Packaging

Abstract

To provide a package to be unsealed by tearing, in which an opening having a broadness presumed can be positively obtained.SOLUTION: A package 1 comprises an on-back seal part 3a that is formed by heat sealing in a convex form, end seal parts 3b and 3c that are heat-sealed in a manner crossing orthogonally thereto, and a body 4. A packaging material is a laminate having a base material layer and a heat-sealable resin layer, in which a pair of unsealing guides 5 and 5 are provided in the on-back seal part 3a and the body 4. The unsealing guide 5 has an unsealing-start point 5a, a first guide portion 5b continuing therefrom and traversing the on-back seal part 3a and the body 4, and a second guide portion 5c continuing from an end point of the first guide portion and extending in an extending direction of the on-back seal part 3a. The unsealing guides 5 and 5 are linear cuts provided in a degree not penetrating the packaging material.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, so-called pillow packages, in which a single sheet of packaging material is formed into a cylindrical shape with a gabled back seal, contents are placed in the internal space, and the top and bottom are sealed, have been used for a variety of purposes. One method for opening a package with this structure is to provide an opening start point in the back seal and tear the package in one direction from that point. For example, in the package disclosed in Patent Document 1, a tear in the packaging material starting from the opening start point in the back seal is captured by opening assistants provided on both sides of the back seal, and opening proceeds along the opening assistants. This provides an opening suitable for removing the contents.

[0003] The package disclosed in Patent Document 1 can also store cooked or semi-cooked food at room temperature, low temperature, or frozen, and is heated in a microwave oven without opening the package for cooking. Because the opening aid is weak against tensile force, a small hole for steam release is formed there due to an increase in internal pressure caused by heating, allowing the food to be sufficiently steamed while preventing the package from bursting. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5948022 Summary of the Invention [Problem to be solved by the invention]

[0005] The package disclosed in Patent Document 1 has an opening aid provided ahead of the tear's direction of travel, and the tear merges with the opening aid, allowing the package to be opened along the shape of the opening aid. However, in reality, the tear immediately after opening does not spread from the spine seal, and therefore cannot merge with the opening aid, progressing near the spine seal, preventing a large opening. Therefore, the object of the present invention is to provide a package that can be torn open and that reliably provides an opening of the expected width. [Means for solving the problem]

[0006] The present invention provides a packaging body comprising a spine seal portion formed by heat-sealing a pair of substantially parallel opposite ends of a substantially rectangular packaging material in a gabled shape, end seal portions formed by heat-sealing another pair of opposite ends of the packaging material perpendicular to the spine seal portion, and a body portion enclosing the space defined by the spine seal portion and the end seal portions, wherein the packaging material is a laminate having a base material layer and a heat-sealable resin layer, and the spine seal portion and the body portion are provided with a pair of opening guide portions on both sides of the gable when viewed from the spine seal portion, and the opening guide portions have an opening start portion at the edge on the spine seal portion side that serves as the starting point for tearing and opening, a first guide portion that continues from the opening start portion and crosses the spine seal portion and the body portion, and a second guide portion that continues from the end point of the first guide portion and extends in the extension direction of the spine seal portion, and the opening guide portions are cut lines that are set so as not to penetrate the packaging material.

[0007] This package can be opened along the opening guide section from the start point of tearing at the back seal to the end point of the opening guide section at the body, so that an opening of the expected width can be reliably obtained.

[0008] In this package, the opening start portion may have multiple endpoints of the cut line per first guide portion. In this case, even if the opening start portion is misaligned between the edges when the packaging material with the opening guide portion formed therein is heat-sealed to form the spine seal portion, the multiple endpoints of the cut line can reduce the impact of the misalignment.

[0009] This package may have a non-sealed portion that is not heat-sealed at the end on the spine seal side, and an opening start portion may also be formed in the non-sealed portion. In this case, even if the opening start portion is misaligned between the edges when the packaging material with the opening guide portion formed therein is heat-sealed to form the spine seal portion, the lack of heat sealing makes it easier to find a starting point for opening.

[0010] The first guide portion may have a portion where the angle between the extending direction of the first guide portion and the extending direction of the spine seal portion is 45° to 85°. This can increase the reliability of opening along the opening guide portion.

[0011] The second guide portion may have a length that does not reach the center of the extension width of the spine seal portion, which prevents the second guide portion from interfering with the printed design when printing is applied to the body portion.

[0012] In this package, a through hole (hereinafter referred to as a "steaming hole") that penetrates the packaging material may be formed in the opening guide section due to an increase in internal pressure of the package during microwave cooking. In this case, a steaming hole is appropriately formed in the opening guide section during microwave cooking, preventing rupture due to an increase in internal pressure and allowing the stored food to be sufficiently steamed.

[0013] The heat-sealable resin layer may be made of polyethylene copolymerized with C4 (butene-1) as a comonomer, and the heat-sealable resin layer may have a Young's modulus (tensile modulus) expressed as the slope of the stress-strain line per unit cross-sectional area of ​​0.2 gigapascals (GPa) or more when measured in accordance with JIS K 7127. In this case, the steam vent hole is more likely to be formed appropriately.

[0014] The laminate may have a Young's modulus (tensile modulus) of 0.45 gigapascals (GPa) or more, as measured in accordance with JIS K7127, which is expressed as the slope of the stress-strain line per unit cross-sectional area for the portion where the opening guide portion is provided.

[0015] In this package, the base layer may be a uniaxially stretched nylon film, and the extension direction of the back seal may coincide with the stretch direction of the nylon film. In this case, the pulling direction when opening coincides with the stretch direction of the nylon film, making it easy to tear in that direction.

[0016] The opening guidance portion may be a continuous line, a broken line, a dotted line, or a combination thereof formed by laser processing. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a packaging body that is tear-opened and that can reliably provide an opening having an intended width. [Brief explanation of the drawings]

[0018] [Figure 1] 1A is a diagram showing the appearance of a package, and FIG. 1B is a plan view of a packaging material before forming the package of FIG. [Figure 2] FIG. 10 is a perspective view of the package in the middle of being opened. [Figure 3] FIG. 10 is a perspective view of the package after it has been opened. [Figure 4] Both (A) and (B) are plan views of the packaging material used in the examples. [Figure 5] FIG. 10 is a plan view of a packaging material used in a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention relates to a pillow-shaped package. This package contains food, and by forming a steam vent in a portion of the package during microwave cooking, it is possible to prevent rupture due to internal pressure. After cooking, the package can be opened from an opening start portion provided in the back seal to easily form an opening with a relatively large opening width in the longitudinal direction of the package, making it easy to remove food and allowing the package to double as tableware. Preferred embodiments of the present invention will now be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be omitted.

[0020] As shown in Figure 1, the packaging body 1 of this embodiment is a bag containing a sealed food item, and includes a back seal portion 3a formed by heat sealing the backs of the pouches together, two end seal portions 3b and 3c heat-sealed perpendicular to the back seal portion 3a, and a body portion 4 enclosing the space defined by the back seal portion 3a and the end seal portions 3b and 3c. The food item is contained in this space. The side with and without the back seal portion 3a form the front and back of the packaging body 1, and the portion connecting the two sides forms a gusset corresponding to the thickness of the packaging body 1.

[0021] When viewed from the spine seal portion 3a side, the package 1 has a pair of opening guide lines (opening guide portions) 5, 5 arranged symmetrically on both sides of the seam of the spine seal portion 3a, with the base 6 of the spine seal portion 3a as the center line, in the spine seal portion 3a and the body portion 4. Here, the base 6 refers to the boundary between the spine seal portion 3a and the body portion 4. When viewed from the spine seal portion 3a side, the opening guide lines 5, 5 are within a range from the base 6 to a position where they do not wrap around to the back of the body portion 4 (here, just before reaching the gusset of the body portion 4). Details of the opening guide lines 5, 5 will be described later.

[0022] Here, the packaging material 100, which is the constituent material of the packaging body 1, is a rectangular resin sheet made of a laminate of resin films. Before the packaging body 1 is formed, the packaging material 100 has a band-shaped heat-sealed portion 3 along its entire peripheral region. That is, the heat-sealed portion 3 extends around the entire periphery of the rectangle, a predetermined distance from the edge of the rectangle into the interior of the rectangle. However, on the two sides that will become the spine seal portion 3a when the packaging body 1 is formed, a predetermined distance from the edge is left as a non-sealed portion 2, 2. In FIG. 1(B), the front surface on which the opening guide lines 5, 5 are provided is the outer surface of the packaging body 1, and the back surface is the inner surface of the packaging body 1. The heat-sealed portion 3 is on the back surface. In FIG. 1(B), a pair of parallel ends of the packaging material 100, which extend in the left-right direction and up-down direction, are heat-sealed together in a palm-to-palm fashion to form the spine seal portion 3a.

[0023] The laminate constituting the packaging material 100 includes at least a base material layer and a heat-sealable resin layer. The heat-sealable resin layer is laminated as the innermost layer of the packaging body 1. An adhesive or a printed layer for bonding the base material layer and the heat-sealable resin layer may be provided between the base material layer and the heat-sealable resin layer. In addition, a gas barrier layer, a light-shielding layer, an ultraviolet absorbing layer, etc. may be provided.

[0024] As the film constituting the base layer, a stretched film such as a polyethylene terephthalate resin film, a stretched polypropylene resin film, or a stretched nylon film is usually used in consideration of printability. From the viewpoint of ensuring that the tear at the time of tearing to open is straight, a uniaxially stretched film is preferred. The uniaxial stretching direction of the uniaxially stretched film preferably coincides with the extending direction of the back seal portion 3a of the package 1. The thickness of the base layer is, for example, 10 μm to 30 μm.

[0025] Polyolefin resins such as polyethylene resin and polypropylene resin are commonly used as the heat-sealable resin layer (sealant). Among polyethylene resins, low-density polyethylene and linear low-density polyethylene are preferred. In the case of the packaging body 1 of this embodiment, linear low-density polyethylene copolymerized with C4 (butene-1) as a comonomer using a Ziegler-Natta catalyst is particularly preferred. This polyethylene is easy to tear by hand, and when heated in a microwave oven, the opening guide wires 5, 5 partially rupture and open, easily forming a steam vent hole that functions as a steam release port. The heat-sealable resin layer may be formed by melting the resin and extruding it onto the substrate layer, or by laminating a film formed thereon.

[0026] In this embodiment, the heat-sealable resin layer has a Young's modulus (tensile modulus) expressed as the slope of the stress-strain line per unit cross-sectional area of ​​0.2 gigapascals (GPa) or more when measured in accordance with JIS K 7127. This Young's modulus may be 0.3 gigapascals or more, or may be 0.4 gigapascals or more. If the Young's modulus is within this range, the heat-sealable resin layer is less likely to stretch, and steam vents are more likely to form when heated in a microwave oven.

[0027] The thickness of the heat seal resin layer may be, for example, 10 μm to 50 μm, or 20 μm to 40 μm.

[0028] Furthermore, the laminate preferably has a Young's modulus (tensile modulus) expressed as the slope of the stress-strain line per unit cross-sectional area of ​​0.45 gigapascals (GPa) or more when measured in accordance with JIS K 7127. In this measurement, a sample having an opening guide line 5 formed thereon is prepared, and this sample is used as the measurement subject, and is stretched at two locations across the opening guide line 5 (two locations in a direction perpendicular to the stretching direction of the cut line described below). If the Young's modulus value is 0.45 gigapascals or more, it is easy to balance the stretching of the laminate due to internal pressure (the degree to which the package 1 can withstand rupture) and the formation of the steam vent hole when heated in a microwave oven.

[0029] The opening guide lines 5,5 are score lines that are provided deep enough so as not to penetrate the packaging material 100. In this embodiment, each of the opening guide lines 5,5 consists of three parts. Each of the opening guide lines 5,5 has an opening start part 5a provided in a position close to the end seal part 3b in the non-sealed parts 2,2 at the edge on the spine seal part 3a side, a first guide part 5b continuing from the opening start part 5a and linearly crossing the spine seal part 3a and the body part 4, and a second guide part 5c continuing from the end point of the first guide part 5b and extending in the extension direction of the spine seal part 3a and toward the end seal part 3c.

[0030] Here, the opening start portion 5a is the starting point for tearing and is located on an extension of the straight line formed by the first guide portion 5b. The connection point of the first guide portion 5b with the second guide portion 5c is closer to the end seal portion 3c than the connection point with the opening start portion 5a. In other words, the crossing of the spine seal portion 3a from the opening start portion 5a toward the body portion 4 proceeds while inclining toward the end seal portion 3c, and the crossing of the body portion 4 continues while maintaining this inclination, resulting in the first guide portion 5b as a whole being linear. Furthermore, the end point of the second guide portion 5c is located at a position that does not reach the center of the extension width of the spine seal portion 3a.

[0031] The angle θ between the direction in which the straight line of the first guide portion 5b extends and the direction in which the spine seal portion 3a extends is preferably 45° to 85°. This angle θ may be 50° to 80°, or may be 55° to 75°.

[0032] The depth of the cut in the opening guide lines 5,5 can be such that the corresponding portion can be made weaker than the other portions and does not penetrate the packaging material 100 (so-called "half cut"). For example, the cut may be formed so that a layer other than the heat-sealable resin layer is cut. Such a cut line can be formed by a method using a blade such as a die cutter or rotary die cutter, or by a method using a laser processing machine such as a carbon dioxide laser. When using laser processing, the material is melted based on the line width of the laser, thereby forming a wide cut line. The width of the cut line formed by melting the material is, for example, 50 to 300 μm, preferably 100 to 250 μm. The width of the cut line may also be 10 μm to 100 μm, or 30 μm to 70 μm.

[0033] The packaging 1 can heat and steam food stored inside by microwave cooking. Normally, when a sealed packaging is heated, the internal pressure increases and the packaging bursts, but in the packaging 1 of this embodiment, when the internal pressure increases and the packaging expands, tension is applied to the entire body 4, and the opening guide lines 5, 5, which are weak against tensile stress, partially break, forming a steam vent. Steam is released from the steam vent, reducing the internal pressure and preventing the packaging 1 from bursting, while allowing the food to be steamed by the steam that fills the interior.

[0034] To open the package 1, first, the spine seal portion 3a, which has fallen over, is raised. Next, the tearing of the package 1 begins by pinching both sides of the opening start portions 5a, 5a of the spine seal portion 3a with the fingers and pulling toward the end seal portion 3c. When the tearing starts at the opening start portions 5a, 5a, the tear 9 travels along the first guide portion 5b, down the spine seal portion 3a toward the body portion 4, and reaches the base portion 6, where it splits into two and continues to travel, forming an opening 11 (Figure 2). As the tearing continues, the tear 9 is guided from the first guide portions 5b, 5b to the second guide portions 5c, 5c, and continues to travel until it reaches the end of the second guide portions 5c, 5c. Further tearing toward the end seal 3c causes the tear 9 to progress linearly in the area where the opening guide lines 5, 5 are not present, forming a larger opening 11 (Fig. 3). This makes it easier to remove the food 13. Furthermore, because the opening 11 is large enough, the packaging material can also serve as a serving dish, eliminating the need to transfer the food 13 to another serving dish.

[0035] In this series of processes of microwave cooking and opening, a steam vent is properly formed because the Young's modulus of the heat-sealable resin layer of the packaging material that makes up package 1 is 0.2 gigapascals (GPa) or more. In packaging materials used in conventional packages, the nylon film base material is highly hygroscopic, which weakens the support for the heat-sealable resin layer in the areas where opening guide lines 5, 5 are provided, causing the heat-sealable resin layer to stretch and making it difficult to form a steam vent. However, in package 1 of this embodiment, a steam vent is properly formed even if the uniaxially oriented nylon film absorbs moisture.

[0036] When opening the package, it is necessary to pinch the edges of the non-sealed portions 2, 2, where the opening initiation portions 5a, 5a are located. However, in some cases, when the packaging material 100 is heat-sealed to form the spine seal portion 3a, misalignment of the opening initiation portions 5a, 5a may occur between the edges. In the package 1 of this embodiment, the edges are the non-sealed portions 2, 2, making it easier to find the opening starting point even when misalignment occurs. After tearing begins, the first guide portion 5b is continuous between the spine seal portion 3a and the body portion 4, so that when the tear 9 branches from the base portion 6 and proceeds, the tear 9 does not deviate from the first guide portion 5b. Furthermore, because the first guide portion 5b is inclined at an angle θ toward the tearing direction (toward the end seal portion 3c), the tear 9 easily proceeds in the direction that widens the opening 11. Furthermore, since the base layer of the packaging material is made of uniaxially oriented nylon film and the stretching direction of the film coincides with the tearing direction, the packaging material can be easily torn in a straight line even after being guided by the opening guide lines 5,5.

[0037] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, in the above embodiment, the opening start portion 5a formed in the non-sealed portion 2 is a single cut line extending from the first guide portion 5b. However, the opening start portion 5a may have multiple end points of the cut line per first guide portion 5b, as in the packaging material 200 shown in FIG. 4(A). In this case, even if misalignment occurs during the formation of the cut line or the heat sealing that forms the back seal portion 3a, it is expected that one of the end points of the cut lines of the opposing non-sealed portions 2, 2 will be close to each other, thereby minimizing the adverse effects of misalignment. Furthermore, the length of the second guide portion 5c in the packaging material 200 is longer than that in the packaging material 100.

[0038] In the above embodiment, the first guide portion 5b is formed such that the portion of the first guide portion 5b present in the spine seal portion 3a and the portion of the first guide portion 5b present in the body portion 4 are aligned in the same straight line. However, as shown in FIG. 4(B) of the packaging material 300, the portion of the first guide portion 5b present in the spine seal portion 3a and the portion of the first guide portion 5b present in the body portion 4 may not be aligned in the same straight line. In the packaging material 300, the portion of the first guide portion 5b present in the spine seal portion 3a extends in a direction perpendicular to the spine seal portion 3a. In the packaging material 300, the shape of the opening start portion 5a is the same as that shown in FIG. 4(A).

[0039] In addition, although the above embodiment has exemplified a package having a gusset in the body, a package without a gusset may also be used. Furthermore, although the above embodiment has described the shape of the opening guide line as a continuous line, it may also be a curved line, and it may be not only a continuous line but also a broken line, a dotted line, or a combination thereof. Furthermore, in the above embodiment, the opening start portion is described as a score line that does not penetrate the packaging material, but the opening start portion may also be a notch that penetrates the packaging material. Note that the packaging material 400 shown in FIG. 5 does not relate to an embodiment of the present invention. [Example]

[0040] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0041] <Materials used> (base material layer) Uniaxially oriented nylon film Uniaxially stretched nylon film. Product name: "Uniathlon," manufactured by Idemitsu Unitech Co., Ltd. Thickness: 15 μm. Uniaxially stretched PET film Uniaxially stretched polyethylene terephthalate film. Product name: "Emblet PC", manufactured by Unitika Ltd. Thickness: 12 μm.

[0042] (Heat-sealable resin layer) A linear low density polyethylene copolymerized with C4 (butene-1) as a comonomer using a Ziegler-Natta catalyst was used. LLDPE (KF101) Linear low-density polyethylene. Product name "KF101", manufactured by Sky Film Co., Ltd. Thickness: 40 μm, 60 μm. Young's modulus: 0.40 GPa. LLDPE (KF201) Linear low-density polyethylene. Product name "KF201", manufactured by Sky Film Co., Ltd. Thickness: 40 μm. Young's modulus: 0.22 GPa. LLDPE (XMTN) Linear low-density polyethylene. Product name "XMTN", manufactured by Futamura Chemical Co., Ltd. Thickness: 40 μm. Young's modulus: 0.16 GPa. LLDPE (HR611) Linear low-density polyethylene. Product name "HR611", manufactured by Sky Film Co., Ltd. Thickness: 40 μm. Young's modulus: 0.17 GPa.

[0043] Example 1 (Preparation of laminate) A uniaxially oriented nylon film serving as a substrate layer was printed using the ink "Riogran" (trade name, manufactured by Toyo Ink Co., Ltd.). A heat-sealable resin layer, "LLDPE (KF101)," was attached to the printed surface using adhesives "Takelac A626" (trade name, manufactured by Mitsui Chemicals, Inc.) and "Takenate A50" (trade name, manufactured by Mitsui Chemicals, Inc.) to produce a laminate.

[0044] (Measurement of Young's modulus of laminate) The laminate was prepared as a sample for measuring Young's modulus. A carbon dioxide laser (25 W output, 800 mm / s scanning speed) was applied from the uniaxially oriented nylon film side in the TD direction to form a weakened line (opening guide line) that did not penetrate the heat-sealable resin layer. The sample was cut to a width of 15 mm so that the MD direction was the longitudinal direction. The specimen was then pulled at a chuck distance of 50 mm and a pulling speed of 200 m / min, with the weakened part positioned at the center of the specimen, and the Young's modulus was calculated (in accordance with JIS K 7127).

[0045] (Formation of packaging body) A carbon dioxide laser was irradiated from the base layer side (output 25 W, scan speed 800 mm / sec) to form an opening guide line that did not penetrate the heat-sealable resin layer, resulting in the shape shown in Figure 1(B). The area was 50 mm in the vertical direction and 70 mm in the horizontal direction. 200 g of frozen fried rice was filled inside, and each end was heat-sealed to form the shape shown in Figure 1(A), resulting in a package. The size of the package was 155 mm x 250 mm x 20 mm.

[0046] <Examples 2 to 7 and Comparative Example 1> A package was produced in the same manner as in Example 1 using the materials shown in Table 1. The appearance of the packaging material used is shown in Figures 4(A), 4(B), and 5 in addition to Figure 1(B). Reference numeral 7 in Figure 5 indicates that a notch will be provided there when the package is made.

[0047] (Microwave cooking and steam permeability evaluation) The packages of Examples 1 to 7 and Comparative Example 1 were heated in a microwave oven at 1000 W for 3 minutes. The steam permeability of each package during microwave cooking was confirmed. If a steam vent was formed and steam escaped normally, the package was rated "good," and if steam did not escape or the bag broke in a part other than the opening guide line, the package was rated "poor."

[0048] (Evaluation of openability) The packages of Examples 1 to 7 and Comparative Example 1 that had been cooked in a microwave oven were torn from the opening start portion and opened. Regarding the tearing condition along the opening guide line, if the package could be opened along the shape of the opening guide line, it was rated as "good." In Comparative Example 1, the tear did not reach the opening guide line, but instead tore along a portion close to the back seal portion, so it was rated as "poor." Furthermore, regarding the tearing condition after the end of the opening guide line, if the package could be torn in a straight line, it was rated as "good," and if the package could not be torn in a straight line, it was rated as "poor."

[0049] The results shown in Table 1 indicate that the packaging materials shown in Figures 1(B), 4(A), and 4(B) can be torn open along the tear guide line. It was also found that a uniaxial nylon film is suitable as the base material for the packaging material to ensure good tearing beyond the end of the tear guide line. It was also found that a Young's modulus of 0.22 GPa or higher for the heat-sealable resin layer is desirable for good vapor permeability.

[0050] [Table 1] [Industrial Applicability]

[0051] The present invention can be used in packaging for microwave cooking. [Explanation of symbols]

[0052] 1...packaging body, 2...non-sealed portion, 3...portion to be heat-sealed, 3a...back seal portion, 3b, 3c...end seal portion, 4...body portion, 5...opening guide line (opening guide portion), 5a...opening start portion, 5b...first guide portion, 5c...second guide portion, 6...base portion, 7...portion that will become the notch (opening start portion), 9...tear, 11...opening, 13...food, 100, 200, 300, 400...packaging material.

Claims

1. A package comprising: a back seal portion formed by heat-sealing a pair of substantially parallel opposite ends of a substantially rectangular packaging material in a palm-to-palm configuration; end seal portions formed by heat-sealing another pair of opposite ends of the packaging material perpendicular to the back seal portion; and a body portion surrounding a space defined by the back seal portion and the end seal portions, the packaging material is a laminate having a base material layer and a heat-sealable resin layer, The spine seal portion and the body portion are provided with a pair of opening guide portions on both sides of the joint of the spine seal portion, as seen from the center, The opening guide portion has an opening start portion that is a starting point for tearing and opening at the edge of the back seal portion side, a first guide portion that continues from the opening start portion and crosses the back seal portion and the body portion, and a second guide portion that continues from the end point of the first guide portion and extends in the extension direction of the back seal portion, The opening guide portion is a cut line provided so as not to penetrate the packaging material, The second guide portion has a length that does not reach a position corresponding to the center of the extending width of the spine seal portion.

2. The package according to claim 1 , wherein the opening start portion has a plurality of end points of the score line per one of the first guide portions.

3. The back seal side has an unsealed portion that is not heat-sealed at the end thereof, The package according to claim 1 or 2, wherein the opening start portion is formed in the non-sealed portion.

4. The packaging body according to any one of claims 1 to 3, wherein the first guide portion has a portion where the angle between the extending direction of the first guide portion and the extending direction of the back seal portion is 45° to 85°.

5. 5. The package according to claim 1, wherein a through hole penetrating the packaging material is formed in the opening guide portion due to an increase in internal pressure of the package during microwave cooking.

6. the heat-sealable resin layer is made of polyethylene copolymerized with C4 (butene-1) as a comonomer, The package according to any one of claims 1 to 5, wherein the heat-sealable resin layer has a Young's modulus (tensile modulus) expressed as the slope of a stress-strain line per unit cross-sectional area of ​​0.2 gigapascals (GPa) or more when measured in accordance with JIS K7127.

7. The laminate has a Young's modulus (tensile modulus) of 0.45 gigapascals (GPa) or more, which is expressed as the slope of a stress-strain line per unit cross-sectional area for the portion where the opening guide portion is provided, measured in accordance with JIS K7127. The package according to any one of claims 1 to 6.

8. the substrate layer is a uniaxially stretched nylon film, 8. The package according to claim 1, wherein the extending direction of the back seal portion coincides with the stretching direction of the nylon film.

9. 9. The package according to claim 1, wherein the opening guide portion is a continuous line, a broken line, a dotted line, or a combination thereof formed by laser processing.

10. A packaging body comprising a back seal portion formed by heat-sealing a pair of substantially parallel opposite ends of a substantially rectangular packaging material in a folded manner, end seal portions formed by heat-sealing another pair of opposite ends of the packaging material perpendicular to the back seal portion, and a body portion surrounding a space defined by the back seal portion and the end seal portions, the packaging material is a laminate having a base material layer and a heat-sealable resin layer, The spine seal portion and the body portion are provided with a pair of opening guide portions on both sides of the joint of the spine seal portion, as seen from the center, The opening guide portion has an opening start portion that is a starting point for tearing and opening at the edge of the back seal portion side, a first guide portion that continues from the opening start portion and crosses the back seal portion and the body portion, and a second guide portion that continues from the end point of the first guide portion and extends in the extension direction of the back seal portion, The opening guide portion is a cut line provided so as not to penetrate the packaging material, The second guide portion has a length that does not reach a position corresponding to the center of the extension width of the spine seal portion, the substrate layer is a uniaxially stretched film, The extending direction of the back seal portion coincides with the stretching direction of the film, The packaging body, wherein the opening guide portion is a continuous line, a broken line, a dotted line, or a combination thereof formed by laser processing.

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