JP7731264B2 - Standing Pouch - Google Patents

Description

The present invention relates to a stand-up pouch. More specifically, it relates to a stand-up pouch that allows water vapor generated from the contents when heated to be released from a designated position in the side seal and/or top seal of the pouch.

Microwave pouches that allow steam to be released from a desired location are known.

For example, Patent Document 1 proposes a standing pouch equipped with an automatic steam release mechanism that can release steam generated from the contents to the outside when cooking in a microwave oven. In Patent Document 1, at least one side edge of the body of the standing pouch is provided with a protruding seal that bends and protrudes toward the inside of the pouch, and when this protruding seal breaks, steam can be released.

Patent Document 2 proposes a laminate as a packaging material for pouches, in which a base layer, a heat-softening layer, and a sealant layer are laminated in that order. A half cut is then made on the sealant layer side of the laminate, and when cooked in a microwave oven, steam is allowed to pass through the half cut at the heat-sealed portion where the sealant layers are heat-sealed together, thereby releasing steam from the pouch.

Japanese Patent Application Laid-Open No. 2020-200048 Japanese Patent Application Laid-Open No. 2017-124859

However, in order for the standing pouch described in Patent Document 1 to function with its automatic steam release mechanism, it was necessary to weaken the seal strength of the protruding seal portion compared to the seal strength of the side edges, and to make the seal width of the protruding seal portion narrower. This not only made the manufacturing process for the standing pouch more complicated, but also sometimes caused problems with the strength of the resulting standing pouch.

Furthermore, the packaging material described in Patent Document 2 had an adhesive layer between the base layer and the sealant layer in addition to the thermosoftening resin layer. The thermosoftening resin layer was embedded and scattered throughout the adhesive layer, and was only located in the half-cut area. As a result, the packaging material described in Patent Document 2 not only complicated the manufacturing process for the laminate, but also had the problem of being costly.

Furthermore, when a stand-up pouch is made from the packaging material described in Patent Document 2, the shape of the space for storing the contents in the stand-up pouch can make it difficult to release steam from the intended location.

Specifically, standing pouches are generally formed by folding and sealing the bottom of the pouch, resulting in a structure in which the space at the bottom is wide and the space at the top is narrow. The peeling force caused by the pressure of steam generated by heating is exerted most heavily on the top seal of the pouch, which is the narrower space. For this reason, even if a steam vent mechanism is provided in the body of the pouch, this difference in peeling force makes it difficult for the steam vent mechanism to function, and in some cases, the top seal of the pouch may burst, causing the pouch to tear.

The present invention was made in light of the above background, and aims to provide a standing pouch that allows water vapor generated from the contents when heated to be released from a desired position in the side seal and/or top seal of the pouch.

The inventors conducted extensive research to solve the above-mentioned problems. They discovered that by providing the side seals and/or top seals of a stand-up pouch with at least one selected from the group consisting of an unsealed portion where the sealant layer is not heat-sealed, a slit, and a cutout, which protrudes from the side edge and/or top edge of the stand-up pouch toward the storage section of the stand-up pouch, and by arranging a half cut made from the sealant layer side so as to cross the unsealed portion, slit, and/or cutout from the storage section side of the stand-up pouch, steam can be released from the intended position in the side seals and/or top seals of the pouch, leading to the completion of the present invention. Specifically, the present invention is as follows:

<<Aspect 1>>
A stand-up pouch comprising a front sheet, a back sheet, and a bottom sheet heat-sealed at least at a top seal and a side seal to form a container for containing contents,
at least one of the front sheet and the back sheet is made of a composite film in which at least a base layer, an adhesive layer, and a sealant layer are laminated in this order, and the front sheet and the back sheet facing each other are heat-sealed via the sealant layer to form the top seal portion and the side seal portion;
the side sealed portion and/or the top sealed portion has at least one selected from the group consisting of an unsealed portion where the front sheet and the back sheet are not heat-sealed, a slit, and a notch;
the unsealed portion, the incision, and/or the notch protrude from a side edge and/or an upper edge of the standing pouch toward the storage portion of the standing pouch,
the composite film has a half cut made from the sealant layer side and reaching the adhesive layer,
The half cut is arranged so as to reach the unsealed portion, the incision, and/or the notch from the storage portion side of the standing pouch.
Standing pouch.
Aspect 2
the side seal portion and/or the top seal portion includes a convex seal portion that protrudes toward the storage portion side of the standing pouch on the storage portion side of the unsealed portion, the notch, and/or the cutout,
The half cut is arranged so as to extend from the storage section side of the standing pouch across the convex seal section and reach the unsealed section, the incision, and/or the notch.
A standing pouch according to aspect 1.
Aspect 3
The standing pouch according to aspect 2, which satisfies the following formula (1):
a+b-c<10mm (1)
(a: width of the side seal portion and/or the top seal portion having the unsealed portion, the incision, and/or the notch in a direction normal to the side edge and/or the top edge of the standing pouch,
b: the width of the convex seal portion in the direction normal to the side edge and / or upper edge of the standing pouch,
c: the width of the unsealed portion, the slit, and/or the notch in the direction normal to the side edge and/or the top edge of the standing pouch).
Aspect 4
the adhesive layer is a thermosoftening resin,
The laminate strength between the base layer and the sealant layer at 25°C is 1.5 N/15 mm or more,
The laminate strength between the substrate layer and the sealant layer at 70°C is less than 1.5 N/15 mm.
Aspect 4. The standing pouch according to any one of aspects 1 to 3.
Aspect 5
Aspect 5. The standing pouch according to any one of Aspects 1 to 4, wherein the adhesive layer has an adhesive strength in accordance with JIS Z0237 of 1.0 N/25 mm or more.
Aspect 6
Aspect 6. The standing pouch according to any one of aspects 1 to 5, which is for use in a microwave oven.

The stand-up pouch of the present invention allows water vapor generated from the contents when heated to be released from the intended location in the side seal and/or top seal of the pouch.

Furthermore, when only one adhesive layer is placed between the base layer and the sealant layer, the manufacturing process for the composite film can be simplified, thereby contributing to the production capacity and production costs of stand-up pouches.

FIG. 1 is a front view of a standing pouch according to an embodiment of the present invention. 1 is a cross-sectional view of a composite film constituting a standing pouch according to one embodiment of the present invention. 1 is a schematic diagram of a composite film used in a standing pouch according to one embodiment of the present invention when steam is released. FIG. 1 is a front view of a standing pouch according to a first embodiment. FIG. 10 is a front view of a standing pouch according to a second embodiment. FIG. 10 is a front view of a standing pouch according to a third embodiment. FIG. 10 is a front view of the standing pouch of Example 4. FIG. 10 is a front view of the standing pouch of Example 5. FIG. 10 is a front view of the standing pouch of Example 6. FIG. 10 is a front view of the standing pouch of Example 7. FIG. 10 is a front view of the standing pouch of Example 8. FIG. 10 is a front view of the standing pouch of Example 9. FIG. 12 is a front view of the standing pouch of Example 10. FIG. 11 is a front view of the standing pouch of Example 11. FIG. 1 is a front view of a standing pouch of Comparative Example 1. FIG. 10 is a front view of the standing pouch of Comparative Example 2. FIG. 10 is a front view of the standing pouch of Comparative Example 3.

Standing pouch
The stand-up pouch of the present invention is a stand-up pouch in which a front sheet, a back sheet, and a bottom sheet are heat-sealed at least at a top seal portion and a side seal portion to form a storage portion for storing contents,
At least one of the front sheet and the back sheet is made of a composite film in which at least a base layer, an adhesive layer, and a sealant layer are laminated in this order, and the opposing front sheet and back sheet are heat-sealed via the sealant layer to form a top seal portion and a side seal portion;
the side sealed portion and/or the upper sealed portion has at least one selected from the group consisting of an unsealed portion where the front sheet and the back sheet are not heat-sealed, a slit, and a notch;
the unsealed portion, the cutout, and/or the notch protrudes from the side edge and/or the top edge of the standing pouch toward the storage portion of the standing pouch,
the composite film has a half cut made from the sealant layer side and reaching the adhesive layer;
The half cut is arranged so as to reach the unsealed portion, the cutout, and/or the notch from the storage portion side of the standing pouch.

In the stand-up pouch of the present invention, the half cut is positioned so that it reaches the unsealed portion, slit, and/or notch from the storage section side of the stand-up pouch, allowing water vapor generated from the contents when heated to be discharged from the intended position in the side seal and/or top seal of the pouch, i.e., the unsealed portion, slit, and/or notch.

Without being limited by theory, this is thought to be because, on the housing side of the side seals and/or top seals, where peeling forces due to water vapor pressure are more likely to be exerted, water vapor penetrates through the half cut in the thickness direction of the composite film, causing delamination between the adhesive layer and the sealant layer and creating a space for steam to escape; on the other hand, on the side edge and/or top edge sides of the side seals and/or top seals, where peeling forces due to water vapor pressure are less likely to be exerted, steam escapes through pre-formed unsealed sections, cuts, and/or notches.

As described above, the stand-up pouch of the present invention has a structure in which the front sheet, back sheet, and bottom sheet are heat-sealed at least at the top seal and side seal to form a storage compartment for storing contents.

At least one of the front and back sheets is made of a composite film consisting of at least a base layer, an adhesive layer, and a sealant layer laminated in that order, and the opposing front and back sheets are heat-sealed via the sealant layer to form a top seal and a side seal.

Figure 1 shows a front view of a stand-up pouch 100 according to one embodiment of the present invention. The stand-up pouch of the present invention has a front sheet 11, a back sheet (not shown), and a bottom sheet (not shown) that are heat-sealed at least at a top seal 12 and a side seal 13 to form a storage compartment 14 for storing contents.

The stand-up pouch 100 shown in Figure 1 has a front sheet 11, back sheet, and bottom sheet formed from a single continuous composite film. Specifically, a single composite film comprising at least a base layer, an adhesive layer, and a sealant layer is mountain-folded at two locations that will form the bottom of the stand-up pouch with the sealant layer facing inward, and then valley-folded along the fold line indicated by F in Figure 1, thereby folding in the area that will become the bottom sheet and forming the area that will become the front sheet 11 and the area that will become the back sheet. Then, both sides of the area that will become the front sheet 11, both sides of the folded-in bottom sheet, and both sides of the area that will become the back sheet are overlapped and heat-sealed, thereby forming side seals 13 on both sides that form the body of the stand-up pouch 100.

The front sheet, back sheet, and bottom sheet may be a single continuous composite film as described above, or they may be separate, independent discontinuous sheets, or a combination of partially continuous and discontinuous sheets.

Furthermore, in the standing pouch of the present invention, at least one of the front sheet and back sheet may be formed from a composite film in which at least a base layer, an adhesive layer, and a sealant layer are laminated in this order. If only one of the front sheet and back sheet is made of this composite film, the top seal and side seal are formed by heat sealing to the other sheet using the sealant layer of the composite film.

If at least one of the front sheet and back sheet is not formed from a composite film, there are no particular restrictions on the sheet, and it can be selected appropriately depending on the desired performance of the stand-up pouch to be produced.

<Unsealed Portions, Cuts, and/or Notches>
The stand-up pouch of the present invention has at least one selected from the group consisting of an unsealed portion where the front sheet and back sheet are not heat-sealed, a notch, and a cutout in the side seal portion and/or the top seal portion, and the unsealed portion, the notch, and/or the cutout are formed so as to protrude from the side edge (the outer edge of the standing pouch in the side seal portion) and/or the top edge (the outer edge of the standing pouch in the top seal portion) of the standing pouch toward the storage section of the standing pouch.

The unsealed portion that the stand-up pouch of the present invention may have, where the front sheet and back sheet are not heat-sealed, is the portion where the front sheet and back sheet are not adhered to each other.

The method for creating the unsealed portion is not particularly limited, but it can be created, for example, by providing an area within the sealed region to which heat is not applied when forming the side sealed portion and/or top sealed portion. Alternatively, it can be created by heat-sealing the front sheet and back sheet to form the side sealed portion and/or top sealed portion, and then peeling off a portion of the side sealed portion and/or top sealed portion.

The notch that the stand-up pouch of the present invention may have is a linear cut that starts from the side edge (the outer edge of the standing pouch at the side seal) and/or the top edge (the outer edge of the standing pouch at the top seal) of the standing pouch, and may be a straight or curved cut.

The method for making the incisions is not particularly limited, but for example, after forming the side seals and/or top seals, the incisions can be made by starting from the side edge (the outer edge of the side seals) and/or the top edge (the outer edge of the top seals) of the standing pouch and cutting through the inside of the side seals and/or top seals toward the storage section of the standing pouch using a cutting tool such as a cutter, knife, or scissors. Alternatively, incisions can be made in the sides and/or top of both the front sheet and the back sheet, and the front sheet and back sheet can be heat-sealed while aligning the incisions to make the side seals and/or top seals with incisions. Alternatively, incisions can be made in the sides and/or top of at least one of the front sheet and back sheet, which is made of the composite film, to make the side seals and/or top seals with incisions.

The cutout that the stand-up pouch of the present invention may have is a cutout having a certain area that originates from the side edge (the outer edge of the standing pouch at the side seal portion) and/or the top edge (the outer edge of the standing pouch at the top seal portion) of the standing pouch.

The shape of the cutout is not particularly limited, and may be any of a variety of shapes, such as a triangle, a rectangle, a polygon, or a semicircle, with the base of the cutout being the side edge of the standing pouch (the outer edge of the standing pouch at the side seal) and/or the top edge (the outer edge of the standing pouch at the top seal).

The method for creating the cutouts is not particularly limited. For example, after forming the side seals and/or top seals, the side edges (outer edges of the standing pouch at the side seals) and/or top edges (outer edges of the standing pouch at the top seals) of the standing pouch can be cut out in the desired shape using a cutting tool such as a knife or scissors. Alternatively, cutouts of the desired shape can be created in the sides and/or top of the front sheet and back sheet, respectively, so that the side edges (outer edges of the sheets) and/or top edges (outer edges of the sheets) form the bottom edges, and the front sheet and back sheet are heat-sealed with the cutouts aligned to create the side seals and/or top seals with cutouts. Alternatively, cutouts can be created in the sides and/or top of at least one of the front sheet and back sheet, which is made of the composite film, to create the side seals and/or top seals with cutouts.

The stand-up pouch 100 shown in FIG. 1 has a single triangular cutout 15 in the side seal 13. The cutout 15 is formed so that it originates from the side edge of the standing pouch 100 (the side end of the side seal 13) and protrudes toward the storage section 14 of the standing pouch. Specifically, the side seal 13 is cut out to form a triangular cutout 15, with the side edge of the standing pouch 100 (the outer end of the side seal 13 of the standing pouch 100) serving as the base and the apex protruding toward the storage section 14 of the standing pouch 100.

In the standing pouch 100 shown in Figure 1, steam 17 is released from the cutout 15 when heated in a microwave oven or the like.

<Half cut>
The composite film used in the present invention has a half cut made from the sealant layer side to reach the adhesive layer, and therefore the standing pouch of the present invention produced using the composite film for at least one of the front sheet and back sheet has a half cut made from the sealant layer side of the composite film to reach the adhesive layer.

Here, a half cut refers to a cut that is formed in the thickness direction of the composite film but does not penetrate through the thickness direction of the composite film.

The half cut in the standing pouch of the present invention is positioned so that it reaches the unsealed portion, slit, and/or notch described above. When heated in a microwave oven or the like, steam can be released from the point where the half cut reaches the unsealed portion, slit, and/or notch. By locating these at the intended positions on the side seal and/or top seal, steam can be released from the intended positions.

The stand-up pouch of the present invention uses a composite film with a half cut on at least one of the front and back sheets, and the sealant layer of the composite film is heat-sealed to the opposing front and back sheets. As a result, the sealant layer is on the inside of the stand-up pouch, i.e., it is the layer that comes into contact with the contents. Therefore, steam generated from the contents when heated penetrates the composite film in the thickness direction through the half cut.

Therefore, by providing the standing pouch of the present invention with the unsealed portions, slits, and/or notches described above, as well as half cuts positioned to reach these, in areas where steam needs to be released, steam can be released from the intended location.

Figure 2 shows a cross-sectional view of one embodiment of a composite film used in the present invention. The composite film 10 shown in Figure 2 comprises a substrate layer 1, an adhesive layer 2 laminated on the inner side of the substrate layer 1, and a sealant layer 3 laminated on the inner side of the adhesive layer 2.

In the composite film 10 shown in Figure 2, the half cut H is made from the sealant layer 3 side and reaches the surface of the adhesive layer 2.

The depth of the half cut may be to the surface of the adhesive layer, or may extend to the interior of the adhesive layer, or may even penetrate the adhesive layer.

However, it is preferable that the half cut be deep enough not to reach the base layer, which is the outermost layer of the composite film. If the half cut reaches the base layer, the strength of the standing pouch formed from the composite film may be reduced.

In particular, it is preferable that the half cut is made only in the sealant layer. If the half cut can be made only in the sealant layer, the strength of the standing pouch can be maximized and the effects of the present invention can be enjoyed.

The shape of the half cut may be either a continuous line or an intermittent line. There is no limit to the number of half cuts, as long as there is at least one. When multiple half cuts are provided, it is preferable that the half cuts are approximately parallel to each other. When multiple half cuts are provided, it is not necessary for all of the half cuts to reach the unsealed portion, cut, and/or notch; it is sufficient that at least one of them reaches the unsealed portion, cut, and/or notch.

Furthermore, the length of the half cut is not particularly limited. It may be long enough to only be present in the area where steam release is desired, or it may be long enough to span the entire width of the standing pouch.

The method for forming the half cut is not particularly limited, and examples include forming the composite film and then using a laser or the like.

Alternatively, half-cuts may be made during the production of the composite film, and the layer having the half-cuts may be laminated with other layers to form the composite film used in the present invention. In this case, for example, a sheet containing a sealant layer may be cut using a rotary die cutter to penetrate the sealant layer in the thickness direction (half-cut making process), and then a base layer and an adhesive layer may be laminated onto the sheet containing the sealant layer (lamination process).

<Convex seal part>
The standing pouch of the present invention may have a convex seal portion in the side seal portion and/or the top seal portion that protrudes toward the storage portion side of the standing pouch on the storage portion side of the unsealed portion, slit, and/or notch described above.

If a convex seal portion is provided, the half cut is positioned so that it crosses the convex seal portion from the storage section side of the standing pouch to the side edge, reaching the unsealed portion, slit, and/or notch.

The convex seal portion is a seal portion formed when the sealant layer of the composite film is heat-sealed to the opposing front and back sheets.

The standing pouch 100 shown in Figure 1 has a single triangular notch 15 formed in the side seal portion 13, originating from the side edge of the standing pouch 100 (the side end portion of the side seal portion 13) and protruding toward the storage portion 14 of the standing pouch. Furthermore, on the storage portion 14 side of the notch 15, there is a triangular convex seal portion 16 that protrudes toward the storage portion 14 of the standing pouch 100.

The triangular convex seal portion 16 is formed so that its base is the side edge of the storage section 14 of the standing pouch 100 (the end of the side seal portion 13 on the storage section 14 side), and its apex protrudes inside the storage section 14 of the standing pouch 100.

The half cut H is positioned so that it passes through the apex of the triangle of the convex seal portion 16, crosses the convex seal portion 16, and reaches the apex of the triangle of the notch 15.

When the standing pouch of the present invention is equipped with a convex seal portion, steam generated from the contents exerts greater pressure on the convex seal portion than on other portions, making it easier to release steam from the intended location.

The shape of the convex seal portion is not particularly limited, and may be any of a variety of shapes, such as a triangle, a rectangle, a polygon, or a semicircle, with the base being the side edge of the storage portion of the standing pouch (the end of the side seal portion facing the storage portion) and/or the top edge (the end of the top seal portion facing the storage portion). Of these, triangles, rectangles, and polygons with corners are preferred, with triangles being even more preferred, from the perspective of being able to utilize stress concentration due to steam pressure.

<Relationship between side seal portion and/or upper seal portion, convex seal portion, unsealed portion, cutout, and/or notch>
In the standing pouch of the present invention, the side seal portion and/or the top seal portion, the convex seal portion, and the unsealed portion, the incision, and/or the notch may satisfy the relationship of the following formula (1).
a+b-c<10mm (1)
(a: width of the side seal portion and/or top seal portion having the unsealed portion, the cut, and/or the notch in the direction normal to the side edge and/or the top edge of the standing pouch,
b: width of the convex seal portion in the direction normal to the side edge and / or upper edge of the standing pouch,
c: Width of the unsealed portion, slit, and/or notch in the direction normal to the side edge and/or top edge of the standing pouch)

By satisfying the relationship of formula (1) above, the standing pouch of the present invention can more reliably release steam from the intended location.

The standing pouch may satisfy the relationship of the following formula (2), or may satisfy the relationship of the following formula (3).
a+b-c<8mm (2)
a+b-c<6mm (3)
(In formulas (2) and (3), a, b, and c are the same as those in formula (1) above.)

Composite film
The composite film used in the standing pouch of the present invention is a composite film having at least a base layer, an adhesive layer, and a sealant layer laminated in this order, and as described above, has a half cut that is made from the sealant layer side and reaches the adhesive layer.

Figure 2 shows a cross-sectional view of one embodiment of a composite film used in the present invention. The composite film 10 shown in Figure 2 comprises a substrate layer 1, an adhesive layer 2 laminated on the inner side of the substrate layer 1, and a sealant layer 3 laminated on the inner side of the adhesive layer 2.

In the composite film 10 shown in Figure 2, the half cut H is made from the sealant layer 3 side and reaches the surface of the adhesive layer 2.

The composite film used in the present invention essentially comprises a substrate layer, an adhesive layer, and a sealant layer, which are laminated in this order. In addition to the substrate layer, adhesive layer, and sealant layer, the present invention may also include optional layers, such as a barrier layer for imparting barrier properties, a reinforcing layer for reinforcing strength, or an adhesive layer for bonding layers together.

The location of the optional layer is not particularly limited, and it may be present, for example, between the substrate layer, adhesive layer, or sealant layer, or on the outside of a laminate containing these layers.

Furthermore, if no layers other than the adhesive layer are placed between the base layer and the sealant layer, the composite film manufacturing process can be simplified, contributing to reduced production capacity and production costs.

The thickness of each layer constituting the composite film used in the present invention can be determined appropriately depending on the intended use of the standing pouch to be formed.

<Base material layer>
The substrate layer is an essential constituent layer in the composite film used in the standing pouch of the present invention.

The composite film used in the stand-up pouch of the present invention has a base layer, adhesive layer, and sealant layer laminated in that order, so the base layer forms the outer layer of the stand-up pouch. Therefore, the base layer can serve as a protective layer when the innermost sealant layer is heat-sealed to form the stand-up pouch. It can also serve as a printing layer for printing to indicate the contents, etc.

The material that makes up the base layer is not particularly limited, as long as it is a resin, particularly a resin that can be used as a protective layer and that can be printed on. Commonly used resins can be used, such as polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT), polyolefins such as polyethylene (PE), polypropylene (PP), and polystyrene (PS), polyamides (PA) such as nylon-6 and nylon-66, and polycarbonate (PC).

The resins constituting the substrate layer may be one type or a blend of two or more types, and additives may be added as needed to impart functionality, etc.

The substrate layer is preferably made from a pre-formed film. The film that serves as the substrate layer may be a film formed from the above-mentioned resins, etc., and may be unstretched or uniaxially or biaxially stretched. Of these, a biaxially stretched film is preferred.

The film that serves as the substrate layer may also be vapor-deposited with a metal such as aluminum or an oxide such as silicon oxide or aluminum oxide.

Furthermore, the film that serves as the substrate layer may be a single layer or a laminate consisting of multiple layers.

<Adhesive layer>
The adhesive layer is an essential constituent layer of the composite film used in the standing pouch of the present invention, and is disposed between the base layer and the sealant layer.

When the composite film used in the standing pouch of the present invention is configured so that no layers other than the adhesive layer are disposed between the base layer and the sealant layer, the manufacturing process for the composite film can be simplified, thereby contributing to improved production capacity and production costs.

The material for the adhesive layer is not particularly limited, but examples include polyolefin, polyester, polyether, polyamide, polylactic acid, thermoplastic elastomer, etc.

(Laminate strength)
The adhesive layer of the composite film used in the standing pouch of the present invention may be an adhesive layer made of a thermosoftening resin that provides a specific laminate strength. Specifically, the adhesive layer may be a thermosoftening resin that provides a laminate strength between the base layer and the sealant layer of 1.5 N/15 mm or more at 25°C and a laminate strength between the base layer and the sealant layer of less than 1.5 N/15 mm at 70°C.

If the laminate strength between the base layer and sealant layer at 25°C is 1.5 N/15 mm or more, a standing pouch formed from the composite film will have sufficient strength at around room temperature, and peeling between the base layer and sealant layer will not occur during storage or handling.

The laminate strength at 25°C between the substrate layer and the sealant layer may be 1.8 N/15 mm or more, 2.0 N/15 mm or more, 2.4 N/15 mm or more, 2.8 N/15 mm or more, or 3.0 N/15 mm or more.

On the other hand, the laminate strength at 25°C between the base layer and the sealant layer may be 6.0 N/15 mm or less, 5.0 N/15 mm or less, 4.5 N/15 mm or less, 4.0 N/15 mm or less, 3.5 N/15 mm or less, or 3.0 N/15 mm or less.

Furthermore, if the laminate strength between the base layer and the sealant layer at 70°C is less than 1.5 N/15 mm, when a standing pouch formed from the composite film is heated, spaces are more likely to form in the heat-softenable adhesive resin layer, and steam can be transported through these spaces, thereby achieving steam release performance equivalent to that of conventional pouches.

The laminate strength at 70°C between the base layer and the sealant layer may be 1.2 N/15 mm or less, 1.0 N/15 mm or less, 0.8 N/15 mm or less, 0.5 N/15 mm or less, 0.2 N/15 mm or less, 0.1 N/15 mm or less, or 0.05 N/15 mm or less.

On the other hand, the laminate strength at 70°C between the base layer and the sealant layer may be 0.01 N/15 mm or more, 0.05 N/15 mm or more, 0.1 N/15 mm or more, 0.2 N/15 mm or more, 0.3 N/15 mm or more, 0.4 N/15 mm or more, or 0.5 N/15 mm or more.

When the adhesive layer of the composite film used in the stand-up pouch of the present invention has the above-mentioned laminate strength, the laminate strength between the base layer and sealant layer at 25°C is greater than the laminate strength at 70°C. In other words, when a standing pouch formed from the composite film is heated in a microwave oven or the like, the laminate strength between the base layer and sealant layer decreases due to the temperature increase, making it easier to form spaces in the softening resin layer, which is the adhesive layer. Steam generated from the contents can then migrate through the formed spaces.

Furthermore, when the adhesive layer of the composite film used in the standing pouch of the present invention has the above-mentioned lamination strength, it is possible to realize a standing pouch with vapor release performance equivalent to that of conventional pouches, even if only one adhesive layer made of a thermosoftening resin is disposed between the base layer and the sealant layer.

Commercially available materials that can achieve the above laminate strength include, for example, LX-500 (DIC Corporation), Elitel (registered trademark) XP-1648-45EA (Unitika Ltd.), and TM-396 (Toyo-Morton Co., Ltd.).

(Adhesive strength)
The adhesive layer of the composite film used in the standing pouch of the present invention may have an adhesive strength in accordance with JIS Z0237 of 1.0 N/25 mm or more.

If the adhesive layer has an adhesive strength of 1.0 N/25 mm or more in accordance with JIS Z0237, it will have sufficient adhesion to adjacent layers, preventing problems such as peeling during storage and handling of standing pouches made from composite films.

In addition, since there is no need to provide a layer between the base layer and the sealant layer to strengthen adhesion, the manufacturing process for the composite film can be simplified, contributing to reduced production capacity and production costs.

The adhesive strength of the adhesive layer in accordance with JIS Z0237 may be 1.5 N/25 mm or more, 2.0 N/25 mm or more, 2.5 N/25 mm or more, 3.0 N/25 mm or more, 3.5 N/25 mm or more, 4.0 N/25 mm or more, or 4.5 N/25 mm or more.

On the other hand, the adhesive strength of the adhesive layer in accordance with JIS Z0237 may be 10.0 N/25 mm or less, 9.0 N/25 mm or less, 8.0 N/25 mm or less, 7.0 N/25 mm or less, 6.0 N/25 mm or less, 5.0 N/25 mm or less, or 4.0 N/25 mm or less.

(Sealant layer)
The sealant layer is an essential constituent layer in the composite film used in the present invention.

The sealant layer is the layer that is heat-sealed when forming the standing pouch. For this reason, the sealant layer is positioned so that it is the innermost layer of the composite film.

The material that makes up the sealant layer is not particularly limited, as long as it is heat-sealable and can provide sufficient sealing strength to the molded standing pouch. Known materials can be used, such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), polypropylene (PP), ethylene-propylene copolymer (EP), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ionomer resin, and ethylene-vinyl acetate copolymer (EVA).

The sealant layer will form a space for filling the contents in the resulting standing pouch. For this reason, it may be possible to impart resistance to the contents by using, for example, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), etc.

The sealant layer may be formed using a pre-formed film made from the above materials, or may be formed by melting and extruding the material for forming the sealant layer onto the surface of a laminate comprising a substrate layer, an adhesive layer, and optionally other layers, and then cooling and solidifying it.

The resins constituting the sealant layer may be a single type or a blend of two or more types, and additives may be added to impart functionality, etc., as needed.

Furthermore, the sealant layer may be a single layer or may be composed of multiple layers.

<Other demographics>
The composite film used in the standing pouch of the present invention may contain layers other than the base layer, adhesive layer, and sealant layer as long as they contain the base layer, adhesive layer, and sealant layer as essential constituent layers.

The other layers are not particularly limited, and examples include a barrier layer to provide barrier properties, a reinforcing layer to increase strength, or an adhesive layer to bond layers together.

Barrier layers for imparting barrier properties include, for example, layers made of ethylene-vinyl alcohol copolymer (EVOH), nylon (NY), polyvinylidene chloride (PVDC), or polyacrylonitrile (PAN), which function to block gases such as oxygen and water vapor.

Examples of materials for the reinforcing layer to increase strength include paper, synthetic paper, and nonwoven fabric. These may be coated with an adhesive to provide adhesion to adjacent layers. It is also possible to provide a layer made of the material that makes up the base layer as a reinforcing layer, separate from the base layer.

Examples of adhesive layers used to bond layers together include layers made of ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), and ionomer.

The other layer may also be a layer made of adhesive used when dry laminating or hot melt laminating layers together.

The resins constituting the other layers may be one type or a blend of two or more types. Furthermore, additives may be added to impart functionality, etc., as needed.

<<Function of the standing pouch>>
The function of the stand-up pouch of the present invention will be described below with reference to the drawings. Fig. 1 is a front view of a stand-up pouch formed using the above-mentioned composite film as a front sheet, Fig. 2 is a cross-sectional view of the composite film used as the front sheet, and Fig. 3 is a schematic view of the composite film used in the stand-up pouch when steam is released.

The composite film 10 that forms the front sheet 11 of the standing pouch 100 shown in FIG. 1 is a laminate consisting of a base layer 1, an adhesive layer 2, and a sealant layer 3, as shown in FIG. 2. As shown in FIG. 1, the composite film 10 that forms the front sheet 11 has each layer extending on the X-Y plane formed by the X and Y directions, and the Z direction (not shown) is the thickness direction of the composite film 10. In other words, FIG. 1 is a front view of the standing pouch 100 as seen from the base layer 1 side.

In the composite film 10 constituting the standing pouch 100 shown in Figure 1, the half cuts H are arranged in discontinuous straight lines, extending from the storage section 14 side of the standing pouch 100 to the side edge, across the convex seal section 16 of the standing pouch 100, and reaching the notch 15 in the side seal section 13.

When such a standing pouch 100 is heated and steam is generated from the contents filled in the storage section 14 of the standing pouch 100, the generated steam 17 is discharged to the outside of the standing pouch 100 through the notch 15 in the side seal section 13, as shown in Figure 1.

Here, we will explain how steam 17 is discharged to the outside of the standing pouch 100 through the notch 15 in the side seal portion 13 using Figure 3.

Figure 3 shows a cross-sectional view in the Z direction (not shown) of the composite film 10, which is the front sheet 11 of the standing pouch 100. When the standing pouch 100 is heated and steam 17 is generated from the contents of the standing pouch 100, the adhesive layer 2 of the composite film 10 is softened by the steam 17.

The steam 17 generated inside the standing pouch 100 penetrates the thickness direction (Z direction) of the composite film 10 through the half cut H formed in the sealant layer 3 of the composite film 10, and when it reaches the adhesive layer 2, it directly applies heat to the adhesive layer 2. This softens and makes the adhesive layer 2 flexible.

The pressure inside the standing pouch 100 increases due to the pressure of steam 17 generated by the contents. As shown in Figure 3, the increase in internal pressure causes delamination between the softened adhesive layer 2 and sealant layer 3, and the adhesive layer 2 is lifted to the outside of the standing pouch 100 by the pressure of steam 17, forming a space 6 in the delaminated area.

The steam 17 generated from the contents moves to the side seal portion 13 through the space 6 that appears in the area of the half cut H that is arranged across the convex seal portion 16, and when it reaches the notch 15 in the side seal portion 13, it is expelled from the notch 15 to the outside of the standing pouch 100.

<<Uses of Stand-Up Pouches>>
The use of the stand-up pouch of the present invention is not particularly limited. Examples of contents that can be filled include liquids such as gels, gels, and even pastes. Examples of liquids include pharmaceuticals, quasi-drugs, cosmetics, detergents, foods, and paints.

Examples of pharmaceuticals and quasi-drugs include injections, intravenous drips, infusions, irrigation agents, and decoctions. Examples of cosmetics include shampoos, conditioners, and hair styling products (e.g., hair water, hair liquid, grease, etc.). Examples of detergents include neutral detergents, alkaline detergents, and acidic detergents. Examples of foods include beverages, cooking oils, soups, creams, and liquid seasonings (e.g., soy sauce, vinegar, noodle soup, simmered sauce, mirin, Worcestershire sauce, dressings, ketchup, Tabasco, sweeteners, etc.). Examples of coatings include paints, varnishes, and oil stains.

The contents may also be in the form of a gel, gel, or paste, such as toothpaste, wasabi, jelly, jam, miso, etc.

The stand-up pouch of the present invention is capable of venting steam generated from the contents when heated, making this effect extremely useful as a stand-up pouch for microwave ovens. Therefore, it is extremely useful for storing food and other items that are heated in a microwave oven while the contents are stored in the stand-up pouch.

The present invention will be explained in more detail below using examples and comparative examples, but the present invention is not limited to these.

<Examples 1 to 11, Comparative Examples 1 to 3>
In Examples 1 to 11 and Comparative Examples 1 to 3, standing pouches that are variations of the standing pouch shown in FIG. 1 were produced, and the steam permeability and steam passage position when heated in a microwave oven were evaluated.

[material]
The materials of the standing pouches produced in Examples 1 to 11 and Comparative Examples 1 to 3 are shown below.

(1) Base layer OPP: biaxially stretched PP film (Pylen (registered trademark) P2161, Toyobo Co., Ltd., thickness: 20 μm)

(2) Heat-softening resin layer: TM-396/CAT-22B (Toyo-Morton Co., Ltd.)

(3) Sealant layer CPP: Unstretched PP film (Pylen (registered trademark) P1128, Toyobo Co., Ltd., thickness: 50 μm)

(4) PET film layer PET: PET film (Ester (registered trademark) film E5100, Toyobo Co., Ltd., thickness: 12 μm)

(5) Adhesive: LX-500/KR-90S (DIC Corporation)

[Preparation of Composite Film]
A PET film and a CPP film serving as a sealant layer were bonded together with an adhesive to produce a sealant laminate. Subsequently, the sealant laminate was subjected to linear, intermittent cuts penetrating through the thickness direction (half-cut production step).

An OPP film serving as a base layer was bonded to the PET film side of the sealant laminate with the cut using a heat-softening adhesive resin, with the coating amount of the heat-softening adhesive resin being 2.0 g/ ^m² , to produce a laminate serving as a composite film.

Example 1
[Production of standing pouches]
The heat seal layers of the prepared composite films were placed facing each other to prepare a standing pouch having outer dimensions of 140 mm in width, 140 mm in height, and a folding width of 30 mm, as shown in Figure 4. At this time, the inside of the standing pouch was filled with Kimwipes (registered trademark) L-100 (470 mm x 425 mm) and 20 g of water.

The half cut was placed so that it crossed both side seals and the container, from one side seal of the standing pouch across the container to the other side seal. The standing pouch was made using an impulse sealer with heating for 1.0 seconds and cooling for 2.0 seconds.

(Preparation of side seal portion)
In Example 1, a standing pouch as shown in Fig. 4 was produced. Specifically, the side seal portion was produced so that the width (a) in the normal direction to the side edge of the standing pouch was 5 mm.

(Production of convex seal portion)
Next, two triangular convex seals were formed on both side seals on the extension lines of the half cuts, with the end of the standing pouch on the storage section side as the base and the apex protruding inside the storage section. At this time, the half cuts were arranged to pass through the apex of the triangle, and the convex seals had a width (b) of 5 mm in the direction normal to the side edge of the standing pouch.

(Creating a cutout)
Next, two equilateral triangular notches were made in both side seals on the half-cut extension line, with the outer edge of the standing pouch in the side seal as the base and the apex protruding toward the container section. The width (c) of the notches in the direction normal to the side edge of the standing pouch was 5 mm.

(a + b - c)
Therefore, the value of the following formula (1) in Example 1 is 5 mm.
a + b - c (1)
(a: width of the side seal portion having the notch in the direction normal to the side edge of the standing pouch,
b: width of the convex seal portion in the direction normal to the side edge of the standing pouch,
c: Width of the notch in the normal direction to the side edge of the standing pouch)

Example 2
As shown in Figure 5, a standing pouch was produced in the same manner as in Example 1, except that the half cut was changed so that it passed through approximately the center of the upper side of the equilateral triangle that would become the convex seal portion.

Example 3
As shown in Figure 6, a standing pouch was produced in the same manner as in Example 1, except that the half cut was changed so that it passed through approximately the center of the bottom side of the equilateral triangle that would become the convex seal portion.

Example 4
As shown in FIG. 7, a standing pouch was produced in the same manner as in Example 1, except that the shape of the convex seal portion was an acute triangle and the shape of the cutout was an acute triangle.

Example 5
As shown in FIG. 8, a standing pouch was produced in the same manner as in Example 1, except that the shape of the convex seal portion was an obtuse triangle and the shape of the cutout was an obtuse triangle.

Example 6
A standing pouch was produced in the same manner as in Example 1, except that the shape of the convex seal portion was changed to an acute triangle and the width (b) of the convex seal portion in the direction normal to the side edge of the standing pouch was changed to 7 mm, as shown in Figure 9. In this example, the value (a + b - c) of formula (1) is 7 mm.

Example 7
As shown in FIG. 10, a standing pouch was produced in the same manner as in Example 1, except that a convex seal and a notch were formed on only one side of the side seal.

Example 8
As shown in Figure 11, a standing pouch was produced in the same manner as in Example 1, except that the shape of the convex seal portion was made rectangular and the half cut was arranged so as to pass through approximately the center of the rectangle.

Example 9
As shown in Figure 12, a standing pouch was produced in the same manner as in Example 1, except that the shape of the convex seal portion was semicircular and the half cut was arranged so as to pass through approximately the center of the semicircle.

Example 10
As shown in Figure 13, a standing pouch was produced in the same manner as in Example 1, except that the width (a) of the side seal portion in the direction normal to the side edge of the standing pouch was 10 mm and no convex seal portion was produced. In this example, the width (b) of the convex seal portion in the direction normal to the side edge of the standing pouch was 0 mm, so the value (a + b - c) of formula (1) was 5 mm.

Example 11
[Production of standing pouches]
The heat seal layers of the prepared composite films were placed facing each other to prepare a standing pouch having outer dimensions of 140 mm in width, 140 mm in height, and a folding width of 30 mm, as shown in Fig. 14. At this time, the inside of the standing pouch was filled with Kimwipes (registered trademark) L-100 (470 mm x 425 mm) and 20 g of water.

The half cut was placed so that it crossed both the top seal of the standing pouch, across the container section, and down to the bottom seal of the standing pouch, crossing both seals and the container section. The standing pouch was made using an impulse sealer with heating for 1.0 seconds and cooling for 2.0 seconds.

(Preparation of upper seal part)
In Example 11, a standing pouch as shown in Fig. 14 was produced. Specifically, the upper seal portion was produced so that the width (a) in the direction normal to the upper edge of the standing pouch was 5 mm.

(Production of convex seal portion)
Next, one triangular convex seal was formed on the upper seal on the extension of the half cut, with the end of the standing pouch on the storage section side as the base and the apex protruding inside the storage section. At this time, the half cut was arranged to pass through the apex of the triangle, and the width (b) of the convex seal in the direction normal to the upper edge of the standing pouch was 5 mm.

(Creating a cutout)
Next, a notch of an equilateral triangle was made in the upper seal part on the extension line of the half cut, with the outer edge of the standing pouch in the upper seal part as the base and the apex protruding toward the storage part. The width (c) of the notch in the direction normal to the upper edge of the standing pouch was 5 mm.

(a + b - c)
Therefore, the value of the following formula (1) in Example 11 is 5 mm.
a + b - c (1)
(a: width of the upper seal portion having the notch in the direction normal to the upper edge of the standing pouch,
b: Width of the convex seal portion in the normal direction to the upper edge of the standing pouch,
c: Width of the notch in the normal direction to the upper edge of the standing pouch)

Comparative Example 1
As shown in Figure 15, a standing pouch was produced in the same manner as in Example 1, except that the convex seal portion and the cutout were not produced. In this example, the width (b) of the convex seal portion in the direction normal to the side edge of the standing pouch and the width (c) of the cutout in the direction normal to the side edge of the standing pouch were 0 mm, so the value (a + b - c) of formula (1) was 5 mm.

Comparative Example 2
As shown in Figure 16, except that no notch was made, a standing pouch was produced in the same manner as in Example 1. In this example, the width (c) of the notch in the direction normal to the side edge of the standing pouch was 0 mm, so the value (a + b - c) of formula (1) was 10 mm.

Comparative Example 3
17, a standing pouch was produced in the same manner as in Example 1, except that the width (a) of the side seal portion in the direction normal to the side edge of the standing pouch was 10 mm, and no convex seal portion or cutout was produced. In this example, the width (b) of the convex seal portion in the direction normal to the side edge of the standing pouch and the width (c) of the cutout in the direction normal to the side edge of the standing pouch are 0 mm, so the value (a + b - c) of formula (1) is 10 mm.

<Evaluation of Standing Pouch>
<Vapor permeability>
The prepared standing pouches were reheated in a microwave oven (700 W) for 60 seconds. It was visually confirmed whether steam inside the pouch had been released from the interlayer between the base layer and the heat seal layer. Each standing pouch was reheated in the microwave three times and evaluated according to the following criteria. The results are shown in Table 1.
⊚: Steam was released in all three cases.
○: Steam was released two out of three times.
△: Steam was emitted once out of three times.
×: No steam was emitted in all three tests.

<Position where steam passes>
The prepared standing pouches were reheated in a microwave oven (700W) for 60 seconds. It was visually confirmed whether steam inside the pouch was released from the side seal or top seal on the extension of the half-cut. Each standing pouch was reheated in the microwave three times and evaluated according to the following criteria. The results are shown in Table 1.
○: In all cases where steam was discharged, it was discharged from the side seal or the top seal on the extension line of the half cut.
△: Of the times when steam was discharged, there were cases where steam was not discharged from the side seal portion or the upper seal portion on the extension line of the half cut.
×: Of the times that steam was discharged, there was no case where steam was discharged from the side seal portion or the upper seal portion on the extension line of the half cut.

《Consideration》
From Examples 1, 4, and 5, it can be seen that even if the shape of the convex seal portion is an acute angle or an obtuse angle, there is no effect on steam permeability or steam passage position, and steam can be discharged from the intended position. Furthermore, from Examples 1, 2, and 3, it can be seen that if a half cut crosses the convex seal portion, there is no effect on steam permeability or steam passage position, and steam can be discharged from the intended position. Furthermore, from Example 8, it can be seen that even when a convex seal portion and a cutout are formed on only one side of the side seal portion, there is no effect on steam permeability or steam passage position, and steam can be discharged from the intended position.

Examples 1 and 7 show that steam can be more reliably discharged from the intended location when the value of equation (1) is less than 10 mm.

Example 1 and Comparative Examples 1 and 2 show that in the case of a standing pouch with no notch in the side seal, steam cannot be released from the intended location.

<Reference Examples 1 to 5, Reference Comparative Examples 1 to 5>
In Reference Examples 1 to 5 and Reference Comparative Examples 1 to 5, pillow bags were made from the composite films, and the laminate strength was measured and the steam permeability when heated in a microwave oven was evaluated.

[material]
In Reference Examples 1 to 5 and Reference Comparative Examples 1 to 5, the following materials were prepared as materials for constituting the layers.

(1) Base layer Ny#15: Nylon film (Bonyl (registered trademark) RX, Kohjin Film & Chemicals Co., Ltd., thickness: 15 μm)

(2) Heat-softening adhesive resin layer or adhesive layer: LX-500 (DIC Corporation)
Eliter (registered trademark) XP-1586-45EA
Eliter (registered trademark) XP-1648-45EA (Unitika Ltd.)
・TM-396 (Toyo Morton Co., Ltd.)
・LX-500/KW-75 (DIC Corporation)
Eliter (registered trademark) XP-1541-45EA (Unitika Ltd.)
Elitel (registered trademark) UE-3223 (Unitika Ltd.)
・TM-396/CAT-22B (Toyo Morton Co., Ltd.)

(3) Sealant layer CPP #30: Unstretched PP film (Pylen (registered trademark) P1128, Toyobo Co., Ltd., thickness: 30 μm)
E1901T#50: Laminated PP film (Diffarene (registered trademark) E1901T, DIC Corporation, thickness: 50 μm)

(4) Others: Release varnish: Polycoat (registered trademark) P-91/P-91 Reducer = 3/1 (DIC Corporation)

Reference Examples 1 to 5, Reference Comparative Examples 1 to 4
[Production of composite film]
A laminate was prepared by bonding a film to be the base layer and a film to be the sealant layer with a heat-softening adhesive resin or adhesive using the materials listed in Table 2. The coating amount of the heat-softening adhesive resin or adhesive was 1.5 g/ ^m2 .

The film that would become the sealant layer in the laminate was cut to penetrate the sealant layer in the thickness direction (half-cut production process), and then a base layer and a heat-softenable adhesive resin layer were laminated onto the sheet containing the sealant layer to obtain a composite film with a half cut.

Comparative Example 5
[Production of composite film]
A release varnish, Polycoat (registered trademark) P-91/P-91 Reducer = 3/1 (DIC Corporation), was applied to Ny#15 nylon film, which served as the base layer, at a coating weight of 1.5 g/ ^m2 . After the release varnish dried, a film, which served as the sealant layer, was adhered to the release varnish-coated surface with an adhesive using the materials listed in Table 1, in the same manner as in Reference Examples 1 to 5 and Reference Comparative Examples 1 to 4, to produce a laminate.

The film that would become the sealant layer in the laminate was cut to penetrate the sealant layer in the thickness direction (half-cut production process), and then a base layer and a heat-softenable adhesive resin layer were laminated onto the sheet containing the sealant layer to obtain a composite film with a half cut.

<<Measurement of Laminate Strength>>
The composite films obtained in Reference Examples 1 to 5 and Reference Comparative Examples 1 to 5 were cut into 15 mm widths, and the interlaminar strength between the base layer and the sealant layer was measured in an atmosphere of 25°C and an atmosphere of 70°C. The measurements were carried out by T-peel at a rate of 300 mm/min, and the average value was calculated over a displacement range of 20 to 50 mm. The results are shown in Table 1.

[Making pillow bags]
Pillow bags with inner dimensions of 130 mm x 135 mm were produced using the composite films produced in Reference Examples 1 to 5 and Reference Comparative Examples 1 to 5. A microwaveable container filled with 10 cc of water was sealed inside the pillow bag. The half-cut was placed in the sealed portion of the pillow bag so as to cross the sealed portion from the containing portion of the pillow bag. The pillow bags were produced using an impulse sealer with heating times of 1.3 seconds and cooling times of 2.0 seconds.

<Evaluation of steam permeability of pillow bags>
The pillow pouches thus prepared were reheated in a microwave oven (700W) for 60 seconds. It was visually confirmed whether steam inside the pouch had been released from the heat-sealed portion. Each pillow pouch was reheated five times and evaluated according to the following criteria. The results are shown in Table 2.
○: Steam was emitted in all five tests.
×: No steam was emitted in all five tests.

Reference Examples 1 to 5 Measurement of adhesive strength of heat-softenable adhesive resin layer The heat-softenable adhesive resin or adhesive used in Reference Examples 1 to 3 and Reference Comparative Examples 2 and 3 was applied to the surface of Ny#15 nylon film (Bonyl (registered trademark) RX, Kohjin Film & Chemicals Co., Ltd., thickness: 15 μm) at a coating amount of 1.5 g/ ^m2 . Subsequently, a sample was cut to a width of 25 mm and attached to a test plate (stainless steel plate) to prepare an evaluation sample. During attachment, a pressure roller (2 kg) was moved back and forth twice to apply pressure.

The adhesive strength of the prepared evaluation samples was measured using a Strograph in an atmosphere of 25°C. Measurements were performed at a 180° peel angle and a rate of 500 mm/min, and the average value was calculated over a displacement range of 20 to 50 mm. The results are shown in Table 3.

100 Standing pouch 11 Front sheet 12 Top seal 13 Side seal 14 Storage section 15 Notch 16 Convex seal 17 Steam 10 Composite film 1 Base layer 2 Adhesive layer 3 Sealant layer H Half cut F Fold-back line a Width of the side seal and/or top seal having the notch in the direction normal to the side edge and/or top edge of the standing pouch b Width of the convex seal in the direction normal to the side edge and/or top edge of the standing pouch c Width of the notch in the direction normal to the side edge and/or top edge of the standing pouch

Claims (4)

A stand-up pouch comprising a front sheet, a back sheet, and a bottom sheet heat-sealed at least at a top seal and a side seal to form a container for containing contents,
at least one of the front sheet and the back sheet is made of a composite film in which at least a base layer, an adhesive layer, and a sealant layer are laminated in this order, and the front sheet and the back sheet facing each other are heat-sealed via the sealant layer to form the top seal portion and the side seal portion;
the side sealed portion and/or the top sealed portion has at least one selected from the group consisting of an unsealed portion where the front sheet and the back sheet are not heat-sealed, a slit, and a notch;
the unsealed portion, the incision, and/or the notch protrude from a side edge and/or an upper edge of the standing pouch toward the storage portion of the standing pouch,
the composite film has a half cut made from the sealant layer side and reaching the adhesive layer,
the half cut is arranged so as to reach the unsealed portion, the slit, and/or the notch from the storage portion side of the standing pouch,
the side seal portion and/or the top seal portion includes a convex seal portion that protrudes toward the storage portion side of the standing pouch on the storage portion side of the unsealed portion, the notch, and/or the cutout,
the half cut is arranged so as to extend from the storage section side of the standing pouch across the convex seal section and reach the unsealed section, the incision, and/or the notch,
A standing pouch that satisfies the following formula (1) :
a+b-c<10mm (1)
(a: width of the side seal portion and/or the top seal portion having the unsealed portion, the incision, and/or the notch in a direction normal to the side edge and/or the top edge of the standing pouch,
b: the width of the convex seal portion in the direction normal to the side edge and / or upper edge of the standing pouch,
c: the width of the unsealed portion, the slit, and/or the notch in the direction normal to the side edge and/or the top edge of the standing pouch) . A stand-up pouch comprising a front sheet, a back sheet, and a bottom sheet heat-sealed at least at a top seal and a side seal to form a container for containing contents,
at least one of the front sheet and the back sheet is made of a composite film in which at least a base layer, an adhesive layer, and a sealant layer are laminated in this order, and the front sheet and the back sheet facing each other are heat-sealed via the sealant layer to form the top seal portion and the side seal portion;
the side sealed portion and/or the top sealed portion has at least one selected from the group consisting of an unsealed portion where the front sheet and the back sheet are not heat-sealed, a slit, and a notch;
the unsealed portion, the incision, and/or the notch protrude from a side edge and/or an upper edge of the standing pouch toward the storage portion of the standing pouch,
the composite film has a half cut made from the sealant layer side and reaching the adhesive layer,
the half cut is arranged so as to reach the unsealed portion, the slit, and/or the notch from the storage portion side of the standing pouch,
the adhesive layer is a thermosoftening resin,
The laminate strength between the base layer and the sealant layer at 25°C is 1.5 N/15 mm or more,
The laminate strength between the substrate layer and the sealant layer at 70°C is less than 1.5 N/15 mm.
Standing pouch. 3. The standing pouch according to claim 1, wherein the adhesive layer has an adhesive strength in accordance with JIS Z0237 of 1.0 N/25 mm or more. The standing pouch according to any one of claims 1 to 3 , which is for use in a microwave oven.