Self-supporting packaging bags

Abstract

To provide a self-standing packaging bag having excellent falling resistance.SOLUTION: A self-standing packaging bag is composed of a laminate having a base material layer and a sealant layer, and includes a body part storing contents and a bottom part. The bottom part has a pair of valley-fold parts formed by bending the laminate, one mountain-fold part formed between the pair of valley-fold parts, and an air sealing part formed by heat sealing a region between the valley-fold parts and the mountain-fold part in a lateral direction of the bottom part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a self-supporting packaging pouch. [Background technology]

[0002] Packaging bags are made from a variety of materials and are made to suit the nature and quantity of the contents to be packaged, post-treatment to protect the contents from deterioration, the form in which the package (the packaging bag containing the contents) will be transported, the method of opening the package, and the method of disposal.

[0003] Standing pouches and other self-supporting packaging bags are becoming more widely used because they can make products stand out on store shelves. In order to ensure that the entire surface of the pouch is visible without bending along the way, the laminate that constitutes the pouch must have a certain degree of rigidity. In addition, if the pouch contains liquid, it must be strong enough not to break when dropped and leak the liquid. To meet these requirements, laminates combining polyester films, nylon films, polyolefin films, etc. have been used (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-237281 [Patent Document 2] Japanese Patent Application Publication No. 7-241967 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, with the growing awareness of environmental issues, there is a demand for resource conservation and reuse in the field of packaging bags. For example, from the viewpoint of resource conservation, there is a trend for one refill pouch to be filled with an amount sufficient for multiple refills. However, as the volume of the contents increases, the impact when dropped increases, increasing the risk of the contents leaking due to the drop. One possible way to improve impact resistance is to thicken the film (e.g., sealant film) that constitutes the pouch. However, this method runs counter to the reduction of the amount of plastic used.

[0006] From the perspective of reuse, technology is being considered to reuse the packaging material as a single material by constructing the laminated body that constitutes the packaging material from the same material. This is called mono-materialization of packaging materials. As mentioned above, conventional packaging materials have improved required physical properties such as impact resistance by combining various different materials. However, when packaging materials are constructed from the same material, there is an issue that it is difficult to ensure sufficient drop resistance.

[0007] The present disclosure provides a self-supporting packaging bag with excellent drop resistance. [Means for solving the problem]

[0008] The self-supporting packaging bag according to the present disclosure is constituted by a laminate including a base layer and a sealant layer, and includes a body portion for accommodating contents, and a bottom portion. The bottom portion has a pair of valley folds formed by folding the laminate, a mountain fold formed between the pair of valley folds, and an air enclosing portion formed by heat sealing the area between the valley folds and the mountain fold in the lateral direction of the bottom portion.

[0009] As described above, the self-supporting packaging bag has an air-enclosed portion at the bottom, and therefore has excellent drop resistance. The height of the air-enclosed portion may be set according to the type and amount of the contents, and is, for example, 5 to 30 mm.

[0010] The self-supporting packaging bag may have at least a pair of cutouts or holes provided in a region between the valley folds and the mountain folds and on the side of the laminate, and may have a fused portion in which the sealant layers are locally fused to each other through the pair of cutouts or the pair of holes. The fused portion may have a semicircular shape, for example. This configuration can further improve the self-supporting ability and drop resistance of the packaging bag. From the viewpoint of excellent drop resistance, the area ratio of the fused portion is preferably 30 to 70%. The area ratio here means a value calculated by the following formula (1). Area ratio (%) = (area of ​​fused part) / (L × 10) × 100…(1) [In formula (1), L represents the distance (unit: mm) from the valley fold to the mountain fold.] When there are multiple fused portions in the target region, the "area of ​​the fused portion" in formula (1) is the "total area of ​​the multiple fused portions."

[0011] In the present disclosure, the base layer and the sealant layer are preferably made of the same resin material. By using the same resin material for these layers, the self-supporting packaging bag can be made of a mono-material, which contributes to promoting the recycling of resin materials. The laminate may further include a gas barrier layer depending on the type of contents, etc. Effect of the Invention

[0012] According to the present disclosure, a self-supporting packaging bag having excellent drop resistance is provided. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a front view showing a schematic diagram of a self-supporting packaging bag according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view that shows a schematic view of the air-enclosed portion of the self-supporting packaging bag shown in FIG. [Diagram 3] FIG. 3 is a perspective view showing a schematic state of the laminate folded into a W shape. [Figure 4] FIG. 4 is a plan view showing a schematic state in which a plurality of through holes are provided in an original sheet of a laminate. [Diagram 5] FIG. 5 is a front view showing a schematic view of a self-supporting packaging bag according to a comparative example. [Figure 6] FIG. 6 is a cross-sectional view that typically shows the structure of the packaging bag shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present disclosure will be described in detail. Here, a standing pouch in which mono-materialization has been realized will be described as an example. The standing pouch is used as a refill pouch for shampoo, hand soap, detergent, etc., or as a pouch for soup, seasoning, etc. Note that the present invention is not limited to the following embodiment.

[0015] <Standing pouch> FIG. 1 is a front view showing a typical example of a standing pouch (self-supporting packaging bag) according to the present embodiment. The standing pouch 10 shown in this figure includes a body 10a in which contents are accommodated, and a bottom 10b, and air-filled portions 5, 6 are formed in the bottom 10b. FIG. 2 is a cross-sectional view showing an enlarged view of the air-filled portions 5, 6 of the standing pouch 10. The air-filled portions 5, 6 act as cushions, thereby preventing the standing pouch 10 from breaking due to the impact of being dropped. According to the study by the present inventors, a conventional standing pouch containing a liquid material often falls with its bottom facing downward, and when dropped in this state, the bottom is easily broken.

[0016] The standing pouch 10 is manufactured through a process of folding a laminate 3 including at least a base layer 1 and a sealant layer 2 into a W shape. Fig. 3 is a perspective view showing a schematic state of the laminate 3 folded into a W shape. As shown in Fig. 3, the laminate 3 is folded into a W shape so that the base layer 1 is disposed on the outside and the sealant layer 2 is disposed on the inside. By folding the laminate 3 into a W shape, the laminate 3 is divided into the following four regions R1a, R1b, R2b, and R2a. Region R1a: Region from the end of the laminate 3 to the valley fold V1 Region R1b: Region from valley fold V1 to mountain fold M1 Region R2b: Region from mountain fold M1 to valley fold V2 Region R2a: Region from the valley fold V2 to the end of the laminate 3

[0017] The sides of the standing pouch 10 are composed of heat-sealed parts 11. The width of the heat-sealed part 11 shown in Fig. 1 is, for example, 5 to 18 mm, and may be 7 to 15 mm. When the width of the heat-sealed part 11 is 5 mm or more, sufficient seal strength tends to be achieved, while when the width is 18 mm or less, a sufficient content volume of the standing pouch 10 tends to be easily ensured.

[0018] The bottom 10b has a pair of valley folds V1, V2 formed by folding the laminate 3 into a W-shape, and a mountain fold M1 formed therebetween. The distance L (see FIG. 1) from the valley fold V1 or the valley fold V2 to the mountain fold M1 is, for example, 10 to 60 mm, and may be 15 to 50 mm. When the distance L is 10 mm or more, it is easy to ensure a sufficient height of the air enclosed portions 5, 6, and the drop resistance of the standing pouch 10 tends to be further improved. On the other hand, when the distance L is 60 mm or less, it is easy to ensure a sufficient content volume of the standing pouch 10.

[0019] The air-enclosed portions 5 and 6 are formed by heat-sealing the area between the valley fold V1 and the mountain fold M1 across the entire width of the bottom 10b. That is, the sealant layer 2 in the region R1a and the sealant layer 2 in the region R1b are heat-sealed in the width direction to form the heat-sealed portion 12 constituting the air-enclosed portion 5. On the other hand, the sealant layer 2 in the region R2a and the sealant layer 2 in the region R2b are heat-sealed in the width direction to form the heat-sealed portion 12 constituting the air-enclosed portion 6. The width W (see FIG. 1) of the heat-sealed portion 12 is, for example, 5 to 15 mm, and may be 7 to 12 mm. A width of the heat-sealed portion 12 of 5 mm or more tends to achieve sufficient seal strength, while a width of 15 mm or less tends to ensure both the capacity of the standing pouch 10 and the height of the air-enclosed portions 5 and 6. The air-enclosed portions 5 and 6 are separated from the body 10a by the heat-sealed portion 12. Therefore, even if the valley folds V1, V2 are damaged due to friction, the contents will not leak.

[0020] When forming the air enclosed portions 5, 6 by heat sealing, the heat sealing may be performed while injecting or blowing air with a nozzle or the like into the portions that will become the air enclosed portions 5, 6, but it is not necessary to inject or blow air. The laminate 3 that constitutes the standing pouch 10 has a certain degree of rigidity and has a restoring force even after being folded once, so that a sufficient amount of air can be accommodated in the air enclosed portions 5, 6 even without injecting or blowing air.

[0021] The height H (see FIG. 1) of the air enclosed portions 5, 6 is, for example, 5 to 30 mm, and may be 8 to 25 mm. When the height H is 5 mm or more, the drop resistance of the standing pouch 10 tends to be further improved, while when the height H is 30 mm or less, a sufficient content volume of the standing pouch 10 tends to be ensured.

[0022] As shown in FIG. 1, the standing pouch 10 has fusion parts 9 on both sides of the bottom 10b. In this embodiment, two fusion parts 9 are formed vertically side by side on one side of the standing pouch 10, and two fusion parts 9 are also formed vertically side by side on the other side. The fusion parts 9 of the standing pouch 10 join the region R1a and the region R2a of the laminate 3. The fusion parts 9 are the portions where the sealant layers 2 of the regions R1a and R2a are locally fused to each other through the cutout parts 8a and 8b provided in the regions R1b and R2b. As shown in FIG. 3, the cutout parts 8a and 8b are provided on the sides of the regions R1b and R2b. By providing the fusion parts 9 on both sides of the bottom 10b, the self-supporting property and drop resistance of the standing pouch 10 can be further improved. The area ratio of the fused portion 9 is preferably 30 to 70%, and more preferably 32 to 50%, from the viewpoint of excellent drop resistance of the standing pouch 10. This area ratio is a value calculated by the following formula (1). Area ratio (%) = (area of ​​fused portion 9) / (L × 10) × 100 ... (1) In formula (1), L represents the distance (unit: mm) from valley fold V1 to mountain fold M1. The number "10" in the denominator of formula (1) represents the width of the region where fused portion 9 is formed on the side of bottom portion 10b.

[0023] <Laminate> In this embodiment, from the viewpoint of achieving a mono-material structure, both the base material layer 1 and the sealant layer 2 are composed of polyester resin. The polyester content in the laminate 3 according to this embodiment is preferably 90% by mass or more. From the viewpoint of achieving a mono-material structure to a higher degree, the polyester content in the laminate 3 is more preferably 92% by mass or more, and even more preferably 95% by mass or more. The configuration of the laminate 3 will be described below.

[0024] [Base material layer] The substrate layer 1 is a film (base film) that serves as a support. The thickness of the substrate layer 1 can be, for example, 5 μm to 1 mm or less, and may be 5 to 800 μm, or may be 5 to 500 μm. For example, a crystalline polyester can be used as the substrate layer 1, and specific examples thereof include polybutylene terephthalate, polybutylene naphthalate, and polyethylene terephthalate.

[0025] The base layer 1 may contain recycled polyester. Examples of recycled polyester include chemically recycled polyester obtained by chemically recycling a container made of polyester mainly composed of ethylene terephthalate units, and mechanically recycled polyester obtained by mechanically recycling a container made of polyester mainly composed of ethylene terephthalate units.

[0026] [Sealant layer] The sealant layer 2 is a layer that imparts heat-sealing sealability to the laminate 3. From the viewpoint of excellent shielding strength, the thickness of the sealant layer 2 is, for example, 15 μm or more, and may be 15 to 100 μm or 20 to 60 μm.

[0027] The sealant layer 2 in this embodiment is composed of a polyester film having a melting point lower than that of the base layer 1 or exhibiting no melting point. The melting point of the sealant layer 2 is, for example, 200°C or lower, and may be 130 to 150°C. Amorphous polyester films that do not exhibit a melting point have sufficient fluidity when heated to a temperature equal to or higher than the glass transition temperature, and therefore can be fused at low temperatures. The crystallinity of the polyester film can be adjusted by changing the type of monomer used for copolymerization. In addition, the degree of progress of crystallization can be adjusted by changing the cooling rate during the formation of the polyester film, thereby adjusting the crystallinity. The crystallinity may also be adjusted by subjecting the formed polyester film to a heat treatment.

[0028] In order to fully exert the function of the sealant layer 2 of the standing pouch 10, the polyester may be polybutylene terephthalate, polybutylene naphthalate, polyethylene terephthalate, or the like. The sealant layer 2 may contain recycled polyester, similar to the base layer 1. The sealant layer 2 may contain various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, and a tackifier. Examples of methods for forming the sealant layer L2 include a casting method and an inflation method.

[0029] The laminate 3 may further include a gas barrier layer, for example, from the viewpoint of improving the gas barrier properties against water vapor and oxygen. The gas barrier layer may be provided between the base layer 1 and the sealant layer 2, or may be provided on the surface of the base layer 1 opposite to the sealant layer 2. The water vapor permeability of the laminate 3 is, for example, 5 g / m 2 day, 1g / m 2 ·day or less or 0.5g / m 2 The oxygen permeability of the laminate 3 may be, for example, 1 cc / m 2 ·atm·day, 0.5g / m 2 ·atm·day or less or 0.2g / m 2 By including a gas barrier layer in the laminate 3, the contents are protected from deterioration due to water vapor and oxygen, and the quality can be easily maintained for a long period of time.

[0030] An example of the gas barrier layer is a vapor-deposited layer of an inorganic oxide. By using a vapor-deposited layer of an inorganic oxide, high barrier properties can be obtained with a very thin layer that does not affect the recyclability of the laminate 3. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. From the viewpoint of transparency and barrier properties, the inorganic oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. The thickness of the vapor-deposited layer of an inorganic oxide can be, for example, 5 nm or more and 100 nm or less, and may be 10 nm or more and 50 nm or less. When the thickness is 5 nm or more, the barrier properties are easily exhibited, and when the thickness is 100 nm or less, the flexibility of the laminate 3 is easily maintained. The vapor-deposited layer can be formed by, for example, physical vapor deposition, chemical vapor deposition, or the like.

[0031] The laminate 3 may include a metal layer (metal foil) instead of or in addition to the inorganic oxide vapor deposition layer. As the metal layer, various metal foils made of aluminum, stainless steel, etc. can be used, and among these, aluminum foil is preferred in terms of moisture resistance, processability such as extensibility, cost, etc. As the aluminum foil, a general soft aluminum foil can be used. Among them, aluminum foil containing iron is preferred in terms of excellent pinhole resistance and extensibility during molding. When a metal layer is provided, its thickness may be 7 to 50 μm, or 9 to 15 μm in terms of barrier properties, pinhole resistance, processability, etc.

[0032] The laminate 3 may have an anchor coat layer between the base layer 1 and the sealant layer 2. The anchor coat layer may be a very thin layer that does not affect the recyclability of the laminate 3, and can be formed using an anchor coat agent. Examples of the anchor coat agent include acrylic resin, epoxy resin, acrylic urethane resin, polyester polyurethane resin, polyether polyurethane resin, and polyvinyl alcohol resin. As the anchor coat agent, acrylic urethane resin and polyester polyurethane resin are preferred from the viewpoints of heat resistance and interlayer adhesive strength.

[0033] The laminate 3 may further include, for example, a printed layer. The printed layer may be provided between the base layer 1 and the sealant layer 2, or may be provided on the surface of the base layer 1 opposite to the sealant layer 2. When providing a printed layer, it is preferable to use a printing ink that does not contain chlorine from the viewpoint of preventing the printed layer from being discolored or from generating an odor when remelted. In addition, it is preferable to use a biomass material as a compound contained in the printing ink from the viewpoint of environmental consideration.

[0034] <Manufacturing method for standing pouches> The standing pouch 10 is manufactured through the following steps. (A) A step of forming a plurality of through holes 20a, which will later become the cutout portions 8a, 8b, in an original roll 20 of the laminate 3 (see FIG. 4). (B) A process of folding the original roll 20 into a W shape. (C) A step of forming a heat-sealed portion 11 on the W-shaped raw material roll 20. (D) A step of forming a heat-sealed portion 12 on the raw material roll 20 to form an air-enclosed portion. (E) A step of obtaining a plurality of standing pouches 10 by cutting the original roll 20 to a predetermined length.

[0035] According to this method, the standing pouch 10 can be efficiently manufactured. Since the air-enclosed portion 5 of the standing pouch 10 acts as a cushion, excellent drop resistance can be achieved, even though there are restrictions on the materials that can be used from the viewpoint of mono-materialization. Therefore, even if the contents are liquid and the content volume is large, for example, 200 mL or more, the risk of the bag breaking due to being dropped can be sufficiently reduced.

[0036] Although the embodiment of the present disclosure has been described in detail above, the present invention is not limited to the above embodiment. For example, in the above embodiment, the two pairs of cutouts 8a, 8b are provided on one side of the standing pouch 10 to form two fusion parts 9, but for example, a pair of cutouts may be provided to form one fusion part 9. Also, the fusion part may be formed by providing a cutout hole instead of the cutouts.

[0037] In the above embodiment, the mono-material is realized by polyester resin, but the mono-material may be realized by polyolefin resin (e.g., polyethylene resin or polypropylene resin). From the viewpoint of realizing the mono-material to a high degree, the content of the specific material (e.g., polyethylene resin or polypropylene resin) in the standing pouch is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 95% by mass or more. On the other hand, when the standing pouch is not required to be a mono-material, the self-supporting packaging bag according to the present disclosure may be constructed by using a laminate combining polyester film, nylon film, polyolefin film, etc., as in the conventional case. EXAMPLES

[0038] The present disclosure will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0039] <Example 1> A biaxially oriented PET film (PET film, thickness: 12 μm) and an oriented nylon film (ONY film, thickness: 15 μm) were used as the base layer. A linear low-density polyethylene film (LLDPE film, thickness: 50 μm) was used as the sealant layer. The PET film, ONY film, and LLDPE film were laminated in this order by the dry lamination method. A urethane resin adhesive was used as the adhesive for dry lamination. The coating amount of this adhesive was 3 g / m. 2(Thickness: 3 μm) was adjusted. Multiple notches were provided on both sides of the obtained laminate.

[0040] The laminate was folded into a W shape, and then both sides and the bottom were heat sealed to obtain a packaging bag as shown in Fig. 1. The packaging bags had the following sizes: Packaging bag width: 130mm Packaging bag height: 250mm Distance from valley fold to mountain fold L: 50mm Width of vertical heat seal on both sides of packaging bag: 10mm Width of horizontal heat seal part for forming air enclosing part: 10mm Height of air enclosure: 15mm -Fusing part: φ15mm semicircle (2 pieces)

[0041] <Example 2> A packaging bag was obtained in the same manner as in Example 1, except that an unstretched high-density polyethylene film (HDPE film, thickness: 32 μm) was used as the base layer, and a linear low-density polyethylene film (LLDPE film, thickness: 50 μm) was used as the sealant layer.

[0042] <Example 3> A packaging bag was obtained in the same manner as in Example 1, except that a stretched polypropylene film (OPP film, thickness: 20 μm) was used as the base layer, and a non-stretched polypropylene film (CPP film, thickness: 50 μm) was used as the sealant layer.

[0043] <Example 4> A biaxially oriented PET film (thickness: 25 μm) and a biaxially oriented PET film (thickness: 12 μm) were used as the base layer. A packaging bag was obtained in the same manner as in Example 1, except that an amorphous PET sealant film (thickness: 50 μm) was used as the sealant layer.

[0044] <Example 5> A packaging bag was obtained in the same manner as in Example 4, except that instead of providing two fused portions formed by cutouts on each side of the packaging bag, one was provided on each side.

[0045] <Example 6> A packaging bag was obtained in the same manner as in Example 4, except that the cutout portion was a semicircle with a diameter of 20 mm instead of a semicircle with a diameter of 15 mm.

[0046] <Example 7> A packaging bag was obtained in the same manner as in Example 4, except that a silica vapor deposition film was provided on one side of the biaxially oriented PET film (thickness: 12 μm) in Example 4 to form a barrier film.

[0047] <Example 8> A packaging bag was obtained in the same manner as in Example 7, except that the height H of the air enclosed portion was 3 mm instead of 15 mm.

[0048] <Example 9> A packaging bag was obtained in the same manner as in Example 7, except that the height H of the air sealed portion was 30 mm instead of 15 mm.

[0049] <Comparative Example 1> A packaging bag having the structure shown in Fig. 5 and Fig. 6 was obtained by using a laminate having the same structure as in Example 1. That is, the sealant layers of the front laminate 3a and the back laminate 3b were placed facing each other, and the bottom laminate 3c, which was folded in half, was placed between them. The bottom laminate 3c was folded so that the sealant layer was on the outside. The facing sealant layers were heat-sealed to obtain a packaging bag according to Comparative Example 1. The size of the packaging bag was as follows. Packaging bag width: 130mm Packaging bag height: 250mm Distance L1 from the bottom of the packaging bag to the fold of the bottom laminate 3c: 40 mm Width of vertical heat seal on both sides of packaging bag: 10mm Bottom seal shape of packaging bag: 60mm radius curve -Fusing part: φ15mm semicircle (2 pieces) The distance L1 shown in FIG. 5 is the distance when the inner surfaces (sealant layers) of the laminate 3a and the laminate 3b are in contact with each other.

[0050] <Comparative Example 2> A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same configuration as in Example 2 was used.

[0051] <Comparative Example 3> A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same configuration as in Example 3 was used.

[0052] <Comparative Example 4> A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same configuration as in Example 4 was used.

[0053] <Comparative Example 5> A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same configuration as in Example 7 was used.

[0054] [Drop test] The contents of the packaging bag were 50ml, 100ml, 200ml, 300ml, 400ml or 500ml of water, and the top of the packaging bag was heat-sealed to obtain a package. These packages were stored in an environment of 5°C for 24 hours. After that, the packaging bag was dropped vertically from a height of 1m so that the bottom of the bag was facing down, and the number of times it was dropped until the bag broke was counted. Tests were carried out on 20 samples under the same conditions, and the samples were evaluated according to the following criteria. The results are shown in Tables 1 to 3. A: 90% or more of the samples did not break after 20 drops B: 50% to less than 90% of the samples were not broken after 20 drops C: Less than 50% of the samples were not broken after 20 drops

[0055] [Oxygen and water vapor barrier properties] The oxygen permeability and water vapor permeability of the laminate were measured in accordance with the method described in JIS K7126B. The results are shown in Tables 1 to 3.

[0056] [Table 1]

[0057] [Table 2]

[0058] [Table 3]

[0059] From the evaluation results of the Examples and Comparative Examples, even if the laminate structure is the same, the drop resistance is significantly improved by providing an air-filled portion at the bottom of the packaging bag. Even with a structure made of a single material (Examples 4 to 9), sufficient drop resistance is obtained, making it possible to provide a packaging bag that combines good preservation properties and recyclability for the contents. In Tables 1 to 3, the area ratio of the fused portion in the Examples is a value calculated by the above formula (1), and the area ratio of the fused portion in the Comparative Examples is a value calculated by the following formula (2). Area ratio (%) = (total area of ​​fused parts) / (L1 × 10) × 100…(2) [In formula (2), L1 represents the distance (unit: mm) from the bottom side of the packaging bag to the fold of the bottom laminate.] [Explanation of symbols]

[0060] 1...base material layer, 2...sealant layer, 3...laminate, 5...air-filled portion, 8a, 8b...cutout portion, 9...fusion portion, 10a...body portion, 10b...bottom portion, 10...standing pouch (self-supporting packaging bag), 11, 12...heat-sealed portion, M1...mountain fold portion, V1, V2...valley fold portion

Claims

1. A self-supporting packaging bag formed by a laminate having a base layer and a sealant layer, A body portion in which contents are accommodated; The bottom and Equipped with The bottom portion is A pair of valley folds formed by folding the laminate; a mountain fold portion formed between the pair of valley fold portions; an air enclosure formed by heat sealing the area between the valley fold and the mountain fold laterally of the base; having the air-enclosing portion has an upper end constituted by a heat-sealed portion formed by the heat seal and a lower end constituted by the valley fold portion, and has a portion in which the distance between inner surfaces of the laminate increases from the upper end toward the lower end, The self-supporting packaging bag, wherein the valley fold portion forms a lower end of the self-supporting packaging bag.

2. The self-supporting packaging bag according to claim 1, wherein the height of the air-enclosed portion is 5 to 30 mm.

3. The laminate has at least one pair of cutouts or holes in a region between the valley fold and the mountain fold and on a side of the laminate, The self-supporting packaging bag according to claim 1 or 2, wherein a fused portion is provided in which the sealant layers are locally fused to each other through the pair of cutout portions or punched holes.

4. The self-supporting packaging bag according to claim 3, wherein the area ratio of the fused portion calculated by the following formula (1) is 30 to 70%. Area ratio (%)=(area of ​​the fused portion) / (L×10)×100 [In formula (1), L represents the distance (unit: mm) from the valley fold to the mountain fold.]

5. The self-supporting packaging bag according to claim 3 or 4, wherein the fused portion has a semicircular shape.

6. the base layer is made of a first polyester resin, the sealant layer is made of a second polyester resin, The self-supporting packaging bag according to any one of claims 1 to 5, wherein the melting point of the second polyester resin is lower than the melting point of the first polyester resin.

7. The substrate layer is made of a first polyolefin resin, and the sealant layer is made of a second polyolefin resin, The self-supporting packaging bag according to any one of claims 1 to 5, wherein the melting point of the second polyolefin resin is lower than the melting point of the first polyolefin resin.

8. The self-supporting packaging bag according to any one of claims 1 to 7, wherein the laminate further comprises a gas barrier layer.

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