Pouch

Abstract

To provide a pouch capable of appropriately discharging steam generated in a storage part to the outside of the pouch.SOLUTION: A pouch comprises: a first side part seal portion positioned in a first side part of the pouch and connecting an inner surface of a front face film and an inner surface of a rear face film; a second side part seal portion positioned in a second side part facing the first side part of the pouch in a first direction, and defining a storage part between the first side part seal portion and itself; a first non-seal portion separated from the storage part by the first side part seal portion, and expanding so as to reach a first side edge of the first side part of the pouch; and a second non-seal portion separated from the storage part by the second side part seal portion, and expanding so as to reach a second side edge of the second side part of the pouch. The first non-seal portion expands to a position at a side of the second side part from an inner edge of a first lower seal portion of the first side part seal portion. The second non-seal portion expands to a position at a side of the first side part from an inner edge of a second lower seal portion of the second side part seal 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 are 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 in which the contents are stored. Also, 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 contained in the pouch.

[0003] When the contents contained in a sealed pouch are heated in a microwave oven, the moisture contained in the contents evaporates as the contents are heated, and the pressure in the storage section increases. If the pressure in the storage section of the pouch increases, the pouch may burst, scattering the contents and soiling the microwave oven. In consideration of such a problem, for example, Patent Document 1 proposes providing the pouch with a steam release mechanism that automatically connects the storage section to the outside when the pressure in the storage section increases, and releases steam in the storage section to the outside. In Patent Document 1, the steam release mechanism has an intermediate seal section located between the upper side seal section and the lower side seal section of the pouch, and a non-seal section that is isolated from the storage section by the intermediate seal section and extends to reach the side edge of the pouch. If the pressure in the storage section increases, the intermediate seal section peels off, and the storage section and the non-seal section communicate with each other. [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 containment section is exhausted through the peeled mid-seal and out the side edges of the pouch, and improper steam exhaust can cause the pouch to burst or the side seals of the pouch to peel.

[0006] An object of the present invention is to provide a pouch that can effectively solve such 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 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 and 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 receiving portion by the first side seal portion, the first unsealed portion extending to a first edge of the first side of the pouch; a second unsealed portion located toward an upper portion of the pouch and separated from the receiving portion by the second side seal portion, the second unsealed portion extending to a second edge of the second side of the pouch; the first side seal portion includes a first bottom seal portion extending along the first side from the first non-seal portion toward a bottom of the pouch; the first unsealed portion extends to a position on the second side portion beyond an inner edge of the first lower seal portion, the second side seal portion includes a second bottom seal portion extending along the second side from the second non-seal portion toward a bottom of the pouch; The second unsealed portion is a pouch that extends beyond an inner edge of the second lower seal portion to a position toward the first side.

[0008] In the pouch according to the present invention, the first side seal portion includes a first upper seal portion extending from the first non-seal portion toward an upper portion of the pouch along the first side portion, the first lower seal portion, and a first intermediate seal portion having one end connected to the first upper seal portion and the other end connected to the first lower seal portion and positioned between the containing portion and the first non-seal portion, and the first non-seal portion extends beyond an inner edge of the first upper seal portion to a position on the second side portion side. the second side seal portion has a second upper seal portion extending along the second side from the second non-sealed portion toward an upper portion of the pouch, the second lower seal portion, and a second intermediate seal portion having one end connected to the second upper seal portion and the other end connected to the second lower seal portion and positioned between the containing portion and the second non-sealed portion, and the second non-sealed portion may extend to a position closer to the first side than an inner edge of the second upper seal portion.

[0009] In the pouch according to the present invention, the first side seal portion has a first upper seal portion extending along the first side from the first non-sealed portion toward the top of the pouch, the first lower seal portion, and a first intermediate seal portion having one end connected to the first upper seal portion and the other end connected to the first lower seal portion, and positioned between the containing portion and the first non-sealed portion, and a maximum distance (L12) in the first direction between an inner edge of the first lower seal portion and an inner edge of the first intermediate seal portion may be 15 mm or less.

[0010] In the pouch according to the present invention, a ratio of the maximum value (L12) to a dimension of the storage portion in the first direction may be 0.10 or less.

[0011] In the pouch according to the present invention, the first non-sealed portion overlaps the first side edge and has a first opening edge portion that is open to the outside, and an extension of a straight line connecting a center point of the containing portion and the first non-sealed portion in the shortest distance may intersect with the first opening edge portion.

[0012] In the pouch according to the present invention, the 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, and the hot seal strength may be a seal strength measured in an environment of 100°C after a test piece including the seal portion is kept in an environment of 100°C for 1 minute.

[0013] In the pouch according to the present invention, the packaging material constituting the front film and the back film comprises a first biaxially oriented plastic film, a second biaxially oriented plastic film, and a sealant film in that order, and there may be only two biaxially oriented plastic films in the packaging material.

[0014] 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 of 100°C after being held in an environment of 100°C for 1 minute.

[0015] In the pouch according to the present invention, the first biaxially oriented plastic film may be a biaxially oriented polyethylene terephthalate film, and the second biaxially oriented plastic film may be a biaxially oriented polyethylene terephthalate film or a biaxially oriented nylon film.

[0016] 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, and the transparent vapor deposition layer may comprise a metal oxide or an inorganic oxide.

[0017] In the pouch according to the present invention, the packaging material constituting the front film and the back film comprises a biaxially oriented plastic film and a sealant film in this order, and the packaging material may contain only one biaxially oriented plastic film.

[0018] 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.

[0019] In the pouch according to the present invention, the packaging material may further comprise a transparent vapor deposition layer provided on a surface of the biaxially oriented plastic film, and the transparent vapor deposition layer may contain a metal oxide or an inorganic oxide.

[0020] In the pouch according to the present invention, the packaging material may further comprise a transparent gas barrier coating film located on a surface of the transparent vapor deposition layer.

[0021] In the pouch according to the present invention, the sealant film may contain a propylene-ethylene block copolymer and an elastomer.

[0022] In the pouch according to the present invention, the compartment of the pouch contains a content including meat, and the pouch may be heated in a microwave oven.

[0023] In the pouch according to the present invention, the contents may include 50 or more pieces of meat having a maximum dimension of 3 mm or more.

[0024] In the pouch according to the present invention, the number of the pieces of meat having a maximum dimension of 3 mm or more divided by the weight of the contents may be 0.3 pieces / g or more.

[0025] In the pouch according to the present invention, the contents may comprise ingredients including the meat and a viscous component, and the ratio of the weight of the ingredients to the weight of the contents may be 8% or more, and the ratio of the weight of the meat to the weight of the ingredients may be 20% or more.

[0026] In the pouch according to the present invention, the first side seal portion has a first upper seal portion extending along the first side from the first non-sealed portion toward the top of the pouch, the first lower seal portion, and a first intermediate seal portion having one end connected to the first upper seal portion and the other end connected to the first lower seal portion and positioned between the storage portion and the first non-sealed portion, and when the pouch is tilted at 17° with respect to a horizontal plane, the distance between the top surface of the contents and the first intermediate seal portion may be 5 mm or more and 30 mm or less. Effect of the Invention

[0027] According to the present invention, steam generated in the storage section can be appropriately discharged to the outside of the pouch. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a front view showing a pouch according to an embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view showing an example of the pouch shown in FIG. 1 when viewed along line AA. [Diagram 3] FIG. 2 is a front view showing the pouch containing the contents. [Figure 4] FIG. 2 is a cross-sectional view showing an example of the state of a pouch when heated in a microwave oven. [Diagram 5] 2 is an enlarged front view showing a first intermediate seal portion and a first non-sealed portion of a first side seal portion of the pouch. FIG. [Figure 6] 13 is an enlarged front view showing a second intermediate seal portion and a second unsealed portion of the second side seal portion of the pouch. FIG. [Figure 7] FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 8A] FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 8B] FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 9] FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 10] FIG. 1 illustrates an example of a method for preparing a test strip. [Figure 11] FIG. 2 is a diagram for explaining a method for measuring hot rupture strength. [Figure 12] FIG. 1 illustrates an example of a method for preparing a test strip. [Figure 13A] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 13B] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 14] FIG. 2 is a plan view showing an example of a loop stiffness measuring device. [Figure 15] FIG. 15 is a cross-sectional view taken along line CC of the loop stiffness measuring device of FIG. 14. [Figure 16] FIG. 1 is a diagram for explaining a process of attaching a test piece to a loop stiffness measuring device. [Figure 17] FIG. 13 is a diagram for explaining a step of forming a loop portion in a test piece. [Figure 18] FIG. 13 is a diagram for explaining a process of applying a load to a loop portion of a test piece. [Figure 19] FIG. 13 is a diagram for explaining a process of applying a load to a loop portion of a test piece. [Figure 20] 13 is a view showing a state in which the first intermediate seal portion of the first side seal portion is peeled off and the containing portion communicates with the first unsealed portion. FIG. [Figure 21] FIG. 13 is a front view showing a modified example of the pouch. [Figure 22] FIG. 13 is a front view showing a modified example of the pouch. [Figure 23] 23 is an enlarged front view of the first middle seal portion and the first non-sealed portion of the first side seal of the pouch of FIG. 22. FIG. [Figure 24] FIG. 13 is a front view showing a modified example of the pouch. [Diagram 25] FIG. 1 is a diagram showing the evaluation results of packaging materials 1 to 3 of the examples. [Figure 26] FIG. 1 is a diagram showing the evaluation results of packaging material 4 of an example. [Figure 27]FIG. 1 shows the results for contents 1 and 2 of the embodiment. [Figure 28] FIG. 1 shows the results for Content 1 of the Example. [Figure 29] FIG. 1 shows the results for contents 1 and 2 of the embodiment. [Diagram 30] FIG. 1 is a diagram showing the evaluation results of pouches of Examples and Comparative Examples. [Diagram 31] FIG. 1 is a diagram showing the evaluation results of pouches of Examples and Comparative Examples. [Diagram 32] FIG. 2 is a front view showing the pouches of Comparative Examples 1 and 2. [Diagram 33] FIG. 11 is a front view showing the pouch of Comparative Example 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] 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 convenience of illustration and understanding.

[0030] In addition, terms used in this specification that specify shapes, geometric conditions, and the extent thereof, such as "parallel," "orthogonal," and "same," as well as values ​​of length and angle, are not bound by strict meanings and are interpreted to include a range within which similar functions can be expected.

[0031] In this specification, when two or more upper limit candidates and two or more lower limit candidates are given for a certain parameter, the numerical range of the parameter may be constructed by combining any one of the upper limit candidates and any one of the lower limit candidates. For example, consider a case where "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.

[0032] Pouch Fig. 1 is a front view showing a pouch 10 according to the present embodiment as viewed from the front side. The pouch 10 includes a storage section 18 for storing contents. Note that Fig. 1 shows the pouch 10 in a state in which no contents are stored therein. The configuration of the pouch 10 will be described below.

[0033] 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. Names such as "upper portion," "lower portion," and "side portion," as well as terms such as "upper" and "lower portion," merely represent the relative positions and directions of pouch 10 and its components when the lower portion is defined as the side that can be located below when pouch 10 is heated. The position of pouch 10 is not limited by the names and terms used in this specification.

[0034] The pouch 10 includes a surface film 15 that constitutes the surface, and a back film 16 that constitutes the back. Each film is made of a packaging material including at least one biaxially oriented plastic film and a sealant film.

[0035] The terms "front film" and "back 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 the pouch 10. For example, the pouch 10 may be manufactured using one film in which the front film 15 and the back film 16 are continuously provided, or may be manufactured using a total of two films, one front film 15 and one back film 16.

[0036] The inner surfaces of the front film 15 and the back film 16 are joined together by a seal portion. In a front view of the pouch 10 such as Fig. 1, the seal portion is hatched. The space defined by the seal portion, the front film 15, and the back film 16 can function as a storage portion 18 for storing contents.

[0037] As long as the opposing films can be joined together, the method for forming the seal portion is not particularly limited. For example, the seal portion may be formed by melting the inner surfaces of the films by heating or the like and fusing the inner surfaces together, i.e., by heat sealing. Alternatively, the seal portion may be formed by bonding the inner surfaces of the opposing films together using an adhesive or the like.

[0038] As shown in FIG. 1, the sealed portion of the pouch 10 has a first side sealed portion 30, a second side sealed portion 35, and an upper sealed portion 11a. The first side sealed portion 30 is located on the first side 13 of the pouch 10. The second side sealed portion 35 is located on the second side 14. The second side 14 faces the first side 13 in the first direction D1. The upper sealed portion 11a is located on the upper portion 11. The upper sealed portion 11a is connected to the first side sealed portion 30 and the second side sealed portion 35. The non-sealed portion surrounded by the first side sealed portion 30, the second side sealed portion 35, and the upper sealed portion 11a functions as a storage portion 18 that stores the contents.

[0039] In a pouch 10 before it is filled with contents (a state in which no contents are contained), the lower part 12 of the pouch 10 has an opening 12b as shown in Fig. 1. 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.

[0040] In addition to the unsealed portion that functions as the storage portion 18, the pouch 10 further includes a first unsealed portion 40 and a second unsealed portion 45 as shown in FIG. 1. The first unsealed portion 40 is separated from the storage portion 18 by the first side seal portion 30. The second unsealed portion 45 is separated from the storage portion 18 by the second side seal portion 35. The unsealed portion is a portion where a film exists in which the opposing inner surfaces are not joined to each other. The first unsealed portion 40 and the second unsealed portion 45 are located closer to the upper portion 11 of the pouch 10. "More toward the upper portion 11" means that the first unsealed portion 40 and the second unsealed portion 45 are located on the upper portion 11 side of the center point C of the storage portion 18.

[0041] 1, the first unsealed portion 40 expands to reach the first side edge 13x of the first side portion 13 of the pouch 10. In other words, the first unsealed portion 40 overlaps the first side edge 13x and has a first opening edge portion 41 that opens to the outside. Steam that is generated in the storage portion 18 and flows into the first unsealed portion 40 can be discharged to the outside from the first opening edge portion 41.

[0042] 1, an extension of the first imaginary straight line M1 may intersect with the first opening edge portion 41. The first imaginary straight line M1 is a straight line that connects the center point C of the storage portion 18 and the first non-sealed portion 40 at the shortest distance as shown in FIG.

[0043] The first side seal portion 30 is configured to define a first non-sealed portion 40. For example, as shown in FIG. 1, the first side seal portion 30 has a first upper seal portion 31, a first lower seal portion 32, and a first intermediate seal portion 33. The first upper seal portion 31 extends from the first non-sealed portion 40 along the first side portion 13 toward the top portion 11 of the pouch 10. The first lower seal portion 32 extends from the first non-sealed portion 40 along the first side portion 13 toward the bottom portion 12 of the pouch 10. The first intermediate seal portion 33 is located between the containing portion 18 and the first non-sealed portion 40. The first intermediate seal portion 33 includes one end connected to the first upper seal portion 31 and the other end connected to the first lower seal portion 32.

[0044] Fig. 2 is a cross-sectional view showing an example of pouch 10 when 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 sealed portion 33 is partially peeled off, and storage section 18 and first non-sealed section 40 communicate with each other. Steam that has flowed from storage section 18 into first non-sealed section 40 can be discharged to the outside from first opening edge section 41. In this way, first intermediate sealed portion 33 and first non-sealed section 40 function as a steam release mechanism that discharges steam from storage section 18 to the outside.

[0045] The second unsealed portion 45, like the first unsealed portion 40, expands to reach the second side edge 14x of the second side portion 14. In other words, the second unsealed portion 45 overlaps the second side edge 14x and has a second opening edge portion 46 that is open to the outside. Steam that is generated in the storage portion 18 and flows into the second unsealed portion 45 can be discharged to the outside from the second opening edge portion 46.

[0046] 1, an extension of the second imaginary straight line M2 may intersect with the second opening edge portion 46. The second imaginary straight line M2 is a straight line that connects the center point C of the storage portion 18 and the second non-sealed portion 45 at the shortest distance as shown in FIG.

[0047] The second side seal portion 35 is configured to define a second non-sealed portion 45, similar to the first side seal portion 30. For example, as shown in FIG. 1, the second side seal portion 35 has a second upper seal portion 36, a second lower seal portion 37, and a second intermediate seal portion 38. The second upper seal portion 36 extends along the second side portion 14 from the second non-sealed portion 45 toward the top portion 11 of the pouch 10. The second lower seal portion 37 extends along the second side portion 14 from the second non-sealed portion 45 toward the bottom portion 12 of the pouch 10. The second intermediate seal portion 38 is located between the containing portion 18 and the second non-sealed portion 45. The second intermediate seal portion 38 includes one end connected to the second upper seal portion 36 and the other end connected to the second lower seal portion 37.

[0048] When pouch 10 is heated and steam is generated in storage section 18, increasing the pressure in storage section 18, second intermediate sealed portion 38 partially peels off, connecting storage section 18 with second non-sealed portion 45. Steam that flows from storage section 18 into second non-sealed portion 45 can be discharged to the outside from second opening edge portion 46. In this way, second intermediate sealed portion 38 and second non-sealed portion 45 function as a steam release mechanism that discharges steam in storage section 18 to the outside.

[0049] In the following description, the steam vent mechanism formed in first side seal portion 30 is also referred to as the first steam vent mechanism, and the steam vent mechanism formed in second side seal portion 35 is also referred to as the second steam vent mechanism. In the present embodiment, since pouch 10 is provided with two steam vent mechanisms, steam generated in the storage portion can be appropriately discharged to the outside of pouch 10.

[0050] As shown in FIG. 1, the pouch 10 may include a first opening means 30a located at the first upper seal portion 31. The first opening means 30a penetrates the front film 15 and the back film 16. The first opening means 30a may be a notch, a cut, or the like. The first opening means 30a may be a starting point for a user to tear the pouch 10. The first opening means 30a extends from the first side edge 13x toward the container 18.

[0051] As shown in FIG. 1, the pouch 10 may include a second opening means 35a located in the second upper seal portion 36. The second opening means 35a penetrates the front film 15 and the back film 16. The second opening means 35a may be a notch, a cut, or the like. Like the first opening means 30a, the second opening means 35a can be a starting point when a user tears the pouch 10. The second opening means 35a extends from the second side edge 14x toward the storage portion 18. The second opening means 35a may be provided to face the first opening means 30a in the first direction D1.

[0052] 3 is a diagram showing pouch 10 in a state in which content 19 is contained and lower portion 12 is sealed. After the content is filled into pouch 10 through opening 12b of lower portion 12, the inner surface of front film 15 and the inner surface of back film 16 are joined at lower portion 12. This forms lower seal portion 12a and seals pouch 10.

[0053] 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.

[0054] Symbol H3 represents the distance in the first direction D1 from the center point C to the first intermediate seal portion 33. The distance H3 is the distance in the first direction D1 from the intersection point of the first virtual straight line M1 and the inner edge 33a of the first intermediate seal portion 33 to the center point C. The distance H3 is, for example, 0.35×H1 or more, and may be 0.40×H1 or more. The distance H3 is, for example, 0.48×H1 or less, and may be 0.45×H1 or less.

[0055] Symbol H4 represents the distance in the second direction D2 from the center point C to the first intermediate seal portion 33. Distance H4 is the distance in the second direction D2 from the intersection point of the virtual straight line M and the inner edge 33a of the first intermediate seal portion 33 to the center point C. Distance H4 is, for example, 0.10×H2 or more, 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, and may be 0.25×H2 or less.

[0056] Symbol H5 represents the distance in the first direction D1 from the center point C to the second intermediate seal portion 38. Distance H5 is the distance in the first direction D1 from the intersection point of the second virtual straight line M2 and the inner edge 38a of the second intermediate seal portion 38 to the center point C. Distance H5 is, for example, 0.35×H1 or more, and may be 0.40×H1 or more. Distance H5 is, for example, 0.48×H1 or less, and may be 0.45×H1 or less.

[0057] Symbol H6 represents the distance in the second direction D2 from the center point C to the second intermediate seal portion 38. Distance H6 is the distance in the second direction D2 from the intersection point of the imaginary line M and the inner edge 38a of the second intermediate seal portion 38 to the center point C. Distance H6 is, for example, 0.10×H2 or more, may be 0.15×H2 or more, or may be 0.20×H2 or more. Distance H6 is, for example, 0.30×H2 or less, and may be 0.25×H2 or less.

[0058] The distance H6 may be substantially the same as the distance H4. For example, the difference between the distance H6 and the distance H4 may be less than 0.01×H2.

[0059] The distance H6 may be different from the distance H4. The difference between the distance H6 and the distance H4 may be, for example, 0.01×H2 or more, 0.02×H2 or more, or 0.03×H2 or more. The difference between the distance H6 and the distance H4 may be 0.10×H2 or less, 0.07×H2 or less, or 0.05×H2 or less.

[0060] The contents 19 contained in the pouch 10 are heated by the 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, boiled dishes, and hamburger steaks.

[0061] The weight of the contents 19 contained in the pouch 10 is, for example, 50 g or more, 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, may be 220 g or less, or may be 200 g or less.

[0062] The ratio of the weight of the ingredients to the total weight of the contents 19 is, for example, 5% or more, may be 8% or more, or may be 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, 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 of the sieve is, for example, 0.7 mm.

[0063] The ratio of the weight of meat to the weight of ingredients is, for example, 8% or more, may be 10% or more, may be 15% or more, may be 20% or more, or may be 25% or more. The ratio of the weight of meat to the weight of ingredients is, for example, 50% or less, may be 40% or less, or may be 30% or less.

[0064] The ratio of the weight of meat to the total weight of the contents 19 is, for example, 1.0% or more, 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, may be 6.0% or less, or may be 4.0% or less.

[0065] The meat may have a grain 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 maximum. The dimension of the meat may be calculated by observing the meat using a microscope. As the microscope, a VHX-6000 manufactured by Keyence may be used. As the lens of the microscope, a VH-ZST manufactured by Keyence may be used. The observation magnification is, for example, 20 times.

[0066] As will be shown in the examples described later, meat having dimensions of 3 mm or more and 12 mm or less is likely to affect the exhaust property of pouch 10. According to the present embodiment, since pouch 10 has two steam venting mechanisms, steam can be appropriately exhausted to the outside of pouch 10 even when contents 19 includes meat having dimensions of 3 mm or more and 12 mm or less.

[0067] The number of pieces of meat having a dimension of 3 mm or more and 12 mm or less contained in the content 19 is, for example, 30 or more, 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 the content 19 is, for example, 200 or less, may be 150 or less, or may be 100 or less.

[0068] The value obtained by dividing the number of pieces of meat having a dimension of 3 mm or more and 12 mm or less contained in the contents 19 by the weight of the contents is, for example, 0.2 pieces / g or more, may be 0.3 pieces / g or more, or may be 0.4 pieces / g or more. The value obtained by dividing the number of pieces of meat having a dimension of 3 mm or more and 12 mm or less contained in the contents 19 by the weight of the contents is, for example, 1.5 pieces / g or less, may be 1.0 pieces / g or less, or may be 0.7 pieces / g or less.

[0069] 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, may be 1200 mPa·S or more, or may be 1500 mPa·S or more. The viscosity of the viscous component at 95°C is, for example, 2500 mPa·S or less, 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.

[0070] The viscosity of the viscous component at 50°C is, for example, 500 mPa·S or more, may be 800 mPa·S or more, or may be 1000 mPa·S or more. The viscosity of the viscous component at 50°C is, for example, 2000 mPa·S or less, 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.

[0071] 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.

[0072] 4 is a cross-sectional view showing an example of the state of the pouch 10 when it is heated in a microwave oven. The cross-section of the pouch 10 shown in FIG. 4 shows the pouch 10 as seen along BB in FIG.

[0073] As shown in Fig. 4, the pouch 10 may be heated in a state inclined at an angle θa with respect to a horizontal plane 120. The pouch 10 may be inclined so that the lower portion 12 is located downward. This can prevent the upper surface 19a of the contents 19 from contacting the first intermediate sealed portion 33 and the second intermediate sealed portion 38 (not shown). The angle θa is, for example, 5° or more, may be 10° or more, or may be 15° or more. The angle θa is, for example, 50° or less, may be 40° or less, or may be 30° or less.

[0074] The angle θa may be achieved, for example, by utilizing a carton 100 for housing the pouch 10. The carton 100 may include a body portion 101 for housing the pouch 10 and a lid 102 connected to the body portion 101.

[0075] For example, a user opens carton 100 so that lid 102 is connected to main body 101 only at connecting portion 103 on the rear surface of carton 100. Next, the user rotates lid 102 toward the rear surface of main body 101 around 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. 4. 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.

[0076] In Fig. 4, the symbol Lm represents the distance between the upper surface 19a of the content 19 and the first intermediate seal portion 33. When the angle θa is 17°, the distance Lm is, for example, 5 mm or more, may be 8 mm or more, or may be 10 mm or more. When the angle θa is 17°, the distance Lm is, for example, 30 mm or less, 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 33a of the first intermediate seal portion 33 when the angle θa is 17°, and then opening the pouch 10 and checking the position of the upper surface 19a.

[0077] A detailed description will be given of the first intermediate sealed portion 33 and the first unsealed portion 40. Fig. 5 is a front view showing the first intermediate sealed portion 33 and the first unsealed portion 40 in an enlarged scale.

[0078] The first intermediate seal portion 33 includes an inner edge 33a which is an edge portion located on the side of the storage portion 18, and an outer edge which is an edge portion located on the side of the first non-sealed portion 40. The outer edge of the first intermediate seal portion 33 defines the outline of a portion of the edge of the first non-sealed portion 40 which is located closer to the storage portion 18 than the first upper seal portion 31 or the first lower seal portion 32.

[0079] The inner edge 33a may include a first inner edge 331, a second inner edge 332 and a third inner edge 333, an inner edge first connecting portion 336 connecting the first inner edge 331 and the second inner edge 332, and an inner edge second connecting portion 337 connecting the second inner edge 332 and the third inner edge 333.

[0080] The first inner edge 331 extends from the inner edge first connecting portion 336 toward the first lower seal portion 32. For example, the first inner edge 331 extends toward the first lower seal portion 32 in approximately a first direction D1. The angle between the extension direction of the first inner edge 331 and the first direction D1 is, for example, 10° or less. As shown in FIG. 5, the first inner edge 331 may be connected to an inner edge 32a of the first lower seal portion 32.

[0081] The second inner edge 332 extends from the inner edge first connecting portion 336 toward the upper portion 11 of the pouch 10 in approximately the second direction D2. The angle formed between the direction in which the second inner edge 332 extends and the second direction D2 is, for example, 10° or less.

[0082] The third inner edge 333 extends from the inner edge second connecting portion 337 toward the first upper seal portion 31. For example, the third inner edge 333 extends toward the first upper seal portion 31. The angle between the extending direction of the third inner edge 333 and the first direction D1 is, for example, 30° or less. As shown in FIG. 5, the third inner edge 333 may be connected to the inner edge 31a of the first upper seal portion 31.

[0083] 5, the direction in which the second inner edge 332 extends may be substantially perpendicular to the direction in which the first inner edge 331 extends. The angle θ11 between the direction in which the first inner edge 331 extends and the direction in which the second inner edge 332 extends is, for example, not less than 85° and not more than 95°.

[0084] The inner edge first connecting portion 336 is located closer to the first lower seal portion 32. "Closer to the first lower seal portion 32" means that the inner edge first connecting portion 336 is located closer to the first lower seal portion 32 than the center of the first opening edge portion 41 in the second direction D2.

[0085] The inner edge second connecting portion 337 is located closer to the first upper seal portion 31. "Closer to the first upper seal portion 31" means that the inner edge second connecting portion 337 is located on the first upper seal portion 31 side relative to the center of the first opening edge portion 41 in the second direction D2.

[0086] In FIG. 5, the symbol L12 indicates the maximum distance in the first direction D1 between the inner edge 32a of the first lower seal portion 32 and the inner edge 33a of the first intermediate seal portion 33. L12 is, for example, 5 mm or more, and may be 7 mm or more, or 9 mm or more. L12 is, for example, 20 mm or less, and may be 15 mm or less, or may be 12 mm or less. In this embodiment, the first non-sealed portion 40 spreads to reach the first side edge 13x, so that the area of ​​the first non-sealed portion 40 is easily secured. Therefore, L12 can be made small. This allows the distance from the center point C to the inner edge 33a of the first intermediate seal portion 33 to be made large. Therefore, it is possible to prevent the first intermediate seal portion 33 from peeling off when a force due to an impact such as a drop is applied to the pouch 10. L12 is also referred to as the projection dimension of the first intermediate seal portion 33.

[0087] The ratio L12 / H1 of L12 to the dimension H1 of the storage section 18 in the first direction D1 is, for example, 0.04 or more, or may be 0.05 or more, or may be 0.06 or more. L12 / H1 is, for example, 0.12 or less, or may be 0.10 or less, or may be 0.08 or less.

[0088] Next, the edge of the first non-sealed portion 40 will be described. The edge of the first non-sealed portion 40 includes a first opening edge 41 located at the first side edge 13x of the first side portion 13, and a seal portion side edge 43 defined by the lower edge of the first upper seal portion 31, the upper edge of the first lower seal portion 32, and the outer edge of the first intermediate seal portion 33. As shown in FIG. 5, the seal portion side edge 43 may include a first edge 431, a second edge 432, and a third edge 433, a first connecting portion 436 connecting the first edge 431 and the second edge 432, and a second connecting portion 437 connecting the second edge 432 and the third edge 433. The first connecting portion 436 faces the inner edge first connecting portion 336, and the second connecting portion 437 faces the inner edge second connecting portion 337. The first edge 431 corresponds to the first inner edge 331. For example, the first edge 431 extends at least partially parallel to the first inner edge 331. The second edge 432 corresponds to the second inner edge 332. For example, the second edge 432 extends at least partially parallel to the second inner edge 332. The third edge 433 may extend at least partially parallel to the third inner edge 333.

[0089] The first non-sealed portion 40 may extend to a position closer to the second side portion 14 than the inner edge 32a of the first lower sealed portion 32. In other words, a part of the edge of the first non-sealed portion 40 may be located closer to the second side portion 14 than the inner edge 32a of the first lower sealed portion 32. For example, the second edge portion 432 may be located closer to the second side portion 14 than the inner edge 32a of the first lower sealed portion 32. This makes it easier for steam to flow from the storage portion 18 into the first non-sealed portion 40. The first non-sealed portion 40 may extend to a position closer to the second side portion 14 than the inner edge 31a of the first upper seal portion 31. For example, the second edge portion 432 may be located closer to the second side portion 14 than the inner edge 31a of the first upper seal portion 31.

[0090] The first edge 431 extends from the first connecting portion 436 toward the first opening edge 41. For example, the first edge 431 extends substantially in a first direction D1 toward the first opening edge 41. The angle between the extension direction of the first edge 431 and the first direction D1 is, for example, 10° or less. In the example shown in FIG. 5, the first edge 431 extends linearly until it reaches the first opening edge 41.

[0091] The second edge portion 432 extends from the first connecting portion 436 toward the upper portion 11 of the pouch 10 in approximately the second direction D2. The angle formed between the direction in which the second edge portion 432 extends and the second direction D2 is, for example, 10° or less.

[0092] The third edge 433 extends from the second connecting portion 437 toward the first opening edge 41. For example, the third edge 433 extends substantially in the first direction D1 toward the first opening edge 41. The angle between the extension direction of the third edge 433 and the first direction D1 is, for example, 10° or less. In the example shown in FIG. 5, the third edge 433 extends linearly until it reaches the first opening edge 41.

[0093] 5, the direction in which the second edge portion 432 extends may be substantially perpendicular to the direction in which the first edge portion 431 extends. The angle θ12 between the direction in which the first edge portion 431 extends and the direction in which the second edge portion 432 extends is, for example, not less than 85° and not more than 95°.

[0094] 5, the reference symbol L11 indicates the dimension of the first opening edge portion 41 in the second direction D2. The dimension L11 is, for example, 4 mm or more, may be 10 mm or more, or may be 12 mm or more. The dimension L11 is, for example, 30 mm or less, may be 20 mm or less, or may be 18 mm or less.

[0095] 5, the symbols W11 and W12 respectively represent the width of the first upper seal portion 31 and the width of the first lower seal portion 32. The widths W11 and W12 are, for example, 4 mm or more and may be 6 mm or more. The widths W11 and W12 are, for example, 15 mm or less and may be 10 mm or less.

[0096] In FIG. 5, the symbols W13, W14, and W15 respectively represent the width of the portion of the first intermediate seal portion 33 that extends along the first inner edge 331, the width of the portion of the first intermediate seal portion 33 that extends along the second inner edge 332, and the width of the portion of the first intermediate seal portion 33 that extends along the third inner edge 333. Preferably, the widths W13, W14, and W15 are smaller than the width W11 of the first upper seal portion 31 and the width W12 of the first lower seal portion 32. The widths W13, W14, and W15 are, for example, 1 mm or more, and may be 2 mm or more. The widths W13, W14, and W15 are, for example, 6 mm or less, and may be 5 mm or less. The widths of the portions of the first intermediate seal portion 33 are the dimensions of the first intermediate seal portion 33 in a direction perpendicular to the direction in which the inner edge of the first intermediate seal portion 33 extends.

[0097] Next, a detailed description will be given of the second intermediate sealed portion 38 and the second unsealed portion 45. Fig. 6 is a front view showing the second intermediate sealed portion 38 and the second unsealed portion 45 in an enlarged scale.

[0098] The second intermediate seal portion 38 includes an inner edge 38a which is an edge portion located on the side of the accommodation portion 18, and an outer edge which is an edge portion located on the side of the second non-sealed portion 45. The outer edge of the second intermediate seal portion 38 defines the outline of a portion of the edge of the second non-sealed portion 45 which is located closer to the accommodation portion 18 than the second upper seal portion 36 or the second lower seal portion 37.

[0099] The inner edge 38a may include a first inner edge 381, a second inner edge 382 and a third inner edge 383, an inner edge first connecting portion 386 connecting the first inner edge 381 and the second inner edge 382, ​​and an inner edge second connecting portion 387 connecting the second inner edge 382 and the third inner edge 383.

[0100] The first inner edge 381 extends from the inner edge first connecting portion 386 toward the second lower seal portion 37. For example, the first inner edge 381 extends toward the second lower seal portion 37 in approximately a first direction D1. The angle between the extension direction of the first inner edge 381 and the first direction D1 is, for example, 10° or less. As shown in FIG. 6, the first inner edge 381 may be connected to an inner edge 37a of the second lower seal portion 37.

[0101] The second inner edge 382 extends from the inner edge first connecting portion 386 toward the upper portion 11 of the pouch 10 in approximately the second direction D2. The angle formed between the direction in which the second inner edge 382 extends and the second direction D2 is, for example, 10° or less.

[0102] The third inner edge 383 extends from the inner edge second connecting portion 387 toward the second upper seal portion 36. For example, the third inner edge 383 extends toward the second upper seal portion 36. The angle between the extending direction of the third inner edge 333 and the first direction D1 is, for example, 30° or less. As shown in FIG. 6, the third inner edge 333 may be connected to the inner edge 31a of the second upper seal portion 36.

[0103] 6, the direction in which the second inner edge 382 extends may be substantially perpendicular to the direction in which the first inner edge 381 extends. The angle θ21 between the direction in which the first inner edge 381 extends and the direction in which the second inner edge 382 extends is, for example, not less than 85° and not more than 95°.

[0104] The inner edge first connecting portion 386 is located closer to the second lower seal portion 37. "Closer to the second lower seal portion 37" means that the inner edge first connecting portion 386 is located on the second lower seal portion 37 side relative to the center of the second opening edge portion 46 in the second direction D2.

[0105] The inner edge second connecting portion 387 is located closer to the second upper seal portion 36. "Closer to the second upper seal portion 36" means that the inner edge second connecting portion 387 is located on the second upper seal portion 36 side relative to the center of the second opening edge portion 46 in the second direction D2.

[0106] In FIG. 6, the symbol L22 indicates the maximum distance in the first direction D1 between the inner edge 37a of the second lower seal portion 37 and the inner edge 38a of the second intermediate seal portion 38. L22 is, for example, 5 mm or more, and may be 7 mm or more, or 9 mm or more. L22 is, for example, 20 mm or less, and may be 15 mm or less, or may be 12 mm or less. In this embodiment, the second non-sealed portion 45 spreads to reach the second side edge 14x, so that the area of ​​the second non-sealed portion 45 is easily secured. Therefore, L22 can be made small. This allows the distance from the center point C to the inner edge 38a of the second intermediate seal portion 38 to be made large. Therefore, it is possible to prevent the second intermediate seal portion 38 from peeling off when a force due to an impact such as a drop is applied to the pouch 10. L22 is also referred to as the projection dimension of the second intermediate seal portion 38.

[0107] The ratio L22 / H1 of L22 to the dimension H1 of the storage section 18 in the first direction D1 is, for example, 0.04 or more, or may be 0.05 or more, or may be 0.06 or more. L22 / H1 is, for example, 0.12 or less, or may be 0.10 or less, or may be 0.08 or less.

[0108] Next, the edge of the second non-sealed portion 45 will be described. The edge of the second non-sealed portion 45 includes a second opening edge 46 located at the second side edge 14x of the second side portion 14, and a seal portion side edge 48 defined by the lower edge of the second upper seal portion 36, the upper edge of the second lower seal portion 37, and the outer edge of the second intermediate seal portion 38. As shown in FIG. 6, the seal portion side edge 48 may include a first edge 481, a second edge 482, and a third edge 483, a first connecting portion 486 connecting the first edge 481 and the second edge 482, and a second connecting portion 487 connecting the second edge 482 and the third edge 483. The first connecting portion 486 faces the inner edge first connecting portion 386, and the second connecting portion 487 faces the inner edge second connecting portion 387. The first edge 481 corresponds to the first inner edge 381. For example, the first edge 481 extends at least partially parallel to the first inner edge 381. The second edge 482 corresponds to the second inner edge 382. For example, the second edge 482 extends at least partially parallel to the second inner edge 382. The third edge 483 may extend at least partially parallel to the third inner edge 383.

[0109] The second non-sealed portion 45 may extend to a position closer to the first side portion 13 than the inner edge 37a of the second lower sealed portion 37. In other words, a part of the edge of the second non-sealed portion 45 may be located closer to the first side portion 13 than the inner edge 37a of the second lower sealed portion 37. For example, the second edge portion 482 may be located closer to the first side portion 13 than the inner edge 37a of the second lower sealed portion 37. This makes it easier for steam to flow from the storage portion 18 into the second non-sealed portion 45. The second non-sealed portion 45 may extend to a position closer to the first side portion 13 than the inner edge 36a of the second upper seal portion 36. For example, the second edge portion 482 may be located closer to the first side portion 13 than the inner edge 36a of the second upper seal portion 36.

[0110] The first edge 481 extends from the first connecting portion 486 toward the second opening edge 46. For example, the first edge 481 extends toward the second opening edge 46 in approximately the first direction D1. The angle between the extension direction of the first edge 481 and the first direction D1 is, for example, 10° or less. In the example shown in FIG. 6, the first edge 481 extends linearly until it reaches the first opening edge 41.

[0111] The second edge portion 482 extends from the first connecting portion 486 toward the upper portion 11 of the pouch 10 in approximately the second direction D2. The angle formed between the direction in which the second edge portion 482 extends and the second direction D2 is, for example, 10° or less.

[0112] The third edge 483 extends from the second connecting portion 487 toward the second opening edge 46. For example, the third edge 483 extends substantially in the first direction D1 toward the second opening edge 46. The angle between the extension direction of the third edge 483 and the first direction D1 is, for example, 10° or less. In the example shown in FIG. 6, the third edge 483 extends linearly until it reaches the second opening edge 46.

[0113] 6, the direction in which the second edge portion 482 extends may be substantially perpendicular to the direction in which the first edge portion 481 extends. The angle θ22 between the direction in which the first edge portion 481 extends and the direction in which the second edge portion 482 extends is, for example, not less than 85° and not more than 95°.

[0114] 6, the symbol L21 indicates the dimension of the second opening edge portion 46 in the second direction D2. The dimension L21 is, for example, 4 mm or more, may be 10 mm or more, or may be 12 mm or more. The dimension L21 is, for example, 30 mm or less, may be 20 mm or less, or may be 18 mm or less.

[0115] The second non-sealed portion 45 may be formed simultaneously with the first non-sealed portion 40 by cutting one non-sealed portion, as disclosed in, for example, JP 2016-74457 A. For example, when a front 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 may become the first non-sealed portion 40 and the other may become the second non-sealed portion 45. In this case, the dimension L21 of the second opening edge portion 46 may be the same as the dimension L11 of the first opening edge portion 41.

[0116] 6, the symbols W21 and W22 respectively represent the width of the second upper seal portion 36 and the width of the second lower seal portion 37. The widths W21 and W22 are, for example, 4 mm or more and may be 6 mm or more. The widths W21 and W22 are, for example, 15 mm or less and may be 10 mm or less.

[0117] In FIG. 6, the symbols W23, W24, and W25 respectively represent the width of the portion of the second intermediate seal portion 38 extending along the first inner edge 381, the width of the portion of the second intermediate seal portion 38 extending along the second inner edge 382, ​​and the width of the portion of the second intermediate seal portion 38 extending along the third inner edge 383. Preferably, the widths W23, W24, and W25 are smaller than the width W21 of the second upper seal portion 36 and the width W22 of the second lower seal portion 37. The widths W23, W24, and W25 are, for example, 1 mm or more, and may be 2 mm or more. The widths W23, W24, and W25 are, for example, 6 mm or less, and may be 5 mm or less. The widths of the portions of the second intermediate seal portion 38 are the dimensions of the second intermediate seal portion 38 in a direction perpendicular to the direction in which the inner edge of the second intermediate seal portion 38 extends.

[0118] Next, a description will be given of the layer structure of the packaging material 50 that constitutes the front film 15 and the back film 16. Fig. 7 is a cross-sectional view showing an example of the layer structure of the packaging material 50.

[0119] 7 includes at least a first biaxially oriented plastic film 51, a first adhesive layer 56, a second biaxially oriented plastic film 52, a second adhesive layer 57, and a sealant film 55, in this order. The first biaxially oriented plastic film 51 is located on the outer surface 50y side, and the sealant film 55 is located on the inner surface 50x side opposite the outer surface 50y. The inner surface 50x faces the storage section 18.

[0120] Each film constituting the packaging material 50, such as the first biaxially oriented plastic film 51, the second biaxially oriented plastic film 52, and the sealant film 55, and the packaging material 50 have a machine direction and a vertical direction. The machine direction is the direction in which the film flows when it is formed, and is called MD (Machine Direction). The vertical direction is the direction perpendicular to the machine direction, and is called 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 vertical direction.

[0121] Each layer of packaging material 50 will now be described in detail.

[0122] (First biaxially stretched plastic film) The first biaxially stretched plastic film 51 is a film made of plastic stretched in two predetermined directions. The biaxially stretched plastic film is a plastic film that is intentionally stretched to improve the mechanical strength of the plastic film. The first biaxially stretched plastic film 51 functions as a base layer for imparting a predetermined strength to the packaging material 50. The stretching direction of the first biaxially stretched plastic film 51 is not particularly limited. For example, the first biaxially stretched plastic film 51 may be stretched in a first direction D1 and a second direction D2. The stretching ratio of the first biaxially stretched plastic film 51 is, for example, 1.05 times or more.

[0123] The first biaxially stretched plastic film 51 contains, for example, polyester as a main component. For example, the first biaxially stretched plastic film 51 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). In addition, the 51% by mass or more of polyester in the first biaxially stretched plastic film 51 may be composed of one type of polyester or may be composed of two or more types of polyester. The content of polyester in the first biaxially stretched plastic film 51 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 content of PET in the first biaxially stretched plastic film 51 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0124] The thickness of the first biaxially stretched plastic film 51 is, for example, 8 μm or more, may be 9 μm or more, or may be 12 μm or more. The thickness of the first biaxially stretched plastic film 51 is, for example, 30 μm or less, may be 25 μm or less, or may be 20 μm or less. By making the thickness of the first biaxially stretched plastic film 51 8 μm or more, the first biaxially stretched plastic film 51 has sufficient strength. By making the thickness of the first biaxially stretched plastic film 51 30 μm or less, the first biaxially stretched plastic film 51 exhibits excellent formability. Therefore, the process of processing the packaging material 50 to manufacture the pouch 10 can be efficiently carried out.

[0125] (First adhesive layer) The first adhesive layer 56 includes an adhesive for bonding the first biaxially oriented plastic film 51 and the second biaxially oriented plastic film 52 by a dry lamination method. The adhesive constituting the first adhesive layer 56 is produced from an adhesive composition produced by mixing a first composition including a base agent and a solvent with a second composition including a curing agent and a solvent. Specifically, the adhesive includes a cured product produced by reaction of the base agent and the solvent in the adhesive composition.

[0126] Examples of adhesives include 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.

[0127] As the isocyanate compound, aromatic isocyanate compounds such as tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), etc., aliphatic isocyanate compounds such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), etc., or adducts or oligomers of the above-mentioned various isocyanate compounds can be used.

[0128] The thickness of the first adhesive layer 56 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the first adhesive layer 56 is, for example, 6 μm or less, and may be 5 μm or less.

[0129] (Second biaxially oriented plastic film) The second biaxially stretched plastic film 52 is a plastic film stretched in two predetermined directions, similar to the first biaxially stretched plastic film 51. The second biaxially stretched plastic film 52 also functions as a base layer for imparting a predetermined strength to the packaging material 50, similar to the first biaxially stretched plastic film 51. The stretching direction of the second biaxially stretched plastic film 52 is not particularly limited, similar to the case of the first biaxially stretched plastic film 51. The stretching ratio of the second biaxially stretched plastic film 52 is, for example, 1.05 times or more.

[0130] The second biaxially stretched plastic film 52 may contain polyester as a main component. As in the case of the first biaxially stretched plastic film 51, examples of polyester include PET and PBT. The range of the polyester content in the second biaxially stretched plastic film 52 may be the same range as that of the first biaxially stretched plastic film 51. The thickness of the second biaxially stretched plastic film 52 containing polyester as a main component is, for example, 8 μm or more, may be 9 μm or more, or may be 12 μm or more. The thickness of the second biaxially stretched plastic film 52 containing polyester as a main component is, for example, 30 μm or less, may be 25 μm or less, or may be 20 μm or less.

[0131] The second biaxially stretched plastic film 52 may contain polyamide as a main component. For example, the second biaxially stretched plastic film 52 may contain 51% by mass or more of polyamide. Examples of polyamide include aliphatic polyamides and aromatic polyamides. Examples of aliphatic polyamides include nylons such as nylon-6, nylon-6,6, and copolymers of nylon 6 and nylon 6,6, and examples of aromatic polyamides include polymetaxylene adipamide (MXD6). The content of polyamide in the second biaxially stretched plastic film 52 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more. The thickness of the second biaxially stretched plastic film 52 containing polyamide as a main component may be, for example, 12 μm or more, or 15 μm or more. The thickness of the second biaxially stretched plastic film 52 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.

[0132] (Second adhesive layer) The second adhesive layer 57 contains an adhesive for bonding the second biaxially oriented plastic film 52 and the sealant film 55 by a dry lamination method. An example of the adhesive for the second adhesive layer 57 is polyurethane, as in the case of the first adhesive layer 56. In addition to the configurations, materials, and characteristics described below, the second adhesive layer 57 can adopt the same configurations, materials, and characteristics as the first adhesive layer 56.

[0133] The thickness of the second adhesive layer 57 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the second adhesive layer 57 is, for example, 6 μm or less, and may be 5 μm or less.

[0134] As described above, the isocyanate compound constituting the curing agent of the adhesive includes aromatic isocyanate compounds and aliphatic isocyanate compounds. In the aromatic isocyanate compound, components that cannot be used for food applications are eluted under high temperature environments such as heat sterilization. The second adhesive layer 57 is in contact with the sealant film 55. Therefore, when the second adhesive layer 57 contains an aromatic isocyanate compound, the components eluted from the aromatic isocyanate compound may adhere to the contents contained in the storage section 18 that is in contact with the sealant film 55.

[0135] Considering these problems, it is preferable to use a cured product produced by reacting a polyol as a base agent with an aliphatic isocyanate compound as a curing agent as the adhesive constituting the second adhesive layer 57. This makes it possible to prevent components that cannot be used for food applications, which are caused by the second adhesive layer 57, from adhering to the contents.

[0136] (Sealant film) Next, the sealant film 55 will be described. The sealant film 55 may be a single layer or a multilayer. The sealant film 55 is preferably made of an unstretched film. The term "unstretched" includes not only a film that is not stretched at all, but also a film that is slightly stretched due to tension applied during film formation.

[0137] The sealant film 55 may satisfy at least one of the following (1) or (2). (1) Young's modulus is less than 1000 MPa in one direction and in a direction perpendicular to the one direction. (2) Tensile elongation of 300% or more in one direction and in a direction perpendicular to the one direction

[0138] The Young's modulus and tensile elongation of the sealant film 55 are measured in accordance with JIS K7127. Using a Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.), the test piece is held for 1 minute in an environment of 23°C temperature and 50% relative humidity, and then the Young's modulus and tensile elongation of the test piece are measured in an environment of 23°C temperature and 50% relative humidity. The measurement is performed using a rectangular test piece with one side of 15 mm and the other side extending in a direction perpendicular to the one side of 150 mm. The measurement is performed in an environment of 23°C after the test piece is held for 1 minute in an environment of 23°C. The initial distance between the pair of gripping tools holding the test piece is 100 mm, and the tensile speed is 300 mm / min. As long as the measurement can be performed with the initial distance between the pair of gripping tools being 100 mm, the length in the direction perpendicular to one side can be adjusted.

[0139] The pouch 10 made of the packaging material 50 is subjected to sterilization treatment at high temperatures, such as boiling or retort treatment. Therefore, the sealant film 55 used has heat resistance that can withstand such high-temperature treatments.

[0140] The melting point of the material constituting the sealant film 55 is preferably 150° C. or higher, and more preferably 160° C. or higher. By increasing the melting point of the sealant film 55, it becomes possible to perform the retort treatment of the pouch 10 at a high temperature, and therefore the time required for the retort treatment can be shortened. The melting point of the material constituting the sealant film 55 is lower than the melting point of the resin constituting the biaxially oriented plastic film.

[0141] The sealant film 55 contains propylene as a main component. For example, the sealant film 55 may contain 51% by mass or more of propylene. The propylene content in the sealant film 55 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0142] Specific examples of materials containing propylene as a main component include polypropylene such as propylene-ethylene block copolymer, propylene-ethylene random copolymer, homopolypropylene, and 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.

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] When a mixture of polypropylene and polyethylene is used as the propylene-based material, the material may have an islands-in-a-sea structure, where the polyethylene is discontinuously dispersed within a region of continuous polypropylene.

[0147] Preferably, the sealant film 55 is a single-layer film containing a propylene-ethylene block copolymer. For example, the sealant film 55 is a single-layer unstretched film mainly composed of a propylene-ethylene block copolymer. By using a propylene-ethylene block copolymer, the impact resistance of the sealant film 55 can be increased, and thus, the pouch 10 can be prevented from breaking due to an impact when dropped. In addition, the puncture resistance of the packaging material 50 can be increased.

[0148] Furthermore, by using a propylene-ethylene block copolymer, the strength of the seal portion formed by the sealant film 55 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 seal portion 33 is easily peeled off, and steam in the containing portion 18 is easily released to the outside of the pouch 10. This makes it possible to prevent the internal pressure of the containing portion 18 from becoming excessive, thereby making it possible to prevent damage to the packaging material 50 during heating.

[0149] The propylene-ethylene block copolymer contains, for example, a sea component made of polypropylene and an island component 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 component can also contribute to improving the impact resistance of the propylene-ethylene block copolymer. Therefore, by adjusting the ratio of the sea component and the island component, the mechanical properties of the sealant film 55 containing the propylene-ethylene block copolymer can be adjusted.

[0150] 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 the 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%, preferably 60 mass% or more, and more preferably 70 mass% or more.

[0151] The single-layer sealant film 55 may further contain a second thermoplastic resin in addition to the first thermoplastic resin made of a propylene-ethylene block copolymer. Examples of the second thermoplastic resin include an α-olefin copolymer 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 55. In addition, by using the second thermoplastic resin, the above-mentioned hot seal strength can be further reduced compared to the room-temperature seal strength.

[0152] Low density polyethylene has a density of 0.910g / cm 3 Above 0.925g / cm 3 Medium density polyethylene has a density of 0.926 g / cm 3 Above 0.940g / cm 3 The following polyethylene: High density polyethylene has a density of 0.941 g / cm 3 Above 0.965g / cm 3 The following polyethylenes are available. Low density polyethylene is obtained by polymerizing ethylene at a high pressure, for example, from 1000 atm to less than 2000 atm. Medium density polyethylene and high density polyethylene are obtained by polymerizing ethylene at a medium or low pressure, for example, from 1 atm to less than 1000 atm.

[0153] The medium-density polyethylene and high-density polyethylene may partially contain a copolymer of ethylene and an α-olefin. Even when ethylene is polymerized at medium or low pressure, if a copolymer of ethylene and an α-olefin is contained, a medium-density or low-density polyethylene can be produced. Such polyethylene is called the above-mentioned linear low-density polyethylene. Linear low-density polyethylene is obtained by copolymerizing an α-olefin with a linear polymer obtained by polymerizing ethylene at 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 Above 0.945g / cm 3 The following is the result.

[0154] 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 means a material having the structural formula shown in the following formula (IV).

[0155] [ka] Both R1 and R2 are H (hydrogen atom) or alkyl groups such as CH3 and C2H5. In addition, both j and k are integers of 1 or more. In addition, j is greater than k. That is, in the α-olefin copolymer shown in formula (IV), the structure on the left side including R1 is the base. R1 is, for example, H, and R2 is, for example, C2H5.

[0156] In the sealant film 55, 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 55, 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.

[0157] As described above, the second thermoplastic resin can contribute to increasing the impact resistance of the sealant film 55. 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 55, the mechanical properties of the sealant film 55 can be adjusted.

[0158] The sealant film 55 may further contain a thermoplastic elastomer. By using a thermoplastic elastomer, the impact resistance and puncture resistance of the sealant film 55 can be further improved.

[0159] 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 made of at least one vinyl aromatic compound and a polymer block B mainly made 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 mass% of ethylene as a main component and an α-olefin as a copolymerization monomer.

[0160] The content of the propylene-ethylene block copolymer in the sealant film 55 is, for example, 80% by mass or more, and preferably 90% by mass or more.

[0161] 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.

[0162] The thickness of the sealant film 55 is, for example, 30 μm or more, may be 40 μm or more, may be 50 μm or more, or may be 60 μm or more. The thickness of the sealant film 55 is, for example, 100 μm or less, and may be 80 μm or less.

[0163] As the monolayer sealant film 55 containing a propylene-ethylene block copolymer, there is a type having high tensile elongation and impact resistance, such as ZK500 described later. This type of sealant film 55 preferably further has a property of low hot seal strength. This can prevent the internal pressure of the storage section 18 from becoming excessive when the pouch 10 is heated.

[0164] The tensile elongation of the sealant film 55 in the machine direction (MD) at 23°C may be, for example, 800% or more, 900% or more, 1000% or more, or 1100% or more. The product of the tensile elongation (%) of the sealant film 55 in the machine direction (MD) and the thickness (μm) of the sealant film 55 may be 45000 or more, 50000 or more, 55000 or more, or 60000 or more. The tensile elongation of the sealant film 55 in the transverse direction (TD) at 23°C may be, for example, 1050% or more, or 1100% or more. The product of the tensile elongation (%) of the sealant film 55 in the transverse direction (TD) and the thickness (μm) of the sealant film 55 may be 53000 or more, or 60000 or more. The sealant film 55 has a high tensile elongation, so that the pouch 10 can be prevented from breaking due to an impact when dropped, for example.

[0165] The Young's modulus of the sealant film 55 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 55 in the machine direction (MD) and the thickness (μm) of the sealant film 55 is, for example, 38,000 or less, and may be 35,000 or less. The Young's modulus of the sealant film 55 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 55 in the transverse direction (TD) and the thickness (μm) of the sealant film 55 is, for example, 30,000 or less, and may be 25,000 or less.

[0166] As shown in FIG. 7, the packaging material 50 may further include a printed layer 61. The printed layer 61 is a layer provided on the packaging material 50 to display product information and to impart an aesthetic feel to the packaging material 50. The printed layer 61 is provided on, for example, the first biaxially stretched plastic film 51. The printed layer 61 expresses letters, numbers, symbols, figures, pictures, and the like. The printed layer 61 includes, 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.

[0167] 8A and 8B are cross-sectional views showing other examples of the layer structure of the packaging material 50. As shown in FIG. 8A and FIG. 8B, the packaging material 50 may include a transparent vapor deposition layer 62 located between the first biaxially stretched plastic film 51 and the second biaxially stretched plastic film 52. The packaging material 50 may include a transparent gas barrier coating film 63 located on the surface of the transparent vapor deposition layer 62. As shown in FIG. 8A, the transparent vapor deposition layer 62 may be provided on the inner surface of the first biaxially stretched plastic film 51. As shown in FIG. 8B, the transparent vapor deposition layer 62 may be provided on the outer surface of the second biaxially stretched plastic film 52.

[0168] [Transparent vapor deposition layer] The transparent deposition layer 62 may be composed of a single deposition layer or may include two or more deposition layers. When the transparent deposition layer 62 includes two or more deposition layers, each layer may have the same composition or different compositions. Examples of methods for forming the transparent deposition layer 62 include physical vapor deposition methods (PVD methods) such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition methods (CVD methods) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. Specifically, the deposition layer can be formed on a film-forming roller using a roller-type deposition film-forming device.

[0169] The transparent deposition layer 62 is made of a transparent inorganic material. Examples of the inorganic material include metal oxides and inorganic oxides. Examples of the 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). Examples of the inorganic oxides include oxides of silicon (Si). As the inorganic material constituting the transparent deposition layer, aluminum oxide (aluminum oxide) or silicon oxide is preferable.

[0170] The thickness of the transparent deposition layer 62 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 62 is, for example, 150 Å or less, 130 Å or less, 120 Å or less, or 110 Å or less.

[0171] [Gas barrier coating film] The transparent gas barrier coating film 63 has transparency. The transparent gas barrier coating film 63 can suppress the transmission of oxygen gas, water vapor, and the like. The transparent gas barrier coating film 63 is a compound represented by the general formula R 1 nM(OR 2 ) m (In the formula, 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 atomic valence of M. The transparent gas barrier composition contains at least one alkoxide represented by the formula (I) and the above-mentioned polyvinyl alcohol resin and / or ethylene-vinyl alcohol copolymer, and is further polycondensed by a sol-gel method in the presence of a sol-gel catalyst, an acid, water, and an organic solvent.

[0172] The above general formula R 1 n M(OR 2 ) m As the alkoxide represented by the formula (I), at least one of the following may be used: partial hydrolysis product of alkoxide, and condensation product of hydrolysis of alkoxide. In addition, the partial hydrolysis product of alkoxide does not need to have all alkoxy groups hydrolyzed, and may be one in which one or more alkoxy groups are hydrolyzed, or a mixture thereof. As the condensation product of hydrolysis of alkoxide, a dimer or more of the partially hydrolyzed alkoxide, specifically, a dimer to hexamer, is used.

[0173] The above 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, for example, silicon and titanium. In the present embodiment, the alkoxide can be used alone or in the form of a mixture of two or more different metal atoms in the same solution.

[0174] 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 (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, etc. In addition, these alkyl groups may be the same or different in the same molecule.

[0175] 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 may 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 may be used. The above-mentioned silane coupling agents may be used alone or in combination of two or more.

[0176] The thickness of the transparent gas barrier coating film 63 is, for example, 100 nm or more, may be 125 nm or more, may be 150 nm or more, or may be 200 nm or more. This allows stable gas barrier properties to be obtained. The thickness of the transparent gas barrier coating film 63 is, for example, 500 nm or less, may be 450 nm or less, may be 400 nm or less, or may be 300 nm or less.

[0177] As shown in Figures 7, 8A, and 8B, the packaging material 50 may contain only two biaxially oriented plastic films. A specific example of the packaging material 50 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 / printed layer / adhesive layer / biaxially oriented PET film / adhesive layer / sealant film Biaxially oriented PET film / printed layer / adhesive layer / transparent gas barrier coating film / transparent vapor deposition layer / biaxially oriented PET film / adhesive layer / sealant film

[0178] The following describes preferred properties of the packaging material 50 when the packaging material 50 contains only two biaxially oriented plastic films. Specifically, the following describes preferred hot breaking strength and hot seal strength of the packaging material 50.

[0179] The packaging material 50 has a breaking strength (hot breaking strength) in one direction measured in a 100°C environment after being held in a 100°C environment for 1 minute, of 33.0 MPa or more. The hot breaking strength in one direction of the packaging material 50 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 in the direction perpendicular to the one direction of the packaging material 50 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 in the one direction of the packaging material 50 is preferably 50.0 MPa or less, and the hot breaking strength in the direction perpendicular to the one direction of the packaging material 50 is preferably 45.0 MPa or less. One direction of the packaging material 50 may be, for example, a first direction D1 in the pouch 10, and a direction perpendicular to the one direction of the packaging material 50 may be, for example, a second direction D2 in the pouch 10. Also, for example, the flow direction (MD) of the packaging material 50 may correspond to the first direction D1 of the pouch 10, and for example, the vertical direction (TD) of the packaging material 50 may correspond to the second direction D2 of the pouch 10. Also, for example, one direction of the packaging material 50 may correspond to the flow direction (MD), and for example, a direction perpendicular to the one direction of the packaging material may correspond to the vertical direction (TD).

[0180] In measuring the properties of the packaging material 50, a test piece cut out from the packaging material 50 is used. When the packaging material 50 is available in a state before the packaging material 50 is processed into the pouch 10, the test piece may be prepared by cutting the packaging material 50. The test piece may be prepared by cutting a product made from the packaging material 50, such as the pouch 10. FIG. 10 is a diagram showing an example of a method for preparing a test piece by cutting the front film 15 or the back film 16 of the pouch 10. When measuring the properties of the packaging material 50 in the machine direction, the test piece 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 piece coincides with the machine direction, as shown by reference numeral 80A in FIG. 10. When measuring the properties of the packaging material 50 in the vertical direction, the test piece 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 piece coincides with the vertical direction, as shown by reference numeral 80B in FIG. 10.

[0181] The hot breaking strength of the packaging material 50 is measured in accordance with JIS K7127, except for the lengths of the test pieces 80A and 80B. The length and width of the test pieces 80A and 80B are 100 mm and 15 mm.

[0182] The hot rupture strength of the test pieces 80A and 80B is measured using a Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.). Specifically, first, the test pieces 80A and 80B are gripped at both ends in the longitudinal direction by grippers 81 and 82 as shown in FIG. 11. Then, the test pieces 80A and 80B are held for one minute in an environment of a temperature of 100° C. and a relative humidity of 5%, and then a tensile test is performed in which the test pieces 80A and 80B are pulled in the longitudinal direction of the test pieces 80A and 80B at a tensile speed of 300 mm / min in an environment of a temperature of 100° C. and a relative humidity of 5%, with an initial gripper distance S1 (see FIG. 11) of 50 mm, to measure the hot rupture strength of the test pieces 80A and 80B. The hot breaking strength of the five test pieces 80A, 80B is measured, and the average value is regarded as the hot breaking strength of the packaging material 50 in the machine direction and perpendicular direction.

[0183] The packaging material 50 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 seal portion 33 may peel off before the contents are sufficiently heated and pressurized, causing a decrease in the pressure and temperature of the storage section 18. In consideration of this point, the hot seal strength of the seal portion of the packaging material 50 may be, for example, 3.0 N or more, 4.0 N or more, or 5.0 N or more. The seal strength of the packaging material 50 may change due to a sterilization treatment such as a retort treatment, and in the case where the pouch 10 is subjected to a retort treatment, unless otherwise specified, the "seal strength" refers to the seal strength of the seal portion in the packaging material 50 of the pouch after the retort treatment.

[0184] In measuring the hot seal strength of the packaging material 50, a test piece cut from the packaging material 50 with the inner surfaces joined together is used. When the packaging material 50 is available in a state before the packaging material 50 is processed into the pouch 10, the test piece may be made by cutting the packaging material 50 with the inner surfaces joined together. The test piece may be made by cutting a product made from the packaging material 50, such as the pouch 10. FIG. 12 is a diagram showing an example of a method for preparing a test piece by cutting the front film 15 and the back film 16 with the inner surfaces joined together. For example, the front film 15 and the back film 16 of the pouch 10 are cut to include the first side seal portion 30 or the second side seal portion 35 to prepare a test piece 80C. The length and width of the test piece 80C are 70 mm and 15 mm.

[0185] The hot seal strength is 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, the two sheets of packaging material 50 in the non-sealed portion of the test piece 80C are gripped by grippers 83 and 84 (see FIG. 13A) of the test machine. Then, the grippers 83 and 84 are pulled at a speed of 300 mm / min in opposite directions perpendicular to the surface direction of the sealed portion of the test piece 80C, and the maximum value MAX of the tensile stress F1 is measured (see FIG. 13B). The distance S2 between the grippers 83 and 84 at the start of pulling is 50 mm, and the distance S2 between the grippers 83 and 84 at the start of pulling is 60 mm. The maximum value MAX is taken as the seal strength (see FIG. 13B). The hot seal strength is measured by holding the test piece 80C in an environment with a temperature of 100° C. and a relative humidity of 5% for 1 minute, and then in an environment with a temperature of 100° C. and a relative humidity of 5%. The hot seal strength is measured for five test pieces 80C, and the average value is regarded as the hot seal strength of the packaging material 50.

[0186] The thickness of the packaging material 50 including only two biaxially stretched plastic films is, for example, 80 μm or more, may be 90 μm or more, or may be 100 μm or more. The thickness of the packaging material 50 including only two biaxially stretched plastic films is, for example, 130 μm or less, or may be 120 μm or less.

[0187] FIG. 9 is a cross-sectional view showing another example of the layer structure of the packaging material 50. The packaging material 50 shown in FIG. 9 includes a biaxially stretched plastic film 53, an adhesive layer 58, and a sealant film 55 in this order. The biaxially stretched plastic film 53 is located on the outer surface 50y side, and the sealant film 55 is located on the inner surface 50x side. The inner surface 50x faces the storage section 18. There is only one biaxially stretched plastic film in the packaging material 50. The packaging material 50 may include a transparent deposition layer 62 provided on the surface of the biaxially stretched plastic film 53. The packaging material 50 may include a transparent gas barrier coating film 63 located on the surface of the transparent deposition layer 62.

[0188] The biaxially stretched plastic film 53 is a film made of plastic and stretched in two predetermined directions, similar to the first biaxially stretched plastic film 51. As the biaxially stretched plastic film 53, the biaxially stretched plastic film described above for the first biaxially stretched plastic film 51 may be used.

[0189] As the biaxially stretched plastic film 53, a biaxially stretched plastic film having a loop stiffness of 0.0017 N or more in at least one direction and containing polyester as a main component may be used. In the following description, a biaxially stretched plastic film having a loop stiffness of 0.0017 N or more in at least one direction and containing polyester as a main component is also referred to as a high-stiffness polyester film. The high-stiffness polyester film has a loop stiffness of 0.0017 N or more in at least one of the machine direction (MD) and the transverse direction (TD), for example. The 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), for example. By including a high-stiffness polyester film in the packaging material 50, even if there is only one biaxially stretched plastic film in the packaging material 50, the packaging material 50 can have excellent puncture strength. The high-stiffness polyester film does not include polyamide.

[0190] The polyester of the high stiffness polyester film is preferably a polyester mainly 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. For example, the polyester is PET, PBT, etc. Examples of the high stiffness polyester film include a high stiffness PET film containing 51% by mass or more of PET as a main component, and a high stiffness PBT film containing 51% by mass or more of PBT as a main component. The content of PET in the high stiffness PET film may be 80% by mass or more, 90% by mass or more, or 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.

[0191] Loop stiffness is a parameter that indicates 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. 14 to 19. The measurement method described below can be used not only for a single-layer film such as a biaxially stretched plastic film, but also for a film having multiple layers such as a vapor deposition film or a laminated film. A vapor deposition film is a film that includes a single-layer film such as a biaxially stretched plastic film and a vapor deposition layer formed on the single-layer film. A laminated film is a film that includes multiple laminated films, such as packaging material 50.

[0192] FIG. 14 is a plan view showing the test piece 80 and the loop stiffness measuring instrument 85, and FIG. 15 is a cross-sectional view of the test piece 80 and the loop stiffness measuring instrument 85 of FIG. 14 taken along the line CC. The test piece 80 is a rectangular film having a long side and a short side. In the present application, the length S3 of the long side of the test piece 80 is set to 150 mm, and the length S4 of the short side is set to 15 mm. As the loop stiffness measuring instrument 85, for example, a No. 581 Loop Stiffness Tester (registered trademark) LOOP STIFFNESS TESTER DA type manufactured by Toyo Seiki Seisakusho Co., Ltd. can be used. The length S3 of the long side of the test piece 80 can be adjusted as long as the test piece 80 can be held by a pair of chuck parts 86 described later.

[0193] The loop stiffness measuring device 85 has a pair of chuck portions 86 for gripping a pair of ends in the long side direction of the test piece 80, and a support member 87 for supporting the chuck portions 86. The chuck portions 86 include a first chuck 861 and a second chuck 862. In the state shown in FIG. 14 and FIG. 15, the test piece 80 is placed on the pair of first chucks 861, and the second chuck 862 does not yet grip the test piece 80 between the first chuck 861 and the second chuck 862. As will be described later, during measurement, the test piece 80 is gripped between the first chuck 861 and the second chuck 862 of the chuck portions 86. The second chuck 862 may be connected to the first chuck 861 via a hinge mechanism.

[0194] When a film to be measured, such as a biaxially oriented plastic film, a vapor deposition film, or a laminated film, is available in a state before the film is processed into a packaged product, the test piece 80 may be prepared by cutting the film to be measured. The test piece 80 may also be prepared by cutting a packaged product made from the packaging material 50, such as a pouch. When measuring the loop stiffness of the packaging material 50 in the machine direction, the test piece 80A shown in FIG. 10 can be used. When measuring the loop stiffness of the packaging material 50 in the vertical direction, the test piece 80B shown in FIG. 10 can be used.

[0195] A method for measuring the loop stiffness of the test piece 80 using the loop stiffness measuring device 85 will be described. First, as shown in FIG. 14 and FIG. 15, the test piece 80 is placed on the first chuck 861 of a pair of chuck parts 86 arranged with a gap S5 therebetween. In the present application, the gap S5 is set so that the length of a loop part 801 (hereinafter also referred to as a loop length) described later is 60 mm. The test piece 80 includes an inner surface 80x located on the first chuck 861 side and an outer surface 80y located on the opposite side of the inner surface 80x. When the test piece 80 is made of the packaging material 50, the inner surface 80x and the outer surface 80y of the test piece 80 coincide with the inner surface 50x and the outer surface 50y of the packaging material 50. When the loop part 801 described later is formed in the test piece 80, the inner surface 80x is located inside the loop part 801, and the outer surface 80y is located outside the loop part 801. 16, the second chuck 862 is placed on the test piece 80 so as to grip the end of the test piece 80 in the long side direction between the first chuck 861 and the second chuck 862. As shown in FIG.

[0196] Next, as shown in FIG. 17, at least one of the pair of chucks 86 is slid on the support member 87 in a direction in which the distance between the pair of chucks 86 is reduced. This allows a loop portion 801 to be formed in the test piece 80. The test piece 80 shown in FIG. 17 has a loop portion 801, a pair of intermediate portions 802, and a pair of fixing portions 803. The pair of fixing portions 803 are portions of the test piece 80 that are gripped by the pair of chucks 86. The pair of intermediate portions 802 are portions of the test piece 80 that are located between the loop portion 801 and the pair of intermediate portions 802. As shown in FIG. 17, the chuck portion 86 is slid on the support member 87 until the inner surfaces 80x of the pair of intermediate portions 802 come into contact with each other. This allows a loop portion 801 having a loop length of 60 mm to be formed. The loop length of the loop portion 801 is the length of the test piece 80 between position Q1 where the surface of one second chuck 862 on the loop portion 801 side intersects with the test piece 80, and position Q2 where the surface of the other second chuck 862 on the loop portion 801 side intersects with the test piece 80. When the thickness of the test piece 80 is ignored, the above-mentioned interval S5 is a value obtained by adding 2×t to the length of the loop portion 801, where t is the thickness of the second chuck 862 of the chuck portion 86.

[0197] Thereafter, as shown in FIG. 18, the posture of the chuck portion 86 is adjusted so that the protruding direction Y of the loop portion 801 relative to the chuck portion 86 is horizontal. For example, the posture of the chuck portion 86 supported by the support member 87 is adjusted by moving the support member 87 so that the normal direction of the support member 87 is horizontal. In the example shown in FIG. 18, the protruding direction Y of the loop portion 801 coincides with the thickness direction of the chuck portion. In addition, the load cell 88 is prepared at a position separated by a distance Z1 from the second chuck 862 in the protruding direction Y of the loop portion 801. In this application, the distance Z1 is set to 50 mm. Next, the load cell 88 is moved at a speed V by a distance Z2 shown in FIG. 18 toward the loop portion 801 of the test piece 80. The distance Z2 is set so that the load cell 88 contacts the loop portion 801 and then the load cell 88 pushes the loop portion 801 toward the chuck portion 86. In this application, the distance Z2 is set to 40 mm. In this case, the distance Z3 between the load cell 88 and the second chuck 862 of the chuck portion 86 in a state in which the load cell 88 presses the loop portion 801 toward the chuck portion 86 is 10 mm. The speed V at which the load cell 88 is moved was set to 3.3 mm / sec.

[0198] 19, in a state where the load cell 88 is pressing the loop portion 801 of the test piece 80, the value of the load applied to the load cell 88 from the loop portion 801 is stabilized, and then the value of the load is recorded. The value of the load thus obtained is used as the loop stiffness of the film constituting the test piece 80. In this application, unless otherwise specified, the environment during the measurement of the loop stiffness is a temperature of 23°C and a relative humidity of 50%.

[0199] 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 53, it is possible to increase the puncture strength of the biaxially stretched plastic film 53. This allows the puncture strength of the packaging material 50 including the biaxially stretched plastic film 53 to be, for example, 12.0 N or more, more preferably 13.0 N or more, and even more preferably 14.0 N or more.

[0200] The preferred mechanical properties of the high stiffness polyester film will now be described further. The puncture strength of the high stiffness polyester film is preferably 10 N or more, and more preferably 11 N or more.

[0201] 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. Also, 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.

[0202] The tensile strength and tensile elongation can be measured in accordance with JIS K7127. As a measuring instrument, a tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used. As a test piece, a rectangular film cut from the high stiffness polyester film having a width of 15 mm and a length of 150 mm can be used. The distance between the pair of chucks holding the test piece at the start of the 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. In this application, unless otherwise specified, the environment during the 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 50 are measured in the same manner as for the high stiffness polyester film, except that a tensile tester RTC-1310A manufactured by Orientec Co., Ltd. is used as the measuring instrument, and the distance between the pair of chucks holding the test piece at the start of the measurement is 50 mm. When measuring the tensile strength and tensile elongation of the packaging material 50, 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 vertical direction, as in the case of measuring the loop stiffness.

[0203] 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.

[0204] Like the tensile strength and tensile elongation, the Young's modulus can be measured in accordance with JIS K7127. As a measuring instrument, a tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used. As a test piece, a rectangular film cut from a high stiffness polyester film having a width of 15 mm and a length of 150 mm can be used. The distance between a pair of chucks holding the test piece at the start of the 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. In this application, unless otherwise specified, the environment during the 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 50 is measured in the same manner as for the high stiffness polyester film, except that a tensile tester RTC-1310A manufactured by Orientec Co., Ltd. is used as the measuring instrument, and the distance between the pair of chucks holding the test piece at the start of the measurement is 50 mm. When measuring the Young's modulus of the packaging material 50, 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 vertical direction.

[0205] In the manufacturing process of the high stiffness polyester film, for example, first, a plastic film obtained by melting and molding polyester is stretched 3 to 4.5 times in the machine direction and the perpendicular direction at 90°C to 145°C in a first stretching step. Then, the plastic film is stretched 1.1 to 3.0 times in the machine direction and the perpendicular direction at 100°C to 145°C in a second stretching step. Then, heat setting is performed at a temperature of 190°C to 220°C. Then, relaxation treatment (treatment to reduce the film width) of about 0.2% to 2.5% is performed at a temperature of 100°C to 190°C in the machine direction and the perpendicular direction. In these steps, a high stiffness polyester film having the above-mentioned mechanical properties can be obtained by adjusting the stretch ratio, stretching temperature, heat setting temperature, and relaxation treatment rate.

[0206] By including a high stiffness polyester film in the packaging material 50, excellent puncture strength can be imparted to the packaging material 50 and to a packaged product such as a pouch 10 formed from the packaging material 50. This can prevent the pouch 10 from being torn when a sharp member having a pointed tip comes into contact with the pouch 10, for example. The puncture strength of the packaging material 50 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 described later.

[0207] In addition, the packaging material 50 includes a high stiffness polyester film, so that the Young's modulus of the packaging material 50 can be increased. The Young's modulus of the packaging material 50 in one direction is, for example, 3600 MPa or more, may be 3700 MPa or more, may be 3800 MPa or more, may be 3900 MPa or more, may be 4000 MPa or more, or may be 4100 MPa or more. For example, the Young's modulus of the packaging material 50 in the machine direction (MD) is, for example, 3600 MPa or more, may be 3700 MPa or more, may be 3800 MPa or more, or may be 3900 MPa or more. In addition, the Young's modulus of the packaging material 50 in the perpendicular direction (TD), which is a direction perpendicular to the machine direction (MD), is, for example, 3600 MPa or more, may be 3700 MPa or more, may be 3800 MPa or more, may be 3900 MPa or more, may be 4000 MPa or more, or may be 4100 MPa or more. The high Young's modulus of the packaging material 50 makes the packaging material 50 less likely to stretch. This increases the processing accuracy when processing the packaging material 50 in the manufacturing process of packaged products such as the pouch 10. Furthermore, when the packaging material 50 is used to produce a gusset-type pouch 10 configured to be self-supporting, as described below, the self-supporting ability of the pouch 10 increases. The Young's modulus of the packaging material 50 in the transverse direction (TD) may be higher than the Young's modulus of the packaging material 50 in the machine direction (MD).

[0208] The high stiffness polyester film may be used as the first biaxially oriented plastic film 51 or the second biaxially oriented plastic film 52 shown in Figures 7, 8A and 8B.

[0209] The packaging material 50 including only one biaxially stretched plastic film may have a hot seal strength equivalent to that of the packaging material 50 including only two biaxially stretched plastic films. The packaging material 50 including only one biaxially stretched plastic film has a seal strength (hot seal strength) of, for example, 13.0 N or less when measured in an environment of 100°C after being held in an environment of 100°C 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 the packaging material 50 including only one biaxially stretched plastic film may be, for example, 3.0 N or more, 4.0 N or more, or 5.0 N or more.

[0210] The adhesive layer 58 includes an adhesive for bonding the biaxially oriented plastic film 53 and the sealant film 55 by a dry lamination method. An example of the adhesive for the adhesive layer 58 is polyurethane, as in the case of the first adhesive layer 56. In addition to the configurations, materials, and characteristics described below, the same configurations, materials, and characteristics as those of the first adhesive layer 56 can be adopted for the adhesive layer 58.

[0211] The thickness of the adhesive layer 58 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the adhesive layer 58 is, for example, 6 μm or less, and may be 5 μm or less.

[0212] The thickness of the packaging material 50 including only one biaxially stretched plastic film is, for example, 70 μm or more, may be 80 μm or more, or may be 90 μm or more. The thickness of the packaging material 50 including only one biaxially stretched plastic film is, for example, 110 μm or less, or may be 100 μm or less.

[0213] How the pouch is made Next, a method for manufacturing the pouch 10 using the packaging material 50 will be described. First, the front film 15 and the back film 16 made of the packaging material 50 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 upper seal portion 11a, the first side seal portion 30, and the second side seal portion 35. The heat-sealing temperature is, for example, 160°C or higher, may be 170°C or higher, or may be 180°C or higher. The heat-sealing temperature is, for example, 250°C or lower, may be 240°C or lower, or may be 230°C or lower.

[0214] The front film 15 and the back film 16 joined together by heat sealing are cut into an appropriate shape. This makes it possible to obtain the pouch 10 shown in FIG. 1. Next, the contents are filled into the pouch 10 through the opening of the lower part 12. After that, the upper part 11 is heat sealed along the upper edge 11x to form the upper sealed part 11a. In this way, it is possible to obtain the pouch 10 in which the contents 19 are contained and sealed, as shown in FIG. 3. Thereafter, the pouch 10 may be subjected to a sterilization treatment such as boiling or retort treatment. The pouch 10 may be housed inside a carton 100.

[0215] 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 to 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. Then, the pouch 10 is heated using the microwave oven. The moisture contained in the contents 19 evaporates, and the pressure in the storage section 18 increases.

[0216] When 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. Therefore, a force is applied to each position of the sealed portion in a direction from the center point C toward the sealed portion. The force applied to each position of the sealed portion increases as the distance from the center point C decreases. The distance from the first intermediate seal portion 33 to the center point C is shorter than the distance from the first lower seal portion 32 to the center point C. For this reason, a larger force is applied to, for example, the inner edge first connecting portion 336 of the first intermediate seal portion 33 than to the inner edge 32a of the first lower seal portion 32. In addition, the distance from the second intermediate seal portion 38 to the center point C is shorter than the distance from the second lower seal portion 37 to the center point C. For this reason, a larger force is applied to, for example, the inner edge first connecting portion 386 of the second intermediate seal portion 38 than to the inner edge 37a of the second lower seal portion 37.

[0217] When a force is applied to the first intermediate seal portion 33, peeling of the first intermediate seal portion 33 progresses. When peeling of the first intermediate seal portion 33 is reached, a flow path 33v is formed in the first intermediate seal portion 33, as shown in FIG. 20. Steam generated in the storage portion 18 flows into the first non-sealed portion 40 through the flow path 33v. Although not shown, peeling also progresses in the second intermediate seal portion 38 in the same manner as in the first intermediate seal portion 33, and a flow path is formed. Steam generated in the storage portion 18 also flows into the second non-sealed portion 45 through the flow path.

[0218] If the amount of steam discharged to the outside of pouch 10 is smaller than the amount of steam generated in storage section 18, the pressure in storage section 18 continues to increase. In this case, peeling may progress in sealed sections other than intermediate sealed sections 33, 38, such as first lower sealed section 32 and lower sealed section 37. In particular, when the output of the microwave oven is high, the rate at which steam is generated in storage section 18 is high, so peeling is likely to occur in sealed sections other than intermediate sealed sections 33, 38. If the pressure in storage section 18 exceeds a certain value, pouch 10 may burst. The high output of the microwave oven is, for example, 800W or more, may be 900W or more, or may be 1000W or more.

[0219] In this embodiment, steam generated in the storage section 18 is discharged to the outside of the pouch 10 through both the first non-sealed section 40 and the second non-sealed section 45. This makes it possible to suppress an increase in pressure in the storage section 18. This makes it possible to suppress peeling in the sealed sections other than the intermediate sealed sections 33 and 38. Also, it makes it possible to suppress rupture of the pouch 10.

[0220] In this embodiment, the sealed portion of the pouch 10 has a hot seal strength of 10 N or less. This allows a flow path to be formed in the intermediate sealed portions 33, 38 before the pressure in the storage portion 18 becomes excessively high. This makes it possible to prevent peeling from occurring in the sealed portions other than the intermediate sealed portions 33, 38. Also, it makes it possible to prevent the pouch 10 from bursting.

[0221] If the contents include a granular ingredient such as minced meat, the ingredient may scatter and block the flow path of the intermediate seal portions 33 and 38. If the flow path 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 allows the width of the flow path to be appropriately secured. This prevents the flow path from being blocked by the contents 19. Also, ingredients including minced meat, such as keema curry, can be stored in the pouch 10.

[0222] In addition, in this embodiment, since the first non-sealed portion 40 spreads to reach the first side edge 13x, it is easy to ensure the area of ​​the first non-sealed portion 40. Therefore, the distance L12 in the first direction D1 between the inner edge 32a of the first lower sealed portion 32 and the inner edge 33a of the first intermediate sealed portion 33 can be reduced. Similarly, since the second non-sealed portion 45 spreads to reach the second side edge 14x, the distance L22 can be reduced. This allows the distance from the center point C to the inner edges 33a, 38a of the intermediate sealed portions 33, 38 to be increased. Therefore, when a force due to an impact such as a drop is applied to the pouch 10, it is possible to suppress the application of a large force to the intermediate sealed portions 33, 38. Therefore, it is possible to suppress the peeling of the intermediate sealed portions 33, 38 due to an impact such as a drop.

[0223] It should be noted that various modifications can be made to the above-described embodiment. Below, the modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above-described embodiment will be used for parts that can be configured in the same manner as in the above-described embodiment, and duplicated descriptions will be omitted. Also, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified examples, the description may be omitted.

[0224] First Variation In the above embodiment, an example has been described in which the overhang dimension L12 of the first intermediate seal portion 33 is the same as the overhang dimension L22 of the second intermediate seal portion 38, but this is not limiting. As shown in Fig. 21, the overhang dimension L12 of the first intermediate seal portion 33 may be different from the overhang dimension L22 of the second intermediate seal portion 38. For example, the overhang dimension L12 may be larger than the overhang dimension L22. Although not shown, the overhang dimension L12 may be smaller than the overhang dimension L22.

[0225] The difference between the overhang dimension L12 and the overhang dimension L22 is, for example, 1 mm or more, may be 2 mm or more, or may be 3 mm or more. The difference between the overhang dimension L12 and the overhang dimension L22 is, for example, 10 mm or less, may be 7 mm or less, or may be 5 mm or less.

[0226] Second Variation Fig. 22 is a front view showing a modified example of pouch 10. Fig. 23 is an enlarged front view showing second intermediate seal portion 38 and second non-sealed portion 45 of second side seal portion 35 of pouch 10 in Fig. 22.

[0227] 23, the second inner edge 382 may extend from the inner edge first connecting portion 386 toward the upper portion 11 of the pouch 10 so as to be at least partially displaced toward the second side portion 14. The angle θ21 between the direction in which the first inner edge 381 extends and the direction in which the second inner edge 332 extends is smaller than 90°. The angle θ21 is, for example, 85° or less, may be 80° or less, or may be 75° or less. The angle θ21 is, for example, 30° or more, may be 40° or more, or may be 50° or more.

[0228] 23, the second edge 482 may extend from the first connecting portion 486 toward the upper portion 11 of the pouch 10 so as to be at least partially displaced toward the second side portion 14. The angle θ22 between the direction in which the first edge 481 extends and the direction in which the second edge 482 extends is smaller than 90°. The angle θ22 is, for example, 85° or less, may be 80° or less, or may be 75° or less. The angle θ22 is, for example, 30° or more, may be 40° or more, or may be 50° or more.

[0229] Third variant Fig. 24 is a front view showing one modified example of the pouch 10. The first intermediate sealed portion 33 and the first non-sealed portion 40 may have the same shapes as the second intermediate sealed portion 38 and the second non-sealed portion 45 shown in Figs. 22 and 23. That is, the second inner edge 332 may extend so as to be at least partially displaced toward the first side portion 13 as it moves from the inner edge first connecting portion 336 toward the upper portion 11 of the pouch 10. Also, the second edge portion 432 may extend so as to be at least partially displaced toward the first side portion 13 as it moves from the first connecting portion 436 toward the upper portion 11 of the pouch 10. EXAMPLES

[0230] Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples as long as it does not depart from the gist of the present invention.

[0231] (Packaging material 1) A biaxially oriented PET film (product name "E5100", manufactured by Toyobo Co., Ltd.) having a thickness of 12 μm was prepared as the first biaxially oriented plastic film. Then, a printed layer was formed on the inner surface of the first biaxially oriented plastic film. The thickness of the printed layer was 3.0 μm.

[0232] In addition, 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. Next, one side of this film was subjected to a corona discharge treatment, and then a transparent deposition layer made of silicon oxide and having a thickness of 10 nm was formed. Next, the transparent deposition layer was subjected to a plasma treatment using a mixed gas of oxygen and argon, and then a coating liquid mainly composed of ethyl silicate and polyvinyl alcohol was applied with a gravure roll coater to form a transparent gas barrier coating film having a thickness of 300 nm after drying.

[0233] In addition, an unstretched polypropylene film (product name "ZK500", manufactured by Toray Advanced Film Co., Ltd.) having a thickness of 60 μm was prepared as a sealant film.

[0234] Then, the first biaxially oriented PET film, the printing layer, the first adhesive layer, the transparent barrier coating film, the transparent vapor deposition layer, the second biaxially oriented PET film, the second adhesive layer, and the unstretched polypropylene film were laminated in this order by dry lamination to produce a packaging material. As the first adhesive layer and the second adhesive layer, a two-liquid polyurethane adhesive (main agent: RU-004, hardener: H-1) manufactured by Rock Paint Co., Ltd. was used. The thickness of the first adhesive layer and the second adhesive layer was 3.0 μm. The packaging material obtained in this manner is also referred to as packaging material 1.

[0235] (Packaging material 2) A packaging material was produced in the same manner as for 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.

[0236] (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 a sealant film. The packaging material obtained in this manner is also referred to as packaging material 3.

[0237] (Packaging material 4) As a biaxially stretched plastic film, a high-stiffness polyester film (hereinafter also referred to as a high-stiffness PET film) having a loop stiffness of 0.0017 N or more and containing 90 mass % or more of PET was prepared. 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.

[0238] Next, one side of the high stiffness PET film was subjected to a corona discharge treatment, and then a transparent 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.

[0239] Then, a high stiffness PET film, a transparent 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-liquid polyurethane adhesive (main agent: RU-004, hardener: 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.

[0240] (Evaluation of packaging materials 1 to 4) The pouch 10 shown in Fig. 1 was produced using the 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 (manufactured by Tester Sangyosha Co., Ltd.) Heat seal temperature: 225℃ Heat seal pressure: 0.1MPa Heat seal time: 1 second

[0241] Next, the pouch 10 was subjected to a retort treatment under the following conditions. Method: Spray type Retort temperature: 121℃ Retort time: 30 minutes

[0242] The dimensions of each part of the pouch 10 are as follows: - Dimensions of storage compartment 18 H1: 118mm - Dimensions of storage compartment 18 H2: 159mm Width of upper seal part 11a, width of lower seal part 12a: 8mm Width W12 of the first lower seal portion 32, width W22 of the lower seal portion 37: 6 mm

[0243] The breaking strength (hot breaking strength) in the machine direction and the perpendicular direction was measured using test pieces 80A and 80B cut out from the pouch 10 composed of the packaging material 1 and the packaging material 2. The measurement method and conditions were the same as those in the above-mentioned embodiment. The results are shown in FIG.

[0244] The Young's modulus in the machine direction and the perpendicular direction was measured using test pieces 80A and 80B cut out from a pouch 10 made of the packaging material 4. The measurement method and conditions were the same as those in the above-mentioned embodiment. The results are shown in FIG.

[0245] The puncture strength of the packaging material 4 was measured in accordance with JIS Z1707 7.4 using a test piece cut out from a pouch 10 made of the packaging material 4. A Tensilon universal material testing machine RTC-1310 manufactured by A&D was used as the measuring device. 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 50y side of the test piece of the packaging material 4 in a fixed state at a speed of 50 mm / min (50 mm per minute). The maximum value of the stress until the needle penetrated the packaging material 4 was measured. The maximum value of the stress was measured for five or more test pieces, and the average value was taken as the puncture strength of the packaging material 4. The environment during the measurement was a temperature of 23°C and a relative humidity of 50%. The results are shown in FIG. 26.

[0246] The hot seal strength was measured using a test piece 80C cut out from a pouch 10 composed of packaging materials 1 to 4. The measurement method and conditions were the same as those in the above-mentioned embodiment. The results are shown in Figs. 25 and 26.

[0247] Example 1 Content 1 and Content 2 were prepared as contents to be filled into pouch 10. Content 1 was 150g of keema curry. Content 2 was 180g of curry. The results of analyzing the ingredients contained in Content 1 and Content 2 are shown in FIG. 27.

[0248] In the analysis, first, the curry roux was removed from the contents using a sieve. The mesh size of the sieve was 0.7 mm. 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.

[0249] The dimensions and number of pieces of meat contained in Content 1 were analyzed in detail, and the results are shown in Figure 28.

[0250] The viscosity of the curry roux of Content 1 and Content 2 was measured. The results are shown in Figure 29. The viscosity was measured using a digital viscometer DV-E manufactured by Eiko Seiki.

[0251] A pouch 10 as shown in Fig. 1 was produced using the packaging material 1. The pouch 10 was then filled with the above-mentioned contents 1 or 2. The lower portion 12 of the pouch 10 was then heat-sealed to form a lower sealed portion 12a. In this manner, the pouch 10 as shown in Fig. 3 containing the contents 1 or 2 was obtained. Specifically, two pouches 10 containing the contents 1 and two pouches 10 containing the contents 2 were produced.

[0252] The dimensions of each part of the pouch 10 are as follows: - Dimensions of storage compartment 18 H1: 118mm - Dimensions of storage compartment 18 H2: 159mm Width of upper seal part 11a, width of lower seal part 12a: 8mm Width W12 of the first lower seal portion 32, width W22 of the lower seal portion 37: 6 mm Width W11 of the first upper seal portion 31, width W36 of the upper seal portion 36: 10 mm Widths W13, W14, W15 of the first intermediate seal portion 33: 3 mm - Protrusion dimension L12 of the first intermediate seal portion 33: 9 mm Length L11 of the first opening edge 41: 15 mm Width of second intermediate seal portion 38 W23, W24, W25: 3 mm - Overhang dimension L22 of the second intermediate seal portion 38: 9 mm Length L21 of the second opening edge 46: 15 mm

[0253] The heat sealing conditions are as follows: Heat sealing device: Heat sealer TP-701-A (manufactured by Tester Sangyosha Co., Ltd.) Heat seal temperature: 225℃ Heat seal pressure: 0.1MPa Heat seal time: 1 second

[0254] Next, the pouch 10 was subjected to a retort treatment under the following conditions. Method: Spray type Retort temperature: 121℃ Retort time: 30 minutes

[0255] Next, 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.

[0256] The carton 100 was then opened and placed in a microwave oven with the pouch 10 tilted at an angle θa to a horizontal plane 120, which is the inside undersurface of the range, as shown in Figure 4. The angle θa was 17°.

[0257] The pouch 10 containing the content 1 was heated for 3 minutes in a microwave oven with an output of 600 W. The pouch 10 containing the content 2 was heated for 3 minutes in a microwave oven with an output of 600 W. The pouch 10 containing the content 1 was heated for 5 minutes in a microwave oven with an output of 1000 W. The pouch 10 containing the content 2 was heated for 5 minutes in a microwave oven with an output of 1000 W. The Panasonic NE-1801 was used as the microwave oven.

[0258] The vapor permeability of each pouch 10 after heating was evaluated. The results are shown in the "Vapor permeability" column of Fig. 30. In the "Vapor permeability" column, "great" means that the flow paths formed in the middle sealed portions 33, 38 were not clogged with the ingredients of the contents, and the pouch 10 did not burst. "Not good" means that the flow paths were clogged with the ingredients of the contents, and the pouch 10 burst. The lowest evaluation result of "vaporability" of each pouch 10 is shown in Figure 31. In Example 1, the evaluation results of "vaporability" of each pouch 10 were all "great", so "great" is shown in Figure 31. If the evaluation results of "vaporability" of multiple pouches 10 include "great" and "not good", "not good" is shown in Figure 31.

[0259] After heating, each pouch 10 was checked for peeling at the first lower sealed portion 32 or the second lower sealed portion 37. The results are shown in the "Seal Recession" column of FIG. 30. In the "Seal Recession" column, "great" means that the width of the peeling at the first lower sealed portion 32 or the second lower sealed portion 37 in the first direction D1 was less than 1 mm, or no peeling occurred. "Good" means that the width of the peeling at the first lower sealed portion 32 or the second lower sealed portion 37 in the first direction D1 was 1 mm or more and less than 2 mm. "Not good" means that the width of the peeling at the first lower sealed portion 32 or the second lower sealed portion 37 in the first direction D1 was 2 mm or more. The lowest evaluation result of "seal recession" for each pouch 10 is shown in Figure 31. In Example 1, the evaluation result of "seal recession" for each pouch 10 was "great," so "great" is shown in Figure 31. If the evaluation results of "seal recession" for multiple pouches 10 include "great" and "not good," "not good" is shown in Figure 31.

[0260] A drop test was also conducted on the pouch 10. First, the pouch 10 of FIG. 1 was made using the packaging material 1. Then, 180 g of water was filled into the pouch 10. Then, the lower portion 12 of the pouch 10 was heat-sealed to form the lower seal portion 12a. In this manner, the pouch 10 shown in FIG. 3 containing water was obtained. Then, the pouch 10 was subjected to a retort treatment under the following conditions. The dimensions of each portion of the pouch 10, the heat-sealing conditions, and the retort treatment conditions were the same as those of the above-mentioned pouch 10 filled with the content 1 or the content 2.

[0261] Next, 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 stored in a refrigerator for one day. Thereafter, the pouch 10 was placed in a carton 100.

[0262] Next, the carton 100 containing the pouches 10 was dropped from a height of 1.2 m. At this time, the position of the carton 100 was determined so that the front or back surface of the carton 100 faced downward. The front and back surfaces of the carton 100 faced the front film 15 and back film 16 of the pouches 10.

[0263] Next, the carton 100 containing the pouches 10 was dropped from a height of 1.2 m. At this time, the position of the carton 100 was determined so that the side of the carton 100 faced downward. The side of the carton 100 faced the first side portion 13 or the second side portion 14 of the pouches 10.

[0264] Thereafter, it was confirmed whether the pouches 10 had burst. Such a drop test was performed on 10 pouches 10. The results are shown in the "Drop Strength" column of FIG. 31. In the "Drop Strength" column, "great" means that none of the 10 pouches 10 burst. "good" means that only one of the 10 pouches 10 burst. "not good" means that two or more of the 10 pouches 10 burst.

[0265] Example 2 1 was produced using the packaging material 2. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The dimensions of each part of the pouch 10 were the same as those in Example 1.

[0266] The "vapor permeability," "seal recession," and "drop strength" were evaluated in the same manner as in Example 1. The results are shown in Figs. 30 and 31.

[0267] Example 3 1 was produced using the packaging material 4. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The dimensions of each part of the pouch 10 were the same as those in Example 1.

[0268] The "vapor permeability," "seal recession," and "drop strength" were evaluated in the same manner as in Example 1. The results are shown in Figs. 30 and 31.

[0269] Comparative Example 1 A pouch 10 shown in FIG. 32 was produced using a packaging material 3. The conditions for heat sealing and retort treatment were the same as those in Example 1. The dimensions of the storage section 18, the first non-sealed section 40, and the first intermediate sealed section 33 of the pouch 10 in Comparative Example 1 were the same as those in Example 1. On the other hand, the second non-sealed section 45 of the pouch 10 in Comparative Example 1 does not extend to a position on the first side section 13 side beyond the inner edge 37a of the second lower sealed section 37. That is, the second non-sealed section 45 is located on the second side section 14 side beyond the inner edge 37a. For this reason, the second non-sealed section 45 does not function as a steam release mechanism as compared to the case of Example 1.

[0270] The "vapor permeability," "seal recession," and "drop strength" were evaluated in the same manner as in Example 1. The results are shown in Figs. 30 and 31.

[0271] Comparative Example 2 Using the packaging material 1, a pouch 10 shown in Fig. 32 was produced in the same manner as in Comparative Example 1. The heat sealing conditions and the retort treatment conditions were the same as in Example 1. The dimensions of each part of the pouch 10 were the same as in Comparative Example 1.

[0272] The "vapor permeability," "seal recession," and "drop strength" were evaluated in the same manner as in Example 1. The results are shown in Figs. 30 and 31.

[0273] Comparative Example 3 The pouch 10 in Fig. 1 was produced using the packaging material 3. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The dimensions of each part of the pouch 10 were the same as those in Example 1.

[0274] The "vapor permeability," "seal recession," and "drop strength" were evaluated in the same manner as in Example 1. The results are shown in Figs. 30 and 31.

[0275] Comparative Example 4 A pouch 10 shown in FIG. 33 was produced using the packaging material 1. The pouch 10 in FIG. 33 differs from the pouch 10 in FIG. 1 in that the first non-sealed portion 40 of the pouch 10 does not reach the first side edge 13x. In this case, in order to ensure the area of ​​the first non-sealed portion 40, the first non-sealed portion 40 and the first intermediate sealed portion 33 need to expand inward compared to the pouch 10 in FIG. 1. As a result, the overhang dimension L12 of the first intermediate sealed portion 33 becomes larger. The second non-sealed portion is not formed on the second side portion 14 side of the pouch 10 in FIG. 33.

[0276] The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The dimensions of each part of the pouch 10 are as follows. - Dimensions of storage compartment 18 H1: 118mm Dimensions of storage compartment 18 H2: 159mm Width of upper seal part 11a, width of lower seal part 12a: 8mm Width W12 of the first lower seal portion 32, width W22 of the lower seal portion 37: 6 mm Width W11 of the first upper seal portion 31, width W36 of the upper seal portion 36: 10 mm Width of first intermediate seal portion 33: 3 mm - Protrusion dimension L12 of the first intermediate seal portion 33: 17 mm Dimensions of through hole 44: 6mm (circular)

[0277] The "vapor permeability," "seal recession," and "drop strength" were evaluated in the same manner as in Example 1. The results are shown in FIG. [Explanation of symbols]

[0278] 10 pouches 11 Top 11a Upper seal part 12 Lower 12a Lower seal part 13 First side 13x 1st side edge 14 Second side 14x 2nd side edge 15 Surface film 16 Back film 18 Storage unit 19 Contents 19a Top side 30 First side seal 31 First upper seal part 31a Inner Marriage 32 First lower seal part 32a Inner border 33 First intermediate seal part 33a Inner border 331 First Marriage 332 Second Marriage 333 Third Marriage 336 Inner edge first joint 337 Inner edge second joint 35 Second side seal 36 Second upper seal part 36a Inner edge 37 Second lower seal part 37a Inner border 38 Second intermediate seal part 38a Inner border 381 First Common Marriage 382 Second Marriage 383 Third Common Marriage 40 First non-sealed part 41 First opening edge portion 43 Edge of seal side 431 First edge 432 Second edge 433 Third edge 436 1st connection part 437 2nd connection part 44 Through hole 45 Second non-sealed part 46 Second opening edge 481 First edge 482 Second edge 483 Third Edge 486 1st connection part 487 2nd connection part 50 Packaging materials 50x inner surface 50y external surface 51 First biaxially stretched plastic film 52 Second biaxially oriented plastic film 55 Sealant Film 56 First adhesive layer 57 Second adhesive layer 61 Printing layer 62 Transparent vapor deposition layer 63 Transparent gas barrier coating film

Claims

1. 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 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 and 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 receiving portion by the first side seal portion, the first unsealed portion extending to a first edge of the first side of the pouch; a second unsealed portion located toward a top of the pouch and separated from the containing portion by the second side seal portion, the second unsealed portion extending to a second edge of the second side of the pouch; the first unsealed portion overlaps the first side edge and has a first opening edge portion that opens to the outside, A dimension (L11) of the first opening edge portion in a second direction perpendicular to the first direction is 12 mm or more, the first side seal portion includes a first lower seal portion extending along the first side portion from the first non-seal portion toward a lower portion of the pouch, and a first intermediate seal portion connected to the first lower seal portion and positioned between the containing portion and the first non-seal portion in the first direction, a maximum value (L12) of a distance in the first direction between an inner edge of the first lower seal portion and an inner edge of the first intermediate seal portion is 12 mm or less; The inner edge of the first intermediate seal portion includes a first inner edge, a second inner edge, and an inner edge first connecting portion connecting the first inner edge and the second inner edge, The first inner edge of the first middle seal portion extends from the inner edge first connecting portion toward the first lower seal portion, the second inner edge of the first middle seal portion extends from the inner edge first juncture toward the top of the pouch; an angle between a direction in which the second inner edge of the first intermediate seal portion extends and the second direction is 10° or less; an edge of the first non-seal portion including a first edge extending at least partially parallel to the first inner edge of the first intermediate seal portion and a second edge extending at least partially parallel to the second inner edge of the first intermediate seal portion; the first unsealed portion extends to a position on the second side portion beyond an inner edge of the first lower seal portion, the second unsealed portion overlaps the second side edge and has a second opening edge portion that opens to the outside, The dimension (L21) of the second opening edge portion in the second direction is 12 mm or more, the second side seal portion includes a second lower seal portion extending along the second side portion from the second non-seal portion toward a lower portion of the pouch, and a second intermediate seal portion connected to the second lower seal portion and positioned between the containing portion and the second non-seal portion in the first direction, A maximum value (L22) of a distance in the first direction between an inner edge of the second lower seal portion and an inner edge of the second intermediate seal portion is 12 mm or less; The inner edge of the second intermediate seal portion includes a first inner edge, a second inner edge, and an inner edge first connecting portion connecting the first inner edge and the second inner edge, The first inner edge of the second intermediate seal portion extends from the inner edge first connecting portion toward the second lower seal portion, the second inner edge of the second intermediate seal portion extends from the inner edge first juncture toward the top of the pouch; an angle between a direction in which the second inner edge of the second intermediate seal portion extends and the second direction is 10° or less; an edge of the second non-seal portion including a first edge extending at least partially parallel to the first inner edge of the second intermediate seal portion and a second edge extending at least partially parallel to the second inner edge of the second intermediate seal portion; The second unsealed portion extends to a position on the first side beyond an inner edge of the second lower seal portion.

2. the first side seal portion includes a first upper seal portion extending along the first side from the first non-seal portion toward an upper portion of the pouch, the first lower seal portion, and the first intermediate seal portion having one end connected to the first upper seal portion and the other end connected to the first lower seal portion and positioned between the containing portion and the first non-seal portion; the first unsealed portion extends to a position on the second side portion beyond an inner edge of the first upper seal portion, the second side seal portion includes a second upper seal portion extending along the second side portion from the second non-seal portion toward an upper portion of the pouch, the second lower seal portion, and the second intermediate seal portion having one end connected to the second upper seal portion and the other end connected to the second lower seal portion and positioned between the containing portion and the second non-seal portion, The pouch of claim 1 , wherein the second unsealed portion extends to a position closer to the first side than an inner edge of the second top seal portion.

3. 3. The pouch according to claim 1 or 2, wherein a ratio of the maximum value (L12) to a dimension of the storage portion in the first direction is 0.10 or less.

4. The pouch according to claim 1 , wherein an extension of a straight line connecting a center point of the containing portion and the first non-sealed portion at the shortest distance intersects with the first opening edge portion.

5. The 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, 5. The pouch according to claim 1, 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 one minute.

6. The packaging material constituting the front film and the back film includes a first biaxially oriented plastic film, a second biaxially oriented plastic film, and a sealant film in this order; 6. The pouch of claim 1, wherein there are only two biaxially oriented plastic films in the packaging material.

7. 7. The pouch according to claim 6, wherein the packaging material has a breaking strength in one direction of 33.0 MPa or more when measured in a 100°C environment after being held in a 100°C environment for 1 minute.

8. the first biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film; 8. The pouch of claim 6 or 7, wherein the second biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film or a biaxially oriented nylon film.

9. the packaging material further comprising a transparent vapor deposition layer located between the first biaxially oriented plastic film and the second biaxially oriented plastic film; 9. The pouch of claim 6, wherein the transparent vapor deposition layer comprises a metal oxide or an inorganic oxide.

10. 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, 6. The pouch of claim 1, wherein the packaging material contains only one biaxially oriented plastic film.

11. 11. The pouch of claim 10, wherein the packaging material has a Young's modulus in one direction of 3600 MPa or more.

12. The packaging material further comprises a transparent deposition layer provided on a surface of the biaxially stretched plastic film; 12. The pouch of claim 10 or 11, wherein the transparent vapor deposition layer comprises a metal oxide or an inorganic oxide.

13. 13. The pouch of claim 9 or 12, wherein the packaging material further comprises a transparent gas barrier coating film located on a surface of the transparent vapor deposition layer.

14. 14. The pouch of claim 6, wherein the sealant film comprises a propylene-ethylene block copolymer and an elastomer.

15. The pouch contains a meat content in the container, The pouch is heated in a microwave oven.

15. The pouch according to any one of claims 1 to 14.

16. 16. The pouch of claim 15, wherein the contents include 50 or more pieces of meat having a dimension of 3 mm or greater.

17. 17. The pouch according to claim 15 or 16, 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.

18. The filling comprises an ingredient including the meat and a viscous component, The ratio of the weight of the ingredient to the weight of the content is 8% or more, 18. The pouch according to claim 15, wherein the ratio of the weight of the meat to the weight of the filling is 20% or more.

19. the first side seal portion includes a first upper seal portion extending along the first side from the first non-seal portion toward an upper portion of the pouch, the first lower seal portion, and the first intermediate seal portion having one end connected to the first upper seal portion and the other end connected to the first lower seal portion and positioned between the containing portion and the first non-seal portion; 19. The pouch according to claim 15, wherein when the pouch is tilted at an angle of 17° with respect to a horizontal plane, the distance between an upper surface of the content and the first intermediate seal portion is 5 mm or more and 30 mm or less.

Images