Pouch

Abstract

To prevent a content from leaking outside of a pouch.SOLUTION: A first side portion seal part of a pouch has a first intermediate portion comprising a first portion, a second portion, and a first connection portion of connecting the first portion with the second portion. The first portion extends toward a first side portion of the pouch from the first connection portion. The second portion extends toward above the pouch from the first connection portion. The first portion comprises: an inner side first portion; an outer side first portion located outside the inner side first portion in a first direction; and a first transition portion that is located between the inner side first portion and the outer side first portion and has a larger width than a width of the inner side first portion. The second portion comprises: a lower side second portion; an upper side second portion located above the lower side second portion; and a second transition portion that is located between the lower side second portion and the upper side second portion and has a larger width than the lower side second 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 inside of 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 a bulging seal section that bulges inward from a seal section that extends along the side edge of the pouch, and a non-seal section that is isolated from the storage section by the bulging seal section and extends to reach the side edge of the pouch. If the pressure in the storage section increases, the bulging 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 container is exhausted from the side edge of the pouch through the peeled portion of the bulging seal. If the bulging seal and the non-sealed portion are improperly constructed, the contents may leak out of the pouch.

[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 embodiments of the present disclosure relate to the following [1] to

[21] . [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 an upper portion of the pouch and separated from the containing portion by the first side seal portion; the first side seal portion includes at least a side lower portion extending along a first side edge of the first side portion from the first non-seal portion toward a lower portion of the pouch, a first intermediate portion located between the containing portion and the first non-seal portion and connected to the side lower portion, and a second intermediate portion located between the first non-seal portion and the first side edge in the first direction and connected to the side lower portion; the first intermediate portion includes a first portion, a second portion, and a first connecting portion connecting the first portion and the second portion, the first portion extends from the first connecting portion toward the first side of the pouch; the second portion extends from the first connecting portion toward the top of the pouch; the first portion includes an inner first portion, an outer first portion located outward in the first direction from the inner first portion, and a first transition portion located between the inner first portion and the outer first portion and having a width greater than a width of the inner first portion; The pouch, wherein the second portion includes a lower second portion, an upper second portion located above the lower second portion, and a second transition portion located between the lower second portion and the upper second portion and having a width greater than that of the lower second portion.

[0008] [2] In the pouch described in [1], the first side seal portion may include an inner edge that is an edge that contacts or faces the containing portion, and an outer edge located opposite the inner edge, the inner first portion may include a portion where the inner edge and the outer edge extend linearly and have a first standard width, the first transition portion may have a width that is 1.2 times or more the first standard width, the lower second portion may include a portion where the inner edge and the outer edge extend linearly and have a second standard width, and the second transition portion may have a width that is 1.2 times or more the second standard width.

[0009] [3] In the pouch described in [1] or [2], a first shielding distance (L11), which is the distance in the first direction between the boundary between the inner first portion and the first transition portion and the inner edge of the lower side portion, may be 1.0 mm or more and 5.0 mm or less.

[0010] [4] In the pouch described in [3], the boundary between the inner first portion and the first transition portion may be located outer in the first direction than the boundary between the lower second portion and the second transition portion.

[0011] [5] In the pouch described in any one of [1] to [4], a first distance (L14) which is the distance between the outer edge of the boundary between the inner first portion and the first transition portion and the outer edge of the boundary between the lower second portion and the second transition portion may be 10 mm or more and 20 mm or less.

[0012] [6] In the pouch described in [5], the ratio (L14 / L13) of the first distance (L14) to the dimension (L13) of the second intermediate portion in a second direction perpendicular to the first direction may be greater than or equal to 0.8 and less than or equal to 2.0.

[0013] [7] In the pouch described in any one of [1] to [6], the boundary between the inner first portion and the first transition portion may be located outside the outer edge of the upper second portion in the first direction.

[0014] [8] In the pouch according to any one of [1] to [6], a second distance (L16) that is the shortest distance between the second portion and the second intermediate portion may be 6 mm or more and 12 mm or less.

[0015] [9] In the pouch described in [8], the first distance (L14) may be greater than the second distance (L16).

[0016]

[10] In the pouch according to [9], a ratio (L14 / L16) of the first distance (L14) to the second distance (L16) may be 1.5 or more and 2.5 or less.

[0017]

[11] In the pouch described in any one of [8] to

[10] , the first non-sealed portion may extend to reach the first side edge, and a dimension (L15) of an opening edge portion which is the portion of the first non-sealed portion which overlaps the first side edge may be greater than the second distance (L16).

[0018]

[12] In the pouch according to

[11] , a ratio (L15 / L16) of the dimension (L15) of the opening edge portion to the second distance (L16) may be 1.2 or more and 2.5 or less.

[0019]

[13] In the pouch described in any one of [8] to

[12] , the ratio (L13 / L16) of the dimension (L13) of the second intermediate portion in a second direction perpendicular to the first direction to the second distance (L16) may be 1.0 or more and 2.5 or less.

[0020]

[14] In the pouch described in any one of [8] to

[13] , a first opening distance (L17), which is the distance in the first direction between an outer edge of the boundary between the inner first portion and the first transition portion and an outer edge of the boundary between the lower second portion and the second transition portion, may be 2.5 mm or less.

[0021]

[15] In the pouch according to

[14] , a ratio (L17 / L16) of the first opening distance (L17) to the second distance (L16) may be 0.30 or less.

[0022]

[16] In the pouch described in any one of [8] to

[15] , the boundary between the lower second portion and the second transition portion may be located above an upper edge of the second intermediate portion.

[0023]

[17] In the pouch described in any one of [8] to

[15] , the boundary between the lower second portion and the second transition portion may be located below an upper edge of the second intermediate portion.

[0024]

[18] In the pouch according to any one of [1] to

[17] , the second transition portion may include an outer edge that extends in a different direction than an outer edge of the lower second portion.

[0025]

[19] In the pouch described in any one of [1] to

[18] , the first side seal portion may include an upper side portion extending along the first side edge from the first unsealed portion toward the top of the pouch, and the first intermediate portion may be connected to the upper side portion of the first side seal portion.

[0026]

[20] The pouch described in

[19] may include an opening means located in the upper side portion.

[0027]

[21] The content contained in the pouch according to any one of [1] to

[18] may have a viscosity of a viscous component at 95°C of 1000 mPa·S or more. Effect of the Invention

[0028] According to the present invention, leakage of the contents to the outside of the pouch can be suppressed. [Brief description of the drawings]

[0029] [Figure 1] FIG. 2 is a front view showing a pouch in the first embodiment. [Diagram 2] 2 is a cross-sectional view showing an example of the pouch shown in FIG. 1 when viewed along line II-II. [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] FIG. 4 is an enlarged front view showing the steam release mechanism. [Figure 6] FIG. 4 is a diagram illustrating a first portion of the first intermediate portion. [Figure 7] FIG. 13 is a diagram illustrating a second portion of the first intermediate portion. [Figure 8] FIG. 13 is a diagram illustrating the dimensions of the components of the steam release mechanism. [Figure 9] 4 is an enlarged front view showing a second side seal portion and a second non-seal portion. FIG. [Figure 10] FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 11A] FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 11B] FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 12]FIG. 2 is a cross-sectional view showing an example of a layer structure of a packaging material that constitutes a pouch. [Figure 13] FIG. 1 illustrates an example of a method for preparing a test strip. [Figure 14] FIG. 2 is a diagram for explaining a method for measuring hot rupture strength. [Figure 15] FIG. 1 illustrates an example of a method for preparing a test strip. [Figure 16A] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 16B] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 16C] FIG. 2 is a diagram for explaining a method for measuring hot seal strength. [Figure 17] 13 is a view showing a state in which a first intermediate portion of a first side seal portion is peeled off. FIG. [Figure 18] 13 is a view showing a state in which a first intermediate portion of a first side seal portion is peeled off. FIG. [Figure 19] FIG. 13 is a diagram showing a state in which steam is discharged from a flow path in a first intermediate portion. [Figure 20] FIG. 13 is a front view showing a modified example of the steam release mechanism. [Figure 21] FIG. 13 is a front view showing a modified example of the steam release mechanism. [Figure 22] FIG. 13 is a front view showing a modified example of the steam release mechanism. [Figure 23] FIG. 13 is a front view showing a modified example of the steam release mechanism. [Figure 24] FIG. 13 is a front view showing a modified example of the steam release mechanism. [Diagram 25] FIG. 13 is a front view showing a modified example of the steam release mechanism. [Figure 26] FIG. 2 is a front view showing an example of a pouch. [Figure 27] FIG. 11 is a front view showing an example of a steam vent mechanism according to a comparative embodiment. [Figure 28] FIG. 1 is a diagram showing the evaluation results of pouches of Examples and Comparative Examples. [Figure 29] FIG. 2 is a diagram showing a peeled portion of the pouch of Example 1. [Diagram 30]FIG. 13 is a view showing a peeled portion of the pouch of Example 2. [Diagram 31] FIG. 2 is a diagram showing a peeled portion of the pouch of Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] 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.

[0031] Terms used in this specification that specify shapes or geometric conditions and their degrees, such as "parallel," "orthogonal," and "same," as well as values ​​of lengths and angles, are not limited to their strict meanings and are interpreted to include a range within which similar functions can be expected.

[0032] 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.

[0033] 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. 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.

[0034] As shown in Fig. 1, pouch 10 includes upper portion 11, lower portion 12, first side portion 13 and second side portion 14, and has a generally rectangular outline in a front view. The names "upper portion", "lower portion" and "side portion", as well as the terms "upper" and "lower" indicate the relative positions and directions of pouch 10 and its components when the lower portion is defined as the side that can be located at the lower side when pouch 10 is heated. When pouch 10 is equipped with a steam venting mechanism to be described later, the position of pouch 10 is adjusted so that the steam venting mechanism is located at the upper side. The position of pouch 10 other than when pouch 10 is heated is not limited by the names and terms in this specification.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] As shown in FIG. 1, the sealed portion of the pouch 10 has a first side sealed portion 30, a second side sealed portion 50, and an upper sealed portion 11a. The first side sealed portion 30 is located on a first side 13 of the pouch 10. The second side sealed portion 50 is located on a second side 14. The second side 14 faces the first side 13 in a first direction D1. The upper sealed portion 11a is located on an upper portion 11. The upper sealed portion 11a is connected to the first side sealed portion 30 and the second side sealed portion 50. The non-sealed portion surrounded by the first side sealed portion 30, the second side sealed portion 50, and the upper sealed portion 11a functions as a storage portion 18 that stores contents.

[0040] 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.

[0041] In addition to the unsealed portion that functions as the storage portion 18, the pouch 10 further includes a first unsealed portion 45 that is isolated from the storage portion 18 by a first side sealed portion 30 as shown in FIG. 1. The unsealed portion is a portion where a film exists in which opposing inner surfaces are not joined to each other. The first unsealed portion 45 is located closer to the upper portion 11 of the pouch 10. "More towards the upper portion 11" means that the first unsealed portion 45 is located on the upper portion 11 side of the center point C of the storage portion 18.

[0042] 1, first unsealed portion 45 may extend to at least partially reach first side edge 13x of first side 13 of pouch 10. In this case, first unsealed portion 45 overlaps first side edge 13x and has an opening edge 46 that is open to the outside. Steam that is generated in storage portion 18 and flows into first unsealed portion 45 can be discharged to the outside from opening edge 46.

[0043] The top seal portion 11a and the first side seal portion 30 are configured to define a first non-sealed portion 45. For example, as shown in FIG. 1, the first side seal portion 30 includes an upper side portion 31, a lower side portion 32, and a first intermediate portion 35. The upper side portion 31 extends along the first side portion 13 from the first non-sealed portion 45 toward the top portion 11 of the pouch 10. The lower side portion 32 extends along the first side portion 13 from the first non-sealed portion 45 toward the bottom portion 12 of the pouch 10. The first intermediate portion 35 is located between the container portion 18 and the first non-sealed portion 45. The first intermediate portion 35 may include a first end connected to the upper side portion 31 and a second end connected to the lower side 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 section 35 is partially peeled off, and storage section 18 and first non-sealed section 45 communicate with each other. Steam that flows from storage section 18 into first non-sealed section 45 can be discharged to the outside from opening edge section 46. In this way, first intermediate section 35 and first non-sealed section 45 function as a steam release mechanism 25 that discharges steam from storage section 18 to the outside.

[0045] As shown in FIG. 1, the first side seal portion 30 may include a second intermediate portion 33. The second intermediate portion 33 is located between the first non-sealed portion 45 and the first side edge 13x, and is connected to the side lower portion 32. The second intermediate portion 33 may face a part of the first intermediate portion 35 in the first direction D1. The second intermediate portion 33 may extend from the upper edge of the side lower portion 32 toward the upper portion 11 along the first side edge 13x. The second intermediate portion 33 may not extend to the side upper portion 31. The opening edge portion 46 may be located between the second intermediate portion 33 and the side upper portion 31 in a second direction D2 perpendicular to the first direction D1.

[0046] An example of the arrangement of the second intermediate portion 33 will be described based on the imaginary straight line M. The imaginary straight line M is a straight line that connects the center point C of the storage portion 18 and the first non-sealed portion 45 at the shortest distance, as shown in FIG. 1. The inner edge 33a of the second intermediate portion 33 may intersect with an extension of the imaginary straight line M. This can prevent the contents 19 from leaking from the opening edge portion 46. The extension of the imaginary straight line M may intersect with the outer edge 33b of the second intermediate portion 33, or may intersect with the opening edge portion 46. The "inner edge" is the edge of the sealed portion located on the side closer to the center point of the storage portion 18. The "inner edge" is in contact with the storage portion 18 or is located so as to face the storage portion 18. For example, the inner edge 35a of the first intermediate portion 35 is in contact with the storage portion 18. For example, the inner edge 33a of the second intermediate portion 33 is located so as to face the storage portion 18. The "outer edge" is the edge of the sealed portion located on the side farther from the storage portion 18. The "outer edge" is located opposite the "inner edge".

[0047] 1, a second unsealed portion 65 may be formed between the second side edge 14x of the second side portion 14 and the second side seal portion 50. In this case, the second unsealed portion 65 may extend to reach the second side edge 14x. In other words, the second unsealed portion 65 may overlap the second side edge 14x and have an opening edge portion 66 that is open to the outside.

[0048] The second side seal portion 50 may include an upper side portion 51, a lower side portion 52, and a middle portion 55. The upper side portion 51 extends along the second side portion 14 from the second non-sealed portion 65 toward the upper portion 11 of the pouch 10. The lower side portion 52 extends along the second side portion 14 from the second non-sealed portion 65 toward the lower portion 12 of the pouch 10. The middle portion 55 is located between the containing portion 18 and the second non-sealed portion 65 in the first direction D1. The middle portion 55 may include a first end connected to the upper side portion 51 and a second end connected to the lower side portion 52.

[0049] As shown in FIG. 1, the pouch 10 may include an opening means 30a located at the first side seal 30. The opening means 30a penetrates the front film 15 and the back film 16. The opening means 30a may be a notch, a cut, or the like. The opening means 30a may be a starting point for a user to tear the pouch 10. The opening means 30a extends from the first side edge 13x toward the container 18.

[0050] As shown in FIG. 1, the opening means 30a may be located in the upper side portion 31. The distance from the upper side portion 31 to the upper portion 11 is shorter than the distance from the second intermediate portion 33 to the upper portion 11. By providing the opening means 30a in the upper side portion 31 instead of the second intermediate portion 33, the pouch 10 can be torn at a position closer to the upper portion 11. The closer to the upper portion 11, the smaller the distance between the front film 15 and the back film 16 is likely to be. This is because the distance between the front film 15 and the back film 16 is limited by the upper seal portion 11a. By providing the opening means 30a at a position where the distance between the front film 15 and the back film 16 is small, the user's work of tearing the pouch 10 is facilitated. In addition, the closer to the upper portion 11, the less the temperature of the pouch 10 is increased when the pouch 10 is heated. This is because the closer to the upper portion 11, the farther from the contents and the first non-sealed portion 45 is. The temperature of the first non-sealed portion 45 is likely to be increased by steam. By providing the opening means 30a at a position close to the top 11, the user is less likely to feel heat when tearing the pouch 10.

[0051] As shown in FIG. 1, the pouch 10 may include an opening means 50a located at the upper side portion 51. The opening means 50a penetrates the front film 15 and the back film 16. The opening means 50a may be a notch, a cut, or the like. Like the opening means 30a, the opening means 50a can be a starting point when a user tears the pouch 10. The opening means 50a extends from the second side edge 14x toward the storage portion 18. The opening means 50a may face the 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 the first direction D1 is determined at the position of the center point C. A dimension H2 of the storage portion 18 in the second direction D2 is determined at the position of the center point C.

[0054] The symbol H3 represents the distance in the first direction D1 from the center point C to the first intermediate portion 35. The distance H3 is the distance in the first direction D1 from the intersection point between the virtual straight line M and the inner edge 35a of the first intermediate portion 35 to the center point C. The distance H3 is, for example, 0.35×H1 or more, and may be 0.37×H1 or more. The distance H3 is, for example, 0.48×H1 or less, and may be 0.45×H1 or less.

[0055] The symbol H4 represents the distance in the second direction D2 from the center point C to the first intermediate portion 35. The distance H4 is the distance in the second direction D2 from the intersection of the virtual straight line M and the inner edge 35a of the first intermediate portion 35 to the center point C. The distance H4 is, for example, 0.10×H2 or more, may be 0.15×H2 or more, or may be 0.20×H2 or more. The distance H4 is, for example, 0.30×H2 or less, and may be 0.27×H2 or less.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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 IV-IV in FIG.

[0068] 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 content 19 from contacting the first intermediate portion 35. 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.

[0069] 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.

[0070] 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.

[0071] In FIG. 4, the symbol Lm represents the distance between the upper surface 19a of the content 19 and the first intermediate portion 35. When the angle θa is 17°, the distance Lm is, for example, 5 mm or more, 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 35a of the first intermediate portion 35 when the angle θa is 17°, and then opening the pouch 10 and checking the position of the upper surface 19a.

[0072] The steam release mechanism 25 will be described in detail below. Fig. 5 is an enlarged front view of the steam release mechanism 25.

[0073] The first intermediate portion 35 includes an inner edge 35a that is an edge located on the side of the storage portion 18, and an outer edge 35b that is an edge located on the side of the first non-sealed portion 45. The outer edge 35b of the first intermediate portion 35 defines a part of the outline of the edge of the first non-sealed portion 45.

[0074] The first intermediate portion 35 may include a first portion 36, a second portion 37, and a first connecting portion 38. The first connecting portion 38 connects the first portion 36 and the second portion 37 together.

[0075] The first connection portion 38 is located closer to the lower side portion 32. "Closer to the lower side portion 32" means that the first connection portion 38 is located closer to the lower side portion 32 than the middle position of the first unsealed portion 45 in the second direction D2. In other words, the distance between the first connection portion 38 and the lower side portion 32 in the second direction D2 is shorter than the distance between the first connection portion 38 and the upper side portion 31 in the second direction D2.

[0076] The first portion 36 extends from the first connecting portion 38 toward the first side portion 13. For example, the inner edge 35a and the outer edge 35b of the first portion 36 extend toward the side lower portion 32 in approximately the first direction D1. The angle between the direction in which the inner edge 35a and the outer edge 35b of the first portion 36 extend and the first direction D1 is, for example, 10° or less. The first portion 36 may be connected to the inner edge 32a of the side lower portion 32. A part of the outer edge 35b of the first portion 36 may extend continuously with the upper edge 32c of the side lower portion 32. For example, an extension line of the outer edge 35b of an outer first portion 362 of the first portion 36 described later may overlap the upper edge 32c of the side lower portion 32.

[0077] The second portion 37 extends from the first connecting portion 38 toward the upper portion 11. For example, the inner edge 35a and the outer edge 35b of the second portion 37 include portions extending substantially in the second direction D2 toward the upper portion 11. The second portion 37 may be connected to the lower edge 31c of the upper side portion 31.

[0078] As shown in FIG. 5, the first portion 36 may include an inner first portion 361, an outer first portion 362, and a first transition portion 363. The inner first portion 361 may be connected to the second portion 37 via a first connecting portion 38. The outer first portion 362 is located outside the inner first portion 361. "Outside" means a side away from the center point of the storage portion 18 in the first direction D1. "Inside" means a side approaching the center point of the storage portion 18 in the first direction D1. The outer first portion 362 may be connected to the side lower portion 32. The first transition portion 363 is located between the inner first portion 361 and the outer first portion 362.

[0079] The first transition portion 363 includes an outer edge 35b that extends in a different direction from the outer edge 35b of the inner first portion 361 and the outer edge 35b of the outer first portion 362. The outer edge 35b of the first transition portion 363 extends so as to be displaced upward in the second direction D2 as it moves outward. Meanwhile, the inner edge 35a of the first transition portion 363 extends along the first direction D1. The width of the first transition portion 363 increases outward, i.e., toward the first side portion 13. Thus, the width of the outer first portion 362 is greater than the width of the inner first portion 361.

[0080] As long as the width of the first transition portion 363 increases toward the outside, the shape of the first transition portion 363 is not limited. For example, the first transition portion 363 may include an inner edge 35a that extends in a direction different from the inner edge 35a of the inner first portion 361 and the inner edge 35a of the outer first portion 362. In this case, the outer edge 35b of the first transition portion 363 may extend along the first direction D1.

[0081] 5, the second portion 37 may include a lower second portion 371, an upper second portion 372, and a second transition portion 373. The lower second portion 371 may be connected to the first portion 36 via the first connecting portion 38. The upper second portion 372 is located above the lower second portion 371. The upper second portion 372 may be connected to the side upper portion 31. The second transition portion 373 is located between the lower second portion 371 and the upper second portion 372.

[0082] The second transition portion 373 includes an outer edge 35b that extends in a different direction from the outer edge 35b of the lower second portion 371 and the outer edge 35b of the upper second portion 372. The outer edge 35b of the second transition portion 373 extends so as to be displaced toward the first side portion 13 in the first direction D1 as it goes upward, i.e., to be displaced outward in the first direction D1. On the other hand, the inner edge 35a of the second transition portion 373 extends along the second direction D2. The width of the second transition portion 373 increases as it goes upward. Therefore, the width of the upper second portion 372 is larger than the width of the lower second portion 371.

[0083] As long as the width of the second transition portion 373 increases upward, the shape of the second transition portion 373 is not limited. For example, the second transition portion 373 may include an inner edge 35a that extends in a direction different from the inner edge 35a of the lower second portion 371 and the inner edge 35a of the upper second portion 372. In this case, the outer edge 35b of the second transition portion 373 may extend along the second direction D2.

[0084] Next, the second intermediate portion 33 will be described. As shown in Fig. 5, the second intermediate portion 33 extends from the upper edge 33c of the side lower portion 32 toward the upper portion 11 along the first side edge 13x. The second intermediate portion 33 includes an inner edge 33a and an upper edge 33c that contact the first non-sealed portion 45. The inner edge 33a may face the outer edge 35b of the second portion 37 in the first direction D1. The upper edge 33c may face the lower edge 31c of the side upper portion 31 in the second direction D2.

[0085] Next, the arrangement of the first intermediate portion 35 and the second intermediate portion 33 will be described.

[0086] 5, the second intermediate portion 33 may be located outward from the first reference line SL1 in the first direction D1. The first portion 36 of the first intermediate portion 35 may be located inward from the first reference line SL1 in the first direction D1.

[0087] The first reference line SL1 is a straight line that passes through the first intersection point EP1 and extends in the second direction D2. The first intersection point EP1 is the intersection point of the line EL11 and the line EL12. The line EL11 is an extension of the inner edge 32a of the lower side portion 32. The line EL12 is an extension of the inner edge 35a of the outer first portion 362 of the first part 36.

[0088] 5, the upper second portion 372 of the second part 37 of the first intermediate portion 35 may be located above the upper edge 33c of the second intermediate portion 33. The second transition portion 373 of the second part 37 of the first intermediate portion 35 may also be located above the upper edge 33c of the second intermediate portion 33. This makes it possible to widen the flow path of steam from an opening, described below, formed in the first intermediate portion 35 to the opening edge portion 46.

[0089] In Fig. 5, the symbol SL2 is a straight line (also referred to as a second reference line) that passes through a middle position of the first unsealed portion 45 in the second direction D2 and extends in the first direction D1. As shown in Fig. 5, the upper second portion 372 of the second part 37 may be located above the second reference line SL2. The upper edge 33c of the second intermediate portion 33 may be located below the second reference line SL2.

[0090] 5, the edge of the first non-sealed portion 45 in the second direction D2 is defined by the lower edge 31c of the upper side portion 31 and the upper edge 32c of the lower side portion 32. In this case, the second reference line SL2 passes through a middle position between the lower edge 31c and the upper edge 32c in the second direction D2.

[0091] θ2 represents the angle (hereinafter also referred to as the second angle) formed between the direction in which the outer edge 35b of the lower second portion 371 of the second part 37 extends and the direction in which the outer edge 35b of the inner first portion 361 of the first part 36 extends. The second angle θ2 is, for example, 100° or less, may be 95° or less, or may be 90° or less. The second angle θ2 is, for example, 70° or more, may be 80° or more, or may be 85° or more.

[0092] The angle (hereinafter also referred to as the first angle) between the direction in which the inner edge 35a of the lower second portion 371 of the second portion 37 extends and the direction in which the inner edge 35a of the inner first portion 361 of the first portion 36 extends may be the same as or different from the second angle θ2. The difference between the first angle and the second angle θ2 is, for example, 5° or less.

[0093] The first portion 36 will be described in detail with reference to FIG. 6. The inner first portion 361 has a width W16S. The width W16S is defined by a portion where the inner edge 35a and the outer edge 35b of the inner first portion 361 extend linearly. The width W16S may be defined by a portion where the inner edge 35a and the outer edge 35b of the inner first portion 361 extend linearly and parallel to each other. When the linear portions of the inner edge 35a and the outer edge 35b of the inner first portion 361 are not parallel, the minimum value of the width of the linear portions is adopted as the width W16S. The width W16S of the inner first portion 361 is also referred to as a first reference width.

[0094] The first reference width W16S is, for example, 2.0 mm or more, may be 2.5 mm or more, or may be 2.7 mm or more. The first reference width W16S is, for example, 4.0 mm or less, may be 3.7 mm or less, or may be 3.5 mm or less.

[0095] The inner first portion 361 may have a constant width. "Constant width" means that the difference between the maximum and minimum values ​​of the width of the straight portion of the inner first portion 361 is 1 mm or less.

[0096] The first transition portion 363 has a width that is 1.2 times the first reference width W16S or more. In other words, the position of the first portion 36 having the width W16 that is 1.2 times the first reference width W16S is the boundary between the inner first portion 361 and the first transition portion 363.

[0097] The width W16E of the outer first portion 362 is equal to or greater than the width of the first transition portion 363. The width W16E is defined by a portion where the inner edge 35a and the outer edge 35b of the outer first portion 362 extend linearly. The width W16E may be defined by a portion where the inner edge 35a and the outer edge 35b of the outer first portion 362 extend linearly and parallel to each other. When the linear portions of the inner edge 35a and the outer edge 35b of the outer first portion 362 are not parallel, the minimum width of the linear portions is adopted as the width W16E.

[0098] The ratio of the width W16E of the outer first portion 362 to the first reference width W16S is, for example, 1.2 or more, may be 1.5 or more, or may be 1.8 or more. The ratio of the width W16E of the outer first portion 362 to the first reference width W16S is, for example, 3.5 or less, may be 3.0 or less, or may be 2.5 or less.

[0099] The second portion 37 will be described in detail with reference to FIG. 7. The lower second portion 371 has a width W17S. The width W17S is defined by a portion where the inner edge 35a and the outer edge 35b of the lower second portion 371 extend linearly. The width W17S may be defined by a portion where the inner edge 35a and the outer edge 35b of the lower second portion 371 extend linearly and parallel to each other. When the linear portions of the inner edge 35a and the outer edge 35b of the lower second portion 371 are not parallel, the minimum value of the width of the linear portions is adopted as the width W17S. The width W17S of the lower second portion 371 is also referred to as the second reference width.

[0100] The second reference width W17S is, for example, 1.5 mm or more, may be 2.0 mm or more, or may be 2.2 mm or more. The second reference width W17S is, for example, 3.5 mm or less, may be 3.2 mm or less, or may be 3.0 mm or less.

[0101] The lower second portion 371 may have a constant width. "Constant width" means that the difference between the maximum and minimum values ​​of the width of the straight portion of the lower second portion 371 is 1 mm or less.

[0102] The second transition portion 373 has a width that is 1.2 times the second reference width W17S or more. In other words, the position of the second portion 37 having the width W17 that is 1.2 times the second reference width W17S is the boundary between the lower second portion 371 and the second transition portion 373.

[0103] The width W17E of the upper second portion 372 is equal to or greater than the width of the second transition portion 373. The width W17E is defined by a portion where the inner edge 35a and the outer edge 35b of the upper second portion 372 extend linearly. The width W17E may be defined by a portion where the inner edge 35a and the outer edge 35b of the upper second portion 372 extend linearly and parallel to each other. When the linear portions of the inner edge 35a and the outer edge 35b of the upper second portion 372 are not parallel, the minimum value of the width of the linear portions is adopted as the width W17E.

[0104] The ratio of the width W17E of the upper second portion 372 to the second reference width W17S is, for example, 1.5 or more, may be 1.8 or more, or may be 2.0 or more. The ratio of the width W17E of the upper second portion 372 to the second reference width W17S is, for example, 3.5 or less, may be 3.0 or less, or may be 2.5 or less.

[0105] An outer edge of the boundary between the inner first portion 361 and the first transition portion 363 may be located outward in the first direction D1 than an outer edge of the boundary between the lower second portion 371 and the second transition portion 373. A first opening distance L17 described later represents the distance in the first direction D1 between the outer edge of the boundary between the inner first portion 361 and the first transition portion 363 and the outer edge of the boundary between the lower second portion 371 and the second transition portion 373.

[0106] When the pouch 10 is heated in a microwave oven, the moisture contained in the contents 19 evaporates, increasing the pressure in the storage section 18. When the pressure in the storage section 18 increases, a force is applied to the first intermediate section 35, causing the first intermediate section 35 to peel off. Peeling of the first intermediate section 35 begins at the first connecting section 38. Peeling of the first section 36 progresses in a direction from the first connecting section 38 toward the lower side section 32. Peeling of the second section 37 progresses upward from the first connecting section 38.

[0107] Peeling of the first portion 36 starts at the inner first portion 361. Since the straight portion of the inner first portion 361 has a substantially constant width, it is considered that peeling of the inner first portion 361 easily progresses smoothly. On the other hand, the inner edge 35a or the outer edge 35b of the first transition portion 363 extends in a direction different from the inner edge 35a or the outer edge 35b of the inner first portion 361. In addition, the width of the first transition portion 363 and the outer first portion 362 is larger than the width of the inner first portion 361. For this reason, it is considered that peeling of the first portion 36 becomes difficult to progress after the peeling of the first portion 36 reaches the first transition portion 363 or the outer first portion 362. That is, it is considered that the first transition portion 363 and the outer first portion 362 function as a peeling suppressing portion that suppresses the progress of peeling of the first portion 36.

[0108] Peeling of the second portion 37 starts at the lower second portion 371. Since the straight portion of the lower second portion 371 has a substantially constant width, it is considered that peeling of the lower second portion 371 easily progresses smoothly. On the other hand, the inner edge 35a or the outer edge 35b of the second transition portion 373 extends in a direction different from the inner edge 35a or the outer edge 35b of the lower second portion 371. In addition, the width of the second transition portion 373 and the upper second portion 372 is larger than the width of the lower second portion 371. For this reason, it is considered that peeling of the second portion 37 becomes difficult to progress after the peeling of the second portion 37 reaches the second transition portion 373 or the upper second portion 372. That is, it is considered that the second transition portion 373 and the upper second portion 372 function as a peeling suppressing portion that suppresses the progress of peeling of the second portion 37.

[0109] Since the first portion 36 and the second portion 37 each include a peel suppressing portion, it becomes easier to imagine the portion of the first portion 36 and the second portion 37 that will peel. In other words, it becomes easier to imagine the portion of the first portion 36 and the portion of the second portion 37 that will remain after the pouch 10 is heated and the peeling of the first portion 36 and the second portion 37 is completed. An opening is formed between the remaining portion of the first portion 36 and the remaining portion of the second portion 37. Steam generated in the storage portion 18 flows into the first non-sealed portion 45 through the opening. The shapes, dimensions, arrangements, etc. of the second intermediate portion 33, the first non-sealed portion 45, and the opening edge portion 46 are determined based on the assumed opening.

[0110] With reference to FIG. 8, the dimensions of the components of the steam release mechanism 25 will be described.

[0111] 8, the reference symbol L11 represents the distance in the first direction D1 between the boundary between the inner first portion 361 and the first transition portion 363 and the inner edge 32a of the side lower portion 32. The distance L11 is also referred to as the first shielding distance. The first shielding distance L11 is an indication of the dimension in the first direction D1 of the first portion 36 remaining after heating.

[0112] The first shielding distance L11 is, for example, 1.0 mm or more, may be 1.5 mm or more, or may be 2.0 mm or more. When the first shielding distance L11 is 1.0 mm or more, the contents 19 that jump up when heated are prevented from entering the first non-sealed portion 45. The first shielding distance L11 is, for example, 5.0 mm or less, may be 4.5 mm or less, or may be 4.0 mm or less.

[0113] In Fig. 8, the reference symbol L12 represents the distance in the second direction D2 between the boundary between the lower second portion 371 and the second transition portion 373 and the lower edge 31c of the side upper portion 31. The distance L12 is also referred to as the second shielding distance. The second shielding distance L12 is an indication of the dimension in the second direction D2 of the second portion 37 remaining after heating.

[0114] The second shielding distance L12 is, for example, 5.0 mm or more, may be 7.0 mm or more, or may be 10.0 mm or more. When the second shielding distance L12 is 5.0 mm or more, the contents 19 mixed with the steam flowing in the first direction D1 are prevented from entering the first non-sealed portion 45. The second shielding distance L12 is, for example, 20.0 mm or less, may be 17.0 mm or less, or may be 15.0 mm or less.

[0115] 8, the symbol L13 indicates the dimension of the second intermediate portion 33 in the second direction D2. The dimension L13 is, for example, 5.0 mm or more, may be 10.0 mm or more, or may be 15.0 mm or more. The dimension L12 is, for example, 30.0 mm or less, may be 25.0 mm or less, or may be 20.0 mm or less.

[0116] 8, the reference symbol L15 indicates the dimension of the opening edge portion 46 in the second direction D2. The dimension L15 is, for example, 8.0 mm or more, may be 13.0 mm or more, or may be 18.0 mm or more. The dimension L15 is, for example, 35.0 mm or less, may be 30.0 mm or less, or may be 25.0 mm or less.

[0117] The dimension L13 of the second intermediate portion 33 may be determined in relation to the dimension L15 of the opening edge portion 46 in the second direction D2. The dimension L13 of the second intermediate portion 33 may be greater than or less than the dimension L15 of the opening edge portion 46. The dimension L13 may be, for example, 0.50×L15 or more, 0.70×L15 or more, 0.90×L15 or more, or 1.10×L15 or more. The dimension L13 may be, for example, 1.50×L15 or less, 1.30×L15 or less, 1.10×L15 or less, or 0.90×L15 or less.

[0118] 8, the reference symbol L14 represents the distance between the outer edge of the interface between the inner first portion 361 and the first transition portion 363 and the outer edge of the interface between the lower second portion 371 and the second transition portion 373. The distance L14 is also referred to as the first distance. The first distance L14 is an indication of the size of the opening formed between the first portion 36 and the second portion 37 remaining after heating.

[0119] The first distance L14 is, for example, 10.0 mm or more, may be 11.0 mm or more, or may be 12.0 mm or more. The first distance L14 is, for example, 20.0 mm or less, may be 19.0 mm or less, or may be 18.0 mm or less.

[0120] The first distance L14 may be determined in relation to the dimension L13 of the second intermediate portion 33. The ratio L14 / L13 of the first distance L14 to the dimension L13 is, for example, 0.8 or more, may be 1.0 or more, or may be 1.2 or more. The ratio L14 / L13 is, for example, 2.0 or less, may be 1.7 or less, or may be 1.5 or less.

[0121] 8, the reference character L17 represents the distance in the first direction D1 between the outer edge of the boundary between the inner first portion 361 and the first transition portion 363 and the outer edge of the boundary between the lower second portion 371 and the second transition portion 373. The distance L17 is also referred to as a first open distance. The first open distance L17 corresponds to the component of the first distance L14 in the first direction D1.

[0122] The first opening distance L17 is, for example, 2.5 mm or less, and may be 2.3 mm or less, 2.1 mm or less, 1.9 mm or less, 1.7 mm or less, or 1.5 mm or less. When the first opening distance L17 is small, the contents 19 that jump up when heated are prevented from entering the first non-sealed portion 45.

[0123] 8, the reference symbol L16 represents the shortest distance between the second portion 37 and the second intermediate portion 33. The distance L16 is also referred to as the second distance. The second distance L16 is a measure of the width of the narrowest flow path in the first non-sealed portion 45 of the pouch 10 after heating.

[0124] The second distance L16 is, for example, 6.0 mm or more, may be 7.0 mm or more, or may be 8.0 mm or more. The second distance L16 is, for example, 12.0 mm or less, may be 11.0 mm or less, or may be 10.0 mm or less.

[0125] The first distance L14 may be greater than the second distance L16. The dimension L15 of the opening edge 46 may be greater than the second distance L16. In this case, the flow of steam discharged from the storage section 18 to the outside of the pouch 10 is mainly controlled by the second distance L16.

[0126] The first distance L14 may be determined in relation to the second distance L16. The ratio L14 / L16 of the first distance L14 to the second distance L16 is, for example, 1.5 or more, may be 1.6 or more, or may be 1.7 or more. The ratio L14 / L16 is, for example, 2.5 or less, may be 2.2 or less, or may be 2.0 or less.

[0127] A first open distance L17, which is a component of the first distance L14 in the first direction D1, may be determined in relation to the second distance L16. The ratio L17 / L16 of the first open distance L17 to the second distance L16 is, for example, 0.30 or less, may be 0.25 or less, or may be 0.21 or less.

[0128] The dimension L15 of the opening edge 46 may be determined in relation to the second distance L16. The ratio L15 / L16 of the dimension L15 to the second distance L16 is, for example, 1.2 or more, may be 1.4 or more, or may be 1.6 or more. The ratio L14 / L16 is, for example, 2.5 or less, may be 2.2 or less, or may be 2.0 or less.

[0129] The dimension L13 of the second intermediate portion 33 may be determined in relation to the second distance L16. The ratio L13 / L16 of the dimension L13 to the second distance L16 is, for example, 1.0 or more, may be 1.2 or more, or may be 1.4 or more. The ratio L13 / L16 is, for example, 2.5 or less, may be 2.0 or less, or may be 1.7 or less.

[0130] 8, the reference symbol L01 denotes the maximum distance in the first direction D1 between the first side edge 13x and the inner edge 35a of the second portion 37. The distance L01 is, for example, 10 mm or more, may be 15 mm or more, or may be 20 mm or more. The distance L01 is, for example, 30 mm or less, may be 27 mm or less, or may be 24 mm or less.

[0131] Distance L02 represents the distance in the second direction D2 from the lower edge 11c of the upper seal portion 11a to the lower edge 31c of the upper side portion 31. Distance L02 is, for example, 5.0 mm or more, may be 7.0 mm or more, or may be 10.0 mm or more. Distance L02 is, for example, 20.0 mm or less, may be 17.0 mm or less, or may be 15.0 mm or less.

[0132] Distance L03 represents the distance in the second direction D2 from the lower edge 11c of the upper seal portion 11a to the inner edge 35a of the first portion 36. Distance L03 is, for example, 20.0 mm or more, may be 25.0 mm or more, or may be 30.0 mm or more. Distance L03 is, for example, 50.0 mm or less, may be 47.0 mm or less, or may be 45.0 mm or less.

[0133] The distance L04 represents the distance in the second direction D2 from the opening means 30a to the lower edge 31c of the upper side portion 31. The distance L04 is, for example, 1.0 mm or more, may be 2.0 mm or more, or may be 4.0 mm or more. The distance L05 is, for example, 10.0 mm or less, may be 8.0 mm or less, or may be 6.0 mm or less.

[0134] As shown in FIG. 1 and FIG. 5, the side lower portion 32 may include a portion in which the width W12 increases from the lower portion 12 toward the first intermediate portion 35. For example, a part of the inner edge 32a of the side lower portion 32 may be inclined with respect to the second direction D2 so as to move away from the first side edge 13x as it approaches the first intermediate portion 35. This allows the width W12_1 of the side lower portion 32 in the vicinity of the first non-sealed portion 45 to be larger than the width W12_2 of the side lower portion 32 in the vicinity of the lower portion 12. The width W12_1 is the distance in the first direction D1 from the first side edge 13x to the first intersection point EP1. The width W12_1 may be the maximum value of the width W12. The width W12_2 is the width of the side lower portion 32 at the position of the lower edge of the storage portion 18. The width W12_2 may be the minimum value of the width W12.

[0135] The width W12 of the lower side portion 32 increases from the bottom toward the first intermediate portion 35, thereby increasing the rigidity of the lower side portion 32 in the vicinity of the first non-sealed portion 45. This makes it possible to prevent the pouch 10 from bending in the vicinity of the first non-sealed portion 45 when the pressure in the storage portion 18 increases due to heating. This makes it possible to prevent the steam flow path from being blocked by the bending of the pouch 10. In addition, by reducing the width W12 of the lower side portion 32 in the vicinity of the lower portion 12, the dimension of the opening 12b of the lower portion 12 in the first direction D1 can be increased. This makes it easier to fill the contents through the opening 12b.

[0136] The ratio of the width W12_1 to the width W12_2 is, for example, 1.1 or more, may be 1.3 or more, or may be 1.5 or more. The ratio of the width W12_1 to the width W12_2 is, for example, 2.5 or less, may be 2.2 or less, or may be 2.0 or less.

[0137] 5, the symbol W13 represents the width of the second intermediate portion 33. The width W13 of the second intermediate portion 33 is smaller than the width W12_1 of the lower side portion 32. The ratio of the width W13 to the width W12_1 is, for example, 0.2 or more, may be 0.3 or more, or may be 0.4 or more. The ratio of the width W13 to the width W12_1 is, for example, 0.8 or less, may be 0.7 or less, or may be 0.6 or less.

[0138] 1, the width W11 of the upper side portion 31 may be larger than the width W12_1 of the lower side portion 32. The ratio of the width W11 to the width W12_1 is, for example, 1.1 or more, may be 1.3 or more, or may be 1.5 or more. The ratio of the width W11 to the width W12_1 is, for example, 3.0 or less, may be 2.5 or less, or may be 2.0 or less.

[0139] The middle portion 55 and the second unsealed portion 65 of the second side portion 14 will now be described in detail. Fig. 9 is an enlarged front view showing the middle portion 55 and the second unsealed portion 65.

[0140] The second non-sealed portion 65 is formed simultaneously with the first non-sealed portion 45 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 becomes the first non-sealed portion 45 and the other becomes the second non-sealed portion 65. A dimension L25 of the second non-sealed portion 65 in the second direction D2 may be the same as a dimension L15 of the first non-sealed portion 45 in the second direction D2.

[0141] 9, symbols W21, W22, and W25 respectively represent the width of the upper side portion 51, the width of the lower side portion 52, and the width of the intermediate portion 55. The width W21 of the upper side portion 51 and the width W22 of the lower side portion 52 may be greater than the width W25 of the intermediate portion 55.

[0142] Next, a description will be given of the layer structure of the packaging material 70 that constitutes the front film 15 and the back film 16. Fig. 10 is a cross-sectional view showing an example of the layer structure of the packaging material 70.

[0143] 10 includes at least a first biaxially oriented plastic film 71, a first adhesive layer 76, a second biaxially oriented plastic film 72, a second adhesive layer 77, and a sealant film 75, in this order. The first biaxially oriented plastic film 71 is located on the outer surface 70y side, and the sealant film 75 is located on the inner surface 70x side opposite the outer surface 70y. The inner surface 70x faces the storage section 18.

[0144] Each film constituting the packaging material 70, such as the first biaxially oriented plastic film 71, the second biaxially oriented plastic film 72, and the sealant film 75, and the packaging material 70 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.

[0145] Each layer of packaging material 70 will now be described in detail.

[0146] (First biaxially stretched plastic film) The first biaxially stretched plastic film 71 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 71 functions as a base layer for imparting a predetermined strength to the packaging material 70. The stretching direction of the first biaxially stretched plastic film 71 is not particularly limited. For example, the first biaxially stretched plastic film 71 may be stretched in the first direction D1 and the second direction D2. The stretching ratio of the first biaxially stretched plastic film 71 is, for example, 1.05 times or more.

[0147] The first biaxially stretched plastic film 71 contains, for example, polyester as a main component. For example, the first biaxially stretched plastic film 71 contains 51% by mass or more of polyester. Examples of polyester include polyethylene terephthalate (hereinafter also referred to as PET) and polybutylene terephthalate (hereinafter also referred to as PBT). In addition, the 51% by mass or more of polyester in the first biaxially stretched plastic film 71 may be composed of one type of polyester or may be composed of two or more types of polyester. The content of polyester in the first biaxially stretched plastic film 71 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more. For example, the content of PET in the first biaxially stretched plastic film 71 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0148] The thickness of the first biaxially stretched plastic film 71 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 71 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 71 8 μm or more, the first biaxially stretched plastic film 71 has sufficient strength. By making the thickness of the first biaxially stretched plastic film 71 30 μm or less, the first biaxially stretched plastic film 71 exhibits excellent formability. Therefore, the process of processing the packaging material 70 to manufacture the pouch 10 can be carried out efficiently.

[0149] (First adhesive layer) The first adhesive layer 76 includes an adhesive for bonding the first biaxially oriented plastic film 71 and the second biaxially oriented plastic film 72 by a dry lamination method. The adhesive constituting the first adhesive layer 76 is produced from an adhesive composition 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.

[0150] 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.

[0151] 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.

[0152] The thickness of the first adhesive layer 76 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the first adhesive layer 76 is, for example, 6 μm or less, and may be 5 μm or less.

[0153] (Second biaxially oriented plastic film) The second biaxially stretched plastic film 72 is a plastic film stretched in two predetermined directions, similar to the first biaxially stretched plastic film 71. The second biaxially stretched plastic film 72 also functions as a base layer for imparting a predetermined strength to the packaging material 70, similar to the first biaxially stretched plastic film 71. The stretching direction of the second biaxially stretched plastic film 72 is not particularly limited, similar to the case of the first biaxially stretched plastic film 71. The stretching ratio of the second biaxially stretched plastic film 72 is, for example, 1.05 times or more.

[0154] The second biaxially stretched plastic film 72 may contain polyester as a main component. As in the case of the first biaxially stretched plastic film 71, examples of polyester include PET and PBT. The range of the polyester content in the second biaxially stretched plastic film 72 may be the same range as that of the first biaxially stretched plastic film 71. The thickness of the second biaxially stretched plastic film 72 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 72 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.

[0155] The second biaxially stretched plastic film 72 may contain polyamide as a main component. For example, the second biaxially stretched plastic film 72 may contain 51% by mass or more of polyamide. Examples of polyamide include aliphatic polyamide and aromatic polyamide. Examples of aliphatic polyamide include nylon-6, nylon-6,6, and a copolymer of nylon 6 and nylon 6,6, and examples of aromatic polyamide include polymetaxylene adipamide (MXD6). The content of polyamide in the second biaxially stretched plastic film 72 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more. The thickness of the second biaxially stretched plastic film 72 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 72 containing polyamide as a main component is, for example, 30 μm or less, may be 25 μm or less, or may be 20 μm or less.

[0156] (Second adhesive layer) The second adhesive layer 77 includes an adhesive for bonding the second biaxially oriented plastic film 72 and the sealant film 75 by a dry lamination method. An example of the adhesive for the second adhesive layer 77 is polyurethane, as in the case of the first adhesive layer 76. In addition to the configurations, materials, and characteristics described below, the second adhesive layer 77 can adopt the same configurations, materials, and characteristics as the first adhesive layer 76.

[0157] The thickness of the second adhesive layer 77 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the second adhesive layer 77 is, for example, 6 μm or less, and may be 5 μm or less.

[0158] As described above, the isocyanate compounds constituting the curing agent of the adhesive include aromatic isocyanate compounds and aliphatic isocyanate compounds. In the aromatic isocyanate compounds, components that cannot be used for food applications are eluted under high temperature environments such as heat sterilization. The second adhesive layer 77 is in contact with the sealant film 75. Therefore, when the second adhesive layer 77 contains an aromatic isocyanate compound, the components eluted from the aromatic isocyanate compound may adhere to the contents contained in the container 18 in contact with the sealant film 75.

[0159] 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 77. This makes it possible to prevent components that cannot be used for food applications, which are caused by the second adhesive layer 77, from adhering to the contents.

[0160] (Sealant film) Next, the sealant film 75 will be described. The sealant film 75 may be a single layer or a multilayer. The sealant film 75 is preferably made of an unstretched film. 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.

[0161] The sealant film 75 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

[0162] The Young's modulus and tensile elongation of the sealant film 75 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 initial distance between the pair of gripping tools can be measured as 100 mm, the length in the direction perpendicular to one side can be adjusted.

[0163] The pouch 10 made of the packaging material 70 is subjected to sterilization treatment at high temperatures, such as boiling or retort treatment. Therefore, the sealant film 75 used has heat resistance that can withstand such high-temperature treatments.

[0164] The melting point of the material constituting the sealant film 75 is preferably 150° C. or higher, and more preferably 160° C. or higher. By increasing the melting point of the sealant film 75, 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. Note that the melting point of the material constituting the sealant film 75 is lower than the melting point of the resin constituting the biaxially oriented plastic film.

[0165] The sealant film 75 contains propylene as a main component. For example, the sealant film 75 may contain 51% by mass or more of propylene. The propylene content in the sealant film 75 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0166] 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.

[0167] [ka]

[0168] [ka]

[0169] [ka]

[0170] 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.

[0171] Preferably, the sealant film 75 is a single-layer film containing a propylene-ethylene block copolymer. For example, the sealant film 75 is a single-layer unstretched film mainly composed of a propylene-ethylene block copolymer. By using a propylene-ethylene block copolymer, the impact resistance of the sealant film 75 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 70 can be increased.

[0172] Furthermore, by using a propylene-ethylene block copolymer, the strength of the seal portion formed by the sealant film 75 at high temperatures, for example 100°C, i.e., the above-mentioned hot seal strength, is extremely small compared to the seal strength at low temperatures, for example 23°C (hereinafter also referred to as room temperature seal strength). Due to the low hot seal strength, when the pouch 10 is heated in a microwave oven, the first intermediate portion 35 is easily peeled off, and steam in the containing portion 18 is easily released to the outside of the pouch 10. This 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 70 when heated.

[0173] 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 75 containing the propylene-ethylene block copolymer can be adjusted.

[0174] 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.

[0175] The single-layer sealant film 75 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 75. 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.

[0176] 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 3The 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.

[0177] 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.

[0178] 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).

[0179] [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.

[0180] In the sealant film 75, the mass ratio of the first thermoplastic resin made of a propylene-ethylene block copolymer is higher than the mass ratio of the second thermoplastic resin containing at least an α-olefin copolymer or polyethylene. For example, in a single-layer sealant film 75, the mass ratio of the first thermoplastic resin made of a propylene-ethylene block copolymer is at least 51 mass% or more, preferably 60 mass% or more, and more preferably 70 mass% or more.

[0181] As described above, the second thermoplastic resin can contribute to increasing the impact resistance of the sealant film 75. Therefore, by adjusting the mass ratio of the second thermoplastic resin containing at least an α-olefin copolymer or polyethylene in the single-layer sealant film 75, the mechanical properties of the sealant film 75 can be adjusted.

[0182] The sealant film 75 may further contain a thermoplastic elastomer. By using a thermoplastic elastomer, the impact resistance and puncture resistance of the sealant film 75 can be further improved.

[0183] 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.

[0184] The content of the propylene-ethylene block copolymer in the sealant film 75 is, for example, 80% by mass or more, and preferably 90% by mass or more.

[0185] 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.

[0186] The thickness of the sealant film 75 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 75 is, for example, 100 μm or less, and may be 80 μm or less.

[0187] As the monolayer sealant film 75 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 75 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.

[0188] The tensile elongation of the sealant film 75 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 75 in the machine direction (MD) and the thickness (μm) of the sealant film 75 may be 45000 or more, 50000 or more, 55000 or more, or 60000 or more. The tensile elongation of the sealant film 75 in the transverse direction (TD) at 23°C may be, for example, 1050% or more, or 1100% or more. The product of the tensile elongation (%) of the sealant film 75 in the transverse direction (TD) and the thickness (μm) of the sealant film 75 may be 53000 or more, or 60000 or more. The sealant film 75 has a high tensile elongation, so that the pouch 10 can be prevented from breaking due to an impact when dropped, for example.

[0189] The Young's modulus of the sealant film 75 in the machine direction (MD) at 23°C is, for example, 670 MPa or less, and may be 650 MPa or less. The product of the Young's modulus (MPa) of the sealant film 75 in the machine direction (MD) and the thickness (μm) of the sealant film 75 is, for example, 38,000 or less, and may be 35,000 or less. The Young's modulus of the sealant film 75 in the transverse direction (TD) at 23°C is, for example, 550 MPa or less, and may be 500 MPa or less. The product of the Young's modulus (MPa) of the sealant film 75 in the transverse direction (TD) and the thickness (μm) of the sealant film 75 is, for example, 30,000 or less, and may be 25,000 or less.

[0190] As shown in FIG. 10, the packaging material 70 may further include a printed layer 81. The printed layer 81 is a layer provided on the packaging material 70 to display product information and to impart an aesthetic feel to the packaging material 70. The printed layer 81 is provided, for example, on the first biaxially stretched plastic film 71. The printed layer 81 expresses letters, numbers, symbols, figures, pictures, and the like. The printed layer 81 contains, for example, a color material such as ink and a binder resin. Finart manufactured by DIC Graphics Corporation can be used as the ink for gravure printing.

[0191] 11A and 11B are cross-sectional views showing other examples of the layer structure of the packaging material 70. As shown in FIG. 11A and FIG. 11B, the packaging material 70 may have a transparent vapor deposition layer 82 located between the first biaxially stretched plastic film 71 and the second biaxially stretched plastic film 72. The packaging material 70 may have a transparent gas barrier coating film 83 located on the surface of the transparent vapor deposition layer 82. As shown in FIG. 11A, the transparent vapor deposition layer 82 may be provided on the inner surface of the first biaxially stretched plastic film 71. As shown in FIG. 11B, the transparent vapor deposition layer 82 may be provided on the outer surface of the second biaxially stretched plastic film 72.

[0192] [Transparent vapor deposited layer] The transparent deposition layer 82 may be composed of a single deposition layer or may include two or more deposition layers. When the transparent deposition layer 82 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 82 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.

[0193] The transparent deposition layer 82 is made of a transparent inorganic material. Examples of inorganic materials include metal oxides and inorganic oxides. Metal oxides include oxides of metals such as aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), and yttrium (Y). Inorganic oxides include oxides of silicon (Si). As inorganic materials constituting the transparent deposition layer, aluminum oxide (aluminum oxide) or silicon oxide is preferable.

[0194] The thickness of the transparent deposition layer 82 is, for example, 20 Å or more, and may be 30 Å or more, 40 Å or more, 50 Å or more, 60 Å or more, or 70 Å or more. The thickness of the transparent deposition layer 82 is, for example, 150 Å or less, 130 Å or less, 120 Å or less, or 110 Å or less.

[0195] [Gas barrier coating film] The transparent gas barrier coating film 83 has transparency. The transparent gas barrier coating film 83 can suppress the transmission of oxygen gas, water vapor, and the like. The transparent gas barrier coating film 83 is a compound represented by the general formula R 1 n M(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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] The thickness of the transparent gas barrier coating film 83 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 83 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.

[0201] As shown in Figures 10, 11A, and 11B, the packaging material 70 may contain only two biaxially oriented plastic films. A specific example of the packaging material 70 in this case is shown below. When listing layers, " / " is used to indicate the boundary between layers. The layers arranged from the outside to the inside of the pouch are listed from left to right. Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented nylon film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / sealant film Biaxially oriented PET film / transparent vapor deposition layer / transparent gas barrier coating film / printed layer / adhesive layer / biaxially oriented nylon film / adhesive layer / sealant film Biaxially oriented PET film / transparent vapor deposition layer / transparent gas barrier coating film / 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

[0202] The following describes preferred properties of the packaging material 70 when the packaging material 70 contains only two biaxially oriented plastic films. Specifically, the following describes preferred hot breaking strength and hot seal strength of the packaging material 70.

[0203] The packaging material 70 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 70 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 70 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 70 is preferably 50.0 MPa or less, and the hot breaking strength in the direction perpendicular to the one direction of the packaging material 70 is preferably 45.0 MPa or less. One direction of the packaging material 70 may be, for example, a first direction D1 in the pouch 10, and a direction perpendicular to the one direction of the packaging material 70 may be, for example, a second direction D2 in the pouch 10. Also, for example, the flow direction (MD) of the packaging material 70 may correspond to the first direction D1 of the pouch 10, and for example, the vertical direction (TD) of the packaging material 70 may correspond to the second direction D2 of the pouch 10. Also, for example, one direction of the packaging material 70 may correspond to the flow direction (MD), and for example, a direction perpendicular to the one direction of the packaging material may correspond to the vertical direction (TD).

[0204] In measuring the properties of the packaging material 70, a test piece cut out from the packaging material 70 is used. When the packaging material 70 is available in a state before the packaging material 70 is processed into the pouch 10, the test piece may be prepared by cutting the packaging material 70. The test piece may be prepared by cutting a product made from the packaging material 70, such as the pouch 10. FIG. 13 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 70 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 90A in FIG. 13. When measuring the properties of the packaging material 70 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 90B in FIG. 13.

[0205] The hot breaking strength of the packaging material 70 is measured in accordance with JIS K7127, except for the lengths of the test pieces 90A and 90B. The length and width of the test pieces 90A and 90B are 100 mm and 15 mm.

[0206] The hot rupture strength of the test pieces 90A and 90B is measured using a Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.). Specifically, first, the test pieces 90A and 90B are gripped at both ends in the longitudinal direction with grippers 91 and 92 as shown in FIG. 14. Then, the test pieces 90A and 90B are held for one minute in an environment with a temperature of 100° C. and a relative humidity of 5%, and then a tensile test is performed in which the test pieces 90A and 90B are pulled in the longitudinal direction of the test pieces 90A and 90B at a tensile speed of 300 mm / min in an environment with a temperature of 100° C. and a relative humidity of 5%, with an initial gripper distance S1 (see FIG. 14) of 50 mm, to measure the hot rupture strength of the test pieces 90A and 90B. The hot breaking strength of the five test pieces 90A, 90B is measured, and the average value is regarded as the hot breaking strength of the packaging material 70 in the machine direction and perpendicular direction.

[0207] The packaging material 70 has a seal strength (hot seal strength) of, for example, 13.0 N or less when measured in a 100°C environment after being held in a 100°C environment for 1 minute. The hot seal strength may be 11.0 N or less, 10.0 N or less, 8.0 N or less, or 6.0 N or less. If the hot seal strength is too low, the first intermediate portion 35 may peel off before the contents are sufficiently heated and pressurized, causing a decrease in the pressure and temperature of the storage section 18. In consideration of this point, the hot seal strength of the sealed portion of the packaging material 70 may be, for example, 3.0 N or more, 4.0 N or more, or 5.0 N or more. The seal strength of the packaging material 70 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 sealed portion in the packaging material 70 of the pouch after the retort treatment.

[0208] In measuring the hot seal strength of the packaging material 70, a test piece cut from the packaging material 70 with the inner surfaces joined together is used. When the packaging material 70 is available in a state before the packaging material 70 is processed into the pouch 10, the test piece may be made by cutting the packaging material 70 with the inner surfaces joined together. The test piece may be made by cutting a product made from the packaging material 70, such as the pouch 10. FIG. 15 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 50 to prepare a test piece 90C. The length and width of the test piece 90C are 70 mm and 15 mm.

[0209] 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 70 in the non-sealed portion of the test piece 90C are gripped by grippers 93 and 94 (see FIG. 16A) of the test machine. Then, the grippers 93 and 94 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 90C, and the maximum value MAX of the tensile stress F1 is measured (see FIG. 16B). The distance S2 between the grippers 93 and 94 at the start of pulling is 50 mm, and the distance S2 between the grippers 93 and 94 at the start of pulling is 60 mm. The maximum value MAX is taken as the seal strength (see FIG. 16B). The hot seal strength is measured by holding the test piece 90C 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 90C, and the average value is regarded as the hot seal strength of the packaging material 70.

[0210] In addition, in the case where the dimensions of the sealed portion in the longitudinal direction are not constant among multiple test pieces 90C made from the pouch 10, the position where the tensile stress F1 begins to increase and the slope of the graph as the tensile stress F1 increases may differ depending on the test piece 90C, as shown in Figures 16B and 16C.

[0211] The thickness of the packaging material 70 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 70 including only two biaxially stretched plastic films is, for example, 130 μm or less, or may be 120 μm or less.

[0212] FIG. 12 is a cross-sectional view showing another example of the layer structure of the packaging material 70. The packaging material 70 shown in FIG. 12 includes a biaxially stretched plastic film 73, an adhesive layer 78, and a sealant film 75 in this order. The biaxially stretched plastic film 73 is located on the outer surface 70y side, and the sealant film 75 is located on the inner surface 70x side. The inner surface 70x faces the storage section 18. There is only one biaxially stretched plastic film in the packaging material 70. The packaging material 70 may include a transparent deposition layer 82 provided on the surface of the biaxially stretched plastic film 73. The packaging material 70 may include a transparent gas barrier coating film 83 located on the surface of the transparent deposition layer 82.

[0213] The biaxially stretched plastic film 73 is a film made of plastic and stretched in two predetermined directions, similar to the first biaxially stretched plastic film 71. As the biaxially stretched plastic film 73, the biaxially stretched plastic film described in the first biaxially stretched plastic film 71 above may be used.

[0214] The packaging material 70 including only one biaxially stretched plastic film may have a hot seal strength equivalent to that of the packaging material 70 including only two biaxially stretched plastic films. The packaging material 70 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 70 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.

[0215] The adhesive layer 78 includes an adhesive for bonding the biaxially oriented plastic film 73 and the sealant film 75 by a dry lamination method. An example of the adhesive for the adhesive layer 78 is polyurethane, as in the case of the first adhesive layer 76. In addition to the configurations, materials, and characteristics described below, the same configurations, materials, and characteristics as those of the first adhesive layer 76 can be adopted for the adhesive layer 78.

[0216] The thickness of the adhesive layer 78 is, for example, 2 μm or more, and may be 3 μm or more. The thickness of the adhesive layer 78 is, for example, 6 μm or less, and may be 5 μm or less.

[0217] The thickness of the packaging material 70 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 70 including only one biaxially stretched plastic film is, for example, 110 μm or less, or may be 100 μm or less.

[0218] How the pouch is made Next, a method for manufacturing the pouch 10 using the packaging material 70 will be described. First, the front film 15 and the back film 16 made of the packaging material 70 are prepared. Next, the inner surface of the front film 15 and the inner surface of the back film 16 are heat-sealed to form seal portions such as the upper seal portion 11a, the first side seal portion 30, and the second side seal portion 50. The heat-sealing temperature is, for example, 160°C or higher, and may be 170°C or higher, or may be 180°C or higher. The heat-sealing temperature is, for example, 250°C or lower, and may be 240°C or lower, or may be 230°C or lower.

[0219] 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 12b of the lower portion 12. After that, the lower portion 12 is heat sealed along the lower edge 12x to form the lower seal portion 12a. 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.

[0220] 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.

[0221] When the pressure in the storage section 18 increases, the pouch 10 expands, for example, in a circular shape around 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.

[0222] When a force is applied to the first intermediate portion 35, peeling of the first intermediate portion 35 progresses. Peeling of the first intermediate portion 35 starts at the first connecting portion 38. When peeling of the first connecting portion 38 reaches the first non-sealed portion 45, an opening 35v is formed in the first intermediate portion 35 as shown in FIG. 17. Steam generated in the storage portion 18 flows into the first non-sealed portion 45 through the opening 35v. In FIG. 17, an example of a peeled portion occurring in the first intermediate portion 35 is shown by a dotted line.

[0223] While the opening 35v is small, steam generated in the storage section 18 is not sufficiently discharged to the outside of the pouch 10. In this case, the pressure in the storage section 18 remains high even after the opening 35v is formed. Therefore, after the opening 35v is formed, the first portion 36 and the second portion 37 are peeled off. The peeling of the first portion 36 proceeds outward from the first connecting portion 38. The peeling of the second portion 37 proceeds upward from the first connecting portion 38.

[0224] Peeling of the first portion 36 starts at the inner first portion 361. The first portion 36 includes a first transition portion 363. The first transition portion 363 can function as a peeling suppression portion that suppresses the progress of peeling of the first portion 36. For example, as shown by the dotted line in FIG. 18, the progress of peeling of the first portion 36 in the first direction D1 can be stopped at the first transition portion 363. This can suppress the contents 19 that are heated and jump up from reaching the first non-sealed portion 45, compared to when the first portion 36 is completely peeled off.

[0225] Peeling of the second portion 37 starts at the lower second portion 371. The second portion 37 includes a second transition portion 373. The second transition portion 373 can function as a peeling suppression portion that suppresses the progress of peeling of the second portion 37. For example, as shown by the dotted line in FIG. 18, the progress of peeling of the second portion 37 in the second direction D2 can be stopped at the second transition portion 373. This can suppress the contents 19 mixed with the steam flowing in the first direction D1 from reaching the first non-sealed portion 45, compared to when the second portion 37 is completely peeled off.

[0226] 19 is a diagram showing an example of the first intermediate portion 35 after the progression of peeling of the first portion 36 and the second portion 37 has stopped. The outer first portion 362 and the upper second portion 372 are expected to remain. An opening 35v is formed between the outer first portion 362 and the upper second portion 372.

[0227] Reference symbol F1 denotes steam generated in the storage portion 18. The steam F1 flows into the first non-sealed portion 45 through the opening 35v. The steam F1 passes through the gap between the second portion 37 and the second intermediate portion 33, and is then discharged from the opening edge portion 46 to the outside of the pouch 10.

[0228] Reference characters F2 and F5 represent the flows of the contents 19 that have splashed upward. The flows F2 and F5 of the contents 19 are blocked by the outer first portion 362 and the upper second portion 372. This prevents the contents 19, which have a relatively large size and have splashed upward, from entering the first non-sealed portion 45. This prevents the flow of steam F1 inside the first non-sealed portion 45 from being obstructed by the contents 19 that have entered the first non-sealed portion 45.

[0229] Symbols F3 and F4 represent flows of the contents 19 mixed with the steam flowing in the first direction D1. The flows F3 and F4 of the contents 19 are blocked by the upper second portion 372 and the second middle portion 33. This prevents the contents 19 from leaking out of the pouch 10.

[0230] According to this embodiment, the first portion 36 and the second portion 37 each have a peel-suppressing portion, thereby preventing the contents 19 from entering the first non-sealed portion 45 and preventing the contents 19 from leaking outside the pouch 10.

[0231] In order to prevent leakage of the contents 19, it is also conceivable to increase the width of the first intermediate portion 35 as a whole. However, in this case, the progress of peeling may stop when the opening 35v is small, and steam may not be properly discharged to the outside of the pouch 10. If steam is not properly discharged to the outside of the pouch 10, the pressure of the storage portion 18 continues to increase. In this case, peeling may progress in seal portions other than the first intermediate portion 35, such as the side lower portion 32 of the first side seal portion 30 and the lower portion 52 of the second side seal portion 50. In particular, when the output of the microwave oven is high, the rate of steam generation in the storage portion 18 is high, so peeling is likely to occur in seal portions other than the first intermediate portion 35. If the pressure of the storage portion 18 exceeds a certain value, the 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.

[0232] According to the present embodiment, the first intermediate portion 35 includes the inner first portion 361 and the lower second portion 371, so that peeling of the first intermediate portion 35 can proceed appropriately. This can prevent peeling from occurring in the sealed portions other than the first intermediate portion 35. In addition, it can prevent the pouch 10 from bursting.

[0233] Preferably, the sealed portion of the pouch 10 has a hot seal strength of 10 N or less. This allows the opening 35v to be formed in the first intermediate portion 35 before the pressure in the storage portion 18 becomes excessively high. This makes it possible to prevent peeling from occurring in the sealed portion other than the first intermediate portion 35. Also, it makes it possible to prevent the pouch 10 from bursting.

[0234] After heating the contents 19, the user tears the pouch 10 starting from the opening means 30a. The opening means 30a is formed in the upper side portion 31 located above the first non-sealed portion 45. This allows the pouch 10 to be torn at a position closer to the top 11. The closer to the top 11, the smaller the distance between the front film 15 and the back film 16 tends to be. This makes it easier for the user to tear the pouch 10. In addition, the user is less likely to feel heat when tearing the pouch 10.

[0235] 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.

[0236] First Variation In the above-described embodiment, an example has been shown in which the inner edge 31a of the upper side portion 31 extends continuously with the inner edge 35a of the upper second portion 372. For example, an example has been shown in which the inner edge 31a of the upper side portion 31 is located on an extension line of the inner edge 35a of the upper second portion 372.

[0237] Fig. 20 is a front view showing a modified example of the steam release mechanism 25. The inner edge 31a of the upper side portion 31 does not have to be located on an extension of the inner edge 35a of the upper second portion 372. For example, as shown in Fig. 20, the inner edge 31a of the upper side portion 31 may be located outboard of the inner edge 35a of the upper second portion 372 in the first direction D1.

[0238] Second Variation Fig. 21 is a front view showing a modified example of the steam release mechanism 25. As shown in Fig. 21, the unsealing means 30a may be adjacent to the first non-sealed portion 45 in the second direction D2.

[0239] Third variant Fig. 22 is a front view showing a modified example of the steam release mechanism 25. In the example shown in Fig. 22, the second shielding distance L12 of the second portion 37 is greater than the second shielding distance L12 of the second portion 37 shown in Fig. 8 described above. As shown in Fig. 22, the boundary between the lower second portion 371 and the second transition portion 373 may be located below the upper edge 33c of the second intermediate portion 33.

[0240] Fourth Variation Fig. 23 is a front view showing a modified example of the steam release mechanism 25. In the example shown in Fig. 23, the second shielding distance L12 of the second portion 37 is smaller than the second shielding distance L12 of the second portion 37 shown in Fig. 8 described above. In both the example shown in Fig. 8 and the example shown in Fig. 23, the boundary between the lower second portion 371 and the second transition portion 373 may be located above the upper edge 33c of the second intermediate portion 33. The boundary between the lower second portion 371 and the second transition portion 373 may be located above the second reference line SL2 shown in Fig. 5.

[0241] Fifth Variation Fig. 24 is a front view showing a modified example of the steam release mechanism 25. In the example shown in Fig. 24, the dimension L13 of the second intermediate portion 33 in the second direction D2 is larger than the dimension L13 of the second intermediate portion 33 shown in Fig. 8 described above. The upper edge 33c of the second intermediate portion 33 may be located above the second reference line SL2 shown in Fig. 5. The boundary between the lower second portion 371 and the second transition portion 373 may be located below the upper edge 33c of the second intermediate portion 33 and above the second reference line SL2 shown in Fig. 5.

[0242] Sixth Variation Figure 25 is a front view showing a modified example of the steam release mechanism 25. In the example shown in Figure 25, the dimension L13 of the second intermediate portion 33 in the second direction D2 is smaller than the dimension L13 of the second intermediate portion 33 shown in Figure 8 described above.

[0243] Seventh Variation Fig. 26 is a front view showing an example of the pouch 10. As shown in Fig. 26, the pouch 10 may be a gusset-type pouch that is configured to be self-supporting.

[0244] In addition to the front film 15 and the back film 16, the pouch 10 may include a lower film 17 located in the lower portion 12. The lower film 17 is disposed between the front film 15 and the back film 16 in a state where it is folded back along a fold-back portion 17f, for example.

[0245] The lower part 12 of the pouch 10 includes a lower sealed part 12a. The lower sealed part 12a includes a part where the inner surface of the front film 15 and the inner surface of the lower film 17 are joined, and a part where the inner surface of the back film 16 and the inner surface of the lower film 17 are joined.

[0246] Comparison Form 27 is a front view showing a comparative vapor release mechanism 25. The comparative vapor release mechanism 25 differs from the present embodiment in that the first portion 36 does not include a first transition portion 363.

[0247] In the steam release mechanism 25 of the comparative embodiment, it is expected that the entire first portion 36 will peel off when the pouch 10 is heated. In this case, an opening will be formed between the upper edge 32c of the side lower portion 32 and the upper second portion 372 or the second transition portion 373 of the second portion 37. In the comparative embodiment, the first distance L14 represents the distance between the upper edge 32c of the side lower portion 32 and the outer edge of the boundary between the lower second portion 371 and the second transition portion 373.

[0248] In the comparative embodiment, since first portion 36 does not remain when pouch 10 is heated, contents 19 that splash upward easily enter first non-sealed portion 45. When contents 19 that enter first non-sealed portion 45 adheres to upper edge 32c of lower side portion 32, the flow of steam F1 inside first non-sealed portion 45 is obstructed.

[0249] In contrast, according to the present embodiment, contents 19 that have splashed upward are blocked by first outer portion 362. This prevents the flow of steam F1 inside first non-sealed portion 45 from being obstructed by contents 19 that have entered first non-sealed portion 45. Therefore, even if dimension L15 of opening edge portion 46 is smaller than in the conventional case, steam is appropriately discharged to the outside of pouch 10.

[0250] The smaller the dimension L15 of the opening edge 46, the easier it is to form the upper side portion 31 between the first non-sealed portion 45 and the upper portion 11. By forming the upper side portion 31 between the first non-sealed portion 45 and the upper portion 11 and forming the opening means 30a in the upper side portion 31, the operation of the user tearing the pouch 10 is facilitated. EXAMPLES

[0251] 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.

[0252] (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.

[0253] 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.

[0254] 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.

[0255] 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.

[0256] Example 1 Content 19 was prepared as the content to be filled into pouch 10. Content 19 was 180 g of curry.

[0257] The pouch 10 of Fig. 1 was produced using the packaging material 1. The components of the steam venting mechanism 25 of the pouch 10 of Fig. 1 have the structure shown in Fig. 8. The pouch 10 was then filled with the above-mentioned contents 19. The lower portion 12 of the pouch 10 was then heat-sealed to form the lower seal portion 12a. In this manner, the pouch 10 shown in Fig. 3 containing the contents 19 was obtained.

[0258] The dimensions of each part of the pouch 10 are as follows: - Dimensions of storage compartment 18 H1: 110mm - Dimensions of storage compartment 18 H2: 157mm Width of upper seal part 11a, width of lower seal part 12a: 8mm Width W11 of upper side portion 31: 15.0 mm Width of lower side portion 32 W12_1: 6.5 mm Width of lower side portion 32 W12_2: 5.0 mm Width W13 of second intermediate portion 33: 3.0mm Distance L01 between the first side edge 13x and the inner edge 35a of the second portion 37: 15.0 mm Distance L02 from the lower edge 11c of the upper seal portion 11a to the lower edge 31c of the upper side portion 31: 13.0 mm Distance L03 from the lower edge 11c of the upper seal portion 11a to the upper edge 32c of the lower side portion 32: 30.0 mm Distance L04 from the opening means 30a to the lower edge 31c of the upper side portion 31: 6.0 mm First reference width W16S of the inner first portion 361: 3.0 mm ·Width of the first outer part 362 E16E: 5.0mm Second reference width W17S of the lower second portion 371: 2.5 mm Width E17E of the upper second portion 372: 5.0 mm First shielding distance L11 of the first portion 36: 3.7 mm Second shielding distance L12 of second portion 37: 13.7 mm Dimension L13 of second intermediate portion 33: 12.0 mm ·1st distance L14: 15.36mm Dimension L15 of opening edge 46: 15.0 mm ·Second distance L16: 8.39mm ·1st opening distance L17: 2.02mm

[0259] 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

[0260] Next, the pouch 10 was subjected to a retort treatment under the following conditions. Method: Spray type Retort temperature: 121℃ Retort time: 30 minutes

[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 placed in a carton 100.

[0262] 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°.

[0263] The pouch 10 containing the content 19 was heated for 3 minutes and 30 seconds in a microwave oven at an output of 600 W. The pouch 10 after heating was evaluated from the following viewpoints. -Dirt in the steam vent ·Box dirty -Stains in the microwave ·Openability ·rupture

[0264] In the items "steam hole stains," "box stains," and "microwave stains," whether the contents had leaked out was evaluated. The evaluation results are shown in FIG. 28. The "steam hole stains" column shows the results of checking whether the contents had adhered to the opening edge 46 of the first non-sealed portion 45. The "box stains" column shows the results of checking whether the contents that had spurted out of the pouch 10 had adhered to the carton 100. The "microwave stains" column shows the results of checking whether the contents that had spurted out of the pouch 10 had adhered to the microwave. "Great" means that almost no adhesion of the contents was confirmed. "Good" means that the amount of the contents that had boiled over was small enough to be wiped off with one tissue. "Not good" means that two or more tissues were needed to wipe off the contents that had boiled over.

[0265] In the "Rupture" category, whether peeling occurred in the side lower portion 32 or the lower portion 52 of the pouch 10 after heating was evaluated. The evaluation results are shown in FIG. 28. In the "Rupture" column, "great" means that the width of the peeling that occurred in the side lower portion 32 or the lower portion 52 in the first direction D1 was less than 1 mm, or no peeling occurred. "Good" means that the peeling that occurred in the side lower portion 32 or the lower portion 52 did not reach the first side edge 13x or the second side edge 14x. "Not good" means that the peeling that occurred in the side lower portion 32 or the lower portion 52 reached the first side edge 13x or the second side edge 14x.

[0266] In the "openability" category, 50 pouches 10 after heating were manually torn starting from the opening means 30a toward the second side edge 14x. In the "openability" column, "great" means that the number of pouches whose tear path reached the second side edge 14x was 40 or more. "good" means that the number of pouches whose tear path reached the second side edge 14x was 20 to 39. "not good" means that the number of pouches whose tear path reached the second side edge 14x was 19 or less.

[0267] The first intermediate portion 35 of the pouch 10 after heating is shown in Fig. 29. It was confirmed that the outer first portion 362 and the upper second portion 372 remained in the pouch 10 after heating.

[0268] Example 2 The pouch 10 in Fig. 20 was produced using the packaging material 1. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Width W11 of upper side portion 31: 10.0 mm

[0269] As in Example 1, "steam hole stains," "box stains," "microwave stains," "burst," and "ease of opening" were evaluated. The results are shown in Fig. 28. Fig. 30 shows the first intermediate portion 35 of the pouch 10 after heating. It was confirmed that the outer first portion 362 and the upper second portion 372 remained in the pouch 10 after heating.

[0270] Example 3 The pouch 10 in Fig. 21 was produced using the packaging material 1. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Distance L04 from the opening means 30a to the lower edge 31c of the upper side portion 31: 1.0 mm

[0271] The "steam vent stains," "box stains," "microwave stains," "bursts," and "ease of opening" were evaluated in the same manner as in Example 1. The results are shown in FIG.

[0272] Example 4 The pouch 10 in Fig. 22 was produced using the packaging material 1. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Second shielding distance L12 of second portion 37: 16.7 mm ·1st distance L14: 12.39mm ·Second distance L16: 7.34mm

[0273] The "steam vent stains," "box stains," "microwave stains," "bursts," and "ease of opening" were evaluated in the same manner as in Example 1. The results are shown in FIG.

[0274] Example 5 The pouch 10 in Fig. 23 was produced using the packaging material 1. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Second shielding distance L12 of second portion 37: 11.7 mm ·1st distance L14: 17.35mm ·Second distance L16: 9.41mm

[0275] The "steam vent stains," "box stains," "microwave stains," "bursts," and "ease of opening" were evaluated in the same manner as in Example 1. The results are shown in FIG.

[0276] Example 6 The pouch 10 in Fig. 24 was produced using the packaging material 1. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Dimension L13 of second intermediate portion 33: 17.0 mm Dimension L15 of opening edge 46: 10.0 mm ·Second distance L16: 7.03mm

[0277] The "steam vent stains," "box stains," "microwave stains," "bursts," and "ease of opening" were evaluated in the same manner as in Example 1. The results are shown in FIG.

[0278] Example 7 The pouch 10 in Fig. 25 was produced using the packaging material 1. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. Dimension L13 of second intermediate portion 33: 10.0 mm Dimension L15 of opening edge 46: 17.0 mm ·Second distance L16: 9.41mm

[0279] The "steam vent stains," "box stains," "microwave stains," "bursts," and "ease of opening" were evaluated in the same manner as in Example 1. The results are shown in FIG.

[0280] Comparative Example 1 The pouch 10 in Fig. 26 was produced using the packaging material 1. The heat sealing conditions and the retort treatment conditions were the same as those in Example 1. The main dimensions that differ from those in Example 1 are shown below. First shielding distance L11 of the first part 36: Not applicable (The first transition portion 363 is not formed.) ·1st distance L14: 16.27mm First opening distance L17: Not applicable (The first transition portion 363 is not formed.)

[0281] As in Example 1, "steam hole stains," "box stains," "microwave stains," "burst," and "ease of opening" were evaluated. The results are shown in Figure 28. Figure 31 shows the first intermediate portion 35 of the pouch 10 after heating. It was confirmed that no first portion 36 remained in the pouch 10 after heating.

[0282] 28, in Comparative Example 1, significant adhesion of the contents to the first non-sealed portion 45 was observed. In Examples 1 to 7, almost no adhesion of the contents to the first non-sealed portion 45 was observed. [Explanation of symbols]

[0283] 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 17 Lower Film 18 Storage unit 19 Contents 19a Top side 25 Steam release mechanism 30 First side seal 31 Upper side part 32 Lower side part 33 Second intermediate part 33a Inner border 33c upper edge 35 1st intermediate part 35a Inner edge 35b Outer edge 36 Part 1 361 Inner 1st part 362 Outer 1st part 363 1st transition part 37 Part 2 371 Lower 2nd part 372 Upper 2nd part 373 Second transition part 38 First connection part 45 First unsealed part 46 Opening edge 47 Penetration 50 Second side seal 51 Upper side part 52 Lower side part 55 Middle part 65 Second non-sealed part 66 Opening edge 70 Packaging materials 70x inner surface 70y external surface 71 First biaxially stretched plastic film 72 Second biaxially oriented plastic film 75 Sealant Film 76 First adhesive layer 77 Second adhesive layer 81 Printing layer 82 Transparent vapor deposition layer 83 Transparent gas barrier coating film

Claims

1. A pouch in which a storage section for storing contents is defined between a 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 containing portion by the first side seal portion; the first side seal portion includes at least a side lower portion extending along a first side edge of the first side from the first non-seal portion toward a lower portion of the pouch, a first intermediate portion located between the containing portion and the first non-seal portion and connected to the side lower portion, and a second intermediate portion located between the first non-seal portion and the first side edge in the first direction and connected to the side lower portion, the first intermediate portion includes a first portion, a second portion, and a first connection portion connecting the first portion and the second portion, the first portion extends from the first connecting portion toward the first side of the pouch; the second portion extends from the first connecting portion toward the top of the pouch; the first portion includes an inner first portion, an outer first portion located outward in the first direction from the inner first portion, and a first transition portion located between the inner first portion and the outer first portion and having a width greater than a width of the inner first portion, The pouch, wherein the second portion includes a lower second portion, an upper second portion located above the lower second portion, and a second transition portion located between the lower second portion and the upper second portion and having a width greater than that of the lower second portion.

2. The first side seal portion includes an inner edge that is an edge that contacts the storage portion or faces the storage portion, and an outer edge that is located opposite the inner edge, the inner first portion includes a portion where the inner edge and the outer edge extend linearly and have a first reference width; the first transition portion has a width that is 1.2 times or more the first reference width; the lower second portion includes a portion where the inner edge and the outer edge extend linearly and have a second reference width; 2. The pouch of claim 1, wherein the second transition portion has a width that is greater than or equal to 1.2 times the second nominal width.

3. 3. The pouch of claim 2, wherein a first shielding distance (L11), which is the distance in the first direction between the boundary between the inner first portion and the first transition portion and the inner edge of the lower side portion, is 1.0 mm or more and 5.0 mm or less.

4. The pouch of claim 3 , wherein a boundary between the inner first portion and the first transition portion is located outside a boundary between the lower second portion and the second transition portion in the first direction.

5. 5. The pouch of claim 4, wherein a first distance (L14) between an outer edge of the boundary between the inner first portion and the first transition portion and an outer edge of the boundary between the lower second portion and the second transition portion is greater than or equal to 10 mm and less than or equal to 20 mm.

6. The pouch of claim 5, wherein a ratio (L14 / L13) of the first distance (L14) to a dimension (L13) of the second intermediate portion in a second direction perpendicular to the first direction is 0.8 or greater and 2.0 or less.

7. The pouch according to any one of claims 1 to 6, wherein the boundary between the inner first portion and the first transition portion is located outside an outer edge of the upper second portion in the first direction.

8. 7. The pouch according to claim 5 or 6, wherein a second distance (L16), which is the shortest distance between the second portion and the second intermediate portion, is equal to or greater than 6 mm and equal to or less than 12 mm.

9. The pouch of claim 8, wherein the first distance (L14) is greater than the second distance (L16).

10. The pouch according to claim 9, wherein a ratio (L14 / L16) of the first distance (L14) to the second distance (L16) is greater than or equal to 1.5 and less than or equal to 2.

5.

11. the first unsealed portion extends to the first side edge; The pouch according to claim 8 , wherein a dimension (L15) of an opening edge portion, which is a portion of the first unsealed portion overlapping the first side edge, is greater than the second distance (L16).

12. The pouch according to claim 11, wherein a ratio (L15 / L16) of the dimension (L15) of the opening edge portion to the second distance (L16) is 1.2 or more and 2.5 or less.

13. The pouch of claim 8, wherein a ratio (L13 / L16) of a dimension (L13) of the second intermediate portion in a second direction perpendicular to the first direction to the second distance (L16) is 1.0 or more and 2.5 or less.

14. 9. The pouch of claim 8, wherein a first opening distance (L17), which is a distance in the first direction between an outer edge of a boundary between the inner first portion and the first transition portion and an outer edge of a boundary between the lower second portion and the second transition portion, is 2.5 mm or less.

15. 15. The pouch of claim 14, wherein a ratio (L17 / L16) of the first opening distance (L17) to the second distance (L16) is less than or equal to 0.

30.

16. The pouch of claim 8 , wherein a boundary between the lower second portion and the second transition portion is located above a top edge of the second intermediate portion.

17. 9. The pouch of claim 8, wherein a boundary between the lower second portion and the second transition portion is located below a top edge of the second intermediate portion.

18. The pouch of any one of claims 1 to 6, wherein the second transition portion includes an outer edge that extends in a different direction than an outer edge of the lower second portion.

19. the first side seal portion includes an upper side portion extending along the first side edge from the first unsealed portion toward the top of the pouch; The pouch of any one of claims 1 to 6, wherein the first middle portion is connected to the upper side portion of the first side seal.

20. 20. The pouch of claim 19, further comprising an opening means located at said upper side portion.

21. The pouch according to any one of claims 1 to 6, wherein the viscosity of a viscous component of the content contained in the pouch at 95°C is 1000 mPa·S or more.

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