JP2023089592A - package - Google Patents

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

The present invention relates to packages.

Conventionally, there are various so-called pillow packaging bodies in which a sheet of packaging material is formed into a cylindrical shape to form a back-pasted seal portion in which palms are joined together, contents are contained in the internal space, and the top and bottom portions are sealed. used for the purpose. As one method for opening the package having such a structure, there is a method in which an opening starting portion is provided in the back-pasted seal portion and the package is torn in one direction from there. For example, in the package disclosed in Patent Document 1, a tear in the packaging material starting from the opening start portion provided in the back-pasted seal portion is captured by the opening assisting portions provided on both sides of the back-pasted seal portion to assist in opening. Proceed with opening along the part. This provides an opening suitable for taking out the contents.

The package disclosed in Patent Document 1 further allows cooked or semi-cooked food to be stored at room temperature, low temperature, or frozen, and heated in a microwave oven without opening during cooking. . Since the unsealing assisting portion is vulnerable to tensile tension, the increase in internal pressure due to heating forms a small hole for steam release, thereby preventing the package from bursting and allowing the food to steam. can be done sufficiently.

Japanese Patent No. 5948022

The package disclosed in Patent Document 1 is provided with an opening assisting part in front of the direction in which the opening tear advances, and the tear joins the opening assisting part, so that after that, the shape of the opening assisting part is obtained. It can be opened according to However, in reality, the tear immediately after opening does not spread around the back-pasted seal portion, so that it cannot join the opening assisting portion, and the tear progresses near the back-pasted seal portion and becomes large. You may not get an opening. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a package which can be tear-opened, and in which an opening having an expected width can be reliably obtained.

A back-pasted seal portion formed by heat-sealing a pair of substantially parallel ends of a substantially rectangular packaging material to each other in a palm-to-palm shape, and another pair of both ends of the packaging material perpendicular to the back-pasted seal portion. and a body portion surrounding a space defined by the back seal portion and the end seal portion, wherein the packaging material is , a base material layer, and a heat-sealable resin layer, and the back-pasted seal part and the body part are provided with opening guide parts that are paired on both sides of the palm when viewed from the center of the back-pasted seal part. is provided, and the opening guide part is an opening starting part that is the starting point of tearing and opening at the edge on the back pasting seal part side, and a third that crosses the back pasting seal part and the body part following the opening start part and a second guide portion extending from the end of the first guide portion in the extending direction of the back-pasted seal portion. A package is provided that is score lines provided.

According to this package, since it can be opened along the opening guide portion from the starting point of tearing opening at the back-pasted seal portion to the end point of the opening guide portion at the trunk portion, it is possible to reliably obtain an opening having an expected width. can be done.

In this package, the opening start part may have a plurality of end points of the score line per one first guiding part. In this case, when the packaging material on which the opening guide portion is formed is heat-sealed to form the back seal portion, even if the opening start portion is misaligned between the edges, there must be a plurality of end points of the cut line. , the influence of misalignment can be reduced.

This package may have a non-sealed portion that is not heat-sealed at the end on the side of the backing seal, and an unsealing start portion may be formed in the non-sealed portion. In this case, when the packaging material having the opening guide portion formed thereon is heat-sealed to form the back-pasted seal portion, even if the opening start portion is misaligned between the edges, the unsealed portion is not heat-sealed. It becomes easier to get a clue of

The first guiding portion may have a portion where the angle formed by the extending direction thereof and the extending direction of the back-pasted seal portion is 45° to 85°. According to this, it is possible to enhance the certainty of opening along the opening guide portion.

Also, the second guide portion may have a length that does not reach the center of the extension width of the back sticker portion. According to this, when printing is applied to the trunk portion, the second guide portion is less likely to interfere with the printed design.

In this package, a through-hole (hereinafter referred to as a "steam port") is formed through the package at the unsealing guide portion due to an increase in the internal pressure of the package during microwave cooking. good too. In this case, since the steam vent is appropriately formed in the opening guide portion during microwave cooking, it is possible to prevent the container from bursting due to an increase in internal pressure, and to sufficiently steam the stored food.

The heat-sealing resin layer is made of polyethylene copolymerized with C4 (butene-1) as a comonomer, and the heat-sealing resin layer has a Young's modulus (tensile modulus ) may be 0.2 gigapascals (GPa) or more as measured according to JIS K7127. In this case, the steam vents are likely to be formed more appropriately.

The laminate has a Young's modulus (tensile modulus) indicated as the slope of the stress-strain line per unit cross-sectional area for the portion provided with the opening guide portion, which is 0.45 Giga in the measurement according to JIS K7127. Pascal (GPa) or more may be sufficient.

In this package, the base material layer may be a uniaxially stretched nylon film, and the extending direction of the backing seal portion may coincide with the stretching direction of the nylon film. In this case, since the pulling direction at the time of unsealing coincides with the stretched direction of the nylon film, it is easy to tear in that direction.

The opening guidance part may consist of a continuous line, a dashed line, a dotted line, or a combination thereof formed by laser processing.

According to the present invention, it is possible to provide a package that can be tear-opened and that can reliably provide an opening having an expected width.

(A) is a diagram showing the appearance of a package. (B) is a plan view of the packaging material before forming the package of (A). It is a perspective view in the middle of opening a package. It is a perspective view when finishing opening of a package. Both (A) and (B) are plan views of packaging materials used in Examples. It is a top view of the packaging material used by the comparative example.

The present invention relates to a so-called pillow type package. This package accommodates food inside, and by forming a steam vent in a part of the package during microwave cooking, it is possible to prevent the package from bursting due to internal pressure. In addition, after cooking, the package can be opened from the unsealing start part provided on the back seal part, and an opening having a relatively large opening width can be easily formed in the longitudinal direction of the package. It is also possible to use the packaging material as tableware. Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.

As shown in FIG. 1, the packaging body 1 of the present embodiment is a bag body in which food is sealed inside, and includes a back-pasted seal portion 3a formed by heat-sealing in a palm-to-palm shape, and a back-pasted seal portion 3a. Two end seal portions 3b and 3c heat-sealed perpendicular to 3a, and a trunk portion 4 surrounding a space defined by the back seal portion 3a and the end seal portions 3b and 3c. It has Food is stored in the space. The side on which the back seal part 3a is formed and the side on which it is not formed form the front and back of the package 1, and the part connecting the two sides constitutes a gusset corresponding to the thickness of the package 1. there is

When viewed from the side of the back-pasted seal 3a, the package 1 has the back-pasted seal 3a and body 4, with the base 6 of the back-pasted-seal 3a as the center line, on both sides of the palm of the back-pasted seal 3a. A pair of opening guide lines (opening guide portions) 5, 5 are provided in line symmetry. Here, the base portion 6 refers to the boundary between the back seal portion 3a and the body portion 4. As shown in FIG. The unsealing guide lines 5, 5 extend from the base portion 6 to a position where they do not go around the back side of the body portion 4 when the package 1 is viewed from the back seal portion 3a side (in this case, until they reach the gusset of the body portion 4). within the range of The details of the opening guide wires 5, 5 will be described later.

Here, the packaging material 100, which is the constituent material of the package 1, is a rectangular resin sheet made of a laminate of resin films. The packaging material 100 before the packaging body 1 is formed has the heat-sealing portion 3 edged in a strip shape in the entire peripheral area. That is, the portion to be heat-sealed 3 extends along the entire circumference of the rectangle with a width of a predetermined distance from the edge of the rectangle to the inside of the rectangle. However, on the two sides that form the backing seal portion 3a when the package 1 is formed, the unsealed portions 2, 2 are formed by a predetermined distance from the edges. In FIG. 1(B), the illustrated surface on which the opening guide lines 5, 5 are provided is the outer surface side of the package 1, and the illustrated back surface is the inner surface side of the package 1. In FIG. The portion to be heat-sealed 3 is located on the rear surface of the drawing. In FIG. 1B, a pair of parallel ends of the packaging material 100 extending in the left-right direction in the figure and extending in the up-down direction in the figure are heat-sealed to each other in a palm-to-arm shape to form a back-sticking seal. A portion 3a is formed.

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 package 1 . Between the base material layer and the heat-sealable resin layer, an adhesive for bonding the two together or a printed layer may be provided. In addition, a gas barrier layer, a light shielding layer, an ultraviolet absorbing layer, and the like may be provided.

As the film constituting the substrate layer, a stretched film such as a polyethylene terephthalate resin film, a stretched polypropylene resin film, a stretched nylon film, or the like is usually used in consideration of suitability for printing. A uniaxially stretched film is preferable from the viewpoint of making the tear go straight when the film is torn open. It is preferable that the direction of uniaxial stretching of the uniaxially stretched film coincides with the extending direction of the backing seal portion 3 a of the package 1 . The thickness of the base layer is, for example, 10 μm to 30 μm.

As the heat-sealable resin layer (sealant), polyolefin resins such as polyethylene resin and polypropylene resin can be used as the most common ones. Among polyethylene resins, low-density polyethylene and linear low-density polyethylene are preferable. In the case of the package 1 of the present embodiment, linear low-density polyethylene obtained by copolymerizing C4 (butene-1) as a comonomer using a Ziegler-Natta catalyst is particularly preferable. This polyethylene is easy to tear by hand, and when heated in a microwave oven, the opening guide wires 5, 5 are partially broken and opened, and a steam vent functioning as a steam vent is easily formed. The heat-sealable resin layer may be formed by melting the resin and extruding it onto the substrate layer for lamination, or by laminating a film formed thereon.

In the present embodiment, the heat-sealable resin layer has a Young's modulus (tensile modulus), which is indicated as the slope of a stress-strain line per unit cross-sectional area, of 0.2 gigapascals (GPa) or more when measured according to JIS K7127. is. This Young's modulus may be 0.3 gigapascal or more, or may be 0.4 gigapascal or more. When the Young's modulus is within this range, the heat-sealable resin layer is difficult to stretch, and steam vents are likely to be formed during heating in a microwave oven.

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

In addition, for the laminate, the stress per unit cross-sectional area - Young's modulus (tensile modulus) indicated as the slope of the strain straight line is preferably 0.45 gigapascals (GPa) or more when measured according to JIS K7127. . In this measurement, a sample on which the opening guide line 5 is formed is prepared, and two points across the opening guide line 5 (two points in the direction perpendicular to the direction in which the cut lines described later) extend are measured. pull. When the value of the Young's modulus is 0.45 gigapascals or more, the elongation of the laminate due to the internal pressure (the extent to which the package 1 can withstand bursting) and the formation of the steam opening are balanced when heated in a microwave oven. It's easy to do.

The unsealing guide lines 5, 5 are cut lines provided with a depth that does not penetrate the packaging material 100. - 特許庁In this embodiment, each of the unsealing guide wires 5, 5 consists of three parts. Each of the opening guide lines 5, 5 has an opening start portion 5a provided at a position closer to the end seal portion 3b in the non-sealed portions 2, 2 at the edge of the back seal portion 3a side, and an opening start portion. Continuing from 5a, a first guiding portion 5b that linearly crosses the back-pasted seal portion 3a and the body portion 4; and a second guide portion 5c extending toward the seal portion 3c.

Here, the opening start portion 5a serves as a starting point for tearing and opening. It is on the 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 of the opening start portion 5a. That is, the traversal of the back-pasted seal portion 3a from the unsealing start portion 5a toward the body portion 4 progresses while being inclined toward the end seal portion 3c, and the traversal of the body portion 4 continues while maintaining the inclination. The entire first guide portion 5b is linear. Also, 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 back sticker portion 3a.

The angle θ between the direction in which the straight line formed by the first guide portion 5b extends and the direction in which the back-pasted seal portion 3a extends is preferably 45° to 85°. This angle θ may be between 50° and 80°, or between 55° and 75°.

The depth of the cut in the opening guide lines 5, 5 is such that the part can have a weaker structure than other parts and does not penetrate the packaging material 100 (so-called "half cut"). Well, for example, it may be formed so that the layers other than the heat-sealable resin layer are cut. Such a score line can be formed by a method using a cutting tool such as a die cutter or a rotary die cutter, or a method using a laser processing machine such as a carbon dioxide gas laser. With laser machining, wide score lines can be formed by melting the material based on the line width of the laser. The width of the cut line formed by melting this material is, for example, 50-300 μm, preferably 100-250 μm. Also, the width of the score line may be 10 μm to 100 μm, or may be 30 μm to 70 μm.

The package 1 can heat and steam the food accommodated inside by microwave cooking. Normally, when a sealed package is heated, the internal pressure increases and the package ruptures. However, in the package 1 of the present embodiment, the internal pressure increases and the package 1 swells, and when tension is applied to the entire body 4, , the unsealing guide wires 5, 5 that are weakened against tensile stress are partially broken, forming a steam vent. By ejecting steam from the steam vent, the internal pressure is lowered to prevent the package 1 from bursting, and the food can be steamed by the steam filled inside.

When opening the package 1, first, the back-pasted seal portion 3a, which has fallen down, is raised. Next, after pinching both sides of the opening start portions 5a, 5a of the back seal portion 3a with fingers, the package body 1 is started to tear by pulling toward the end seal portion 3c. When tearing starts from the opening start portions 5a, 5a, the tear 9 descends the back-pasted seal portion 3a along the first guiding portion 5b toward the body portion 4, reaches the base portion 6, and bifurcates at the base portion 6. and proceed further while forming an opening 11 (FIG. 2). After that, if tearing is continued, the tear 9 is guided from the first guiding portions 5b, 5b to the second guiding portions 5c, 5c, and reaches the end point of the second guiding portions 5c, 5c. Further, if tearing is continued toward the end seal portion 3c side, the tear 9 progresses linearly in the portion where the unsealing guide lines 5, 5 do not exist, and the opening 11 can be formed large (Fig. 3). This makes it easier to take out the food 13 . In addition, since the opening 11 is sufficiently large, the packaging material can also serve as tableware, and there is no need to transfer the food 13 to another tableware.

In such a series of processes of microwave cooking and opening, since the Young's modulus of the heat-sealable resin layer of the packaging material constituting the package 1 is 0.2 gigapascals (GPa) or more, the steam vent is properly formed. In the packaging material used for the conventional packaging body, the strength of supporting the heat-sealing resin layer at the part where the opening guide lines 5, 5 are provided is weak because the nylon film as the base material has high hygroscopicity. As a result, the heat-sealing resin layer stretches, making it difficult to form the steam vent. However, in the package 1 of the present embodiment, the steam vent is properly formed even if the uniaxially stretched nylon film absorbs moisture. .

When unsealing, it is necessary to pinch the end points of the unsealed portions 2, 2 where the unsealing start portions 5a, 5a are provided. When the seal portion 3a is formed, the opening start portions 5a, 5a may be misaligned between the edges. Since the edges of the package 1 of the present embodiment are the non-sealed portions 2, 2, even if the package is misaligned, it is easy to get a hint of opening. After the tearing starts, the first guide portion 5b is continuous between the back-pasted seal portion 3a and the body portion 4, so when the tear 9 advances from the base portion 6 bifurcating, the tear 9 is split into two. 1 advances without deviating from the guiding portion 5b. Since the first guide portion 5b is inclined at an angle θ toward the tearing direction (the direction toward the end seal portion 3c), the tear 9 easily progresses in the direction in which the width of the opening 11 widens. . In addition, since the base layer of the packaging material is made of a uniaxially stretched nylon film, and the stretching direction is the same as the tearing direction, it is easy to tear linearly even when tearing after the guidance by the opening guide lines 5, 5 is finished. .

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the unsealing start portion 5a formed in the non-sealed portion 2 is a single cut line on the extension line of the first guide portion 5b, but the unsealing start portion 5a , as in the packaging material 200 shown in FIG. 4(A), each first guiding portion 5b may have a plurality of end points of the cut line. In this case, even if misalignment occurs in the formation of the cut lines and the heat sealing that forms the back-pasted seal portion 3a, either of the end points of the cut lines of the facing non-sealed portions 2, 2 is close to each other. Therefore, the adverse effect of misalignment can be reduced. In the packaging material 200, the length of the second guide portion 5c is longer than that in the packaging material 100. As shown in FIG.

Further, in the above-described embodiment, the portion present in the back-pasted seal portion 3a and the portion present in the trunk portion 4 as the first guide portion 5b form the same straight line. ), the portion present in the back seal portion 3a and the portion present in the body portion 4 may not form the same straight line. In the packaging material 300, the portion of the first guiding portion 5b that is present in the back-pasted seal portion 3a extends in a direction orthogonal to the back-pasted seal portion 3a. In the packaging material 300, the shape of the unsealing start portion 5a is the same shape as that shown in FIG. 4(A).

Moreover, in the above-described embodiment, the package body having a gusset in the body portion is used as an example, but the package may have a shape without a gusset. Further, in the above embodiment, the shape of the opening guide line is composed of a continuous line, but it may be composed of a curved line, and may be composed of not only a continuous line but also a broken line, a dotted line, or a combination thereof. Further, in the above-described embodiment, the unsealing start portion is a cut line that does not penetrate the packaging material, but the unsealing start portion may be a notch that is a line that penetrates the packaging material. It should be noted that the packaging material 400 shown in FIG. 5 is not according to an embodiment of the present invention.

EXAMPLES The content of the present invention will be more specifically described below with reference to examples and comparative examples. In addition, the present invention is not limited to the following examples.

<Materials used>
(Base material layer)
・Uniaxially stretched nylon film Monoaxially stretched nylon film. Product name: Uniathlon, manufactured by Idemitsu Unitech Co., Ltd. 15 μm thick.
- Uniaxially stretched PET film A polyethylene terephthalate film that has been uniaxially stretched. Trade name "Emblet PC", manufactured by Unitika Ltd. 12 μm thick.

(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. Trade 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. Trade name "KF201", manufactured by Sky Film Co., Ltd. 40 μm thick. Young's modulus 0.22 GPa.
・LLDPE (XMTN)
Linear low density polyethylene. Trade name "XMTN", manufactured by Futamura Chemical Co., Ltd. 40 μm thick. Young's modulus 0.16 GPa.
・LLDPE (HR611)
Linear low density polyethylene. Trade name "HR611", manufactured by Sky Film Co., Ltd. 40 μm thick. Young's modulus 0.17 GPa.

<Example 1>
(Preparation of laminate)
A uniaxially stretched nylon film as a substrate layer was printed with an ink "Riogran" (trade name, manufactured by Toyo Ink Co., Ltd.). To this printed surface, "LLDPE (KF101)" as a heat-sealable resin layer was applied with adhesives "Takelac A626" (trade name, manufactured by Mitsui Chemicals, Inc.) and "Takenate A50" (trade name, Mitsui Chemicals, Inc.). (manufactured) to produce a laminate.

(Measurement of Young's modulus of laminate)
A laminate was prepared as a sample for Young's modulus measurement. A carbon dioxide laser was irradiated from the uniaxially stretched nylon film side in the TD direction (output 25 W, scanning speed 800 mm/sec) to form a fragile processing line (opening guide line) that does 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, and the distance between chucks was 50 mm, and the tensile speed was 200 m / min. It was calculated (based on JIS K 7127).

(Formation of package)
A carbon dioxide laser was irradiated from the substrate layer side (output 25 W, scanning speed 800 mm/sec) to form an unsealing guide line that did not penetrate the heat-sealable resin layer so as to have the shape shown in FIG. 1(B). The existing area in the vertical direction of the drawing is set to 50 mm, and the existing area in the horizontal direction of the drawing is set to 70 mm. 200 g of frozen fried rice was filled inside, and each end was heat-sealed so as to have the shape shown in FIG. 1(A) to obtain a package. The size of the package was 155 mm x 250 mm x 20 mm.

<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 FIGS. 4(A), 4(B) and 5 in addition to FIG. 1(B). Reference numeral 7 in FIG. 5 indicates that a notch is provided there when the package is formed.

(Evaluation of microwave cooking and vapor permeation)
The packages of Examples 1 to 7 and Comparative Example 1 were heated in a microwave oven at 1000 W for 3 minutes. Vapor permeability during microwave cooking of each package was confirmed. A case where a steam vent was formed and steam escaped normally was rated as "good", and a case where steam did not escape or a bag break occurred in a portion other than the opening guide line was rated as "bad".

(Evaluation of unsealability)
The microwave-cooked packages of Examples 1 to 7 and Comparative Example 1 were torn from the opening start portion and opened. As for the state of tearing on the opening guide line, the case where the opening could be opened along the shape of the opening guide line was rated as "good". In Comparative Example 1, the tear did not reach the opening guide line, but was torn along the portion near the back-pasted seal portion. In addition, regarding the state of tearing after the end of the opening guide line, a case where a linear tear was possible was evaluated as "good", and a case where a linear tear was not possible was evaluated as "bad".

According to the results shown in Table 1, it was found that when the packaging materials shown in FIGS. rice field. In addition, it was found that a uniaxial nylon film is suitable as the base material of the packaging material in order to improve the tearability after the end of the opening guide wire. It was also found that the Young's modulus of the heat-sealable resin layer should be 0.22 GPa or more to obtain good vapor permeability.

INDUSTRIAL APPLICATION This invention can be utilized for the package for microwave oven cooking.

DESCRIPTION OF SYMBOLS 1... Package, 2... Non-sealing part, 3... Part to be heat-sealed, 3a... Back sealing part, 3b, 3c... Edge sealing part, 4... Body part, 5... Opening guide line (opening guide part), 5a... Unsealing start part 5b... First guide part 5c... Second guide part 6... Base part 7... Notch (opening start part) part 9... Crack 11... Opening 13... Food , 100, 200, 300, 400 ... Packaging materials.

Claims (10)

A pair of substantially parallel end portions of a substantially rectangular packaging material are heat-sealed in a palm-to-palm shape to form a back-pasted seal portion, and another pair of the packaging material perpendicular to the back-pasted seal portion. A package comprising: an end seal portion formed by heat-sealing both ends; and a trunk portion surrounding a space defined by the back seal portion and the end seal portion. ,
The packaging material is a laminate having a substrate layer and a heat-sealable resin layer,
The back-pasted seal portion and the body portion are provided with opening guide portions that are paired on both sides of the palm facing the back-pasted seal portion as viewed from the center,
The opening guide portion includes an opening starting portion that is a starting point for tearing and opening at the edge on the side of the back pasting seal portion, and a first opening that crosses the back pasting seal portion and the trunk portion following the opening start portion. and a second guide portion extending from the end point of the first guide portion in the extending direction of the back-pasted seal portion,
The package body, wherein the opening guide portion is a cut line provided to the extent that it does not penetrate the packaging material. 2. The package according to claim 1, wherein said opening start portion has a plurality of end points of said score lines per said first guide portion. It has a non-sealed portion that is not heat-sealed at the end on the back sticker side,
3. The package according to claim 1, wherein said opening start portion is formed in said non-sealed portion. 4. The first guiding portion has a portion at an angle of 45° to 85° between the extending direction of the first guiding portion and the extending direction of the back-pasted seal portion. 1. Package according to item 1. The package according to any one of claims 1 to 4, wherein said second guide portion has a length that does not reach the center of the extension width of said back-pasted seal portion. The package according to any one of claims 1 to 5, wherein a through-hole penetrating through the package is formed at the unsealing guide portion due to an increase in internal pressure of the package during microwave cooking. The heat-sealable resin layer is made of polyethylene copolymerized with C4 (butene-1) as a comonomer,
The heat-sealable resin layer has a Young's modulus (tensile modulus), which is indicated as the slope of a stress-strain line per unit cross-sectional area, of 0.2 gigapascals (GPa) or more as measured according to JIS K7127. Item 7. The package according to any one of items 1 to 6. The laminate has a Young's modulus (tensile modulus), which is indicated as the slope of a stress-strain line per unit cross-sectional area, of 0.00 in accordance with JIS K7127. The package according to any one of claims 1 to 7, which is 45 gigapascals (GPa) or more. The base layer is a uniaxially stretched nylon film,
The package according to any one of claims 1 to 8, wherein the extending direction of the backing seal portion matches the stretching direction of the nylon film. 10. The package according to any one of claims 1 to 9, wherein said unsealing guide portion is formed by laser processing and is composed of a continuous line, a broken line, a dotted line, or a combination thereof.

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