Pouch

Abstract

To prevent the content from leaking out of a pouch.SOLUTION: A pouch comprises: a first side seal part; a second side seal part which is located in a second side part that is opposed to a first side part of the pouch in a first direction; a first non-seal part which is separated from a storage part by the first side seal part and spreads so as to at least partially reach a first side edge of the first side part of the pouch; and a penetration part which is located on the inner side of a contour of the first non-seal part. The first side seal part comprises: a lower portion which extends along the first side edge toward the lower part of the pouch from the first non-seal part; a first intermediate portion which is located between the storage part and the first non-seal part and is connected to the lower portion; and a second intermediate portion which is located between the first non-seal part and the first side edge and is connected to the lower portion. The penetration part is located above the second intermediate portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pouch. [Background technology]

[0002] Conventionally, many pouches made of plastic laminates have been available on the market, filled and sealed with cooked or semi-cooked liquid, viscous material, or a mixture of liquid and solid. In the pouch, the non-sealed portion where the laminates are not joined constitutes the storage portion where the contents are stored. The sealed portion where the laminates are joined seals the storage portion. The contents are, for example, cooked foods such as curry, stew, soup, etc. The contents are heated in a microwave oven or the like while stored in the pouch.

[0003] When contents contained in a sealed pouch are heated in a microwave oven, the moisture in the contents evaporates as the heat is applied, increasing the pressure in the pouch. If the pressure in the pouch's storage compartment increases, the pouch may burst, causing the contents to spill and contaminate the microwave. In consideration of this issue, Patent Document 1, for example, proposes providing a pouch with a steam release mechanism that automatically connects the storage compartment to the outside when the pressure in the storage compartment increases, allowing steam inside the storage compartment to escape. In Patent Document 1, the steam release mechanism includes a bulging seal portion that bulges inward from a seal portion extending along the side edge of the pouch, and an unsealed portion that is isolated from the storage compartment by the bulging seal portion and extends to reach the side edge of the pouch. When the pressure in the storage compartment increases, the bulging seal portion peels off, connecting the storage compartment to the unsealed portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-101154 Summary of the Invention [Problem to be solved by the invention]

[0005] Steam generated in the storage section is released from the side edge of the pouch through the peeled portion of the bulging seal. If the bulging seal and the non-sealed portion are not properly configured, the contents may leak out of the pouch.

[0006] An object of the present invention is to provide a pouch that can effectively solve these problems. [Means for solving the problem]

[0007] The present invention provides a pouch in which a storage section for storing contents is defined between a front film and a back film, a first side seal portion located on a first side of the pouch and joining the inner surface of the front film and the inner surface of the back film; a second side seal portion located on a second side portion opposite the first side portion of the pouch in a first direction, the second side seal portion defining the containing portion between the first side seal portion and the second side seal portion; a first unsealed portion located toward a top of the pouch and separated from the containing portion by the first side seal portion, the first unsealed portion extending to at least partially reach a first side edge of the first side of the pouch; a through-hole located inside the outline of the first non-sealed portion and penetrating at least one of the front surface film and the back surface film, the first side seal portion has a lower portion extending along the first side edge from the first non-seal portion toward a lower portion of the pouch, a first intermediate portion located between the containing portion and the first non-seal portion and connected to the lower portion, and a second intermediate portion located between the first non-seal portion and the first side edge and connected to the lower portion, The penetration portion is a pouch located above the second intermediate portion.

[0008] In the pouch according to the present invention, the first intermediate portion may include a first portion, a second portion, and a first connecting portion connecting the first portion and the second portion, The first portion may extend from the first connecting portion toward the first side of the pouch; The second portion may extend from the first connecting portion toward the top of the pouch; The second portion may include a lower second portion, an upper second portion located higher than the lower second portion, and a transition portion located between the lower second portion and the upper second portion, The transition portion may include an inner edge that extends in a different direction than an inner edge of the lower second portion, or may include an outer edge that extends in a different direction than an outer edge of the lower second portion.

[0009] In the pouch according to the present invention, the upper second portion may have a width greater than that of the lower second portion.

[0010] In the pouch according to the present invention, the first intermediate portion may include a first portion, a second portion, and a first connecting portion connecting the first portion and the second portion, The first portion may extend from the first connecting portion toward the first side of the pouch; The second portion may extend from the first connecting portion toward the top of the pouch; The second portion may include a lower second portion and an upper second portion located above the lower second portion and having a width greater than that of the lower second portion.

[0011] In the pouch according to the present invention, the penetrating portion may be located above the second lower portion.

[0012] In the pouch according to the present invention, the upper second portion may be located above the second intermediate portion.

[0013] In the pouch according to the present invention, the penetration portion may be located closer to the first side portion than the first portion of the first intermediate portion.

[0014] The pouch according to the present invention may further include an upper seal portion located at the upper portion of the pouch and joining an inner surface of the front film and an inner surface of the back film, The first intermediate portion may be connected to the upper seal portion.

[0015] In the pouch according to the present invention, the first side seal portion may have an upper portion extending along the first side edge from the first unsealed portion toward the top of the pouch, The first middle portion may be connected to the upper portion of the first side seal.

[0016] In the pouch according to the present invention, the penetration portion may be located above a middle position of the first unsealed portion in a second direction perpendicular to the first direction.

[0017] In the pouch according to the present invention, a maximum value (L15) of the distance in the first direction between the first side edge and an inner edge of the first intermediate portion may be 24 mm or less.

[0018] In the pouch according to the present invention, the ratio of the maximum value (L15) to the dimension of the storage section in the first direction may be 0.24 or less.

[0019] In the pouch according to the present invention, a seal portion joining an inner surface of the surface film and an inner surface of the back film may have a hot seal strength of 10 N or less, The hot seal strength may be a seal strength measured in an environment of 100°C after a test piece including the sealed portion is kept in an environment of 100°C for 1 minute.

[0020] In the pouch according to the present invention, the packaging material constituting the front film and the back film may include a first biaxially oriented plastic film, a second biaxially oriented plastic film, and a sealant film in this order, The packaging material may contain only two biaxially oriented plastic films.

[0021] In the pouch according to the present invention, the packaging material may have a breaking strength in one direction of 33.0 MPa or more when measured in an environment at 100°C after being kept in an environment at 100°C for 1 minute.

[0022] In the pouch according to the present invention, the first biaxially oriented plastic film may be a biaxially oriented polyethylene terephthalate film, The second biaxially oriented plastic film may be a biaxially oriented polyethylene terephthalate film or a biaxially oriented nylon film.

[0023] In the pouch according to the present invention, the packaging material may further comprise a transparent vapor deposition layer located between the first biaxially oriented plastic film and the second biaxially oriented plastic film; The transparent vapor-deposited layer may contain a metal oxide or an inorganic oxide.

[0024] In the pouch according to the present invention, the packaging material constituting the front film and the back film may include a biaxially stretched plastic film and a sealant film in this order, The packaging material may contain only one biaxially oriented plastic film.

[0025] In the pouch according to the present invention, the packaging material may have a Young's modulus in one direction of 3600 MPa or more.

[0026] In the pouch according to the present invention, the packaging material may further include a transparent vapor deposition layer provided on a surface of the biaxially stretched plastic film, The transparent vapor-deposited layer may contain a metal oxide or an inorganic oxide.

[0027] In the pouch according to the present invention, the packaging material may further comprise a transparent gas barrier coating film located on the surface of the transparent vapor deposition layer.

[0028] In the pouch according to the present invention, the sealant film may contain a propylene-ethylene block copolymer and an elastomer.

[0029] In the pouch according to the present invention, the storage portion of the pouch may contain a content including meat, The pouch may be heated in a microwave oven.

[0030] In the pouch according to the present invention, the contents may contain 50 or more pieces of meat having a size of 3 mm or more.

[0031] In the pouch according to the present invention, the value obtained by dividing the number of pieces of meat having a dimension of 3 mm or more by the weight of the contents may be 0.3 pieces / g or more.

[0032] In the pouch according to the present invention, the contents may include the meat-containing filling and a viscous component, The ratio of the weight of the ingredients to the weight of the filling may be 8% or more, The ratio of the weight of the meat to the weight of the ingredients may be 20% or more.

[0033] In the pouch according to the present invention, when the pouch is tilted at an angle of 17° relative to the horizontal plane, the distance between the top surface of the contents and the first intermediate portion of the first side seal portion may be 5 mm or more and 30 mm or less. [Effects of the Invention]

[0034] According to the present invention, leakage of the contents to the outside of the pouch can be suppressed. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a front view showing a pouch according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing an example of the pouch shown in FIG. 1 when viewed along line AA. [Figure 3] FIG. 2 is a cross-sectional view showing an example of the pouch shown in FIG. 1 when viewed along line AA. [Figure 4] FIG. 2 is a front view showing the pouch containing the contents. [Figure 5] FIG. 10 is a cross-sectional view showing an example of the state of the pouch when heated in a microwave oven. [Figure 6] FIG. 4 is an enlarged front view of the steam release mechanism. [Figure 7] FIG. 2 is a diagram illustrating a first reference line. [Figure 8] FIG. 10 is a diagram illustrating a second reference line. [Figure 9] FIG. 10 is a diagram illustrating the dimensions of the components of the vapor release mechanism. [Figure 10] FIG. 4 is an enlarged front view showing a second side seal portion and a second non-seal portion. [Figure 11] FIG. 2 is a cross-sectional view showing an example of the layer structure of a packaging material that constitutes a pouch. [Figure 12A] FIG. 2 is a cross-sectional view showing an example of the layer structure of a packaging material that constitutes a pouch. [Figure 12B] FIG. 2 is a cross-sectional view showing an example of the layer structure of a packaging material that constitutes a pouch. [Figure 13] FIG. 2 is a cross-sectional view showing an example of the layer structure of a packaging material that constitutes a pouch. [Figure 14] FIG. 1 illustrates an example of a method for preparing a test specimen. [Figure 15] FIG. 2 is a diagram for explaining a method for measuring hot breaking strength. [Figure 16] FIG. 1 illustrates an example of a method for preparing a test specimen. [Figure 17A] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 17B] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 17C] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 18] FIG. 1 is a plan view showing an example of a loop stiffness measuring device. [Figure 19]FIG. 19 is a cross-sectional view of the loop stiffness measuring device of FIG. 18 taken along line CC. [Figure 20] FIG. 10 is a diagram illustrating a process of attaching a test piece to a loop stiffness measuring instrument. [Figure 21] FIG. 10 is a diagram illustrating a step of forming a loop portion in a test piece. [Figure 22] FIG. 10 is a diagram illustrating a process of applying a load to a loop portion of a test piece. [Figure 23] FIG. 10 is a diagram illustrating a process of applying a load to a loop portion of a test piece. [Figure 24] 10 is a view showing a state in which a first intermediate portion of the first side seal portion is peeled off and the containing portion communicates with the first unsealed portion. FIG. [Figure 25] FIG. 10 is a front view showing a modified example of the steam release mechanism. [Figure 26] FIG. 10 is a front view showing a modified example of the steam release mechanism. [Figure 27] FIG. 10 is a front view showing a modified example of the steam release mechanism. [Figure 28] FIG. 10 is a front view showing a modified example of the steam release mechanism. [Figure 29] FIG. 10 is a front view showing a steam vent mechanism in a second embodiment. [Figure 30] FIG. 10 is a front view showing a modified example of the steam release mechanism. [Figure 31] FIG. 10 is a front view showing a steam vent mechanism in a third embodiment. [Figure 32] FIG. 10 is a front view showing a pouch in a fourth embodiment. [Figure 33] FIG. 1 is a diagram showing the evaluation results of packaging materials 1 to 3 of the examples. [Figure 34] FIG. 1 is a diagram showing the evaluation results of packaging material 4 of an example. [Figure 35] FIG. 1 is a diagram showing the analysis results of Content 1 of the Example. [Figure 36] FIG. 1 is a diagram showing the analysis results of Content 1 of the Example. [Figure 37] FIG. 1 is a diagram showing the evaluation results of pouches of Examples and Comparative Examples. [Figure 38]FIG. 2 is a view showing the peeled portion of the pouch of Example 1. [Figure 39] FIG. 1 is a view showing a peeled portion of the pouch of Example 2. [Figure 40] FIG. 10 is a view showing the peeled portion of the pouch of Example 3. [Figure 41] FIG. 10 is a view showing the peeled portion of the pouch of Example 4. [Figure 42] FIG. 10 is a view showing the peeled portion of the pouch of Example 5. [Figure 43] FIG. 1 is a view showing the peeled portion of the pouch of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0036] First embodiment An embodiment of the present invention will be described with reference to the drawings. In the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

[0037] Terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel," "orthogonal," and "identical," as well as values ​​of lengths and angles, are not limited to strict meanings and are interpreted to include a range within which similar functions can be expected.

[0038] In this specification, when two or more upper limit candidates and two or more lower limit candidate values ​​are listed for a certain parameter, the numerical range of the parameter may be constructed by combining any one upper limit candidate with any one lower limit candidate. For example, consider a description that reads, "Parameter B may be, for example, A1 or more and may be A2 or more. Parameter B may be, for example, A3 or less and may be A4 or less." In this case, the numerical range of parameter B may be A1 or more and A3 or less, A1 or more and A4 or less, A2 or more and A3 or less, or A2 or more and A4 or less.

[0039] Pouch Fig. 1 is a front view showing a pouch 10 according to the present embodiment as seen from the front side. Pouch 10 has a storage section 18 for storing contents. Fig. 1 shows pouch 10 in a state where no contents are stored therein. The configuration of pouch 10 will be described below.

[0040] As shown in FIG. 1 , pouch 10 includes an upper portion 11, a lower portion 12, a first side portion 13, and a second side portion 14, and has a generally rectangular outline in a front view. Terms such as "upper portion," "lower portion," and "side portion," as well as terms such as "upper" and "lower," describe the relative positions and directions of pouch 10 and its components, with the lower portion being defined as the side that can be positioned lower when pouch 10 is heated. If pouch 10 is equipped with a steam release mechanism, as described below, the position of pouch 10 is adjusted so that the steam release mechanism is positioned upper. The position of pouch 10 other than when pouch 10 is heated is not limited by the names and terms used in this specification.

[0041] The pouch 10 includes a surface film 15 that forms the surface and a back film 16 that forms the back. Each film is made of a packaging material that includes at least one biaxially oriented plastic film and a sealant film.

[0042] The terms "surface film" and "back surface film" are merely used to divide each film according to their positional relationship, and the above terms do not limit the method of providing the films when manufacturing pouch 10. For example, pouch 10 may be manufactured using one film in which surface film 15 and back surface film 16 are continuously provided, or may be manufactured using a total of two films, one surface film 15 and one back surface film 16.

[0043] The inner surfaces of the front film 15 and the back film 16 are joined together by a seal. In a front view of the pouch 10 such as Figure 1, the seal is hatched. The space defined by the seal, the front film 15, and the back film 16 can function as a storage section 18 for storing contents.

[0044] The method for forming the sealed portion is not particularly limited as long as it can join the opposing films together. For example, the sealed portion may be formed by melting the inner surfaces of the films by heating or the like to weld the inner surfaces together, i.e., by heat sealing. Alternatively, the sealed portion may be formed by bonding the inner surfaces of the opposing films together using an adhesive or the like.

[0045] As shown in FIG. 1 , the sealed portion of the pouch 10 includes a first side seal portion 30, a second side seal portion 50, and a top seal portion 11a. The first side seal portion 30 is located on a first side 13 of the pouch 10. The second side seal portion 50 is located on a second side 14. The second side portion 14 faces the first side 13 in a first direction D1. The top seal portion 11a is located on the top portion 11. The top seal portion 11a is connected to the first side seal portion 30 and the second side seal portion 50. The non-sealed portion surrounded by the first side seal portion 30, the second side seal portion 50, and the top seal portion 11a functions as a storage portion 18 that stores contents.

[0046] In a pouch 10 before it is filled with contents (a state in which no contents are contained), as shown in Fig. 1, the lower part 12 of the pouch 10 forms an opening 12b. Although not shown, a lower seal part may be formed in the lower part 12, and an opening may be formed in the upper part 11.

[0047] In addition to the unsealed portion that functions as the storage portion 18, the pouch 10 further includes a first unsealed portion 45 that is separated from the storage portion 18 by the first side seal portion 30, as shown in FIG. 1. The unsealed portion is a portion where there is a film where opposing inner surfaces are not joined together. The first unsealed portion 45 is located closer to the upper portion 11 of the pouch 10. "Closer to the upper portion 11" means that the first unsealed portion 45 is located closer to the upper portion 11 than the center point C of the storage portion 18.

[0048] 1, first non-sealed portion 45 may extend to at least partially reach first side edge 13x of first side portion 13 of pouch 10. In this case, first non-sealed portion 45 overlaps first side edge 13x and has opening edge 46 that is open to the outside. Steam generated in storage portion 18 and flowing into first non-sealed portion 45 can be discharged to the outside from opening edge 46.

[0049] Top seal portion 11a and first side seal portion 30 are configured to define first non-seal portion 45. For example, as shown in FIG. 1 , first side seal portion 30 has a lower portion 32 and a first intermediate portion 35. Lower portion 32 extends along first side 13 from first non-seal portion 45 toward bottom 12 of pouch 10. First intermediate portion 35 is located between container portion 18 and first non-seal portion 45. First intermediate portion 35 may include a first end connected to top seal portion 11a and a second end connected to lower portion 32.

[0050] Fig. 2 is a cross-sectional view showing an example of pouch 10 as viewed along line AA in Fig. 1. When pouch 10 is heated and steam is generated in storage section 18, increasing the pressure in storage section 18, first intermediate section 35 partially peels off, connecting storage section 18 and first non-sealed section 45. Steam that flows from storage section 18 into first non-sealed section 45 can be discharged to the outside from opening edge section 46. In this way, first intermediate section 35 and first non-sealed section 45 function as a steam release mechanism 25 that discharges steam from storage section 18 to the outside.

[0051] As shown in Fig. 1, the pouch 10 may further include a perforation portion 47 located inside the outline of the first non-sealed portion 45. The perforation portion 47 penetrates at least one of the front film 15 or the back film 16. For example, as shown in Fig. 2, the perforation portion 47 may penetrate both the front film 15 and the back film 16. Steam that is generated in the storage portion 18 and flows into the first non-sealed portion 45 can also be discharged to the outside through the perforation portion 47.

[0052] The through-holes 47 may be slits formed in the front film 15 and the back film 16. The width of the slit is, for example, not less than 0 mm and not more than 1.0 mm.

[0053] Figure 3 is a cross-sectional view showing another example of the pouch 10 when viewed along the line AA in Figure 1. The perforated portion 47 may penetrate the surface film 15 but not the back surface film 16. In other words, the perforated portion 47 may be formed in the surface film 15, but may not be formed in the back surface film 16.

[0054] As shown in FIG. 1 , the first side seal portion 30 may include a second intermediate portion 33. The second intermediate portion 33 is located between the first non-sealed portion 45 and the first side edge 13x and is connected to the lower portion 32. The second intermediate portion 33 may face a part of the first intermediate portion 35 in the first direction D1. The second intermediate portion 33 may extend from the upper edge of the lower portion 32 toward the upper portion 11 along the first side edge 13x. The second intermediate portion 33 does not have to extend to the upper seal portion 11a. The opening edge portion 46 may be located between the second intermediate portion 33 and the upper seal portion 11a.

[0055] An example of the arrangement of the second intermediate portion 33 will be described based on the imaginary line M. As shown in FIG. 1, the imaginary line M is the line connecting the center point C of the storage portion 18 and the first unsealed portion 45 in the shortest distance. The inner edge 33a of the second intermediate portion 33 may intersect with an extension of the imaginary line M. This can prevent the contents 19 from leaking from the opening edge portion 46. The extension of the imaginary line M may intersect with the outer edge 33b of the second intermediate portion 33, or may intersect with the opening edge portion 46. The "inner edge" refers to the edge of the sealed portion located closer to the storage portion 18. The "outer edge" refers to the edge of the sealed portion located farther from the storage portion 18.

[0056] 1, the through-hole 47 may be located above the second intermediate portion 33. The distance from the through-hole 47 to the upper seal portion 11a may be shorter than the distance from the second intermediate portion 33 to the upper seal portion 11a. As shown in FIG. 1, the through-hole 47 may be located above an extension of the virtual straight line M.

[0057] 1, a second unsealed portion 65 may be formed between the second side edge 14x of the second side portion 14 and the second side seal portion 50. In this case, the second unsealed portion 65 may extend to reach the second side edge 14x. In other words, the second unsealed portion 65 may overlap the second side edge 14x and have an opening edge portion 66 that is open to the outside.

[0058] Second side seal portion 50 may have a lower portion 52 and a middle portion 55. Lower portion 52 extends along second side 14 from second non-seal portion 65 toward bottom portion 12 of pouch 10. Middle portion 55 is located between container portion 18 and second non-seal portion 65 in first direction D1. Middle portion 55 may include a first end connected to top seal portion 11a and a second end connected to lower portion 52.

[0059] As shown in FIG. 1 , the pouch 10 may include an opening means 30a located at the first side seal 30. The opening means 30a penetrates the front film 15 and the back film 16. The opening means 30a may be a notch, cutout, or the like. The opening means 30a can serve as a starting point for a user to tear the pouch 10. The opening means 30a extends from the first side edge 13x toward the container 18.

[0060] 1, the opening means 30a may be located in the second intermediate portion 33 of the first side seal 30. When viewed along the first direction D1, the opening means 30a overlaps the first unsealed portion 45 and the first intermediate portion 35. When a user tears the pouch 10, the tearing is not impeded by the first intermediate portion 35, provided that the area of ​​the first intermediate portion 35 that overlaps the opening means 30a in the first direction D1 is peeled away.

[0061] As shown in FIG. 1 , the pouch 10 may include an opening means 50a located in the second side seal portion 50. The opening means 50a penetrates the front film 15 and the back film 16. The opening means 50a may be a notch, a cut, or the like. Similar to the opening means 30a, the opening means 50a can serve as a starting point for a user to tear the pouch 10. The opening means 50a extends from the second side edge 14x toward the storage portion 18. The opening means 50a may be formed in a portion of the second side seal portion 50 facing the second middle portion 33 in the first direction D1. For example, the opening means 50a may be formed in the lower portion 52.

[0062] 4 is a diagram showing pouch 10 with contents 19 contained therein and lower portion 12 sealed. After contents are filled into pouch 10 through opening 12b of lower portion 12, the inner surfaces of front film 15 and back film 16 are joined at lower portion 12. This forms lower seal portion 12a, sealing pouch 10.

[0063] The above-mentioned center point C is defined as the midpoint of a line segment connecting a midpoint Y1 of the inner edge of the upper seal portion 11a and a midpoint Y2 of the inner edge of the lower seal portion 12a in a plan view. A dimension H1 of the storage portion 18 in a first direction D1 is determined at the position of the center point C. A dimension H2 of the storage portion 18 in a second direction D2 is determined at the position of the center point C. The second direction D2 is a direction perpendicular to the first direction D1.

[0064] The symbol H3 represents the distance in the first direction D1 from the center point C to the first intermediate portion 35. The distance H3 is the distance in the first direction D1 from the intersection of the virtual straight line M and the inner edge 35a of the first intermediate portion 35 to the center point C. The distance H3 is, for example, equal to or greater than 0.35×H1, and may be equal to or greater than 0.37×H1. The distance H3 is, for example, equal to or less than 0.48×H1, and may be equal to or less than 0.45×H1.

[0065] Symbol H4 represents the distance in the second direction D2 from the center point C to the first intermediate portion 35. Distance H4 is the distance in the second direction D2 from the intersection of the virtual line M and the inner edge 35a of the first intermediate portion 35 to the center point C. Distance H4 is, for example, 0.10×H2 or more, or may be 0.15×H2 or more, or may be 0.20×H2 or more. Distance H4 is, for example, 0.30×H2 or less, or may be 0.27×H2 or less.

[0066] The contents 19 contained in the pouch 10 are heated in a microwave oven. The contents 19 may include ingredients and liquid ingredients. The ingredients may include ingredients containing oil, such as meat. Examples of the contents 19 are cooked foods such as curry, stew, soup, simmered dishes, and hamburger steaks.

[0067] The weight of the contents 19 contained in the pouch 10 is, for example, 50 g or more, or may be 100 g or more, or may be 130 g or more. The weight of the contents 19 contained in the pouch 10 is, for example, 250 g or less, or may be 220 g or less, or may be 200 g or less.

[0068] The ratio of the weight of the ingredients to the total weight of the contents 19 is, for example, 5% or more, or may be 8% or more, or 10% or more. The ratio of the weight of the ingredients to the total weight of the contents 19 is, for example, 20% or less, or may be 15% or less, or may be 13% or less. The ingredients are obtained by removing liquid components from the contents 19. For example, the ingredients can be obtained by straining the liquid components in the contents 19 using a sieve. The mesh size of the sieve is, for example, 0.7 mm.

[0069] The ratio of meat weight to ingredient weight is, for example, 8% or more, or may be 10% or more, 15% or more, 20% or more, or 25% or more. The ratio of meat weight to ingredient weight is, for example, 50% or less, or may be 40% or less, or may be 30% or less.

[0070] The ratio of the weight of meat to the total weight of the contents 19 is, for example, 1.0% or more, or may be 1.5% or more, or may be 2.0% or more. The ratio of the weight of meat to the total weight of the contents 19 is, for example, 10.0% or less, or may be 6.0% or less, or may be 4.0% or less.

[0071] The meat may have a granular shape. For example, the meat may be minced meat. The dimension of the meat may be 1 mm or more, 3 mm or more, or 5 mm or more. The dimension of the meat may be 12 mm or less, 10 mm or less, or 7 mm or less. The dimension is measured in the direction in which the dimension of the meat is greatest. The dimension of the meat can be calculated by observing the meat using a microscope. As the microscope, a VHX-6000 manufactured by Keyence can be used. As the microscope lens, a VH-ZST manufactured by Keyence can be used. The observation magnification is, for example, 20x.

[0072] Meat having dimensions of 3 mm or more and 12 mm or less is likely to affect the exhaust performance of pouch 10. According to the present embodiment, by forming perforations 47 in pouch 10, steam can be properly exhausted to the outside of pouch 10 even when contents 19 include meat having dimensions of 3 mm or more and 12 mm or less.

[0073] The number of pieces of meat having a dimension of 3 mm or more and 12 mm or less contained in content 19 is, for example, 30 or more, or may be 50 or more, or may be 70 or more. The number of pieces of meat having a dimension of 3 mm or more and 12 mm or less contained in content 19 is, for example, 200 or less, or may be 150 or less, or may be 100 or less.

[0074] The value obtained by dividing the number of pieces of meat contained in content 19 having dimensions of 3 mm or more and 12 mm or less by the weight of the content is, for example, 0.2 pieces / g or more, or alternatively 0.3 pieces / g or more, or 0.4 pieces / g or more. The value obtained by dividing the number of pieces of meat contained in content 19 having dimensions of 3 mm or more and 12 mm or less by the weight of the content is, for example, 1.5 pieces / g or less, or alternatively 1.0 pieces / g or less, or alternatively 0.7 pieces / g or less.

[0075] The liquid component of the contents 19 may be a viscous component having viscosity. The viscosity of the viscous component at 95°C is, for example, 1000 mPa·S or more, or may be 1200 mPa·S or more, or 1500 mPa·S or more. The viscosity of the viscous component at 95°C is, for example, 2500 mPa·S or less, or may be 2000 mPa·S or less, or may be 1800 mPa·S or less. An example of such a viscous component is a roux for keema curry.

[0076] The viscosity of the viscous component at 50°C is, for example, 500 mPa·S or more, or may be 800 mPa·S or more, or 1000 mPa·S or more. The viscosity of the viscous component at 50°C is, for example, 2000 mPa·S or less, or may be 1500 mPa·S or less, or may be 1300 mPa·S or less. An example of such a viscous component is a common curry roux.

[0077] The viscosity can be measured using a digital viscometer DV-E manufactured by Eiko Seiki Co., Ltd. The spindle is, for example, S63, and the rotation speed is, for example, 60 rpm.

[0078] 5 is a cross-sectional view showing an example of the state of pouch 10 when heated in a microwave oven. The cross-section of pouch 10 shown in FIG. 5 shows pouch 10 as seen along line BB in FIG.

[0079] As shown in FIG. 5, pouch 10 may be heated while tilted at angle θa with respect to horizontal plane 120. Pouch 10 may be tilted so that lower portion 12 is positioned downward. This prevents upper surface 19a of content 19 from coming into contact with first intermediate portion 35. Angle θa is, for example, 5° or more, or may be 10° or more, or may be 15° or more. Angle θa is, for example, 50° or less, or may be 40° or less, or may be 30° or less.

[0080] The angle θa may be achieved, for example, by using a carton 100 for housing the pouches 10. The carton 100 may include a main body 101 for housing the pouches 10 and a lid 102 connected to the main body 101.

[0081] For example, a user opens carton 100 so that lid 102 is connected to main body 101 only at connecting portion 103 on the back of carton 100. Next, the user rotates lid 102 toward the back of main body 101, using connecting portion 103 as an axis. This allows lid 102 to be positioned between horizontal plane 120 and main body 101, as shown in FIG. 5 . Therefore, upper portion 11 of pouch 10 can be positioned higher than lower portion 12 according to the dimensions of lid 102. This causes pouch 10 to be tilted at angle θa with respect to horizontal plane 120.

[0082] In Figure 5, the symbol Lm represents the distance between the upper surface 19a of the content 19 and the first intermediate portion 35. When the angle θa is 17°, the distance Lm is, for example, 5 mm or more, or may be 8 mm or more, or 10 mm or more. When the angle θa is 17°, the distance Lm is, for example, 30 mm or less, or may be 25 mm or less, or may be 20 mm or less. The distance Lm is calculated, for example, by checking the position of the inner edge 35a of the first intermediate portion 35 when the angle θa is 17°, and then opening the pouch 10 and checking the position of the upper surface 19a.

[0083] The steam release mechanism 25 will be described in detail below. Fig. 6 is an enlarged front view of the steam release mechanism 25.

[0084] The first intermediate portion 35 includes an inner edge 35a that is an edge located on the side of the storage portion 18, and an outer edge 35b that is an edge located on the side of the first non-sealed portion 45. The outer edge 35b of the first intermediate portion 35 defines a part of the outline of the edge of the first non-sealed portion 45.

[0085] The first intermediate portion 35 may include a first portion 36, a second portion 37, and a first connecting portion 38. The first connecting portion 38 connects the first portion 36 and the second portion 37.

[0086] The first connecting portion 38 is located closer to the lower portion 32. "Closer to the lower portion 32" means that the first connecting portion 38 is located closer to the lower portion 32 than the middle position of the first unsealed portion 45 in the second direction D2.

[0087] The first portion 36 extends from the first connecting portion 38 toward the first side portion 13. For example, the inner edge 35a and the outer edge 35b of the first portion 36 extend substantially in the first direction D1 toward the lower portion 32. The angle formed between the direction in which the inner edge 35a and the outer edge 35b extend and the first direction D1 is, for example, 10° or less. The first portion 36 may be connected to the inner edge 32a of the lower portion 32. The outer edge 35b of the first portion 36 may extend continuously with the upper edge 32c of the lower portion 32. For example, an extension line of the outer edge 35b of the first portion 36 may overlap the upper edge 32c of the lower portion 32.

[0088] The second portion 37 extends from the first connecting portion 38 toward the upper portion 11. For example, the inner edge 35a and the outer edge 35b of the second portion 37 include portions that extend substantially in the second direction D2 toward the upper portion 11. The second portion 37 may be connected to the inner edge 11d of the upper seal portion 11a.

[0089] θ1 represents the angle between the direction in which the inner edge 35a of the second portion 37 extends and the direction in which the inner edge 35a of the first portion 36 extends. The angle θ1 is, for example, 100° or less, or may be 95° or less, or 90° or less. The angle θ1 is, for example, 70° or more, or may be 80° or more, or may be 85° or more.

[0090] θ2 represents the angle between the direction in which the outer edge 35b of the second portion 37 extends and the direction in which the outer edge 35b of the first portion 36 extends. The angle θ2 is, for example, 100° or less, or may be 95° or less, or 90° or less. The angle θ2 is, for example, 70° or more, or may be 80° or more, or 85° or more.

[0091] 6, the second portion 37 may include a lower second portion 371, an upper second portion 372, and a transition portion 373. The lower second portion 371 may be connected to the first portion 36 via the first connecting portion 38. The upper second portion 372 is located higher than the lower second portion 371. The upper second portion 372 may be connected to the upper seal portion 11a. The transition portion 373 is located between the lower second portion 371 and the upper second portion 372.

[0092] The transition portion 373 includes an outer edge 35b that extends in a different direction from the outer edges 35b of the lower second portion 371 and the upper second portion 372. The outer edge 35b of the transition portion 373 extends so as to be displaced toward the first side portion 13 in the first direction D1 as it extends upward. Meanwhile, the inner edge 35a of the transition portion 373 extends along the second direction D2. The width of the transition portion 373 increases as it extends upward. Therefore, the width of the upper second portion 372 is greater than the width of the lower second portion 371.

[0093] As will be described later, the transition portion 373 may include an inner edge 35a that extends in a different direction than the inner edges 35a of the lower second portion 371 and the upper second portion 372. In this case, the outer edge 35b of the transition portion 373 may extend along the second direction D2.

[0094] Next, the second intermediate portion 33 will be described. As shown in Fig. 6, the second intermediate portion 33 extends from the upper edge 32c of the lower portion 32 toward the upper portion 11 along the first side edge 13x. The second intermediate portion 33 includes an inner edge 33a and an upper edge 33c that contact the first unsealed portion 45. The inner edge 33a may face the outer edge 35b of the second portion 37 in the first direction D1. The upper edge 33c may face the inner edge 11d of the upper seal portion 11a in the second direction D2.

[0095] Next, the through portion 47 will be described. The outline of the through portion 47 may be a sector shape such as a semicircle. For example, the slit of the through portion 47 may be an arc. The central angle θ3 of the arc is, for example, 120° or more, 150° or more, or 180° or more. The dimension of the through portion 47 is, for example, 3 mm or more, 4 mm or more, or 5 mm or more. The dimension of the through portion 47 is, for example, 20 mm or less, 15 mm or less, or 10 mm or less. When the through portion 47 is made of an arc-shaped slit, the dimension of the through portion 47 is the diameter of a circle corresponding to the arc.

[0096] Next, the arrangement of the first intermediate portion 35, the second intermediate portion 33, and the through portion 47 will be described.

[0097] 6, the through-hole 47 may be located closer to the first side portion 13 than the first portion 36 of the first intermediate portion 35. For example, the through-hole 47 may be located closer to the first side portion 13 than the first reference line SL1. For example, the midpoint of the through-hole 47 in the first direction D1 may be located above the upper edge 32c of the lower portion 32. This prevents the contents 19 that have splashed upward from reaching the through-hole 47 through the peeled portion of the first intermediate portion 35. This prevents the contents 19 from leaking from the through-hole 47.

[0098] The first reference line SL1 will be described with reference to Figure 7. The first reference line SL1 is a straight line that passes through the first intersection point EP1 and extends in the second direction D2. The first intersection point EP1 is the intersection point of the line EL11 and the line EL12. The line EL11 is an extension of the inner edge 32a of the lower portion 32. The line EL12 is an extension of the inner edge 35a of the first portion 36.

[0099] 6, the transition portion 373 may be located closer to the second side portion 14 than the first reference line SL1. The upper second portion 372 may also be located closer to the second side portion 14 than the first reference line SL1.

[0100] 6, the upper second portion 372 of the second part 37 of the first intermediate portion 35 may be located higher than the upper edge 33c of the second intermediate portion 33. The transition portion 373 of the second part 37 of the first intermediate portion 35 may also be located higher than the upper edge 33c of the second intermediate portion 33. This widens the flow path of steam from the peeled portion of the first intermediate portion 35 to the penetration portion 47 and the opening edge portion 46.

[0101] 6, the symbol SL2 denotes a straight line (also referred to as a second reference line) that passes through the middle of the first unsealed portion 45 in the second direction D2 and extends in the first direction D1. As shown in FIG. 6, the through-hole 47 may be located above the second reference line SL2. This can prevent the contents 19 from leaking from the through-hole 47.

[0102] 6, the edge of the first unsealed portion 45 in the second direction D2 is defined by the inner edge 11d of the upper seal portion 11a and the upper edge 32c of the lower portion 32. In this case, the second reference line SL2 passes through a midpoint between the inner edge 11d and the upper edge 32c in the second direction D2.

[0103] As shown in FIG. 6, the transition portion 373 and the upper second portion 372 of the second portion 37 of the first intermediate portion 35 may be located above the second reference line SL2.

[0104] As shown in FIG. 6, the second intermediate portion 33 may be located below the second reference line SL2.

[0105] Next, with reference to FIG. 8, the boundary between the lower second portion 371 and the transition portion 373 of the second part 37 of the first intermediate portion 35 will be described. In FIG. 8, reference symbols 35b1, 35b2, and 35b3 represent the outer edge of the lower second portion 371, the outer edge of the upper second portion 372, and the outer edge of the transition portion 373, respectively. Reference symbol SL3 represents a line tangent to the outer edge 35b3 (also referred to as a third reference line). Reference symbol θS3 represents an angle (also referred to as a third reference angle) formed between the third reference line SL3 and the outer edge 35b1 of the lower second portion 371. The third reference angle θS3 increases as the position of the tangent point of the third reference line SL3 to the outer edge 35b3 increases. The boundary between the lower second portion 371 and the transition portion 373 may be defined as the position where the third reference angle θS3 is 20°.

[0106] The through portion 47 may be located above the lower second portion 371. For example, the through portion 47 may be located above the boundary between the lower second portion 371 and the transition portion 373.

[0107] 8, reference numerals 35a1 and 35a2 respectively denote the inner edge of the lower second portion 371 and the inner edge of the upper second portion 372. The transition portion 373 may be defined as a portion where the direction of extension of the inner edge changes with respect to the inner edge 35a1 of the lower second portion 371. For example, although not shown, when a reference line similar to the third reference line SL3 is drawn so as to be tangent to the inner edge of the transition portion 373, the position where the angle formed between the reference line and the inner edge 35a1 of the lower second portion 371 is 20° may be defined as the boundary between the lower second portion 371 and the transition portion 373.

[0108] The width W72 of the upper second portion 372 is larger than the width W71 of the lower second portion 371. The widths of the first intermediate portion 35, such as width W71 and width W72, are dimensions of the first intermediate portion 35 in a direction perpendicular to the direction in which the first intermediate portion 35 extends. The width W72 is, for example, 1.2 times or more, or alternatively 1.5 times or more, or even 1.8 times or more, the width W71. The width W72 is, for example, 3.0 times or less, or alternatively 2.5 times or less, or alternatively 2.2 times or less, the width W71.

[0109] When pouch 10 is heated using a microwave oven, the moisture contained in content 19 evaporates, increasing the pressure in storage section 18. As the pressure in storage section 18 increases, a force is applied to first intermediate section 35, causing first intermediate section 35 to peel off. Peeling of first intermediate section 35 begins at first connecting section 38. Peeling of first section 36 progresses in a direction from first connecting section 38 toward lower section 32. Peeling of second section 37 progresses upward from first connecting section 38.

[0110] The lower second portion 371 of the second part 37 includes an inner edge 35a and an outer edge 35b that extend linearly. The lower second portion 371 also has a constant width W71. This is thought to facilitate smooth peeling of the lower second portion 371. The "constant width" means that the difference between the maximum and minimum values ​​of the width W71 of the lower second portion 371 is 1 mm or less. On the other hand, the inner edge 35a or the outer edge 35b of the transition portion 373 extends in a different direction from the inner edge 35a or the outer edge 35b of the lower second portion 371. Furthermore, the width W72 of the upper second portion 372 is larger than the width W71 of the lower second portion 371. For this reason, it is considered that once peeling of the second portion 37 reaches the transition portion 373 or the upper second portion 372, the peeling becomes less likely to progress. In other words, it is considered that the transition portion 373 and the upper second portion 372 function as peel-suppressing portions 37R that suppress the progression of peeling of the second portion 37.

[0111] The second portion 37 includes the peel-prevention portion 37R, which makes it easier to predict the portion of peeling that may occur in the second portion 37. Therefore, the arrangement of the second intermediate portion 33, the through portion 47, and the like can be determined based on the predicted portion of peeling. For example, the through-hole 47 may be positioned higher than the lower second portion 371. That is, the through-hole 47 may be positioned higher than the lower end of the peel-prevention portion 37R. This prevents the contents 19 that are heated and splashed upward from reaching the through-hole 47 through the peeled portion of the first intermediate portion 35. For example, the upper edge 33c of the second intermediate portion 33 may be positioned higher than the lower end of the peeling suppression portion 37R, which makes it easier for steam from the storage portion 18 to pass through the peeled portion of the first intermediate portion 35 and reach the opening edge portion 46.

[0112] Next, the dimensions of the components of the steam release mechanism 25 will be described with reference to FIG.

[0113] 9, the symbol L11 indicates the dimension of the first unsealed portion 45 in the second direction D2. The dimension L11 is, for example, 20 mm or more, or may be 30 mm or more, or 35 mm or more. The dimension L11 is, for example, 50 mm or less, or may be 45 mm or less, or may be 40 mm or less.

[0114] The dimension L11 of the first unsealed portion 45 may be determined in relation to the dimension H2 of the storage portion 18 in the second direction D2. The dimension L11 is, for example, 0.10×H2 or more, or may be 0.15×H2 or more, or 0.20×H2 or more. The dimension L11 is, for example, 0.35×H2 or less, or may be 0.30×H2 or less, or 0.27×H2 or less.

[0115] 9, the symbol L12 indicates the dimension of the opening edge 46 in the second direction D2. The dimension L12 is, for example, 8 mm or more, or may be 13 mm or more, or 18 mm or more. The dimension L12 is, for example, 35 mm or less, or may be 30 mm or less, or may be 25 mm or less.

[0116] The dimension L12 of the opening edge portion 46 may be determined in relation to the dimension L11 of the first non-sealed portion 45 in the second direction D2. The dimension L12 is, for example, 0.20×L11 or more, or may be 0.30×L11 or more, or 0.40×L11 or more. The dimension L12 is, for example, 0.80×L11 or less, or may be 0.70×L11 or less, or may be 0.60×L11 or less.

[0117] 9, the symbol L13 represents the dimension of the second intermediate portion 33 in the second direction D2. The dimension L13 is, for example, 5 mm or more, or may be 10 mm or more, or may be 15 mm or more. The dimension L12 is, for example, 30 mm or less, or may be 25 mm or less, or may be 20 mm or less.

[0118] The dimension L13 of the second intermediate portion 33 may be determined relative to the dimension L11 of the first unsealed portion 45 in the second direction D2. The dimension L13 may be, for example, 0.15×L11 or more, 0.25×L11 or more, or 0.35×L11 or more. The dimension L13 may be, for example, 0.75×L11 or less, 0.65×L11 or less, or 0.55×L11 or less.

[0119] The dimension L13 of the second intermediate portion 33 may be determined relative to the dimension L12 of the opening edge portion 46 in the second direction D2. The dimension L13 of the second intermediate portion 33 may be greater than or less than the dimension L12 of the opening edge portion 46. The dimension L13 may be, for example, 0.50×L12 or greater, 0.70×L12 or greater, 0.90×L12 or greater, or 1.10×L12 or greater. The dimension L13 may be, for example, 1.50×L12 or less, 1.30×L12 or less, 1.10×L12 or less, or 0.90×L12 or less.

[0120] 9, the symbol L14 represents the distance in the second direction D2 from the outer edge 35b of the first portion 36 of the first intermediate portion 35 to the through-hole 47. The distance L14 may be determined in relation to the dimension L11 of the first unsealed portion 45 in the second direction D2. The distance L14 is, for example, 0.50×L11 or more, or may be 0.55×L11 or more, or may be 0.60×L11 or more. The distance L14 is, for example, 0.75×L11 or less, or may be 0.70×L11 or less, or may be 0.65×L11 or less.

[0121] 9, the symbol L15 represents the maximum distance in the first direction D1 between the first side edge 13x and the inner edge 35a of the first intermediate portion 35. The distance L15 is, for example, 10 mm or more, or may be 15 mm or more, or may be 20 mm or more. The distance L15 is, for example, 30 mm or less, or may be 27 mm or less, or may be 24 mm or less.

[0122] The distance L15 may be determined in relation to the dimension H1 of the storage section 18 in the first direction D1. The distance L15 is, for example, 0.10×H1 or more, or may be 0.13×H1 or more, or 0.16×H1 or more. The distance L15 is, for example, 0.28×H1 or less, or may be 0.26×H1 or less, or 0.24×H1 or less.

[0123] 9, symbol L16 represents the distance in the first direction D1 from the inner edge 33a of the second intermediate portion 33 to the outer edge 35b of the lower second portion 371 of the second part 37. Symbol L17 represents the distance in the first direction D1 from the opening edge 46 to the outer edge 35b of the lower second portion 371 of the second part 37. Symbol L18 represents the distance in the first direction D1 from the opening edge 46 to the outer edge 35b of the upper second portion 372 of the second part 37. When the transition portion 373 is positioned above the upper edge 33c of the second intermediate portion 33, distance L17 is greater than distance L16 and distance L18.

[0124] The distance L16 is, for example, 6 mm or more, may be 8 mm or more, or may be 10 mm or more. The distance L16 is, for example, 20 mm or less, may be 16 mm or less, or may be 14 mm or less.

[0125] 9, the symbol L19 represents the distance between the transition portion 373 of the first intermediate portion 35 and the second intermediate portion 33. The distance L19 is, for example, 8 mm or more, or may be 10 mm or more, or may be 12 mm or more. The distance L19 is, for example, 20 mm or less, or may be 18 mm or less, or may be 16 mm or less.

[0126] 9, the symbol L20 represents the distance in the second direction D2 between the upper edge 33c of the second intermediate portion 33 and the opening means 30a. The distance L20 is, for example, 2 mm or more, or may be 4 mm or more, or may be 6 mm or more. The distance L20 is, for example, 15 mm or less, or may be 12 mm or less, or may be 10 mm or less.

[0127] 9, the symbol L21 represents the distance in the second direction D2 from the lower edge of the first unsealed portion 45 to the transition portion 373 of the second section 37. In the example shown in FIG. 9, the lower edge of the first unsealed portion 45 includes the outer edge 35b of the first portion 36 of the first intermediate portion 35. The distance L21 is, for example, 15 mm or more, or may be 18 mm or more, or may be 21 mm or more. The distance L21 is, for example, 30 mm or less, or may be 28 mm or less, or may be 26 mm or less.

[0128] In Fig. 9, the symbol L22 represents the distance in the second direction D2 from the upper edge of the first unsealed portion 45 to the transition portion 373 of the second section 37. In the example shown in Fig. 9, the upper edge of the first unsealed portion 45 includes the inner edge 11d of the upper sealed portion 11a. The distance L22 is, for example, 5 mm or more, or may be 7 mm or more, or 9 mm or more. The distance L22 is, for example, 15 mm or less, or may be 13 mm or less, or may be 11 mm or less.

[0129] 9, the symbol L23 represents the dimension of the transition portion 373 of the second portion 37 of the first intermediate portion 35 in the second direction D2. The dimension L23 is, for example, 1 mm or more, or may be 2 mm or more, or 3 mm or more. The dimension L23 is, for example, 7 mm or less, or may be 6 mm or less, or may be 5 mm or less.

[0130] As shown in FIGS. 1 and 9 , the lower portion 32 may include a portion in which the width W12 increases toward the first intermediate portion 35. For example, part of the inner edge 32a of the lower portion 32 may be inclined with respect to the second direction D2 so as to move away from the first side edge 13x as it approaches the first intermediate portion 35. This allows the width W12_1 of the lower portion 32 near the first unsealed portion 45 to be larger than the width W12_2 of the lower portion 32 near the lower part 12. The width W12_1 is the distance in the first direction D1 from the first side edge 13x to the first intersection point EP1. The width W12_1 may be the maximum value of the width W12. The width W12_2 is the width of the lower portion 32 at the position of the lower end of the storage section 18. The width W12_2 may be the minimum value of the width W12.

[0131] The width W12 of the lower portion 32 increases from the bottom toward the first intermediate portion 35, thereby increasing the rigidity of the lower portion 32 near the first unsealed portion 45. This makes it possible to prevent the pouch 10 from bending near the first unsealed portion 45 when the pressure in the storage section 18 increases due to heating. This makes it possible to prevent the steam flow path from being blocked by the pouch 10 bending. Furthermore, by reducing the width W12 of the lower portion 32 in the vicinity of the lower portion 12, the dimension of the opening 12b of the lower portion 12 in the first direction D1 can be increased. This makes it easier to fill the contents through the opening 12b.

[0132] The ratio of the width W12_1 to the width W12_2 is, for example, 1.1 or more, or may be 1.3 or more, or may be 1.5 or more. The ratio of the width W12_1 to the width W12_2 is, for example, 2.5 or less, or may be 2.2 or less, or may be 2.0 or less.

[0133] 9, the symbol W13 represents the width of the second intermediate portion 33. The width W13 of the second intermediate portion 33 is smaller than the width W12 of the lower portion 32 in the vicinity of the first unsealed portion 45. The ratio of the width W13 to the maximum value of the width W12 is, for example, 0.20 or more, or alternatively, 0.30 or more, or even 0.40 or more. The ratio of the width W13 to the maximum value of the width W12 is, for example, 0.80 or less, or alternatively, 0.70 or less, or alternatively, 0.60 or less.

[0134] The width W13 of the second intermediate portion 33 may be larger than the width W71 of the lower second portion 371 of the second part 37 of the first intermediate portion 35. This makes it possible to prevent peeling from reaching the first side edge 13x even if peeling occurs in the second intermediate portion 33.

[0135] Next, the middle portion 55 and the second unsealed portion 65 of the second side portion 14 will be described in detail. Figure 10 is an enlarged front view showing the middle portion 55 and the second unsealed portion 65.

[0136] As disclosed in JP 2016-74457 A, for example, the second non-sealed portion 65 is formed by cutting one non-sealed portion at the same time as the first non-sealed portion 45. For example, when a surface film 15 and a back film 16 that are partially joined to each other and extend along the conveyance direction are cut along the sealed portion and the non-sealed portion to manufacture a plurality of pouches 10, one of the cut non-sealed portions becomes the first non-sealed portion 45 and the other becomes the second non-sealed portion 65.

[0137] 10, symbols W22 and W25 respectively represent the width of the lower portion 52 and the width of the middle portion 55. The width W22 of the lower portion 52 may be larger than the width W25 of the middle portion 55.

[0138] Next, a description will be given of the layer structure of the packaging material 70 that constitutes the front film 15 and the back film 16. Fig. 11 is a cross-sectional view showing an example of the layer structure of the packaging material 70.

[0139] 11 includes at least a first biaxially oriented plastic film 71, a first adhesive layer 76, a second biaxially oriented plastic film 72, a second adhesive layer 77, and a sealant film 75, in this order. The first biaxially oriented plastic film 71 is located on the outer surface 70y side, and the sealant film 75 is located on the inner surface 70x side opposite the outer surface 70y. The inner surface 70x faces the storage section 18.

[0140] Each film constituting the packaging material 70, such as the first biaxially oriented plastic film 71, the second biaxially oriented plastic film 72, and the sealant film 75, as well as the packaging material 70, has a machine direction and a perpendicular direction. The machine direction is the direction in which the film flows when it is formed, and is known as the MD (Machine Direction). The perpendicular direction is the direction perpendicular to the machine direction, and is known as the TD (Transverse Direction). In the pouch 10 shown in FIG. 1, the first direction D1 is the machine direction, and the second direction D2 is the perpendicular direction.

[0141] Each layer of packaging material 70 will now be described in detail.

[0142] (First biaxially stretched plastic film) The first biaxially stretched plastic film 71 is a film made of plastic and stretched in two predetermined directions. A biaxially stretched plastic film is a plastic film that has been intentionally stretched to improve the mechanical strength of the plastic film. The first biaxially stretched plastic film 71 functions as a base layer that provides the packaging material 70 with a predetermined strength. The stretching direction of the first biaxially stretched plastic film 71 is not particularly limited. For example, the first biaxially stretched plastic film 71 may be stretched in a first direction D1 and a second direction D2. The stretching ratio of the first biaxially stretched plastic film 71 is, for example, 1.05 times or more.

[0143] The first biaxially stretched plastic film 71 contains, for example, polyester as a main component. For example, the first biaxially stretched plastic film 71 contains 51% by mass or more of polyester. Examples of polyester include polyethylene terephthalate (hereinafter also referred to as PET) and polybutylene terephthalate (hereinafter also referred to as PBT). The 51% by mass or more of polyester in the first biaxially stretched plastic film 71 may be composed of one type of polyester or two or more types of polyester. The polyester content in the first biaxially stretched plastic film 71 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more. For example, the PET content in the first biaxially stretched plastic film 71 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0144] The thickness of the first biaxially stretched plastic film 71 is, for example, 8 μm or more, or may be 9 μm or more, or 12 μm or more. The thickness of the first biaxially stretched plastic film 71 is, for example, 30 μm or less, or may be 25 μm or less, or may be 20 μm or less. By making the thickness of the first biaxially stretched plastic film 71 8 μm or more, the first biaxially stretched plastic film 71 has sufficient strength. By making the thickness of the first biaxially stretched plastic film 71 30 μm or less, the first biaxially stretched plastic film 71 exhibits excellent formability. Therefore, the process of processing the packaging material 70 to produce the pouch 10 can be carried out efficiently.

[0145] (First adhesive layer) The first adhesive layer 76 contains an adhesive for bonding the first biaxially oriented plastic film 71 and the second biaxially oriented plastic film 72 by a dry lamination method. The adhesive constituting the first adhesive layer 76 is produced from an adhesive composition prepared by mixing a first composition containing a base agent and a solvent with a second composition containing a curing agent and a solvent. Specifically, the adhesive contains a cured product produced by reaction of the base agent and the solvent in the adhesive composition.

[0146] An example of an adhesive is polyurethane. Polyurethane is a cured product produced by reacting a polyol as a base agent with an isocyanate compound as a curing agent. Examples of polyurethane include polyether polyurethane and polyester polyurethane. Polyether polyurethane is a cured product produced by reacting a polyether polyol as a base agent with an isocyanate compound as a curing agent. Polyester polyurethane is a cured product produced by reacting a polyester polyol as a base agent with an isocyanate compound as a curing agent.

[0147] As the isocyanate compound, aromatic isocyanate compounds such as tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), and xylylene diisocyanate (XDI), aliphatic isocyanate compounds such as hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI), or adducts or polymers of the above-mentioned various isocyanate compounds can be used.

[0148] The thickness of the first adhesive layer 76 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the first adhesive layer 76 is, for example, 6 μm or less, and may be 5 μm or less.

[0149] (Second biaxially stretched plastic film) The second biaxially stretched plastic film 72 is a plastic film stretched in two predetermined directions, similar to the first biaxially stretched plastic film 71. Like the first biaxially stretched plastic film 71, the second biaxially stretched plastic film 72 also functions as a base layer that provides a predetermined strength to the packaging material 70. The stretching direction of the second biaxially stretched plastic film 72 is not particularly limited, similar to the case of the first biaxially stretched plastic film 71. The stretching ratio of the second biaxially stretched plastic film 72 is, for example, 1.05 times or more.

[0150] The second biaxially oriented plastic film 72 may contain polyester as a primary component. As with the first biaxially oriented plastic film 71, examples of polyester include PET and PBT. The range of the polyester content in the second biaxially oriented plastic film 72 may be the same as that of the first biaxially oriented plastic film 71. The thickness of the second biaxially oriented plastic film 72 containing polyester as a primary component is, for example, 8 μm or more, or may be 9 μm or more, or may be 12 μm or more. The thickness of the second biaxially oriented plastic film 72 containing polyester as a primary component is, for example, 30 μm or less, or may be 25 μm or less, or may be 20 μm or less.

[0151] The second biaxially stretched plastic film 72 may contain polyamide as a primary component. For example, the second biaxially stretched plastic film 72 may contain 51% by mass or more of polyamide. Examples of polyamide include aliphatic polyamides and aromatic polyamides. Aliphatic polyamides include nylons such as nylon-6, nylon-6,6, and copolymers of nylon 6 and nylon 6,6. Aromatic polyamides include polymetaxylene adipamide (MXD6). The polyamide content in the second biaxially stretched plastic film 72 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or even 95% by mass or more. The thickness of the second biaxially stretched plastic film 72 containing polyamide as a primary component may be, for example, 12 μm or more, or 15 μm or more. The thickness of the second biaxially stretched plastic film 72 containing polyamide as a main component is, for example, 30 μm or less, may be 25 μm or less, or may be 20 μm or less.

[0152] (Second adhesive layer) The second adhesive layer 77 contains an adhesive for bonding the second biaxially oriented plastic film 72 and the sealant film 75 by dry lamination. An example of the adhesive for the second adhesive layer 77 is polyurethane, as in the case of the first adhesive layer 76. In addition to the configuration, materials, and properties described below, the second adhesive layer 77 can also be configured, made of the same materials, and properties as the first adhesive layer 76.

[0153] The thickness of the second adhesive layer 77 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the second adhesive layer 77 is, for example, 6 μm or less, and may be 5 μm or less.

[0154] As described above, the isocyanate compounds that constitute the curing agent of the adhesive include aromatic isocyanate compounds and aliphatic isocyanate compounds. Aromatic isocyanate compounds leach out components that cannot be used in food applications under high-temperature conditions, such as heat sterilization. The second adhesive layer 77 is in contact with the sealant film 75. Therefore, if the second adhesive layer 77 contains an aromatic isocyanate compound, components leach out from the aromatic isocyanate compound may adhere to the contents contained in the container 18 that is in contact with the sealant film 75.

[0155] In consideration of these issues, a cured product produced by the reaction of a polyol as the main agent with an aliphatic isocyanate compound as the curing agent is preferably used as the adhesive that constitutes the second adhesive layer 77. This makes it possible to prevent components that cannot be used for food applications, which originate from the second adhesive layer 77, from adhering to the contents.

[0156] (sealant film) Next, the sealant film 75 will be described. The sealant film 75 may be a single layer or a multilayer. The sealant film 75 is preferably made of an unstretched film. Note that the term "unstretched" is a concept that includes not only a film that is not stretched at all, but also a film that is slightly stretched due to the tension applied during film formation.

[0157] The sealant film 75 may satisfy at least one of the following (1) and (2). (1) Young's modulus is less than 1000 MPa in one direction and in the direction perpendicular to the one direction. (2) Tensile elongation of 300% or more in one direction and in the direction perpendicular to the one direction

[0158] The Young's modulus and tensile elongation of the sealant film 75 were measured in accordance with JIS K7127. Using a Tensilon universal testing machine RTC-1310A (manufactured by A&D Co., Ltd.), the test specimen was held for 1 minute at 23°C and 50% relative humidity, after which the Young's modulus and tensile elongation of the test specimen were measured at 23°C and 50% relative humidity. Measurements were performed using rectangular test specimens with one side measuring 15 mm and the other side extending perpendicular to the first side being 150 mm. The test specimen was held for 1 minute at 23°C, and then again at 23°C. The initial distance between the pair of gripping tools holding the test specimen was 100 mm, and the tensile speed was 300 mm / min. The length perpendicular to one side was adjustable, as long as measurements could be performed with an initial distance of 100 mm between the pair of gripping tools.

[0159] The pouch 10 made of the packaging material 70 is subjected to a sterilization treatment such as boiling or retort treatment at high temperatures. Therefore, the sealant film 75 used has heat resistance that can withstand these high-temperature treatments.

[0160] The melting point of the material constituting the sealant film 75 is preferably 150°C or higher, and more preferably 160°C or higher. Increasing the melting point of the sealant film 75 makes it possible to perform the retort treatment of the pouch 10 at a high temperature, thereby shortening the time required for the retort treatment. Note that the melting point of the material constituting the sealant film 75 is lower than the melting point of the resin constituting the biaxially stretched plastic film.

[0161] The sealant film 75 contains propylene as a main component. For example, the sealant film 75 may contain 51% by mass or more of propylene. The propylene content in the sealant film 75 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0162] Examples of materials containing propylene as a main component include polypropylenes such as propylene-ethylene block copolymers, propylene-ethylene random copolymers, and homopolypropylenes, as well as mixtures of polypropylene and polyethylene. "Propylene-ethylene block copolymer" refers to a material having the structural formula shown in formula (I) below. "Propylene-ethylene random copolymer" refers to a material having the structural formula shown in formula (II) below. "Homopolypropylene" refers to a material having the structural formula shown in formula (III) below.

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] When a mixture of polypropylene and polyethylene is used as the propylene-based material, the material may have an island-in-a-sea structure, where the polyethylene is discontinuously dispersed within a continuous polypropylene region.

[0167] Preferably, the sealant film 75 is a single-layer film containing a propylene-ethylene block copolymer. For example, the sealant film 75 is a single-layer unstretched film whose main component is a propylene-ethylene block copolymer. By using a propylene-ethylene block copolymer, the impact resistance of the sealant film 75 can be increased, thereby preventing the pouch 10 from breaking due to an impact when dropped. In addition, the puncture resistance of the packaging material 70 can be increased.

[0168] Furthermore, by using a propylene-ethylene block copolymer, the strength of the seal formed by the sealant film 75 at high temperatures, for example, 100°C, i.e., the above-mentioned hot seal strength, is extremely small compared to the seal strength at low temperatures, for example, 23°C (hereinafter also referred to as room temperature seal strength). Due to the low hot seal strength, when the pouch 10 is heated in a microwave oven, the first intermediate portion 35 is easily peeled off, and steam in the containing portion 18 is easily released to the outside of the pouch 10. This prevents the internal pressure of the containing portion 18 from becoming excessive, thereby preventing damage to the packaging material 70 during heating.

[0169] The propylene-ethylene block copolymer contains, for example, a sea component made of polypropylene and island components made of an ethylene-propylene copolymer rubber component. The sea component can contribute to improving the blocking resistance, heat resistance, rigidity, seal strength, etc. of the propylene-ethylene block copolymer. The island components can also contribute to improving the impact resistance of the propylene-ethylene block copolymer. Therefore, by adjusting the ratio of the sea component to the island components, the mechanical properties of the sealant film 75 containing the propylene-ethylene block copolymer can be adjusted.

[0170] In the propylene-ethylene block copolymer, the mass ratio of the sea part made of polypropylene is higher than the mass ratio of the island part made of ethylene-propylene copolymer rubber component. For example, in the propylene-ethylene block copolymer, the mass ratio of the sea part made of polypropylene is at least 51 mass% or more, preferably 60 mass% or more, and more preferably 70 mass% or more.

[0171] The single-layer sealant film 75 may further contain a second thermoplastic resin in addition to the first thermoplastic resin consisting of a propylene-ethylene block copolymer. Examples of the second thermoplastic resin include α-olefin copolymers and polyethylene. The α-olefin copolymer is, for example, linear low-density polyethylene. Examples of polyethylene include low-density polyethylene, medium-density polyethylene, and high-density polyethylene. The second thermoplastic resin can contribute to increasing the impact resistance of the sealant film 75. Furthermore, by using the second thermoplastic resin, the hot seal strength can be further reduced compared to the room-temperature seal strength.

[0172] Low density polyethylene has a density of 0.910 g / cm 3 or more and 0.925g / cm 3 Medium density polyethylene has a density of 0.926 g / cm 3 or more and 0.940 g / cm 3High density polyethylene is polyethylene with a density of 0.941 g / cm 3 or more and 0.965g / cm 3 The following polyethylenes are available: Low-density polyethylene is obtained by polymerizing ethylene at a high pressure, for example, of 1000 atmospheres or more and less than 2000 atmospheres; medium-density polyethylene and high-density polyethylene are obtained by polymerizing ethylene at a medium or low pressure, for example, of 1 atmosphere or more and less than 1000 atmospheres.

[0173] It should be noted that medium-density polyethylene and high-density polyethylene may partially contain a copolymer of ethylene and an α-olefin. Even when ethylene is polymerized under medium or low pressure, medium-density or low-density polyethylene can be produced if it contains a copolymer of ethylene and an α-olefin. Such polyethylene is referred to as the linear low-density polyethylene mentioned above. Linear low-density polyethylene is obtained by copolymerizing an α-olefin with a linear polymer obtained by polymerizing ethylene under medium or low pressure to introduce short-chain branches. Examples of α-olefins include 1-butene (C4), 1-hexene (C6), 4-methylpentene (C6), and 1-octene (C8). The density of linear low-density polyethylene is, for example, 0.915 g / cm. 3 or more and 0.945 g / cm 3 The following is the result.

[0174] The α-olefin copolymer constituting the second thermoplastic resin of the propylene-ethylene block copolymer is not limited to the linear low-density polyethylene described above. The α-olefin copolymer refers to a material having the structural formula shown in formula (IV) below.

[0175] [ka] Both R1 and R2 are H (hydrogen atom) or alkyl groups such as CH3 and C2H5. Furthermore, both j and k are integers of 1 or greater. Furthermore, j is greater than k. That is, in the α-olefin copolymer represented by formula (IV), the structure on the left side including R1 is the base. R1 is, for example, H, and R2 is, for example, C2H5.

[0176] In the sealant film 75, the mass ratio of the first thermoplastic resin made of a propylene-ethylene block copolymer is higher than the mass ratio of the second thermoplastic resin containing at least an α-olefin copolymer or polyethylene. For example, in a single-layer sealant film 75, the mass ratio of the first thermoplastic resin made of a propylene-ethylene block copolymer is at least 51 mass% or more, preferably 60 mass% or more, and more preferably 70 mass% or more.

[0177] As described above, the second thermoplastic resin can contribute to increasing the impact resistance of the sealant film 75. Therefore, by adjusting the mass ratio of the second thermoplastic resin containing at least an α-olefin copolymer or polyethylene in the single-layer sealant film 75, the mechanical properties of the sealant film 75 can be adjusted.

[0178] The sealant film 75 may further contain a thermoplastic elastomer. By using a thermoplastic elastomer, the impact resistance and puncture resistance of the sealant film 75 can be further improved.

[0179] The thermoplastic elastomer is, for example, a hydrogenated styrene-based thermoplastic elastomer. The hydrogenated styrene-based thermoplastic elastomer has a structure consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one hydrogenated conjugated diene compound. The thermoplastic elastomer may also be an ethylene-α-olefin elastomer. The ethylene-α-olefin elastomer is a low-crystalline or amorphous copolymer elastomer, and is a random copolymer of 50 to 90% by mass of ethylene as the main component and an α-olefin as a copolymerization monomer.

[0180] The content of the propylene-ethylene block copolymer in the sealant film 75 is, for example, 80% by mass or more, and preferably 90% by mass or more.

[0181] Propylene-ethylene block copolymers can be produced by polymerizing the raw materials propylene and ethylene using a catalyst, such as a Ziegler-Natta catalyst or a metallocene catalyst.

[0182] The thickness of the sealant film 75 is, for example, 30 μm or more, or may be 40 μm or more, 50 μm or more, or 60 μm or more. The thickness of the sealant film 75 is, for example, 100 μm or less, or may be 80 μm or less.

[0183] As a single-layer sealant film 75 containing a propylene-ethylene block copolymer, there is a type that has high tensile elongation and impact resistance, such as ZK500, which will be described later. This type of sealant film 75 preferably also has the property of low hot seal strength. This prevents the internal pressure of the storage section 18 from becoming excessive when the pouch 10 is heated.

[0184] The tensile elongation of the sealant film 75 in the machine direction (MD) at 23°C may be, for example, 800% or more, or may be 900% or more, or 1000% or more, or may be 1100% or more. The product of the tensile elongation (%) of the sealant film 75 in the machine direction (MD) and the thickness (µm) of the sealant film 75 may be 45,000 or more, or may be 50,000 or more, or may be 55,000 or more, or may be 60,000 or more. The tensile elongation of the sealant film 75 in the transverse direction (TD) at 23°C may be, for example, 1050% or more, or may be 1100% or more. The product of the tensile elongation (%) of the sealant film 75 in the transverse direction (TD) and the thickness (µm) of the sealant film 75 may be 53,000 or more, or may be 60,000 or more. The sealant film 75 has a high tensile elongation, which can prevent the pouch 10 from breaking due to an impact when dropped, etc.

[0185] The Young's modulus of the sealant film 75 in the machine direction (MD) at 23°C is, for example, 670 MPa or less, and may be 650 MPa or less. The product of the Young's modulus (MPa) of the sealant film 75 in the machine direction (MD) and the thickness (μm) of the sealant film 75 is, for example, 38,000 or less, and may be 35,000 or less. The Young's modulus of the sealant film 75 in the transverse direction (TD) at 23°C is, for example, 550 MPa or less, and may be 500 MPa or less. The product of the Young's modulus (MPa) of the sealant film 75 in the transverse direction (TD) and the thickness (μm) of the sealant film 75 is, for example, 30,000 or less, and may be 25,000 or less.

[0186] As shown in FIG. 11 , the packaging material 70 may further include a printed layer 81. The printed layer 81 is a layer provided on the packaging material 70 to display product information and to add an aesthetic appeal to the packaging material 70. The printed layer 81 is provided, for example, on the first biaxially oriented plastic film 71. The printed layer 81 represents letters, numbers, symbols, figures, pictures, etc. The printed layer 81 contains, for example, a color material such as ink and a binder resin. Finart, manufactured by DIC Graphics Corporation, can be used as the ink for gravure printing.

[0187] 12A and 12B are cross-sectional views showing other examples of the layer structure of the packaging material 70. As shown in FIGS. 12A and 12B, the packaging material 70 may include a transparent vapor deposition layer 82 located between a first biaxially oriented plastic film 71 and a second biaxially oriented plastic film 72. The packaging material 70 may include a transparent gas barrier coating film 83 located on the surface of the transparent vapor deposition layer 82. As shown in FIG. 12A, the transparent vapor deposition layer 82 may be provided on the inner surface of the first biaxially oriented plastic film 71. As shown in FIG. 12B, the transparent vapor deposition layer 82 may be provided on the outer surface of the second biaxially oriented plastic film 72.

[0188] [Transparent vapor deposition layer] The transparent vapor deposition layer 82 may consist of a single vapor deposition layer or may include two or more vapor deposition layers. When the transparent vapor deposition layer 82 includes two or more vapor deposition layers, each layer may have the same composition or different compositions. Examples of methods for forming the transparent vapor deposition layer 82 include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. Specifically, the vapor deposition layer can be formed on a film-forming roller using a roller-type vapor deposition film-forming device.

[0189] The transparent vapor deposition layer 82 is made of a transparent inorganic material. Examples of inorganic materials include metal oxides and inorganic oxides. Metal oxides include oxides of metals such as aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), and yttrium (Y). Inorganic oxides include oxides of silicon (Si). Aluminum oxide (aluminum oxide) or silicon oxide is preferred as the inorganic material constituting the transparent vapor deposition layer.

[0190] The thickness of the transparent deposition layer 82 is, for example, 20 Å or more, and may be 30 Å or more, 40 Å or more, 50 Å or more, 60 Å or more, or 70 Å or more. The thickness of the transparent deposition layer 82 is, for example, 150 Å or less, 130 Å or less, 120 Å or less, or 110 Å or less.

[0191] [Gas barrier coating film] The transparent gas barrier coating film 83 has transparency. The transparent gas barrier coating film 83 can suppress the permeation of oxygen gas, water vapor, etc. The transparent gas barrier coating film 83 is a compound represented by the general formula R 1 n M(OR 2 ) m (wherein, R 1 , R 2 represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M. The transparent gas barrier composition contains at least one alkoxide represented by the formula (I) and the polyvinyl alcohol resin and / or ethylene-vinyl alcohol copolymer as described above, and is further polycondensed by a sol-gel method in the presence of a sol-gel catalyst, an acid, water, and an organic solvent.

[0192] The general formula R 1 n M(OR 2 )m As the alkoxide represented by the formula (I), at least one of a partial hydrolyzate of an alkoxide and a condensate of the hydrolysis of an alkoxide can be used. In addition, the partial hydrolyzate of the alkoxide does not necessarily have to have all of the alkoxy groups hydrolyzed, and may be one in which one or more alkoxy groups are hydrolyzed, or a mixture thereof. As the condensate of the hydrolysis of an alkoxide, a dimer or higher of the partially hydrolyzed alkoxide, specifically a dimer to hexamer, is used.

[0193] The general formula R 1 n M(OR 2 ) m In the alkoxide represented by the formula (I), silicon, zirconium, titanium, aluminum, and the like can be used as the metal atom represented by M. Preferred metals include silicon and titanium. In the present embodiment, the alkoxide can be used alone or as a mixture of two or more alkoxides of different metal atoms in the same solution.

[0194] In addition, the above general formula R 1 n M(OR 2 ) m In the alkoxide represented by the formula 1 Specific examples of the organic group represented by the general formula R include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-hexyl, n-octyl, and the like. 1 n M(OR 2 ) m In the alkoxide represented by the formula 2 Specific examples of the organic group represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, etc. These alkyl groups may be the same or different in the same molecule.

[0195] When preparing the transparent gas barrier composition, for example, a silane coupling agent may be added. As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group can be used. In particular, an organoalkoxysilane having an epoxy group is preferably used, and specifically, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, or β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane can be used. The above-mentioned silane coupling agents may be used alone or in combination of two or more.

[0196] The thickness of the transparent gas barrier coating film 83 is, for example, 100 nm or more, and may be 125 nm or more, 150 nm or more, or 200 nm or more. This allows stable gas barrier properties to be obtained. The thickness of the transparent gas barrier coating film 83 is, for example, 500 nm or less, and may be 450 nm or less, 400 nm or less, or 300 nm or less.

[0197] As shown in Figures 11, 12A, and 12B, the packaging material 70 may contain only two biaxially oriented plastic films. A specific example of packaging material 70 in this case is shown below. When listing layers, " / " is used to indicate the boundary between layers. The layers arranged from the outside to the inside of the pouch are listed from left to right. Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented nylon film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / sealant film Biaxially oriented PET film / transparent vapor deposition layer / transparent gas barrier coating film / printed layer / adhesive layer / biaxially oriented nylon film / adhesive layer / sealant film Biaxially oriented PET film / transparent vapor deposition layer / transparent gas barrier coating film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / transparent gas barrier coating film / transparent vapor deposition layer / biaxially oriented PET film / adhesive layer / sealant film

[0198] The following describes preferred properties of the packaging material 70 when the packaging material 70 contains only two biaxially oriented plastic films. Specifically, the following describes preferred hot breaking strength and hot seal strength of the packaging material 70.

[0199] The packaging material 70 has a unidirectional breaking strength (hot breaking strength) of 33.0 MPa or more when measured in a 100°C environment after being held in a 100°C environment for 1 minute. The hot breaking strength of the packaging material 70 in one direction is preferably 36.0 MPa or more, more preferably 39.0 MPa or more, even more preferably 42.0 MPa or more, and even more preferably 45.0 MPa or more. The hot breaking strength of the packaging material 70 in a direction perpendicular to the one direction is preferably 29.0 MPa or more, more preferably 32.0 MPa or more, even more preferably 35.0 MPa or more, and most preferably 38.0 MPa or more. The hot breaking strength of the packaging material 70 in the one direction is preferably 50.0 MPa or less, and the hot breaking strength of the packaging material 70 in the direction perpendicular to the one direction is preferably 45.0 MPa or less. One direction of the packaging material 70 may be, for example, a first direction D1 in the pouch 10, and a direction perpendicular to the one direction of the packaging material 70 may be, for example, a second direction D2 in the pouch 10. Also, for example, the machine direction (MD) of the packaging material 70 may correspond to the first direction D1 of the pouch 10, and for example, the vertical direction (TD) of the packaging material 70 may correspond to the second direction D2 of the pouch 10. Also, for example, one direction of the packaging material 70 may correspond to the machine direction (MD), and for example, a direction perpendicular to the one direction of the packaging material may correspond to the vertical direction (TD).

[0200] When measuring the properties of the packaging material 70, a test specimen cut from the packaging material 70 is used. If the packaging material 70 is available in a state before being processed into the pouch 10, the test specimen may be prepared by cutting the packaging material 70. The test specimen may also be prepared by cutting a product made from the packaging material 70, such as the pouch 10. FIG. 14 shows an example of a method for preparing a test specimen by cutting the front film 15 or the back film 16 of the pouch 10. When measuring the properties of the packaging material 70 in the machine direction, the test specimen is prepared by cutting the front film 15 or the back film 16 of the pouch 10 so that the long side direction of the test specimen coincides with the machine direction, as shown by reference numeral 90A in FIG. 14. When measuring the properties of the packaging material 70 in the vertical direction, the test specimen is prepared by cutting the front film 15 or the back film 16 of the pouch 10 so that the long side direction of the test specimen coincides with the vertical direction, as shown by reference numeral 90B in FIG. 14.

[0201] The hot breaking strength of the packaging material 70 is measured in accordance with JIS K7127, except for the lengths of the test pieces 90A and 90B, which are 100 mm in length and 15 mm in width.

[0202] The hot fracture strength of the test pieces 90A and 90B was measured using a Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.). Specifically, first, both longitudinal ends of the test pieces 90A and 90B were held with grippers 91 and 92 as shown in Figure 15. Then, the test pieces 90A and 90B were held for 1 minute in an environment with a temperature of 100°C and a relative humidity of 5%, and then a tensile test was performed in which the test pieces 90A and 90B were pulled in the longitudinal direction of the test pieces 90A and 90B at a tension speed of 300 mm / min under an environment with a temperature of 100°C and a relative humidity of 5%, with an initial gripper distance S1 (see Figure 15) of 50 mm. The hot fracture strength of the test pieces 90A and 90B was measured. The hot breaking strength of the five test pieces 90A and 90B is measured, and the average value is taken as the hot breaking strength of the packaging material 70 in the machine direction and the perpendicular direction.

[0203] The packaging material 70 has a seal strength (hot seal strength) of, for example, 13.0 N or less when measured in a 100°C environment after being held in a 100°C environment for 1 minute. The hot seal strength may be 11.0 N or less, 10.0 N or less, 8.0 N or less, or 6.0 N or less. If the hot seal strength is too low, the first intermediate portion 35 may peel off before the contents are sufficiently heated and pressurized, causing a decrease in the pressure and temperature of the storage section 18. Taking this into consideration, the hot seal strength of the sealed portion of the packaging material 70 may be, for example, 3.0 N or more, 4.0 N or more, or 5.0 N or more. Note that the seal strength of the packaging material 70 can also be changed by a sterilization treatment such as retort treatment. When the pouch 10 is subjected to retort treatment, unless otherwise specified, the "seal strength" refers to the seal strength of the sealed portion of the packaging material 70 of the pouch after retort treatment.

[0204] In measuring the hot seal strength of the packaging material 70, a test specimen cut from the packaging material 70 with its inner surfaces bonded together is used. If the packaging material 70 is available in a state before being processed into the pouch 10, the test specimen may be prepared by cutting the packaging material 70 with its inner surfaces bonded together. The test specimen may also be prepared by cutting a product made from the packaging material 70, such as the pouch 10. FIG. 16 shows an example of a method for preparing a test specimen by cutting the front film 15 and back film 16 with their inner surfaces bonded together. For example, the front film 15 and back film 16 of the pouch 10 are cut to include the first side seal portion 30 or the second side seal portion 50 to prepare a test specimen 90C. The length and width of the test specimen 90C are 70 mm and 15 mm.

[0205] The hot seal strength was measured using a Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.) in accordance with JIS Z1707:1997 7.5. First, two sheets of packaging material 70 in the unsealed portion of test piece 90C were gripped with grippers 93 and 94 (see Figure 17A). Then, grippers 93 and 94 were pulled in opposite directions perpendicular to the surface of the sealed portion of test piece 90C at a rate of 300 mm / min, and the maximum tensile stress F1 (MAX) was measured (see Figure 17B). The distance S2 between grippers 93 and 94 at the start of pulling was 50 mm, and the distance S2 between grippers 93 and 94 at the start of pulling was 60 mm. The maximum value MAX was taken as the seal strength (see Figure 17B). The hot seal strength is measured by holding the test piece 90C in an environment at a temperature of 100°C and a relative humidity of 5% for 1 minute, and then returning it to an environment at 100°C and a relative humidity of 5%. The hot seal strength of five test pieces 90C is measured, and the average value is taken as the hot seal strength of the packaging material 70.

[0206] Furthermore, if the dimensions of the seal portion in the longitudinal direction are not constant among multiple test pieces 90C made from the pouch 10, the position at which the tensile stress F1 begins to increase, the slope of the graph as the tensile stress F1 increases, etc. may differ depending on the test piece 90C, as shown in Figures 17B and 17C.

[0207] The thickness of the packaging material 70 including only two biaxially oriented plastic films is, for example, 80 μm or more, or may be 90 μm or more, or may be 100 μm or more. The thickness of the packaging material 70 including only two biaxially oriented plastic films is, for example, 130 μm or less, or may be 120 μm or less.

[0208] FIG. 13 is a cross-sectional view showing another example of the layer structure of a packaging material 70. The packaging material 70 shown in FIG. 13 includes a biaxially oriented plastic film 73, an adhesive layer 78, and a sealant film 75, in this order. The biaxially oriented plastic film 73 is located on the outer surface 70y, and the sealant film 75 is located on the inner surface 70x. The inner surface 70x faces the storage section 18. The packaging material 70 includes only one biaxially oriented plastic film. The packaging material 70 may include a transparent vapor deposition layer 82 provided on the surface of the biaxially oriented plastic film 73. The packaging material 70 may include a transparent gas barrier coating film 83 located on the surface of the transparent vapor deposition layer 82.

[0209] The biaxially stretched plastic film 73 is a film made of plastic and stretched in two predetermined directions, similar to the first biaxially stretched plastic film 71. The biaxially stretched plastic film 73 may be the biaxially stretched plastic film described above for the first biaxially stretched plastic film 71.

[0210] The biaxially oriented plastic film 73 may be a biaxially oriented plastic film having a loop stiffness of 0.0017 N or more in at least one direction and containing polyester as a primary component. In the following description, a biaxially oriented plastic film having a loop stiffness of 0.0017 N or more in at least one direction and containing polyester as a primary component is also referred to as a high-stiffness polyester film. A high-stiffness polyester film may have a loop stiffness of 0.0017 N or more in at least one of the machine direction (MD) and the transverse direction (TD). A high-stiffness polyester film may have a loop stiffness of 0.0017 N or more in both the machine direction (MD) and the transverse direction (TD). By including a high-stiffness polyester film in the packaging material 70, the packaging material 70 can have excellent puncture strength even if it contains only one biaxially oriented plastic film. The high-stiffness polyester film does not contain polyamide.

[0211] The polyester of the high-stiffness polyester film is preferably a polyester primarily composed of an aromatic polyester consisting of at least one aromatic dicarboxylic acid selected from terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid and at least one aliphatic alcohol selected from ethylene glycol, 1,3-propanediol, and 1,4-butanediol. Examples of the polyester include PET and PBT. Examples of high-stiffness polyester films include high-stiffness PET films containing 51% by mass or more of PET as a primary component, and high-stiffness PBT films containing 51% by mass or more of PBT as a primary component. The PET content of the high-stiffness PET film may be 80% by mass or more, 90% by mass or more, or even 95% by mass or more. The thickness of the high-stiffness polyester film is, for example, 5 μm or more, 7 μm or more, 10 μm or more, 12 μm or more, or 4 μm or more. The thickness of the high stiffness polyester film is, for example, 30 μm or less, may be 25 μm or less, or may be 20 μm or less.

[0212] Loop stiffness is a parameter that represents the stiffness of a film such as a biaxially stretched plastic film. A method for measuring loop stiffness will be described below with reference to FIGS. 18 to 23. The measurement method described below can be used not only for single-layer films such as biaxially stretched plastic films, but also for multi-layer films such as vapor-deposited films and laminated films. A vapor-deposited film is a film that includes a single-layer film such as a biaxially stretched plastic film and a vapor-deposited layer formed on the single-layer film. A laminated film is a film that includes multiple laminated films, such as packaging material 70.

[0213] FIG. 18 is a plan view showing a test piece 90 and a loop stiffness measuring device 95, and FIG. 19 is a cross-sectional view of the test piece 90 and the loop stiffness measuring device 95 of FIG. 18 taken along line CC. The test piece 90 is a rectangular film having long and short sides. In the present application, the length S3 of the long side of the test piece 90 is 150 mm, and the length S4 of the short side is 15 mm. As the loop stiffness measuring device 95, for example, No. 581 Loop Stiffness Tester (registered trademark) LOOP STIFFNESS TESTER DA type manufactured by Toyo Seiki Seisakusho, Ltd. can be used. The length S3 of the long side of the test piece 90 is adjustable as long as the test piece 90 can be gripped by a pair of chucks 96, which will be described later.

[0214] The loop stiffness measuring device 95 has a pair of chuck portions 96 for gripping a pair of ends in the long side direction of the test specimen 90, and a support member 97 for supporting the chuck portions 96. The chuck portions 96 include a first chuck 961 and a second chuck 962. In the state shown in FIGS. 18 and 19 , the test specimen 90 is placed on the pair of first chucks 961, and the second chuck 962 has not yet gripped the test specimen 90 between the first chuck 961 and the second chuck 962. As will be described later, during measurement, the test specimen 90 is gripped between the first chuck 961 and the second chuck 962 of the chuck portions 96. The second chuck 962 may be connected to the first chuck 961 via a hinge mechanism.

[0215] When a film to be measured, such as a biaxially oriented plastic film, a vapor-deposited film, or a laminated film, is available in a state before being processed into a packaging product, the test piece 90 may be prepared by cutting the film to be measured. The test piece 90 may also be prepared by cutting a packaging product made from the packaging material 70, such as a pouch. When measuring the loop stiffness of the packaging material 70 in the machine direction, the test piece 90A shown in FIG. 14 can be used. When measuring the loop stiffness of the packaging material 70 in the perpendicular direction, the test piece 90B shown in FIG. 14 can be used.

[0216] A method for measuring the loop stiffness of a test piece 90 using a loop stiffness measuring device 95 will be described. First, as shown in FIGS. 18 and 19 , the test piece 90 is placed on a first chuck 961 of a pair of chuck units 96 arranged with a gap S5 therebetween. In the present application, the gap S5 is set so that the length of a loop portion 901 (described later, also referred to as the loop length) is 60 mm. The test piece 90 includes an inner surface 90x located on the first chuck 961 side and an outer surface 90y located opposite the inner surface 90x. When the test piece 90 is made of a packaging material 70, the inner surface 90x and the outer surface 90y of the test piece 90 coincide with the inner surface 70x and the outer surface 70y of the packaging material 70. When a loop portion 901 (described later) is formed in the test piece 90, the inner surface 90x is located inside the loop portion 901, and the outer surface 90y is located outside the loop portion 901. Subsequently, as shown in FIG. 20, the second chuck 962 is placed on the test piece 90 so that the end of the test piece 90 in the long side direction is gripped between the second chuck 962 and the first chuck 961.

[0217] Next, as shown in FIG. 21 , at least one of the pair of chuck portions 96 is slid on the support member 97 in a direction that reduces the distance between the pair of chuck portions 96. This allows a loop portion 901 to be formed on the test piece 90. The test piece 90 shown in FIG. 21 has a loop portion 901, a pair of intermediate portions 902, and a pair of fixing portions 903. The pair of fixing portions 903 are portions of the test piece 90 that are gripped by the pair of chuck portions 96. The pair of intermediate portions 902 are portions of the test piece 90 that are located between the loop portion 901 and the pair of intermediate portions 902. As shown in FIG. 21 , the chuck portion 96 is slid on the support member 97 until the inner surfaces 90x of the pair of intermediate portions 902 come into contact with each other. This allows a loop portion 901 having a loop length of 60 mm to be formed. The loop length of the loop portion 901 is the length of the test piece 90 between position Q1 where the surface of one second chuck 962 on the loop portion 901 side intersects with the test piece 90, and position Q2 where the surface of the other second chuck 962 on the loop portion 901 side intersects with the test piece 90. If the thickness of the test piece 90 is ignored, the above-mentioned distance S5 is the value obtained by adding 2×t to the length of the loop portion 901, where t is the thickness of the second chuck 962 of the chuck portion 96.

[0218] Then, as shown in FIG. 22 , the posture of the chuck portion 96 is adjusted so that the protruding direction Y of the loop portion 901 relative to the chuck portion 96 is horizontal. For example, the posture of the chuck portion 96 supported by the support member 97 is adjusted by moving the support member 97 so that the normal direction of the support member 97 is horizontal. In the example shown in FIG. 22 , the protruding direction Y of the loop portion 901 coincides with the thickness direction of the chuck portion. Furthermore, a load cell 98 is prepared at a position a distance Z1 away from the second chuck 962 in the protruding direction Y of the loop portion 901. In this application, the distance Z1 is set to 50 mm. Next, the load cell 98 is moved toward the loop portion 901 of the test specimen 90 at a speed V by a distance Z2 shown in FIG. 22 . The distance Z2 is set so that the load cell 98 contacts the loop portion 901 and then pushes the loop portion 901 toward the chuck portion 96. In this application, the distance Z2 is set to 40 mm. In this case, the distance Z3 between the load cell 98 and the second chuck 962 of the chuck portion 96 when the load cell 98 is pressing the loop portion 901 toward the chuck portion 96 is 10 mm. The speed V at which the load cell 98 is moved was set to 3.3 mm / sec.

[0219] Next, in the state shown in Fig. 23 where the load cell 98 is pressing into the loop portion 901 of the test piece 90, the value of the load applied to the load cell 98 from the loop portion 901 is recorded after it has stabilized. The load value thus obtained is used as the loop stiffness of the film constituting the test piece 90. In this application, unless otherwise specified, the environment during the measurement of loop stiffness is a temperature of 23°C and a relative humidity of 50%.

[0220] By using a high-stiffness film having a loop stiffness of 0.0017 N or more in at least one direction as the biaxially stretched plastic film 73, it is possible to increase the puncture strength of the biaxially stretched plastic film 73. This makes it possible to increase the puncture strength of the packaging material 70 including the biaxially stretched plastic film 73 to, for example, 12.0 N or more, more preferably 13.0 N or more, and even more preferably 14.0 N or more.

[0221] The preferred mechanical properties of the high stiffness polyester film will be further described. The puncture strength of the high stiffness polyester film is preferably 10 N or more, and more preferably 11 N or more.

[0222] The tensile strength of the high-stiffness polyester film in at least one direction is preferably 250 MPa or more, more preferably 280 MPa or more. For example, the tensile strength of the high-stiffness polyester film in the machine direction is preferably 250 MPa or more, more preferably 280 MPa or more. The tensile strength of the high-stiffness polyester film in the perpendicular direction is preferably 250 MPa or more, more preferably 280 MPa or more. The tensile elongation of the high stiffness polyester film in at least one direction is preferably 130% or less, more preferably 120% or less. For example, the tensile elongation of the high stiffness polyester film in the machine direction is preferably 130% or less, more preferably 120% or less. The tensile elongation of the high stiffness polyester film in the perpendicular direction is preferably 120% or less, more preferably 110% or less. Preferably, the tensile strength of the high-stiffness polyester film divided by the tensile elongation in at least one direction is 2.0 [MPa / %] or more. For example, the tensile strength of the high-stiffness polyester film divided by the tensile elongation in the transverse direction (TD) is preferably 2.0 [MPa / %] or more, more preferably 2.2 [MPa / %] or more. The tensile strength of the high-stiffness polyester film divided by the tensile elongation in the machine direction (MD) is preferably 1.8 [MPa / %] or more, more preferably 2.0 [MPa / %] or more.

[0223] The tensile strength and tensile elongation can be measured in accordance with JIS K7127. A tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used as a measuring instrument. A rectangular film cut from a high stiffness polyester film with a width of 15 mm and a length of 150 mm can be used as a test piece. The distance between the pair of chucks holding the test piece at the start of measurement is 100 mm, and the tensile speed is 300 mm / min. The length of the test piece can be adjusted as long as the test piece can be held by the pair of chucks. Unless otherwise specified in this application, the environment during measurement of the tensile strength and tensile elongation of the high stiffness polyester film is a temperature of 23°C and a relative humidity of 50%. The tensile strength and tensile elongation of the packaging material 70 are measured in the same manner as for the high-stiffness polyester film, except that an Orientec RTC-1310A tensile tester is used as the measuring instrument and the distance between the pair of chucks holding the test piece is 50 mm at the start of the measurement. When measuring the tensile strength and tensile elongation of the packaging material 70, a test piece can be prepared by cutting the front film 15 or the back film 16 of the pouch 10 so that the long side direction of the test piece coincides with the machine direction or the perpendicular direction, as in the case of measuring loop stiffness.

[0224] The heat shrinkage of the high stiffness polyester film in at least one direction is preferably 0.7% or less, more preferably 0.5% or less. For example, the heat shrinkage of the high stiffness polyester film in the machine direction is preferably 0.7% or less, more preferably 0.5% or less. The heat shrinkage of the high stiffness polyester film in the perpendicular direction is preferably 0.7% or less, more preferably 0.5% or less. The heating temperature for measuring the heat shrinkage is 100°C, and the heating time is 40 minutes. The Young's modulus of the high-stiffness polyester film in at least one direction is preferably 4.0 GPa or more, more preferably 4.5 MPa or more. For example, the Young's modulus of the high-stiffness polyester film in the machine direction is preferably 4.0 GPa or more, more preferably 4.5 MPa or more. The Young's modulus of the high-stiffness polyester film in the perpendicular direction is preferably 4.0 GPa or more, more preferably 4.5 GPa or more.

[0225] Like tensile strength and tensile elongation, Young's modulus can be measured in accordance with JIS K7127. A tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used as a measuring instrument. A rectangular film cut from a high stiffness polyester film with a width of 15 mm and a length of 150 mm can be used as a test piece. The distance between the pair of chucks holding the test piece at the start of measurement is 100 mm, and the tensile speed is 300 mm / min. The length of the test piece can be adjusted as long as the test piece can be held by the pair of chucks. Unless otherwise specified in this application, the environment during measurement of the Young's modulus of the high stiffness polyester film is a temperature of 23°C and a relative humidity of 50%. The Young's modulus of the packaging material 70 is measured in the same manner as for the high-stiffness polyester film, except that the measuring instrument is an Orientec RTC-1310A tensile tester, and the distance between the pair of chucks holding the test piece is 50 mm at the start of the measurement. When measuring the Young's modulus of the packaging material 70, a test piece can be prepared by cutting the front film 15 or the back film 16 of the pouch 10 so that the long side direction of the test piece coincides with the flow direction or the perpendicular direction.

[0226] In the manufacturing process of a high-stiffness polyester film, for example, a plastic film obtained by melting and molding a polyester is first stretched 3 to 4.5 times in both the machine direction and the perpendicular direction at 90 to 145°C in a first stretching step. This is followed by a second stretching step in which the plastic film is stretched 1.1 to 3.0 times in both the machine direction and the perpendicular direction at 100 to 145°C in a second stretching step. This is followed by heat setting at 190 to 220°C. This is followed by relaxation treatment (treatment to reduce the film width) at 100 to 190°C in both the machine direction and the perpendicular direction at approximately 0.2 to 2.5%. By adjusting the stretch ratio, stretching temperature, heat setting temperature, and relaxation treatment rate in these steps, a high-stiffness polyester film having the above-mentioned mechanical properties can be obtained.

[0227] By including a high-stiffness polyester film in the packaging material 70, excellent puncture strength can be imparted to the packaging material 70 and to packaged products such as the pouch 10 formed from the packaging material 70. This can prevent the pouch 10 from being torn when a sharp object with a pointed tip comes into contact with the pouch 10, for example. The puncture strength of the packaging material 70 is preferably 12.0 N or more, more preferably 13.0 N or more, and more preferably 14.0 N or more. A method for measuring the puncture strength will be described in the examples below.

[0228] Furthermore, by including a high-stiffness polyester film in the packaging material 70, the Young's modulus of the packaging material 70 can be increased. The Young's modulus of the packaging material 70 in one direction is, for example, 3600 MPa or more, or may be 3700 MPa or more, 3800 MPa or more, 3900 MPa or more, 4000 MPa or more, or 4100 MPa or more. For example, the Young's modulus of the packaging material 70 in the machine direction (MD) is, for example, 3600 MPa or more, or may be 3700 MPa or more, or may be 3800 MPa or more, or may be 3900 MPa or more. The Young's modulus of the packaging material 70 in the transverse direction (TD), which is the direction perpendicular to the machine direction (MD), is, for example, 3600 MPa or more, or may be 3700 MPa or more, or may be 3800 MPa or more, or may be 3900 MPa or more, or may be 4000 MPa or more, or may be 4100 MPa or more. A high Young's modulus of the packaging material 70 makes the packaging material 70 less likely to stretch. This increases the processing accuracy when processing packaging material 70 in the manufacturing process of packaged products such as pouch 10. Furthermore, when packaging material 70 is used to produce a gusset-type pouch 10 configured to be self-supporting, as described below, the self-supporting ability of pouch 10 is increased. The Young's modulus of packaging material 70 in the transverse direction (TD) may be higher than the Young's modulus of packaging material 70 in the machine direction (MD).

[0229] The high stiffness polyester film may be used as the first biaxially stretched plastic film 71 or the second biaxially stretched plastic film 72 shown in Figures 11, 12A and 12B.

[0230] A packaging material 70 containing only one biaxially oriented plastic film may have a hot seal strength equivalent to that of a packaging material 70 containing only two biaxially oriented plastic films. A packaging material 70 containing only one biaxially oriented plastic film may have a seal strength (hot seal strength) of, for example, 13.0 N or less when measured in a 100°C environment after being held in a 100°C environment for 1 minute. The hot seal strength may be 11.0 N or less, 10.0 N or less, 8.0 N or less, or 6.0 N or less. The hot seal strength of the sealed portion of a packaging material 70 containing only one biaxially oriented plastic film may be, for example, 3.0 N or more, 4.0 N or more, or 5.0 N or more.

[0231] The adhesive layer 78 contains an adhesive for bonding the biaxially oriented plastic film 73 and the sealant film 75 by dry lamination. An example of the adhesive for the adhesive layer 78 is polyurethane, as in the case of the first adhesive layer 76. In addition to the configuration, materials, and properties described below, the adhesive layer 78 can also adopt the same configuration, materials, and properties as the first adhesive layer 76.

[0232] The thickness of the adhesive layer 78 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the adhesive layer 78 is, for example, 6 μm or less, and may be 5 μm or less.

[0233] The thickness of the packaging material 70 including only one biaxially stretched plastic film is, for example, 70 μm or more, or may be 80 μm or more, or 90 μm or more. The thickness of the packaging material 70 including only one biaxially stretched plastic film is, for example, 110 μm or less, or may be 100 μm or less.

[0234] Pouch manufacturing method Next, a method for manufacturing a pouch 10 using the packaging material 70 will be described. First, a front film 15 and a back film 16 made of the packaging material 70 are prepared. Next, the inner surface of the front film 15 and the inner surface of the back film 16 are heat-sealed to form seal portions such as the top seal portion 11a, the first side seal portion 30, and the second side seal portion 50. The heat-sealing temperature is, for example, 160°C or higher, or may be 170°C or higher, or 180°C or higher. The heat-sealing temperature is, for example, 250°C or lower, or may be 240°C or lower, or may be 230°C or lower.

[0235] The front film 15 and the back film 16, which have been joined together by heat sealing, are cut into an appropriate shape. A perforation 47 is formed in the first non-sealed portion 45. This allows the pouch 10 shown in FIG. 1 to be obtained. The perforation 47 may be formed in the film before the inner surface of the front film 15 and the inner surface of the back film 16 are heat-sealed together. Next, the contents are filled into the pouch 10 through the opening 12b of the lower portion 12. The lower portion 12 is then heat-sealed along the lower edge 12x to form the lower seal portion 12a. In this way, the pouch 10 containing the contents 19 and sealed can be obtained, as shown in FIG. 4. The pouch 10 may then be subjected to a sterilization treatment such as boiling or retorting. The pouch 10 may be placed inside a carton 100.

[0236] Pouch heating method Next, a method for heating the above-mentioned pouch 10 will be described. First, the lid 102 of the carton 100 is opened. Next, the lid 102 is rotated toward the rear side of the main body 101. The pouch 10 contained in the carton 100 in this state is placed in a microwave oven. The pouch 10 is then heated using the microwave oven. The moisture contained in the contents 19 evaporates, increasing the pressure in the storage section 18.

[0237] As the pressure in the storage section 18 increases, the pouch 10 expands, for example, in a circular shape, centered on the center point C of the storage section 18. As a result, a force is applied to each position of the sealed section in a direction from the center point C toward the sealed section. The force applied to each position of the sealed section increases as the distance from the center point C decreases. The distance from the first intermediate section 35 to the center point C is shorter than the distance from the lower section 32 of the first side seal section 30 to the center point C and the distance from the lower section 52 of the second side seal section 50 to the center point C. As a result, a greater force is applied to, for example, the inner edge 35a of the first connecting section 38 of the first intermediate section 35 than to the inner edge 32a of the lower section 32 and the inner edge 52a of the lower section 52.

[0238] When a force is applied to the first intermediate portion 35, peeling of the first intermediate portion 35 progresses. When the peeling of the first intermediate portion 35 reaches the first unsealed portion 45, a flow path 35v is formed in the first intermediate portion 35, as shown in Fig. 24. Steam generated in the storage portion 18 flows into the first unsealed portion 45 through the flow path 35v. In Fig. 24, an example of a peeled portion that occurs in the first intermediate portion 35 is shown by a dotted line.

[0239] When steam generated in the storage section 18 is properly discharged to the outside of the pouch 10 through the flow path 35v and the first non-sealed section 45, the increase in pressure in the storage section 18 is suppressed. On the other hand, if steam is not properly discharged to the outside of the pouch 10, the pressure in the storage section 18 continues to increase. In this case, peeling may progress in seal sections other than the first intermediate section 35, such as the lower section 32 of the first side seal section 30 and the lower section 52 of the second side seal section 50. In particular, when the microwave output is high, the rate of steam generation in the storage section 18 is high, making peeling more likely to occur in seal sections other than the first intermediate section 35. If the pressure in the storage section 18 exceeds a certain value, the pouch 10 may burst. A high microwave output is, for example, 800 W or more, or may be 900 W or more, or may be 1000 W or more.

[0240] In this embodiment, a through-hole 47 is provided inside the outline of the first non-sealed portion 45. Therefore, steam that has flowed into the first non-sealed portion 45 is discharged to the outside not only through the opening edge portion 46 but also through the through-hole 47. This makes it possible to suppress an increase in pressure in the containing portion 18. Therefore, peeling can be suppressed in the sealed portion other than the first intermediate portion 35. Furthermore, rupture of the pouch 10 can be suppressed.

[0241] Furthermore, in this embodiment, the transition portion 373 of the second portion 37 of the first intermediate portion 35 is located higher than the upper edge 33c of the second intermediate portion 33. This increases the distance L19 between the upper edge 33c of the second intermediate portion 33 and the transition portion 373. This allows the steam that has flowed into the first unsealed portion 45 to smoothly reach the through portion 47 and the opening edge portion 46. This prevents an increase in pressure in the storage portion 18.

[0242] In this embodiment, the sealed portion of the pouch 10 has a hot seal strength of 10 N or less. This allows the flow path 35v to be formed in the first intermediate portion 35 before the pressure in the storage portion 18 becomes excessively high. This prevents peeling from occurring in the sealed portion other than the first intermediate portion 35. It also prevents the pouch 10 from bursting.

[0243] Furthermore, in this embodiment, the penetration portion 47 is located above the upper edge 33c of the second intermediate portion 33 of the first side seal portion 30. Therefore, even if the contents 19 splash up and enter the first unsealed portion 45, the contents 19 can be prevented from reaching the penetration portion 47. This prevents the contents 19 from leaking from the penetration portion 47.

[0244] 24, the progress of peeling of the first intermediate portion 35 in the second direction D2 may stop midway through the second portion 37. For example, the progress of peeling may stop at the transition portion 373 of the second portion 37. This can prevent the contents 19 from reaching the penetration portion 47, compared to when the second portion 37 is completely peeled off.

[0245] If the contents include a granular ingredient such as minced meat, the ingredient may scatter and block the flow path 35v. If the flow path 35v is blocked, the pressure in the storage section 18 continues to increase. In this embodiment, for example, the seal portion of the pouch 10 has a hot seal strength of 10 N or less. This ensures an appropriate width for the flow path 35v. This prevents the flow path 35v from being blocked by the contents 19. Furthermore, ingredients including minced meat, such as for keema curry, can be stored in the pouch 10.

[0246] Furthermore, in this embodiment, the first unsealed portion 45 extends to reach the first side edge 13x, making it easy to ensure the area of ​​the first unsealed portion 45. This reduces the distance L15 in the first direction D1 between the first side edge 13x and the inner edge 35a of the first intermediate portion 35. This increases the distance from the center point C to the inner edge 35a of the first intermediate portion 35. This prevents a large force from being applied to the first intermediate portion 35 when a force resulting from an impact, such as being dropped, is applied to the pouch 10. This prevents the first intermediate portion 35 from peeling off due to an impact, such as being dropped.

[0247] After heating the contents 19, the user tears the pouch 10 starting from the opening means 30a. The opening means 30a is arranged to overlap the lower second portion 371 of the first intermediate portion 35 when viewed along the first direction D1. Therefore, after heating the contents 19, the first intermediate portion 35 that overlaps the opening means 30a when viewed along the first direction D1 is peeled off. Therefore, the user can tear the pouch 10 without being hindered by the first intermediate portion 35.

[0248] It should be noted that various modifications can be made to the above-described embodiment. Below, modifications will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiment will be designated by the same reference numerals as those used for the corresponding parts in the above-described embodiment, and duplicated explanations will be omitted. Furthermore, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified embodiment, the explanations thereof may be omitted.

[0249] First Modification FIG. 25 is a front view showing a modified example of the steam release mechanism 25. As shown in FIG. 25, the through-hole 47 may include a hole that penetrates the front film 15 or the back film 16. The outline of the hole may be circular. Although not shown, the outline of the hole does not have to be circular. For example, the outline of the hole may be elliptical. For example, the outline of the hole may be polygonal with chamfered corners.

[0250] Reference symbol S11 denotes the dimension of the through-hole 47 in the first direction D1. Reference symbol S12 denotes the dimension of the through-hole 47 in the second direction D2. The dimensions S11 and S12 are, for example, 5 mm or more, or may be 6 mm or more, or 7 mm or more. This allows steam to be appropriately discharged from the through-hole 47. The dimensions S11 and S12 are, for example, 12 mm or less, or may be 10 mm or less, or 8 mm or less. This prevents the contents 19 from leaking from the through-hole 47.

[0251] Second Variant FIG. 26 is a front view showing a modified example of the steam vent mechanism 25. As shown in FIG. 26, the second portion 37 of the first intermediate portion 35 may include a lower second portion 371 and an upper second portion 372 having a width greater than that of the lower second portion 371. The upper second portion 372 may include one end connected to the lower second portion 371. The upper second portion 372 may include the other end connected to the upper seal portion 11a. The upper second portion 372 may include a portion whose width increases upward. In the example of FIG. 26, the upper second portion 372 can function as the peel-off suppression portion 37R.

[0252] Third Variant 27 is a front view showing a modified example of the steam release mechanism 25. The symbol d21 represents the distance in the second direction D2 between the lower second portion 371 of the second part 37 of the first intermediate portion 35 and the through-hole 47. The distance d21 is, for example, 1.0 mm or more, and may be 2.0 mm or more. The distance d21 is, for example, 5.0 mm or less, and may be 4.0 mm or less.

[0253] Fourth Variant FIG. 28 is a front view showing a modified example of the vapor release mechanism 25. As shown in FIG. 28, the transition portion 373 of the second portion 37 of the first intermediate portion 35 may include an inner edge 35a that extends in a different direction from the inner edge 35a of the lower second portion 371 and an outer edge 35b that extends in a different direction from the outer edge 35b of the lower second portion 371. The inner edge 35a of the transition portion 373 may extend in a different direction from the inner edge 35a of the upper second portion 372. The outer edge 35b of the transition portion 373 may extend in a different direction from the outer edge 35b of the upper second portion 372. In the example of FIG. 28, the transition portion 373 can function as the peeling prevention portion 37R.

[0254] 28, the lower second portion 371 of the second part 37 may be located below the second reference line SL2, and may be located below the upper edge 33c of the second intermediate portion 33. The transition portion 373 of the second part 37 may be located below the second reference line SL2, and may be located below the upper edge 33c of the second intermediate portion 33. As shown in FIG. 28, the upper edge 33c of the second intermediate portion 33 may be located above the second reference line SL2.

[0255] In Figure 28, the symbol L24 represents the distance in the second direction D2 from the middle position of the through-hole 47 in the second direction D2 to the upper edge of the first unsealed portion 45. In the example shown in Figure 28, the distance L24 also corresponds to the distance in the second direction D2 from the middle position of the through-hole 47 in the second direction D2 to the inner edge 11d of the upper seal portion 11a. The distance L24 is, for example, 3 mm or more, or may be 5 mm or more, or 7 mm or more. The distance L24 is, for example, 15 mm or less, or may be 12 mm or less, or may be 10 mm or less.

[0256] The distance L24 may be determined in relation to the dimension L11 of the first unsealed portion 45 in the second direction D2. The distance L24 is, for example, 0.08×L11 or more, or may be 0.12×L11 or more, or 0.16×L11 or more. The distance L24 is, for example, 0.40×L11 or less, or may be 0.35×L11 or less, or 0.30×L11 or less.

[0257] Second embodiment Next, a second embodiment will be described. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiment will be designated by the same reference numerals as those used for the corresponding parts in the above-described embodiment, and duplicated explanations will be omitted. Furthermore, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the second embodiment, the explanations may be omitted.

[0258] Fig. 29 is a front view showing a steam release mechanism 25 according to the second embodiment. As shown in Fig. 29, the second portion 37 of the first intermediate portion 35 may include an outer edge 35b extending linearly from the first connecting portion 38 to the upper edge of the first non-sealed portion 45, and an inner edge 35a extending parallel to the outer edge 35b.

[0259] In this embodiment, distance L16 refers to the distance in the first direction D1 from the inner edge 33a of the second intermediate portion 33 to the outer edge 35b of the second portion 37. Distance L17 refers to the distance in the first direction D1 from the opening edge 46 to the outer edge 35b of the second portion 37 at a position below the through portion 47. Distance L18 refers to the distance in the first direction D1 from the opening edge 46 to the outer edge 35b of the second portion 37 at a position above the through portion 47.

[0260] In this embodiment, as in the first embodiment, the penetration part 47 is located above the upper edge 33c of the second intermediate part 33 of the first side seal part 30. Therefore, even if the contents 19 splash up and enter the first unsealed part 45, the contents 19 can be prevented from reaching the penetration part 47. This prevents the contents 19 from leaking from the penetration part 47.

[0261] First Modification FIG. 30 is a front view showing a modified example of the steam vent mechanism 25. As shown in FIG. 30, the through-hole 47 may include a hole penetrating the front film 15 or the back film 16. The outline of the hole may be circular. Although not shown, the outline of the hole does not have to be circular. For example, the outline of the hole may be elliptical. For example, the outline of the hole may be polygonal with chamfered corners. The range of dimensions of the through-hole 47 can be the same as the range of values ​​in the case of the embodiment shown in FIG. 25.

[0262] Third embodiment Next, a third embodiment will be described. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiments will be designated by the same reference numerals as those used for the corresponding parts in the above-described embodiments, and duplicated descriptions will be omitted. Furthermore, if it is clear that the effects obtained in the above-described embodiments can also be obtained in the third embodiment, the description of those effects may be omitted.

[0263] FIG. 31 is a front view showing a steam release mechanism 25 according to a third embodiment. As shown in FIG. 31 , the first side seal portion 30 may have an upper portion 31, a lower portion 32, and a first intermediate portion 35. The upper portion 31 extends from the first non-seal portion 45 toward the upper portion 11 along the first side portion 13. The upper portion 31 may be connected to the upper seal portion 11a. The lower portion 32 extends from the first non-seal portion 45 toward the lower portion 12 of the pouch 10 along the first side portion 13. The first intermediate portion 35 is located between the storage portion 18 and the first non-seal portion 45. The first intermediate portion 35 may include a first end connected to the upper portion 31 and a second end connected to the lower portion 32.

[0264] The first intermediate portion 35 may include a first portion 36, a second portion 37, a first connecting portion 38, a third portion 39, and a second connecting portion 40. The first connecting portion 38 connects the first portion 36 and the second portion 37. The second connecting portion 40 connects the second portion 37 and the third portion 39.

[0265] The second connecting portion 40 is located closer to the upper portion 31. "Closer to the upper portion 31" means that the second connecting portion 40 is located closer to the upper portion 31 than the middle position of the first unsealed portion 45 in the second direction D2.

[0266] The third portion 39 extends from the second connecting portion 40 toward the first side portion 13. For example, the inner edge 35a and the outer edge 35b of the third portion 39 extend substantially in the first direction D1 toward the upper portion 31. The angle formed between the direction in which the inner edge 35a and the outer edge 35b extend and the first direction D1 is, for example, 10° or less. The third portion 39 may be connected to the inner edge 31a of the upper portion 31. The outer edge 35b of the third portion 39 may extend continuously with the lower edge 31d of the upper portion 31. For example, an extension line of the outer edge 35b of the third portion 39 may overlap the lower edge 31d of the upper portion 31.

[0267] In this embodiment, as in the first embodiment, the penetration part 47 is located above the upper edge 33c of the second intermediate part 33 of the first side seal part 30. Therefore, even if the contents 19 splash up and enter the first unsealed part 45, the contents 19 can be prevented from reaching the penetration part 47. This prevents the contents 19 from leaking from the penetration part 47.

[0268] Although not shown, the through-holes 47 may include holes that penetrate the front surface film 15 or the back surface film 16 .

[0269] Fourth embodiment Next, a fourth embodiment will be described. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiments will be designated by the same reference numerals as those used for the corresponding parts in the above-described embodiments, and duplicated descriptions will be omitted. Furthermore, if it is clear that the effects obtained in the above-described embodiments can also be obtained in the fourth embodiment, the description of those effects may be omitted.

[0270] Fig. 32 is a front view showing a pouch 10 according to the fourth embodiment. As shown in Fig. 32, the pouch 10 may be a gusset-type pouch that is configured to be self-standing.

[0271] In addition to the surface film 15 and the back film 16, the pouch 10 may also include a lower film 17 located in the lower portion 12. The lower film 17 is disposed between the surface film 15 and the back film 16 in a state where it is folded back along a folded portion 17f, for example.

[0272] The lower portion 12 of the pouch 10 includes a lower seal portion 12a. The lower seal portion 12a includes a portion where the inner surface of the front film 15 and the inner surface of the lower film 17 are joined, and a portion where the inner surface of the back film 16 and the inner surface of the lower film 17 are joined.

[0273] 31, in this embodiment, the first side seal portion 30 may include an upper portion 31. The first intermediate portion 35 may include a first end connected to the upper portion 31 and a second end connected to the lower portion 32.

[0274] In this embodiment, as in the first embodiment, the penetration part 47 is located above the upper edge 33c of the second intermediate part 33 of the first side seal part 30. Therefore, even if the contents 19 splash up and enter the first unsealed part 45, the contents 19 can be prevented from reaching the penetration part 47. This prevents the contents 19 from leaking from the penetration part 47. [Example]

[0275] Next, the present invention will be explained in more detail with reference to examples. However, the present invention is not limited to the following examples as long as it does not depart from the gist of the present invention.

[0276] (Packaging material 1) A 12 μm thick biaxially oriented PET film (product name "E5100", manufactured by Toyobo Co., Ltd.) was prepared as the first biaxially oriented plastic film. A printed layer was then formed on the inner surface of the first biaxially oriented plastic film. The thickness of the printed layer was 3.0 μm.

[0277] A 12 μm-thick biaxially oriented PET film (product name "E5100", manufactured by Toyobo Co., Ltd.) was prepared as the second biaxially oriented plastic film. One side of this film was then subjected to a corona discharge treatment, after which a 10 nm-thick transparent vapor-deposited layer of silicon oxide was formed. The transparent vapor-deposited layer was then subjected to a plasma treatment using a mixed gas of oxygen and argon, after which a coating liquid primarily composed of ethyl silicate and polyvinyl alcohol was applied using a gravure roll coater to form a transparent gas barrier coating film with a thickness of 300 nm after drying.

[0278] In addition, a 60 μm thick unstretched polypropylene film (product name "ZK500", manufactured by Toray Advanced Film Co., Ltd.) was prepared as a sealant film.

[0279] Then, a packaging material was produced by laminating a first biaxially oriented PET film, a printed layer, a first adhesive layer, a transparent barrier coating film, a transparent vapor deposition layer, a second biaxially oriented PET film, a second adhesive layer, and an unstretched polypropylene film in this order using a dry lamination method. A two-component polyurethane adhesive (main agent: RU-004, curing agent: H-1) manufactured by Rock Paint Co., Ltd. was used for the first and second adhesive layers. The thickness of the first and second adhesive layers was 3.0 μm. The packaging material obtained in this manner is also referred to as packaging material 1.

[0280] (Packaging material 2) A packaging material was produced in the same manner as packaging material 1, except that a 15 μm thick biaxially oriented nylon film (product name "Bonyl W", Kohjin Film & Chemicals Co., Ltd.) was used instead of a biaxially oriented PET film (product name "E5100", manufactured by Toyobo Co., Ltd.) as the second biaxially oriented plastic film. The packaging material obtained in this manner is also referred to as packaging material 2.

[0281] (Packaging material 3) A packaging material was produced in the same manner as packaging material 2, except that a 60 μm thick unstretched polypropylene film (product name "ZK207", manufactured by Toray Advanced Film Co., Ltd.) was used instead of an unstretched polypropylene film (product name "ZK500", manufactured by Toray Advanced Film Co., Ltd.) as the sealant film. The packaging material obtained in this manner is also referred to as packaging material 3.

[0282] (Packaging material 4) A high-stiffness polyester film (hereinafter also referred to as high-stiffness PET film) having a loop stiffness of 0.0017 N or more and containing 90% by mass or more of PET was prepared as a biaxially stretched plastic film. Specifically, XP-55 manufactured by Toray Industries, Inc. was used as the high-stiffness PET film. The thickness of the high-stiffness PET film was 16 μm.

[0283] Next, one side of the high-stiffness PET film was subjected to a corona discharge treatment, and then a transparent vapor deposition layer, a transparent gas barrier coating film, and a printed layer were formed in the same manner as in the case of packaging material 1. In addition, a 60 μm-thick unstretched polypropylene film (product name "ZK500", manufactured by Toray Advanced Film Co., Ltd.) was prepared as a sealant film.

[0284] Then, a high-stiffness PET film, a transparent vapor deposition layer, a transparent barrier coating film, a printed layer, an adhesive layer, and an unstretched polypropylene film were laminated in this order by dry lamination to produce a packaging material. A two-component polyurethane adhesive (main agent: RU-004, curing agent: H-1) manufactured by Rock Paint Co., Ltd. was used as the adhesive layer. The thickness of the adhesive layer was 3.0 μm. The packaging material obtained in this manner is also referred to as packaging material 4.

[0285] (Evaluation of packaging materials 1 to 4) The pouch 10 shown in Fig. 1 was made using packaging materials 1 to 4. 200 ml of water was filled inside the pouch 10. The heat sealing conditions were as follows: Heat sealing device: Heat sealer TP-701-A (Tester Sangyosha Co., Ltd.) Heat sealing temperature: 225℃ Heat sealing pressure: 0.1MPa Heat sealing time: 1 second

[0286] Next, the pouch 10 was subjected to a retort treatment under the following conditions. Method: Spray type Retort temperature: 121°C Retort time: 30 minutes

[0287] The dimensions of each part of the pouch 10 are as follows: Dimensions of storage compartment 18 H1: 110mm Storage compartment 18 dimensions H2: 159mm Width of upper seal part 11a, width of lower seal part 12a: 8mm The minimum and maximum width W12 of the lower part 32: 6mm and 10mm The minimum and maximum width W22 of the lower part 52: 6mm and 10mm

[0288] The breaking strength (hot breaking strength) in the machine direction and perpendicular direction was measured using test pieces 90A and 90B cut out from pouch 10 composed of packaging material 1 and packaging material 2. The measurement method and conditions were the same as those in the above-mentioned embodiment. The results are shown in Figure 33.

[0289] The Young's modulus in the machine direction and perpendicular direction was measured using test pieces 90A and 90B cut out from a pouch 10 made of packaging material 4. The measurement method and conditions were the same as those in the above-described embodiment. The results are shown in FIG.

[0290] The puncture strength of packaging material 4 was measured in accordance with JIS Z1707 7.4 using test pieces cut from pouches 10 made of packaging material 4. A Tensilon universal testing machine RTC-1310 manufactured by A&D was used as the measuring instrument. Specifically, a semicircular needle with a diameter of 1.0 mm and a tip radius of 0.5 mm was pierced from the outer surface 70°C of the test piece of packaging material 4 at a speed of 50 mm / min (50 mm per minute). The maximum stress until the needle penetrated packaging material 4 was measured. The maximum stress was measured for five or more test pieces, and the average value was used as the puncture strength of packaging material 4. The measurement was performed in an environment of 23°C and 50% relative humidity. The results are shown in Figure 34.

[0291] The hot seal strength was measured using test piece 90C cut out from pouch 10 made of packaging material 1 to packaging material 4. The measurement method and conditions were the same as those in the above-mentioned embodiment. The results are shown in Figures 33 and 34.

[0292] Example 1 Content 1 was prepared as the content to be filled into pouch 10. Content 1 was 180 g of curry. The results of analyzing the ingredients contained in content 1 are shown in FIG.

[0293] In the analysis, first, the curry roux was removed from the contents using a sieve. The sieve had 0.7 mm openings. Next, the ingredients contained in contents 1 and 2 were observed using a microscope. The microscope used was a Keyence VHX-6000. The microscope lens used was a Keyence VH-ZST. The observation magnification was 20x.

[0294] The viscosity of the curry roux in Content 1 was measured. The results are shown in Figure 36. The viscosity was measured using a digital viscometer DV-E manufactured by Eiko Seiki.

[0295] The pouch 10 shown in Fig. 1 was produced using the packaging material 1. The components of the steam venting mechanism 25 of the pouch 10 in Fig. 1 have the dimensions shown in Fig. 9. The pouch 10 was then filled with the above-described contents 1. The bottom 12 of the pouch 10 was then heat-sealed to form a bottom seal portion 12a. In this way, the pouch 10 shown in Fig. 4 containing the contents 1 was obtained.

[0296] The dimensions of each part of the pouch 10 are as follows: Dimensions of storage compartment 18 H1: 110mm Storage compartment 18 dimensions H2: 159mm Width of upper seal part 11a, width of lower seal part 12a: 8mm The minimum and maximum width W12 of the lower part 32: 6mm and 12mm The minimum and maximum width W22 of the lower part 52: 6mm and 12mm Width of the first portion 36 and the lower second portion 371 of the first intermediate portion 35: 3 mm Width of the upper second portion 372 of the first intermediate portion 35: 6 mm Dimension L11 of the first unsealed portion 45: 39 mm Dimension of opening edge 46 L12: 22mm Dimension L13 of the second intermediate portion 33: 17 mm Maximum distance L15 between the first side edge 13x and the inner edge 35a of the first intermediate portion 35: 21 mm Distance L16 between the inner edge 33a of the second intermediate portion 33 and the outer edge 35b of the lower second portion 371: 12 mm Distance L17 between the opening edge 46 and the outer edge 35b of the lower second portion 371: 27 mm Distance L18 between the opening edge 46 and the outer edge 35b of the upper second portion 372: 15 mm Distance L19 between the transition portion 373 and the second intermediate portion 33: 15 mm Distance L21 from the lower edge of the first non-sealed portion 45 to the transition portion 373: 24.1 mm Distance L22 from the upper edge of the first non-sealed portion 45 to the transition portion 373: 10.3 mm Dimension L23 of transition part 373: 4.6mm Distance L24 from the middle position of the through-hole 47 to the upper edge of the first unsealed portion 45: 11 mm Diameter of the penetration 47: 6mm

[0297] The heat sealing conditions are as follows: Heat sealing device: Heat sealer TP-701-A (Tester Sangyosha Co., Ltd.) Heat sealing temperature: 225℃ Heat sealing pressure: 0.1MPa Heat sealing time: 1 second

[0298] Next, the pouch 10 was subjected to a retort treatment under the following conditions. Method: Spray type Retort temperature: 121°C Retort time: 30 minutes

[0299] Subsequently, the moisture on the surface of the pouch 10 was wiped off, and the pouch 10 was left to stand for one day. Thereafter, the pouch 10 was placed in a carton 100.

[0300] The carton 100 was then opened and placed in a microwave oven so that the pouch 10 was tilted at an angle θa relative to a horizontal plane 120, which is the bottom surface of the interior of the microwave, as shown in Figure 5. The angle θa was 17°.

[0301] The pouch 10 containing the content 1 was heated for 125 seconds in a microwave oven with an output of 1000 W. The microwave oven used was a Sharp RE-SX50.

[0302] After heating, each pouch 10 was checked for peeling at the lower portion 32 or the lower portion 52. The results are shown in the "Seal Recession" column of Figure 37. In the "Seal Recession" column, "great" means that the width of the peeling that occurred at the lower portion 32 or the lower portion 52 in the first direction D1 was less than 1 mm, or no peeling occurred. "Good" means that the width of the peeling that occurred at the lower portion 32 or the lower portion 52 in the first direction D1 was 1 mm or more and less than 2 mm. "Not good" means that the width of the peeling that occurred at the lower portion 32 or the lower portion 52 in the first direction D1 was 2 mm or more.

[0303] 38, the peeled portion of the first intermediate portion 35 is indicated by a dotted line. As shown in FIG. 38, the progress of the peeling that occurred in the second portion 37 stopped at the transition portion 373.

[0304] It was checked whether the contents had spilled out of the pouch 10. The results are shown in the "Stains on the Penetration Part," "Stains on the Box," and "Stains on the Microwave" columns in Figure 37. The "Stains on the Penetration Part" column shows the results of checking whether the contents had adhered around the penetration part 47. The "Stains on the Box" column shows the results of checking whether the contents that had spilled out of the pouch 10 had adhered to the box. The "Stains on the Microwave" column shows the results of checking whether the contents that had spilled out of the pouch 10 had adhered to the microwave. "Great" means that almost no adhesion of the contents was confirmed. "Good" means that the amount of contents that had spilled out was small enough to be wiped up with one tissue. "Not good" means that two or more tissues were required to wipe up the spilled contents.

[0305] Example 2 The pouch 10 shown in Fig. 28 was produced using the packaging material 1. The heat sealing conditions and retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Width of the upper second portion 372 of the first intermediate portion 35: 3 mm Dimension of opening edge 46 L12: 15mm Dimension L13 of the second intermediate portion 33: 24 mm Distance L21 from the lower edge of the first non-sealed portion 45 to the transition portion 373: 15 mm Distance L22 from the upper edge of the first non-sealed portion 45 to the transition portion 373: 21 mm Dimensions of transition section 373 L23: 3mm Distance L24 from the middle position of the through-hole 47 to the upper edge of the first unsealed portion 45: 7.5 mm

[0306] As in Example 1, "seal recession," "penetration staining," "box staining," and "range staining" were evaluated. The results are shown in Figure 37. The peeled portion of the first intermediate portion 35 is shown by a dotted line in Figure 39. As shown in Figure 39, the progression of the peeling that occurred in the second portion 37 stopped at the transition portion 373.

[0307] Example 3 The pouch 10 shown in Fig. 29 was produced using the packaging material 1. The heat sealing conditions and retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Width of the second part 37 of the first intermediate part 35: 3 mm Dimension of opening edge 46 L12: 15mm Dimension L13 of the second intermediate portion 33: 24 mm Distance L16 between the inner edge 33a of the second intermediate portion 33 and the outer edge 35b of the second portion 37: 12 mm Distance L18 between the opening edge 46 and the outer edge 35b of the second portion 37: 18 mm Distance L24 from the middle position of the through-hole 47 to the upper edge of the first unsealed portion 45: 7.5 mm

[0308] As in Example 1, "seal recession," "penetration staining," "box staining," and "range staining" were evaluated. The results are shown in Figure 37. The peeled portion of first intermediate portion 35 is shown by a dotted line in Figure 40. As shown in Figure 40, the progress of peeling that occurred in second portion 37 stopped midway through second portion 37.

[0309] Example 4 The pouch 10 shown in Fig. 30 was produced using the packaging material 1. The heat sealing conditions and retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Width of the second part 37 of the first intermediate part 35: 3 mm Dimension of opening edge 46 L12: 15mm Dimension L13 of the second intermediate portion 33: 24 mm Distance L16 between the inner edge 33a of the second intermediate portion 33 and the outer edge 35b of the second portion 37: 12 mm Distance L18 between the opening edge 46 and the outer edge 35b of the second portion 37: 18 mm Distance L24 from the middle position of the through-hole 47 to the upper edge of the first unsealed portion 45: 7.5 mm

[0310] As in Example 1, "seal recession," "penetration staining," "box staining," and "range staining" were evaluated. The results are shown in Figure 37. The peeled portion of first intermediate portion 35 is shown by a dotted line in Figure 41. As shown in Figure 41, the progress of peeling that occurred in second portion 37 stopped midway through second portion 37.

[0311] Example 5 The pouch 10 shown in Fig. 31 was produced using the packaging material 1. The heat sealing conditions and retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Width of the second part 37 of the first intermediate part 35: 3 mm Dimension L11 of the first unsealed portion 45: 30 mm Dimension of opening edge 46 L12: 15mm Dimension L13 of the second intermediate portion 33: 15 mm Distance L16 between the inner edge 33a of the second intermediate portion 33 and the outer edge 35b of the second portion 37: 12 mm Distance L18 between the opening edge 46 and the outer edge 35b of the second portion 37: 18 mm Distance L24 from the middle position of the through-hole 47 to the upper edge of the first unsealed portion 45: 16.5 mm

[0312] As in Example 1, "seal recession," "penetration staining," "box staining," and "range staining" were evaluated. The results are shown in Figure 37. The peeled portion of the first intermediate portion 35 is shown by a dotted line in Figure 42. As shown in Figure 42, the progression of the peeling that occurred in the first intermediate portion 35 stopped at the second connecting portion 40.

[0313] (Comparative Example 1) A pouch 10 was produced using packaging material 1. The pouch of Comparative Example 1 does not have a perforation portion 47. The other configurations of the pouch of Comparative Example 1 are the same as those of pouch 10 of Example 3. The heat sealing conditions and retort treatment conditions are the same as those of Example 1.

[0314] As in Example 1, "seal recession," "penetration staining," "box staining," and "range staining" were evaluated. The results are shown in Figure 37. The peeled portion of the first intermediate portion 35 is shown by a dotted line in Figure 43. As shown in Figure 43, the peeling that occurred in the second portion 37 progressed further upward than in Example 3. [Explanation of symbols]

[0315] 10 pouches 11 Upper 11a Upper seal part 12 Lower 12a Lower seal 13 First side 13x 1st side edge 14 Second side 14x 2nd side edge 15 Surface film 16 Back film 17 Lower film 18 Storage section 19 Contents 19a Top side 25 Steam release mechanism 30 First side seal 31 Upper part 32 Lower part 33 Second intermediate part 33a Inner rim 33c upper edge 35 1st intermediate part 35a Inner edge 35b outer edge 36 Part 1 37 Part 2 371 Lower 2nd part 372 Upper 2nd part 373 Transition part 38 1st connection part 39 Part 3 40 Second connection part 45 First unsealed part 46 Opening edge 47 Penetration 50 Second side seal 51 Upper part 52 Lower part 55 Middle part 65 Second unsealed part 66 Opening edge 70 Packaging materials 70x inner surface 70y external surface 71 First biaxially stretched plastic film 72 Second biaxially oriented plastic film 75 Sealant Film 76 First adhesive layer 77 Second adhesive layer 81 Printing layer 82 Transparent vapor deposition layer 83 Transparent gas barrier coating film

Claims

1. A pouch in which a storage section for storing contents is defined between a surface film and a back film, a first side seal portion located on a first side of the pouch and joining an inner surface of the front film and an inner surface of the back film; a second side seal portion located on a second side portion opposite the first side portion of the pouch in a first direction, the second side seal portion defining the containing portion between the first side seal portion and the second side seal portion; a first unsealed portion located toward an upper portion of the pouch and separated from the containing portion by the first side seal, the first unsealed portion extending to at least partially reach a first side edge of the first side of the pouch; a through-hole located inside the contour of the first non-sealed portion and penetrating at least one of the front surface film and the back surface film, the first side seal portion has a lower portion extending along the first side edge from the first non-seal portion toward a lower portion of the pouch, a first intermediate portion located between the containing portion and the first non-seal portion and connected to the lower portion, and a second intermediate portion located between the first non-seal portion and the first side edge and connected to the lower portion, the first intermediate portion includes a first portion, a second portion, and a first connecting portion connecting the first portion and the second portion; the first portion extends from the first connecting portion toward the first side of the pouch; the second portion extends from the first connecting portion toward the top of the pouch; the width of the second intermediate portion is smaller than the width of the lower portion; The through portion is located closer to the first side portion than a first reference line (SL1), The first reference line (SL1) is a straight line that passes through the first intersection point (EP1) and extends in a second direction perpendicular to the first direction, The first intersection (EP1) is an intersection of a line (EL11) and a line (EL12), The line (EL11) is an extension of the inner edge of the lower portion, The line (EL12) is an extension of the inner edge of the first portion, the through portion is located above the second intermediate portion, The pouch, wherein the second portion includes a lower second portion and an upper second portion located above the lower second portion and having a width greater than that of the lower second portion.

2. the second portion further includes a transition portion located between the lower second portion and the upper second portion; 2. The pouch of claim 1, wherein the transition portion includes an inner edge that extends in a different direction than an inner edge of the lower second portion or an outer edge that extends in a different direction than an outer edge of the lower second portion.

3. The pouch according to claim 1, wherein the through-hole is located above the second lower portion.

4. The pouch according to any one of claims 1 to 3, wherein the upper second portion is positioned higher than the second intermediate portion.

5. The pouch according to any one of claims 1 to 4, wherein the through portion is located closer to the first side portion than the first portion of the first intermediate portion.

6. an upper seal portion located at the upper portion of the pouch and joining an inner surface of the front film and an inner surface of the back film; The pouch of any one of claims 1 to 5, wherein the first intermediate portion is connected to the top seal portion.

7. the first side seal has an upper portion extending along the first side edge from the first non-seal portion toward the top of the pouch; The pouch of any one of claims 1 to 5, wherein the first middle portion is connected to the upper portion of the first side seal.

8. The pouch according to any one of claims 1 to 7, wherein the through portion is located above a middle position of the first unsealed portion in a second direction perpendicular to the first direction.

9. The pouch according to any one of claims 1 to 8, wherein a maximum value (L15) of the distance in the first direction between the first side edge and the inner edge of the first intermediate portion is 24 mm or less.

10. 10. The pouch of claim 9, wherein the ratio of the maximum value (L15) to the dimension of the containing portion in the first direction is 0.24 or less.

11. a seal portion joining the inner surface of the front film and the inner surface of the back film has a hot seal strength of 10 N or less; The pouch according to any one of claims 1 to 10, wherein the hot seal strength is a seal strength measured in an environment of 100°C after a test piece including the sealed portion is kept in an environment of 100°C for 1 minute.

12. The packaging material constituting the front surface film and the back surface film includes a first biaxially oriented plastic film, a second biaxially oriented plastic film, and a sealant film in this order; 12. The pouch according to claim 1, wherein the packaging material contains only two biaxially oriented plastic films.

13. 13. The pouch according to claim 12, wherein the packaging material has a breaking strength in one direction of 33.0 MPa or more when measured in an environment at 100°C after being held in an environment at 100°C for 1 minute.

14. the first biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film; 14. The pouch of claim 12 or 13, wherein the second biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film or a biaxially oriented nylon film.

15. the packaging material further comprises a transparent vapor deposition layer located between the first biaxially oriented plastic film and the second biaxially oriented plastic film; The pouch of any one of claims 12 to 14, wherein the transparent vapor deposition layer comprises a metal oxide or an inorganic oxide.

16. The packaging material constituting the front surface film and the back surface film includes a biaxially oriented plastic film and a sealant film in this order, The pouch according to any one of claims 1 to 11, wherein the packaging material contains only one biaxially oriented plastic film.

17. 17. The pouch of claim 16, wherein the packaging material has a Young's modulus in one direction of 3600 MPa or more.

18. The packaging material further comprises a transparent vapor deposition layer provided on a surface of the biaxially stretched plastic film, 18. The pouch of claim 16 or 17, wherein the transparent vapor deposition layer comprises a metal oxide or an inorganic oxide.

19. 19. The pouch according to claim 15 or 18, wherein the packaging material further comprises a transparent gas barrier coating film located on a surface of the transparent vapor deposition layer.

20. The pouch according to any one of claims 12 to 19, wherein the sealant film comprises a propylene-ethylene block copolymer and an elastomer.

21. The storage portion of the pouch contains a content including meat, The pouch is heated in a microwave oven. The pouch according to any one of claims 1 to 20.

22. 22. The pouch of claim 21, wherein the contents include 50 or more pieces of meat having a dimension of 3 mm or greater.

23. 23. The pouch according to claim 21 or 22, wherein the number of pieces of meat having a dimension of 3 mm or more divided by the weight of the contents is 0.3 pieces / g or more.

24. The filling comprises ingredients including the meat and a viscous component, The ratio of the weight of the ingredients to the weight of the contents is 8% or more, The pouch according to any one of claims 21 to 23, wherein the ratio of the weight of the meat to the weight of the filling is 20% or more.

25. The pouch according to any one of claims 21 to 24, wherein when the pouch is tilted at an angle of 17° relative to a horizontal plane, the distance between the upper surface of the content and the first intermediate portion of the first side seal portion is 5 mm or more and 30 mm or less.

Images