bag

Abstract

To provide a bag from which contents can be easily taken out. [Solution] A bag having a steam vent mechanism and containing contents includes a front film, a back film, a lower film located between the front and back films and constituting the lower part of the bag, a first half-cut line formed in the front film so as to be located at least partially below the steam vent mechanism and at least partially having a shape that is convex downward, and a second half-cut line formed in the back film so as to at least partially overlap with the first half-cut line. The front film does not include a half-cut line that is provided to bulge toward the upper end.

Description

[Technical Field]

[0001] The present invention relates to a bag with a vapor venting mechanism. [Background technology]

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

[0003] When a sealed bag containing food is heated in a microwave oven, the moisture in the food evaporates as the food is heated, causing the pressure in the bag to increase. This increased pressure in the bag's storage compartment can cause the bag to burst, scattering the food contents and contaminating the microwave. In consideration of this issue, Patent Document 1, for example, proposes providing a bottom-gusseted bag with a steam vent mechanism that automatically connects the storage compartment to the outside when the pressure in the storage compartment increases, allowing steam inside the storage compartment to escape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-120550 Summary of the Invention [Problem to be solved by the invention]

[0005] After heating the contents of the bag in a microwave oven, consumers open the top of the bag and remove the contents through the opening. However, when a bottom-gusseted bag is heated in a microwave oven, the pressure in the bag's container increases, which can cause the width of the gusset at the bottom of the bag to expand. As the width of the bottom of the bag expands, the front and back films connected to the bottom of the bag tilt relative to the vertical, narrowing the gap between the front and back films at the top of the bag and making it difficult to remove the contents through the opening.

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

[0007] The present invention is a bag having a steam release mechanism and for containing contents, comprising a surface film and a back film, a lower film located between the surface film and the back film and constituting the lower part of the bag, a first half-cut line formed in the surface film so as to be located at least partially below the steam release mechanism, the first half-cut line having at least a partial shape that is convex downward, and a second half-cut line formed in the back film so as to at least partially overlap with the first half-cut line, wherein the surface film does not include a half-cut line that is arranged to bulge toward the upper end side.

[0008] In the bag according to the present invention, at least one of one end and the other end of the first half-cut line may overlap with at least one of one end and the other end of the second half-cut line.

[0009] In the bag according to the present invention, the first half-cut line may be located at least partially below the second half-cut line.

[0010] In the bag according to the present invention, the first half-cut line and the second half-cut line do not necessarily overlap over the entire area.

[0011] In the bag according to the present invention, one end of the first half-cut line and one end of the second half-cut line may be located on a first side of the bag below the steam vent mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located on a second side of the bag opposite the first side below the steam vent mechanism.

[0012] In the bag according to the present invention, one end of the first half-cut line and one end of the second half-cut line may be located on a first side of the bag above the steam vent mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located on a second side of the bag above the steam vent mechanism and opposite the first side.

[0013] In the bag according to the present invention, the steam release mechanism may be located on a first side of the bag, one end of the first half-cut line and one end of the second half-cut line may be located on the first side of the bag below the steam release mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located on a second side of the bag above the steam release mechanism and facing the first side.

[0014] In the bag according to the present invention, the steam release mechanism may be located on a first side of the bag, one end of the first half-cut line and one end of the second half-cut line may be located on the first side of the bag below the steam release mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located at the top of the bag.

[0015] The bag according to the present invention may further include zipper tapes provided on the inner surface of the front film and the inner surface of the back film so as to extend from a first side of the bag to a second side opposite the first side above the steam vent mechanism. [Effects of the Invention]

[0016] According to the present invention, it is possible to improve the ease of taking out the contents. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a front view showing a bag according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded view showing the film that constitutes the bag shown in FIG. [Figure 3] 3 is a cross-sectional view of the bag shown in FIG. 1 taken along line III-III. [Figure 4] FIG. 2 is a cross-sectional view showing an example of a layer structure of a laminate that constitutes a bag. [Figure 5] FIG. 1 is a front view showing the bag with the top sealed. [Figure 6] FIG. 2 is a perspective view showing the bag in an opened state. [Figure 7] FIG. 10 is a front view showing a modified example of the bag. [Figure 8] FIG. 10 is a front view showing a modified example of the bag. [Figure 9] FIG. 10 is a front view showing a modified example of the bag. [Figure 10] FIG. 10 is a front view showing a modified example of the bag. [Figure 11] FIG. 10 is a front view showing a modified example of the bag. [Figure 12] FIG. 10 is a front view showing a modified example of the bag. [Figure 13] FIG. 10 is a front view showing a modified example of the bag. [Figure 14] FIG. 10 is a front view showing a modified example of the bag. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the present invention will be described with reference to Figures 1 to 6. In the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

[0019] Furthermore, terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel," "orthogonal," and "identical," as well as values ​​of lengths and angles, are not to be construed as being bound by strict meanings, but rather as including a range within which similar functions can be expected.

[0020] FIG. 1 is a front view showing bag 10 according to this embodiment as seen from the front side. FIG. 2 is an exploded view showing the film that constitutes the bag shown in FIG. 1. Bag 10 has a storage section 18 that stores contents. Note that FIG. 1 shows bag 10 in a state before the contents are filled. Bag 10 according to this embodiment is configured so that it can be suitably used as a microwave pouch in which the contents are heated in a microwave oven.

[0021] There are no particular limitations on the contents that can be placed in bag 10, as long as they can be heated in a microwave oven. For example, contents that can be filled into bag 10 include cooked foods such as curry, stew, soup, simmered dishes, and hamburger steaks.

[0022] As shown in FIG. 1, the bag 10 according to the present embodiment includes a steam release mechanism 20, a first half-cut line 25, and a second half-cut line . Steam release mechanism 20 is a mechanism for releasing to the outside steam that is generated when the contents contained in bag 10 are heated. Steam release mechanism 20 is configured to communicate between the inside and outside of bag 10 to release steam when the steam pressure reaches or exceeds a predetermined value, and to prevent steam from being released from anywhere other than steam release mechanism 20. The first half-cut line 25 and the second half-cut line 26 are configured so that the film that constitutes the bag 10 can be easily torn along the first half-cut line 25 and the second half-cut line 26. The first half-cut line 25 and the second half-cut line 26 are used by the consumer when opening the bag 10 after heating the contents of the bag 10 using a microwave oven. The structure of the bag 10 will be described below.

[0023] bag In this embodiment, bag 10 is a bottom-gusset bag configured to be self-standing. Bag 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. Note that names such as "upper portion," "lower portion," and "side portion," as well as terms such as "above" and "below," merely describe the relative positions and orientations of bag 10 and its components relative to a state in which bag 10 is standing on its own with the gusset portion facing downward. The position of bag 10 during transportation or use is not limited by the names and terms used in this specification.

[0024] As shown in Fig. 1, bag 10 includes a surface film 15 that forms the surface, a back film 16 that forms the back surface, and a lower film 17 that forms the lower portion 12. Lower film 17 is folded back at folded portion 17f and disposed between surface film 15 and back film 16. Note that in Fig. 1, components that are not visible when bag 10 is viewed from the surface side, such as back film 16, are indicated by dotted lines.

[0025] The terms "surface film," "back film," and "lower film" mentioned above merely distinguish each film according to its positional relationship, and the terms do not limit the method of providing the films when manufacturing bag 10. For example, bag 10 may be manufactured using one film in which surface film 15, back film 16, and lower film 17 are connected together, or may be manufactured using two films: one film in which surface film 15 and lower film 17 are connected together and one back film 16, or may be manufactured using three films: one surface film 15, one back film 16, and one lower film 17.

[0026] The inner surfaces of the front film 15, back film 16, and bottom film 17 are joined together by sealed portions. In a plan view of the bag 10 such as Fig. 1, the sealed portions are hatched.

[0027] As shown in FIG. 1, the seal portion includes an outer edge seal portion that extends along the outer edge of bag 10, and a steam release seal portion 20a that constitutes steam release mechanism 20. The outer edge seal portion includes a lower seal portion 12a that extends to lower portion 12, a first side seal portion 13a that extends along first side portion 13, and a second side seal portion 14a that extends along second side portion 14 opposite first side portion 13. Steam release seal portion 20a is connected to first side seal portion 13a. Before contents are filled into bag 10, as shown in FIG. 1, an upper portion 11 of bag 10 forms an opening 11b. After contents are placed in bag 10, the inner surfaces of front film 15 and back film 16 are joined at upper portion 11 to form an upper seal portion, thereby sealing bag 10.

[0028] The first side seal portion 13a, the second side seal portion 14a, the steam release seal portion 20a, and the upper seal portion are seal portions formed by joining the inner surface of the front film 15 and the inner surface of the back film 16. On the other hand, the lower seal portion 12a includes a seal portion formed by joining the inner surface of the front film 15 and the inner surface of the bottom film 17, and a seal portion formed by joining the inner surface of the back film 16 and the inner surface of the bottom film 17.

[0029] There are no particular limitations on the method for forming the seal portion, as long as it is possible to join opposing films together and seal bag 10. For example, the seal portion may be formed by melting the inner surfaces of the films by heating or the like, welding the inner surfaces together, i.e., by heat sealing. Alternatively, the seal portion may be formed by bonding the inner surfaces of opposing films together using an adhesive or the like.

[0030] Steam release mechanism Next, a description will be given of the configuration of the steam release mechanism 20. Figure 3 is a cross-sectional view showing the steam release mechanism 20 of the bag 10 shown in Figure 1 as viewed along line III-III.

[0031] The steam release seal portion 20a of the steam release mechanism 20 has a shape that makes it easy to peel as the pressure in the storage section 18 increases. For example, the steam release seal portion 20a has a shape that protrudes from the first side seal portion 13a toward the inside of the bag 10. This makes it possible to make the force applied to the steam release seal portion 20a greater than the force applied to the first side seal portion 13a when the pressure in the storage section 18 increases. Furthermore, the width of the steam release seal portion 20a is smaller than the width of the first side seal portion 13a. Furthermore, as shown in FIGS. 1 and 3, a non-sealed portion 20b is formed between the steam release seal portion 20a and the outer edge of the first side portion 13. This makes it easier for communication between the storage section 18 and the outside to occur due to peeling of the seal portion in the steam release seal portion 20a than in the first side seal portion 13a.

[0032] First half-cut line and second half-cut line Next, a description will be given of the first half-cut line 25 and the second half-cut line 26. The first half-cut line 25 is formed in the front film 15, and the second half-cut line 26 is formed in the back film 16.

[0033] 1, the first half-cut line 25 has one end 25a located on the first side portion 13 below the steam release mechanism 20, and the other end 25b located on the second side portion 14 below the steam release mechanism 20, and extends from the first side portion 13 to the second side portion 14. The first half-cut line 25 has a curved shape that is convex downward throughout its entire length.

[0034] 1, the symbol H1 represents the vertical distance between one end 25a or the other end 25b of the first half-cut line 25 and the lowest portion of the first half-cut line 25. The distance H1 is, for example, 3 mm or more, and preferably 10 mm or more. The distance H1 is, for example, 50 mm or less, and preferably 20 mm or less.

[0035] The second half-cut line 26 is a half-cut line formed on the back surface film 16 so as to at least partially overlap the first half-cut line 25. In the example shown in FIG. 1 , the second half-cut line 26 has one end 26a that overlaps one end 25a of the first half-cut line 25 and the other end 26b that overlaps the other end 25b of the first half-cut line 25. The second half-cut line 26 also extends linearly from the first side portion 13 to the second side portion 14. In the example shown in FIG. 1 , the direction in which the second half-cut line 26 extends is parallel to the horizontal direction. Therefore, the second half-cut line 26 is located above the first half-cut line 25 in a portion other than the one end 26a and the other end 26b. In other words, the first half-cut line 25 is located below the second half-cut line 26 in a portion other than the one end 25a and the other end 25b. It can also be expressed as the first half-cut line 25 and the second half-cut line 26 being at least partially spaced apart in the up-down direction. Although not shown, the second half-cut line 26 may extend in a direction inclined with respect to the horizontal direction.

[0036] 1, the symbol H2 represents the maximum distance between the first half-cut line 25 and the second half-cut line 26 in the vertical direction. The maximum distance H2 is, for example, 3 mm or more, and more preferably 10 mm or more. The maximum distance H2 is, for example, 50 mm or less, and more preferably 20 mm or less. When the second half-cut line 26 extends linearly in the horizontal direction, the maximum distance H2 is equal to the above-mentioned distance H1.

[0037] Next, the structure of the first half-cut line 25 and the second half-cut line 26 formed in the front film 15 and the back film 16 will be described with reference to Figure 4, along with the layer structure of the laminate 30 that constitutes the front film 15 and the back film 16.

[0038] First, the layer structure of the laminate 30 will be described. The laminate 30 includes at least a base layer 31 and a sealant layer 32. In the example shown in FIG. 4, the base layer 31 forms the outer surface 30y of the laminate 30, and the sealant layer 32 forms the inner surface 30x of the laminate 30. The laminate 30 may further include an adhesive layer 33 that bonds the base layer 31 and the sealant layer 32 together. The thickness of the laminate 30 is, for example, 60 μm or more, and more preferably 70 μm or more. The thickness of the laminate 30 is, for example, 110 μm or less, and more preferably 100 μm or less.

[0039] Examples of materials that can be used to form the base layer 31 include plastics such as polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and polyolefins such as high-density polyethylene and polypropylene. The thickness of the base layer 31 is, for example, 10 μm or more and 30 μm or less.

[0040] The sealant layer 32 may be made of a material such as polyethylene or polypropylene, for example, ethylene-methacrylic acid copolymer (EMMA), low-density polyethylene (LDPE), or linear low-density polyethylene (LLDPE).

[0041] To improve the heat resistance of the sealant layer 32, it is preferable to use a material primarily composed of propylene as the material constituting the sealant layer 32. Here, a material "primarily composed of" propylene means a material having a propylene content of 90% by mass or more. Specific examples of materials primarily composed of propylene include polypropylenes such as propylene-ethylene block copolymers, propylene-ethylene random copolymers, and homopolypropylenes, as well as mixtures of polypropylene and polyethylene. Here, "propylene-ethylene block copolymers" refer to materials having the structural formula shown in formula (I) below. Furthermore, "propylene-ethylene random copolymers" refer to materials having the structural formula shown in formula (II) below. Furthermore, "homopolypropylene" refers to materials having the structural formula shown in formula (III) below.

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] When a mixture of polypropylene and polyethylene is used as the propylene-based material, the material may have an island-in-a-sea structure, where the polyethylene is discontinuously dispersed within a continuous polypropylene region.

[0046] Examples of materials that may be used for the sealant layer 32 include polyethylene, polypropylene, and a combination thereof. Examples of polyethylene include medium-density polyethylene, linear low-density polyethylene, and a combination thereof.

[0047] Preferably, the sealant layer 32 contains a propylene-ethylene block copolymer. For example, the sealant layer 32 is composed of an unstretched film containing the propylene-ethylene block copolymer as a main component. The content of the propylene-ethylene block copolymer in the sealant layer 32 is, for example, 80% by mass or more, and preferably 90% by mass or more. Examples of methods for producing the propylene-ethylene block copolymer include a method in which raw materials such as propylene and ethylene are polymerized using a catalyst. Examples of catalysts that can be used include Ziegler-Natta catalysts and metallocene catalysts.

[0048] The sealant layer 32 may further contain a thermoplastic elastomer. The thermoplastic elastomer is, for example, a hydrogenated styrene-based thermoplastic elastomer. The hydrogenated styrene-based thermoplastic elastomer has a structure consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one hydrogenated conjugated diene compound. The thermoplastic elastomer may also be an ethylene-α-olefin elastomer. The ethylene-α-olefin elastomer is a low-crystalline or amorphous copolymer elastomer, and is a random copolymer of 50 to 90% by mass of ethylene as a main component and an α-olefin as a copolymerization monomer.

[0049] The thickness of the sealant layer 32 is, for example, 40 μm or more, and more preferably 50 μm or more, and the thickness of the sealant layer 32 is, for example, 100 μm or less, and more preferably 70 μm or less.

[0050] Next, the structures of the first half-cut lines 25 and the second half-cut lines 26 will be described. As shown in Fig. 4, the first half-cut lines 25 and the second half-cut lines 26 include non-through holes 27 formed on the outer surface 30y of the laminate 30. In the example shown in Fig. 4, the non-through holes 27 are configured to penetrate the base material layer 31 and reach the adhesive layer 33. Although not shown, the non-through holes 27 may also be configured not to penetrate the base material layer 31.

[0051] The width S2 and depth S3 of the non-through holes 27 in the first half-cut lines 25 and the second half-cut lines 26 are set so that the first half-cut lines 25 and the second half-cut lines 26 break when the user applies an appropriate force to the bag 10. For example, the width S2 of the non-through holes 27 is 10 μm or more and 1 mm or less. The depth S3 of the non-through holes 27 is 5 μm or more and 10 μm or less. Such non-through holes 27 can be formed, for example, by processing the laminate 30 by irradiating the laminate 30 with laser light from the outer surface 30y side. Alternatively, the non-through holes 27 may be formed by processing the laminate 30 from the outer surface 30y side using a cutting blade or the like.

[0052] Layer structure of the bottom film Next, the layer structure of the lower film 17 will be described.

[0053] The layer structure of the lower film 17 is arbitrary as long as it has an inner surface that can be bonded to the inner surfaces of the front film 15 and the back film 16. For example, the above-mentioned laminate 30 may be used as the lower film 17, similar to the front film 15 and the back film 16. Alternatively, a film whose inner surface is formed by a sealant layer and has a different structure from the laminate 30 may be used as the lower film 17.

[0054] Bag manufacturing method Next, a method for manufacturing the bag 10 described above will be described. First, the surface film 15 and the back film 16 made of the laminate 30 are prepared. The folded-over bottom film 17 is inserted between the surface film 15 and the back film 16. The inner surfaces of the films are then heat-sealed to form seals such as the bottom seal 12a, the first side seal 13a, and the second side seal 14a. The heat-sealed films are then cut into an appropriate shape to obtain the bag 10 shown in FIG. 1. The contents 19 are then filled into the bag 10 through the opening 11b of the top 11. The top 11 is then heat-sealed to form the top seal 11a. In this manner, the bag 10 containing and sealed with the contents 19 can be obtained, as shown in FIG. 5.

[0055] How to open the bag Next, a method for opening the above-described bag 10 will be described. First, bag 10 is placed inside a microwave oven with bottom 12 facing upright. Next, the contents are heated using the microwave. This increases the temperature of contents 19, which in turn evaporates the water contained in contents 19, increasing the pressure in storage section 18. When the pressure in storage section 18 increases, front film 15 and back film 16 bulge outward, applying force to steam release seal portion 20a of steam release mechanism 20 and causing steam release seal portion 20a to peel off. This allows steam in storage section 18 to escape to the outside via non-sealed portion 20b of steam release mechanism 20.

[0056] Next, the bag 10 is torn from one side of the first side portion 13 or the second side portion 14 to the other along the first half-cut line 25 and the second half-cut line 26. This allows the bag 10 to be opened and an opening formed at the top, as shown in Fig. 6. As shown in Fig. 6, the portion of the front film 15 torn along the first half-cut line 25 becomes the first opening edge 25e of the opening, and the portion of the back film 16 torn along the second half-cut line 26 becomes the second opening edge 26e of the opening.

[0057] When a bottom-gusseted bag 10 is heated in a microwave oven, the width W1 of the gusset portion of the lower portion 12 of the bag 10 may increase as the pressure in the storage portion 18 of the bag 10 increases, as shown in Figure 6. As the width W1 of the lower portion 12 of the bag 10 increases, the surface film 15 and the back film 16 connected to the lower portion of the bag 10 tilt relative to the vertical, narrowing the gap between the surface film 15 and the back film 16 at the top of the opened bag 10. In Figure 6, the symbol W2 represents the width of the opening when it is assumed that the half-cut line formed in the surface film 15 is a horizontal half-cut line 25f that extends linearly in the horizontal direction, similar to the second half-cut line 26. In this case, the width W2 of the opening is narrower than the width W1 of the lower portion 12 of the bag 10, making it difficult to remove the contents through the opening.

[0058] In this embodiment, the first half-cut line 25 formed in the surface film 15 has a shape that convex downward. This allows the width of the opening of the bag 10 to be wider than when horizontal half-cut lines 25f that extend linearly in the horizontal direction are formed in the surface film 15. This improves the ease of removing the contents. This makes it possible, for example, to eat the contents contained in the bag 10 directly using a spoon or the like without transferring them to another container such as a plate. Of course, the contents contained in the bag 10 may also be removed to another container such as a plate. In this case, the wider width of the opening of the bag 10 also improves the ease of removing the contents.

[0059] In this embodiment, the first half-cut line 25 is located below the second half-cut line 26 in a portion other than the one end 25a and the other end 25b. The distance between the front film 15 and the back film 16 increases toward the bottom 12. Therefore, by positioning the first opening edge 25e of the opening further downward, the width of the opening can be increased, improving the ease of removing the contents. Furthermore, because the second opening edge 26e of the back film 16 is located above the first opening edge 25e of the front film 15, it becomes possible to remove the contents from the opening by pressing them against the inner surface of the back film 16. This also improves the ease of removing the contents.

[0060] Furthermore, in the present embodiment, one end 25a of the first half-cut line 25 and one end 26a of the second half-cut line 26 located on the first side portion 13 are located below the steam release mechanism 20. Therefore, by tearing the bag 10 along the first half-cut line 25 and the second half-cut line 26, it is possible to prevent the steam release mechanism 20 from remaining in the opened bag 10, as shown in FIG. Because the steam release seal portion 20a of the steam release mechanism 20 protrudes inward, there is a possibility that removing the contents may be hindered if the steam release mechanism 20 remains in the bag 10. Therefore, by removing the steam release mechanism 20 when tearing the bag 10, it is possible to improve the ease of removing the contents. Furthermore, if steam release mechanism 20 remains in bag 10, there is a possibility that the contents may leak out through non-sealed portion 20b when the contents are removed. Therefore, by removing steam release mechanism 20 when tearing bag 10, it is possible to prevent such leakage from occurring.

[0061] It should be noted that various modifications can be made to the above-described embodiment. Below, modifications will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiment will be designated by the same reference numerals as those used for the corresponding parts in the above-described embodiment, and duplicated explanations will be omitted. Furthermore, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified embodiment, the explanations thereof may be omitted.

[0062] (First Modification of the First Half-Cut Line and the Second Half-Cut Line) In the above-described embodiment, an example has been shown in which the first half-cut line 25 is positioned partially below the second half-cut line 26. However, this is not limited to this, and the first half-cut line 25 and the second half-cut line 26 may overlap over their entire areas, as shown in FIG.

[0063] (Second Modification of the First Half-Cut Line and the Second Half-Cut Line) In the above-described embodiment, one end 25a of the first half-cut line 25 and one end 26a of the second half-cut line 26 are located in the first side portion 13 below the steam release mechanism 20, and the other end 25b of the first half-cut line 25 and the other end 26b of the second half-cut line 26 are located in the second side portion 14 below the steam release mechanism 20. However, this is not limited to this. As shown in FIG. 8 , one end 25a of the first half-cut line 25 and one end 26a of the second half-cut line 26 may be located in the first side portion 13 below the steam release mechanism 20, and the other end 25b of the first half-cut line 25 and the other end 26b of the second half-cut line 26 may be located in the upper portion 11 of the bag 10. In this case, since a large portion of the opened bag 10 remains on the second side portion 14 side, the consumer can hold the portion on the second side portion 14 with their hand or the like. This makes it easier to control the position of the bag 10, improving the ease of removing the contents.

[0064] In the example shown in FIG. 8, although not shown, the first half-cut line 25 and the second half-cut line 26 may also be at least partially separated in the up-down direction.

[0065] (Third Modification of First Half-Cut Line and Second Half-Cut Line) As shown in Fig. 9, one end 25a of the first half-cut line 25 and one end 26a of the second half-cut line 26 may be located in the first side portion 13 below the steam release mechanism 20, and the other end 25b of the first half-cut line 25 and the other end 26b of the second half-cut line 26 may be located in the second side portion 14 above the steam release mechanism 20. In the example shown in Fig. 9, as in the example shown in Fig. 8, a large portion of the opened bag 10 remains on the second side portion 14, allowing the consumer to hold the portion on the second side portion 14 with their hand or the like. This makes it easier to control the position of the bag 10, thereby improving the ease of removing the contents.

[0066] In the example shown in FIG. 9, although not shown, the first half-cut line 25 and the second half-cut line 26 may also be at least partially separated in the up-down direction.

[0067] (Fourth Modification of the First Half-Cut Line and the Second Half-Cut Line) Furthermore, in the above-described embodiment and each modified example, an example has been shown in which one end 25a of the first half-cut line 25 and one end 26a of the second half-cut line 26 are located in the first side portion 13 below the steam release mechanism 20. However, this is not limited to this, and as shown in Fig. 10 , one end 25a of the first half-cut line 25 and one end 26a of the second half-cut line 26 may be located in the first side portion 13 above the steam release mechanism 20, and the other end 25b of the first half-cut line 25 and the other end 26b of the second half-cut line 26 may be located in the second side portion 14 above the steam release mechanism 20. In this case, as shown in Fig. 10 , the first half-cut line 25 has a curved shape that is convex downward so that it is located partially below the steam release mechanism 20.

[0068] 10, the vertical distance H1 between one end 25a or the other end 25b of the first half-cut line 25 and the lowermost portion of the first half-cut line 25 is, for example, 20 mm or more, and preferably 30 mm or more. Also, the distance H1 is, for example, 70 mm or less, and preferably 50 mm or less.

[0069] 10, the second half-cut line 26 may extend horizontally in a straight line from the first side portion 13 to the second side portion 14. In this case, the maximum distance H2 between the first half-cut line 25 and the second half-cut line 26 in the up-down direction is, for example, 20 mm or more, and more preferably 30 mm or more. Moreover, the maximum distance H2 is, for example, 70 mm or less, and more preferably 50 mm or less.

[0070] Although not shown, the second half-cut line 26 may also have a curved shape that is convex downward, similar to the first half-cut line 25, so that the second half-cut line 26 is located partially below the steam vent mechanism 20. Furthermore, the second half-cut line 26 may overlap the first half-cut line 25 over the entire area.

[0071] (Other Modifications of the First Half-Cut Line and the Second Half-Cut Line) In the above-described embodiment and each modified example, an example has been shown in which one end 25a of the first half-cut line 25 overlaps one end 26a of the second half-cut line 26, and the other end 25b of the first half-cut line 25 overlaps the other end 26b of the second half-cut line 26. However, this is not limited to this, and it is sufficient that at least one of the one end 25a or the other end 25b of the first half-cut line 25 overlaps at least one of the one end 26a or the other end 26b of the second half-cut line 26.

[0072] (Example of attaching zipper tape) 11, bag 10 may further include zipper tape 28 extending from first side portion 13 to second side portion 14. Although not shown, zipper tape 28 has a first member provided on the inner surface of front film 15 and a second member provided on the inner surface of back film 16 and engageable with the first member. By providing zipper tape 28 on bag 10, bag 10 can be freely opened or sealed before being heated.

[0073] 11, an opening initiation portion 29 that serves as a trigger for tearing open the bag 10 may be formed in the first side seal portion 13a or the second side seal portion 14a above the steam release mechanism 20. The opening initiation portion 29 is, for example, a notch or a cutout.

[0074] An example of how to use the bag 10 shown in FIG. 11 will be described. First, the bag 10 is opened by tearing it starting from the opening initiation portion 29. Next, one of the first and second members of the zipper tape 28 is detached from the other, and a seasoning or other food is placed into the storage portion 18 through the opening of the zipper tape 28. Then, one of the first and second members of the zipper tape 28 is mated with the other to seal the bag 10, and the contents are heated in this state using a microwave oven. When the pressure in the storage portion 18 increases, a force is applied to the steam release seal portion 20a of the steam release mechanism 20, causing the steam release seal portion 20a to peel off. Next, as in the above-described embodiment, the bag 10 is torn from one side of the first side portion 13 or the second side portion 14 to the other along the first half-cut line 25 and the second half-cut line 26.

[0075] According to this modification, by providing zipper tape 28 on bag 10, bag 10 can be opened and a predetermined ingredient such as seasoning can be placed in storage section 18 before heating the contents in a microwave oven. This increases the flexibility of how bag 10 can be used.

[0076] (First Modification of Steam Release Mechanism) In the above-described embodiment, an example has been shown in which the non-sealed portion 20b of the steam release mechanism 20 is in communication with the outside of the bag 10. However, this is not limited to this, and as shown in Fig. 12, the non-sealed portion 20b may be surrounded by the first side seal portion 13a and the steam release seal portion 20a connected to the first side seal portion 13a. In other words, the non-sealed portion 20b does not have to be in communication with the outside of the bag 10. In this case, the steam release mechanism 20 further has a through-hole 20c formed in at least one of the front film 15 or the back film 16 in the non-sealed portion 20b.

[0077] 12, when the pressure in the storage section 18 increases, a force is applied to the steam release seal section 20a of the steam release mechanism 20, causing the steam release seal section 20a to peel off. Steam that flows into the non-sealed section 20b through the peeled portion of the steam release seal section 20a is discharged to the outside through the through-hole 20c. This prevents the pressure in the storage section 18 from becoming excessively high.

[0078] (Second Modification of Steam Release Mechanism) In the above-described embodiment and each modified example, an example has been shown in which the steam release seal portion 20a of the steam release mechanism 20 is connected to the first side seal portion 13a. However, this is not limited to this, and as shown in Fig. 13, the steam release seal portion 20a does not have to be connected to a seal portion on the outer edge of the bag 10, such as the first side seal portion 13a or the second side seal portion 14a. In this case, the steam release mechanism 20 further has a through-hole 20c located in the area surrounded by the steam release seal portion 20a.

[0079] In the bag 10 shown in Figure 13, when the pressure in the storage section 18 increases, force is applied to the steam release seal section 20a of the steam release mechanism 20, causing the steam release seal section 20a to peel off, allowing steam to escape to the outside through the through hole 20c on the inside of the steam release seal section 20a.

[0080] (Third Modification of Steam Release Mechanism) In the above-described embodiment and each modified example, the steam release seal portion 20a of the steam release mechanism 20 is a seal portion formed by joining the inner surface of the front film 15 and the inner surface of the back film 16. However, this is not limited to this, and the steam release seal portion 20a may also be a seal portion formed by joining the inner surfaces of the front films 15 located on the front side. For example, as shown in FIG. 14 , the steam release seal portion 20a is formed by joining the inner surfaces of the front films 15 at a joint portion where a portion of the front film 15 on the upper side 11 and a portion of the front film 15 on the lower side 12 are overlapped. In this case, as shown in FIG. 14 , the steam release seal portion 20a may be formed midway between the first side portion 13 and the second side portion 14.

[0081] 14, the steam release mechanism 20 further has a non-sealed portion 20b surrounded by a steam release seal portion 20a, and a through-hole 20c formed in at least one of the front film 15 or the back film 16 in the non-sealed portion 20b. In the bag 10 shown in FIG. 14, when the pressure in the storage portion 18 increases, a force is applied to the steam release seal portion 20a of the steam release mechanism 20, causing the steam release seal portion 20a to peel off, allowing steam to escape to the outside through the through-hole 20c on the inside of the steam release seal portion 20a.

[0082] Another aspect of the present invention is a bag for containing contents and having a steam vent mechanism, comprising a surface film and a back film, a lower film located between the surface film and the back film and constituting the lower part of the bag, a first half-cut line formed in the surface film so as to be located at least partially below the steam vent mechanism, the first half-cut line having at least a portion of a shape that is convex downward, and a second half-cut line formed in the back film so as to at least partially overlap the first half-cut line.

[0083] In the bag according to another aspect of the present invention, at least one of one end and the other end of the first half-cut line may overlap with at least one of one end and the other end of the second half-cut line.

[0084] In the bag according to another aspect of the present invention, the first half-cut line may be located at least partially below the second half-cut line.

[0085] In the bag according to another aspect of the present invention, the first half-cut line and the second half-cut line do not necessarily overlap over the entire area.

[0086] In another aspect of the bag of the present invention, one end of the first half-cut line and one end of the second half-cut line may be located on a first side of the bag below the steam vent mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located on a second side of the bag opposite the first side below the steam vent mechanism.

[0087] In another aspect of the bag of the present invention, one end of the first half-cut line and one end of the second half-cut line may be located on a first side of the bag above the steam vent mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located on a second side of the bag above the steam vent mechanism and opposite the first side.

[0088] In a bag according to another aspect of the present invention, the steam release mechanism may be located on a first side of the bag, one end of the first half-cut line and one end of the second half-cut line may be located on the first side of the bag below the steam release mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located on a second side of the bag above the steam release mechanism and facing the first side.

[0089] In a bag according to another aspect of the present invention, the steam vent mechanism may be located on a first side of the bag, one end of the first half-cut line and one end of the second half-cut line may be located on the first side of the bag below the steam vent mechanism, and the other end of the first half-cut line and the other end of the second half-cut line may be located at the top of the bag.

[0090] In another aspect of the bag of the present invention, the bag may further include zipper tape provided on the inner surface of the front film and the inner surface of the back film so as to extend from a first side of the bag to a second side opposite the first side above the steam vent mechanism.

[0091] Although several modifications of the above-described embodiment have been described, it is of course possible to combine a plurality of modifications as appropriate. [Explanation of symbols]

[0092] 10 bags 11 Upper 11a Upper seal part 12 Lower 12a Lower seal 13 First side 13a First side seal portion 14 Second side 14a Second side seal portion 15 Surface film 16 Back film 17 Lower film 18 Storage section 19 Contents 20 Steam release mechanism 20a Steam release seal 20b Non-sealed part 20c through hole 25 First half cut line 25e First opening edge 26 Second half cut line 26e Second opening edge 28 Zipper tape 30 laminate 31 Base material layer 32 Sealant layer 33 Adhesive layer

Claims

1. A bag having a steam vent mechanism and containing contents, a surface film and a back film; a lower film positioned between the front film and the back film and constituting a lower portion of the bag; a first half-cut line formed in the surface film so as to be at least partially below the steam vent mechanism, the first half-cut line having at least a portion of a shape that is convex toward the lower portion of the bag; a second half-cut line formed on the back surface film so as to at least partially overlap the first half-cut line, the front surface film and the back surface film comprise a laminate having an inner surface and an outer surface, The laminate includes a base layer that forms the outer surface and a sealant layer that forms the inner surface, the first half-cut line and the second half-cut line include non-through holes formed in the outer surface of the laminate so as not to reach the sealant layer, The surface film does not include a half-cut line that is provided so as to bulge toward the upper end portion, the first half-cut line and the second half-cut line overlap each other over the entire area, the first half-cut line has a curved shape that is convex toward the bottom of the bag over its entire area, one end of the first half-cut line and one end of the second half-cut line are located on a first side portion of the bag, The other end of the first half-cut line and the other end of the second half-cut line are located on a second side portion of the bag opposite the first side portion.

2. one end of the first half-cut line and one end of the second half-cut line are located below the steam vent mechanism, The bag according to claim 1 , wherein the other end of the first half-cut line and the other end of the second half-cut line are located below the steam release mechanism.

3. one end of the first half-cut line and one end of the second half-cut line are located above the steam vent mechanism, The bag according to claim 1 , wherein the other end of the first half-cut line and the other end of the second half-cut line are located above the steam release mechanism.

4. the vapor vent mechanism is located on a first side of the bag; one end of the first half-cut line and one end of the second half-cut line are located below the steam vent mechanism, The bag according to claim 1 , wherein the other end of the first half-cut line and the other end of the second half-cut line are located above the steam release mechanism.

5. The bag according to any one of claims 1 to 4, further comprising zipper tape provided on the inner surface of the front film and the inner surface of the back film so as to extend from a first side of the bag to a second side opposite the first side above the steam release mechanism.

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