Not disclosed (only physical properties disclosed).

Evaluation Items and Evaluation Method The elastic modulus of the sealant layer was measured.
Additionally, the drop bag test and independence were evaluated as evaluation items.
The measurement and evaluation methods are as follows.

(Elastic Modulus)
The measurement was carried out in accordance with JIS K 7161. The unit of pressure was MPa.
・Test piece size: TD direction 300 mm x width 20 mm
Number of test pieces: n=5.
Measurement conditions: chuck distance 250 mm, tensile speed 5 mm/min. Elastic modulus calculation method: two-point slope (strain 0.05% 0.25%)
It was decided.

(Dropped bag test)
The prepared packaging bag for evaluation was filled with 250 ml of water as the content, and the top of the packaging bag was heat sealed.
At room temperature, the bag was dropped vertically from a height of 1 m with the bottom tape facing downwards, and the number of drops until the bag broke was counted.
Ten samples were evaluated under the same conditions and were evaluated according to the following evaluation criteria.
(Evaluation criteria)
◎◎: All 10 samples had less than 10 breaks and no breaks (average number of breaks of 25 or more)
◎: All 10 samples were not broken in less than 10 tries (average number of breakages: 10 or more and less than 25) ○: Some samples broke in less than 10 tries (number of samples that did not break in less than 10 tries: 6 to 9)
△: Some samples broke in less than 10 tries (1 to 5 samples did not break in less than 10 tries)
x: All of the 10 samples were broken in less than 10 tries.

(Autonomy)
The prepared packaging bag for evaluation was filled with 250 ml of water as the content, and the top of the packaging bag was heat sealed.
While it was standing on a flat surface, we tilted the surface to check whether it could stand on its own (tilted in the width direction).
(Evaluation criteria)
◯: Able to stand on its own on a table inclined at 10 degrees △: Able to stand on its own on a flat surface, but fell over on a table inclined at 10 degrees ×: Cannot stand on its own even on a flat surface.

The configurations of the samples of Examples 1 to 22 and Comparative Examples 1 to 4 are shown below. The names and symbols of each part are as shown in the main text, as well as in Figures 1, 2, and 4.

Example 1
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 66 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.15
W/2L (opening width/bottom height) = 0.83
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 2
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 66 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.15
W/2L (opening width/bottom height) = 0.83
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 3
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Body part = Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 66 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.15
W/2L (opening width/bottom height) = 0.83
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 4
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Grade C Elastic modulus: 505 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 45°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 66 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.15
W/2L (opening width/bottom height) = 0.83
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 5
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 10 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 60 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.25
W/2L (opening width/bottom height) = 0.75
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 6
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 10 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 60 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.25
W/2L (opening width/bottom height) = 0.75
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 7
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 45°
a (minimum width of bottom seal) = 10 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 60 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.25
W/2L (opening width/bottom height) = 0.75
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 8
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 52 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.65
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 9>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 52 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.65
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 10
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 45°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 52 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.65
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 11
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Grade C Elastic modulus: 505 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 45°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 52 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.65
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 12
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 25°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 36 mm
Width = 140mm Height = 180mm
W (opening width) = 53 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.17
W/2L (opening width/bottom height) = 0.74
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 13>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 25°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 36 mm
Width = 140mm Height = 180mm
W (opening width) = 53 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.17
W/2L (opening width/bottom height) = 0.74
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 14>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 25°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 36 mm
Width = 140mm Height = 180mm
W (opening width) = 53 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.17
W/2L (opening width/bottom height) = 0.74
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

Example 15
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 25°
a (minimum width of bottom seal) = 10 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 51 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.25
W/2L (opening width/bottom height) = 0.64
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 16>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 25°
a (minimum width of bottom seal) = 10 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 51 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.25
W/2L (opening width/bottom height) = 0.64
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 17>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 25°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 45 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.56
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 18>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Body part>Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 25°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 45 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.56
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 19>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 25°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 45 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.56
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 20>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Grade C Elastic modulus: 505 MPa
Bottom: Brand C Elastic modulus 505 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 25°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 45 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.56
S2/S1 (punch hole area ratio) = 0.22
It was decided.
All of these are within the scope provided in this disclosure.

<Example 21>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 25°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 50 mm
Punch hole radius: 6mm Number: 2
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.63
S2/S1 (punch hole area ratio) = 0.37
It was decided.
All of these are within the scope provided in this disclosure.

<Example 22>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 25°
a (minimum width of bottom seal) = 15 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 50 mm
Punch hole radius: 7.5 mm Number: 2
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.38
W/2L (opening width/bottom height) = 0.63
S2/S1 (punch hole area ratio) = 0.44
It was decided.
All of these are within the scope provided in this disclosure.

<Comparative Example 1>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand A Elastic modulus 850 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 45°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 66 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.15
W/2L (opening width/bottom height) = 0.83
S2/S1 (punch hole area ratio) = 0.22
It was decided.
Among these, the elastic modulus of CPP (sealant layer non-oriented polypropylene) falls outside the range specified in this disclosure.

<Comparative Example 2>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand A Elastic modulus: 850 MPa
Bottom: Brand A' Elastic modulus 1090 MPa
Elastic modulus Body part < Bottom part Bottom shape α (angle between bottom seal line and horizontal ridge line of bottom tape) = 45°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 66 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.15
W/2L (opening width/bottom height) = 0.83
S2/S1 (punch hole area ratio) = 0.22
It was decided.
Among these, the elastic modulus of CPP (sealant layer non-oriented polypropylene) falls outside the range specified in this disclosure.

<Comparative Example 3>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 55°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 68 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.15
W/2L (opening width/bottom height) = 0.83
S2/S1 (punch hole area ratio) = 0.22
It was decided.
Of these, the angle α (degrees) between the bottom seal line and the horizontal ridge line of the bottom tape deviates upward from the range specified in this disclosure.

<Comparative Example 4>
CPP (sealant layer non-oriented polypropylene) physical properties Main body: Brand B Elastic modulus: 660 MPa
Bottom: Brand B Elasticity: 660 MPa
Elastic modulus Main body = Bottom Bottom shape α (angle between bottom seal line and horizontal ridge of bottom tape) = 18°
a (minimum width of bottom seal) = 6 mm
L (bottom height) = 40 mm
Width = 140mm Height = 180mm
W (opening width) = 68 mm
Punch hole radius: 7.5mm Quantity: 1
Parameter a/L (minimum width of bottom seal part/bottom height) = 0.21
W/2L (opening width/bottom height) = 0.55
S2/S1 (punch hole area ratio) = 0.22
It was decided.
Of these, the angle α between the bottom seal line and the horizontal ridge line of the bottom tape deviates downwardly from the range specified in this disclosure.

The evaluation results are shown in Table 1.

From the results shown in Table 1, all products with an elastic modulus of CPP (sealant layer unoriented polypropylene) outside the range specified in this disclosure, and all products with an angle α between the bottom seal line and the horizontal ridge line of the bottom tape outside the range specified in this disclosure, are rated x in the drop bag test, and some are rated x for self-supporting properties as well.

In contrast, Examples 1 to 22, which are within the ranges specified in this disclosure, were all rated △ or higher in both the drop bag test and self-supporting properties, clearly demonstrating the superiority of the self-supporting packaging bags according to this disclosure.

In this way, it was possible to verify that it is possible to provide a self-supporting mono-material packaging bag that can improve drop impact resistance without changing the appearance, without requiring additional reinforcement parts or excessive material configuration, and without compromising the self-supporting properties.

1: Side seal portion 2: Side seal line 3: Bottom seal portion 4: Bottom seal line 8: Upper seal portion 10: Front body portion 11: Plastic film 12: Sealant layer 20: Rear body portion 21: Bottom edge of body portion 30: Bottom tape 31: Plastic film 32: Sealant layer 33: Ridge line 34: Joint portion 40: Bottom 50: Contents 60: Mouth plug 100: Self-supporting packaging bag a: Minimum width of bottom seal portion b: Width L: Bottom height W: Opening width

Claims (8)

A self-supporting packaging bag formed by heat-sealing a pair of main body portions each including a base layer and a sealant layer, and a bottom tape including the base layer and the sealant layer and having a mountain fold,
A pair of side seal portions that bond the pair of main body portions to each other in the vertical direction of the self-supporting packaging bag;
a bottom seal portion that bonds the pair of main body portions and the bottom tape in the lateral direction of the self-supporting packaging bag,
the base layer and the sealant are made of the same resin material,
a ratio a/L of a minimum width a of the bottom seal portion to a distance L from a bottom side of the main body portion to the mountain fold is 0.15 or more and 0.50 or less;
When the boundary between the bottom sealed portion and the unsealed portion is defined as a bottom seal line, an angle α between the mountain fold portion and the bottom seal line at a point where the mountain fold portion and the bottom seal line intersect is 20° or more and 45° or less;
When the elastic modulus of the sealant used in the main body is A and the elastic modulus of the sealant used in the bottom tape is B,
A self-supporting packaging bag, wherein B<800 MPa and A≧B. The self-supporting packaging bag according to claim 1, wherein the angle α is greater than or equal to 25° and less than 30°. The self-supporting packaging bag according to claim 1, wherein the angle α is greater than or equal to 40° and less than or equal to 45°. 2. The self-supporting packaging bag according to claim 1, wherein, when the elastic modulus of the sealant used in the main body is A and the elastic modulus of the sealant used in the bottom tape is B, the elastic modulus B is at least 600 MPa. The self-supporting packaging bag according to claim 1, which satisfies the condition expressed by the following inequality (1).
0.4≦W/2L≦0.8 (1)
(In the formula, the open width of the self-supporting packaging bag is indicated as W, and the distance from the bottom side of the main body portion to the mountain fold is indicated as the bottom height L). By providing a cutout portion on each side of the bottom tape,
The pair of main body portions are bonded to each other through the cutout portions,
Between the bottom side of the main body and the mountain fold,
With respect to the area S1 of the region R1 up to a vertical distance of 10 mm from the side edge of the main body,
2. The self-supporting packaging bag according to claim 1, wherein a ratio S2/S1 of the area S2 of the joint portion is 0.35 or more and 0.60 or less. The self-supporting packaging bag according to any one of claims 1 to 6, wherein the pair of main body portions and the bottom tape further include a gas barrier layer. The self-supporting packaging bag according to claim 7, which is used in applications where heat treatment at 80°C or higher is performed.

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