Packaging body and manufacturing method of the same

Abstract

To provide a packaging body that can prevent a lid material from peeling off from a flange part during transportation and can prevent an increase in the frequency of maintenance work for a manufacturing device.SOLUTION: A package 1 consists of a container 2 and a lid 3 heat-sealed to a flange part 21 of the container 2. A main seal part 41 is formed in which a heat-fusible resin constituting a container-side heat-seal layer 64 and a heat-fusible resin constituting the lid-side heat-seal layer 74 are fused to an inner side part than an outer peripheral edge of the flange part 21. An unsealing starting seal part 42 is formed in a part of the flange part 21 in a peripheral direction so as to extend from the main seal part 41 to the outer peripheral edge of the flange part 21. An annular pseudo-seal part 43 is formed in close contact so that the heat-fusible resin constituting the container-side heat-seal layer 64 and the heat-fusible resin constituting the lid-side heat-seal layer 74 have a boundary that are placed between the main seal part 41 and the outer peripheral edge of the flange part 21 in a part excluding the unsealing starting seal part 42.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a package for hermetically packaging food, medicine, electronic parts, industrial products, etc. as contents, and a method for producing the same.

[0002] In this specification, the term "aluminum" includes aluminum alloys as well as pure aluminum.

[0003] In addition, in this specification and claims, the top and bottom of Figures 2, 4 to 8, and 11 to 13 are referred to as top and bottom. The inside and outside are based on the storage section of the container in which the contents are stored, and the inside of the storage section is referred to as the inside and the opposite side is referred to as the outside. [Background technology]

[0004] Examples of packages for hermetically packaging liquid foods such as beverages, semi-solid foods such as pudding, jelly, yogurt, butter, and jam, foods containing fats and oils or liquids such as curry, tuna, and soup, medicines such as oral medicines and transdermal medicines, medicines requiring sterile packs, viscous industrial products such as grease, adhesives, and pressure sensitive adhesives, and liquid industrial products such as oils that require long-term storage or prevention of deterioration include a cup-shaped container formed from a container laminate including a base layer including a barrier layer and a container-side heat seal layer made of a heat fusion resin provided on one side of the base layer, and having an outward flange portion on the opening periphery, and a base layer including a barrier layer and a heat seal layer on one side of the base layer. A widely used package is formed from a lid material laminate having a lid material-side heat seal layer made of a heat-fusible resin and a lid material whose outer peripheral edge is heat-sealed to the flange portion of the container so as to cover the opening of the container, the entire flange portion of the container and the lid material are heat-sealed using the container-side heat seal layer and the lid material-side heat seal layer, the entire heat seal portion forms a main seal portion that ensures the airtightness of the heat seal portion and a circumferential portion of the heat seal portion forms an opening start seal portion, and an outwardly protruding opening tab is provided at a location on the outer peripheral edge of the lid material corresponding to the opening start seal portion.

[0005] Known examples of the above-mentioned packaging bodies include one in which the portion of the outer edge of the lid material excluding the opening tab coincides with the tip surface of the flange portion, as described in Patent Document 1, and one in which the portion of the outer edge of the lid material excluding the opening tab protrudes slightly outward from the outer edge of the flange portion, as described in Patent Documents 2 to 4.

[0006] The packaging body described in Patent Document 1 is generally produced by a method in which a coiled lid material laminate is unrolled and placed on the flange portion of a container, the lid material laminate and the flange portion of the container are heat-sealed using a sealing disk, and then the lid material laminate and the flange portion are cut together using a trimming blade, while the packaging bodies described in Patent Documents 2 to 4 are generally produced by a method in which a coiled lid material laminate is unrolled and placed on the flange portion of a container, the lid material laminate and the flange portion of the container are heat-sealed using a sealing disk, and then only the lid material laminate is cut using a trimming blade. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 2610875 [Patent Document 2] JP 2006-160353 A [Patent Document 3] Patent No. 4610357 [Patent Document 4] JP 2014-198576 A Summary of the Invention [Problem to be solved by the invention]

[0008] In the case of the package described in Patent Document 1, except for the opening tab, there is no difference in outer dimensions between the outer periphery of the lid material and the tip surface of the flange, and as a result, peeling from other than the opening start seal is suppressed, and the lid material is unlikely to peel off from the flange, causing leakage of contents, even when subjected to vibration or impact during transportation, etc. However, as described above, during production, the lid material laminate and the flange of the container are cut together with a trimming blade, so that the trimming blade wears out quickly, and the trimming blade needs to be replaced more frequently, which increases the work of checking the cut surfaces, resulting in an increase in the frequency of maintenance work and higher maintenance costs.

[0009] In the case of the packages described in Patent Documents 2 to 4, as described above, only the lid laminate is cut by the trimming blade during production, so that the wear of the trimming blade is reduced and the frequency of maintenance work is reduced. However, in the packages described in Patent Documents 2 to 4, the part of the outer periphery of the lid excluding the opening tab also protrudes slightly outward from the outer periphery of the flange, so that the protruding part protruding outward from the outer periphery of the flange of the lid can easily cause the lid to peel off from the flange due to vibrations or impacts during transportation, which may cause the contents to leak.

[0010] The present invention aims to provide a packaging body and a manufacturing method thereof that can prevent the lid material from peeling off from the flange portion due to impact or vibration during transportation, and that can prevent an increase in the frequency of maintenance work for the equipment used in production. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention comprises the following aspects.

[0012] 1) A package comprising a cup-shaped container having an outward flange around the periphery of the opening and containing contents, and a lid material whose outer periphery is heat-sealed to the flange of the container so as to cover the opening of the container, the container comprising a base layer and a container-side heat seal layer made of a heat-sealable resin provided on one side of the base layer and covering an upper surface of the flange, the lid material comprising a base layer and a lid material-side heat seal layer made of a heat-sealable resin provided on one side of the base layer and covering an underside of the lid material, the flange of the container and the lid material are heat-sealed using the container-side heat seal layer and the lid material-side heat seal layer, an opening start seal portion is provided at a portion of the circumference of the heat seal portion between the flange and the lid material, and the entire outer periphery of the lid material protrudes outward beyond the outer periphery of the flange of the container, A package in which a heat-sealing resin constituting the container-side heat seal layer and a heat-sealing resin constituting the lid material-side heat seal layer are fused together in a portion inside the outer peripheral edge of a flange portion of a container, and a ring-shaped main seal portion that ensures the hermeticity of the heat seal portion is formed around the entire circumference, an opening start seal portion is formed from the main seal portion to the outer peripheral edge of the flange portion, and a ring-shaped pseudo seal portion is formed in the portion between the main seal portion and the outer peripheral edge of the flange portion of the container, excluding the opening start seal portion, in which the heat-sealing resin constituting the container-side heat seal layer and the heat-sealing resin constituting the lid material-side heat seal layer are in close contact with each other so that there is a boundary between them.

[0013] 2) The package described in 1) above, wherein the outer peripheral edge of the lid material protrudes outwardly from the outer peripheral edge of the flange portion of the container by 1 to 3 mm in a portion other than the opening start seal portion.

[0014] 3) The package described in 1) above, in which an outwardly protruding opening tab is provided on the outer periphery of the lid at a location corresponding to the opening start seal portion.

[0015] 4) A package as described in 1) above, wherein in the opening start seal portion, the outer end of the heat seal mark between the flange portion of the container and the lid material, which appears on the upper surface of the lid material, is located at a position coinciding with the outer peripheral edge of the flange portion or at a position outer than the outer peripheral edge of the flange portion, and in the portion excluding the opening start seal portion, the outer end of the heat seal mark is located at a position inner than the outer peripheral edge of the flange portion.

[0016] 5) A package as described in 1) above, in which a resin pool is formed around the entire circumference between the tip surface of the flange of the container and the underside of the lid, the resin pool formed in the opening start seal portion is a resin pool derived from a mixture of the heat fusion resin constituting the container side heat seal layer and the heat fusion resin constituting the lid side heat seal layer, the resin pool formed in the portion excluding the opening start seal portion is a resin pool derived from the heat fusion resin constituting the lid side heat seal layer, and the resin pool formed in the opening start seal portion is larger than the resin pool formed in the portion excluding the opening start seal portion.

[0017] 6) The packaging body described in 1) above, in which a notch is formed around the entire circumference on the upper surface of the flange of the container, in the portion inside the main seal portion.

[0018] 7) A method for producing the package according to any one of 1) to 6) above, a container comprising a laminate for a container, the laminate comprising a base layer and a container-side heat seal layer made of a heat-fusible resin provided on one side of the base layer, the upper surface of an outward flange portion provided on the periphery of an opening being covered with the container-side heat seal layer, and containing contents; and a lid material laminate comprising a base layer and a lid material-side heat seal layer made of a heat-fusible resin provided on one side of the base layer, the lower surface being covered with the lid material-side heat seal layer, and having an outer shape larger than the outer shape of the flange portion of the container, a first heat seal is performed by placing the lid material laminate on the flange portion of the container so that the outer peripheral edge of the lid material laminate projects outward beyond the outer peripheral edge of the flange portion of the container, and then applying heat to the lid material laminate and the flange portion of the container while pressing the lid material laminate over the entire circumference using an annular first sealing plate, thereby forming an annular main seal portion in a portion inside the outer peripheral edge of the flange portion of the container, in which the heat fusion resin constituting the container side heat seal layer and the heat fusion resin constituting the lid material side heat seal layer are fused together and which ensures the hermeticity of the heat seal portion, and forming an annular pseudo seal portion in a portion between the main seal portion and the outer peripheral edge of the flange portion of the container, in which the heat fusion resin constituting the container side heat seal layer and the heat fusion resin constituting the lid material side heat seal layer are in close contact with each other so as to have a boundary therebetween; After the first heat seal, a ring-shaped second sealing disk is used to press and heat the entire widthwise range of the main seal portion between the lid material laminate and the flange portion of the container, and a second heat seal is performed by pressing and heating a portion of the entire circumference of the flange portion from the main seal portion to the outer periphery of the flange portion, and an opening start seal portion is formed in a portion of the outer periphery side of the main seal portion by fusing the heat-sealing resin constituting the container side heat seal layer and the heat-sealing resin constituting the lid material side heat seal layer, from the main seal portion to the outer periphery of the flange portion; and after the second heat sealing, trimming only the lid material laminate with a trimming blade to form a lid material whose outer periphery protrudes outward beyond the outer periphery of the flange portion of the container. A method for producing a package comprising the steps of:

[0019] 8) The first sealing disk is provided with a first annular sealing surface having an inner dimension larger than that of a flange portion of the container and an outer dimension larger than that of the flange portion, and the cross-sectional shape of the first annular sealing surface is an arc shape in which a portion slightly outer than the inner peripheral edge of the flange portion of the container protrudes furthest toward the lid material laminate and gradually moves away from the lid material laminate toward the outer peripheral side, and the first annular sealing surface has a first portion provided on the inner peripheral side and forming a main seal portion, and a second portion provided continuous with the outer peripheral side of the first portion and moving the heat-fusible resin of the lid material side heat seal layer to the outer peripheral side and forming a pseudo seal portion, 7) A method for producing a package as described above in 7), wherein the second sealing plate has a second annular sealing surface having the same inner dimension as the first annular sealing surface, the second annular sealing surface having an outer dimension smaller than the outer dimension of the first annular sealing surface, and the second sealing plate comprises a first sealing portion having an outer dimension smaller than the outer dimension of the first annular sealing surface, and pressing a portion of the lid material laminate within the inner and outer range of this sealing portion excluding a portion that will become the opening start seal portion, and a second sealing portion located between both longitudinal ends of the first sealing portion and having an outer end located outside the outer end of the flange portion of the container, pressing a portion that will become the opening start seal portion of the lid material laminate, wherein the cross-sectional shape of the first sealing portion is a semicircle whose inner end is connected to the inner peripheral surface of the second sealing plate and whose inner and outer central portions protrude most toward the lid material laminate, and the cross-sectional shape of the second sealing portion is a straight line whose inner end is connected to the inner peripheral surface of the second sealing plate via a curve having the same curvature as the cross-sectional curvature of the first sealing portion.

[0020] 9) The first seal disk is provided with a first annular seal surface having an inner dimension larger than that of a flange portion of the container and an outer dimension smaller than that of the flange portion, the first annular seal surface is a flat surface, and the outer shape of the first annular seal surface is located slightly inward from the outer circumferential edge of the flange portion of the container. 7) A method for producing a package as described above in 7), wherein the second sealing plate has a second annular sealing surface having the same inner dimension as the first annular sealing surface, the second annular sealing surface having an outer dimension smaller than the outer dimension of the first annular sealing surface, and the second sealing plate comprises a first sealing portion having an outer dimension smaller than the outer dimension of the first annular sealing surface, and pressing a portion of the lid material laminate within the inner and outer range of this sealing portion excluding a portion that will become the opening start seal portion, and a second sealing portion located between both longitudinal ends of the first sealing portion and having an outer end located outside the outer end of the flange portion of the container, pressing a portion that will become the opening start seal portion of the lid material laminate, wherein the cross-sectional shape of the first sealing portion is a semicircle whose inner end is connected to the inner peripheral surface of the second sealing plate and whose inner and outer central portions protrude most toward the lid material laminate, and the cross-sectional shape of the second sealing portion is a straight line whose inner end is connected to the inner peripheral surface of the second sealing plate via a curve having the same curvature as the cross-sectional curvature of the first sealing portion. Effect of the Invention

[0021] According to the above-mentioned packages 1) to 6), a ring-shaped main seal portion is formed around the entire circumference of the container, which is formed by fusing the heat-sealing resin constituting the container-side heat seal layer and the heat-sealing resin constituting the lid material-side heat seal layer together, and which ensures the hermetic sealing of the heat seal portion. The opening start seal portion is formed so as to extend from the main seal portion to the outer periphery of the flange portion. In the portion between the main seal portion and the outer periphery of the flange portion of the container in the portion excluding the opening start seal portion, a ring-shaped pseudo seal portion is formed in which the heat-sealing resin constituting the container-side heat seal layer and the heat-sealing resin constituting the lid material-side heat seal layer are in close contact with each other so as to have a boundary. Therefore, when a force in the opening direction is applied to the outward protruding portion protruding outward from the flange portion of the lid material in the portion excluding the opening start seal portion due to impact or vibration during transportation, the lid material peels off from the flange portion at the pseudo seal portion, and the force is weakened. Therefore, the force acting on the outward protruding portion of the lid material in the opening direction is suppressed from acting on the main seal portion, and peeling of the lid material from the flange portion at the main seal portion is prevented. Furthermore, because peeling of the lid material from the flange portion at the main seal portion is prevented, the outer peripheral edge of the lid material may protrude outward beyond the outer peripheral edge of the flange portion, and during the manufacture of the package, only the lid material laminate can be cut with a trimming blade, reducing the frequency of replacing the trimming blade and reducing maintenance work and maintenance costs.

[0022] Furthermore, since the opening start seal portion is formed so as to extend from the main seal portion to the outer peripheral edge of the flange portion, when the portion of the lid material that protrudes outward from the flange portion at the opening start seal portion is pinched and pulled upward, the lid material can be easily peeled off from the flange portion, improving ease of opening.

[0023] According to the package of 2) above, the outer peripheral edge of the lid, excluding the opening start seal, protrudes outward by 1 to 3 mm from the outer peripheral edge of the flange of the container, so that when the package is manufactured, only the lid can be reliably cut off with a trimming blade. Also, because the protruding width is 3 mm or less, it is less likely to be opened due to vibrations or impacts during transportation.

[0024] According to the package of 3) above, the package can be easily opened from the opening start seal portion by pulling the opening tab upward.

[0025] According to the package of 4) above, the formation of the main seal portion and the opening start seal portion can be easily confirmed by visually checking the heat seal mark from above the lid material.

[0026] According to the package of 5) above, the resin pool formed in the opening start seal portion improves the ease of opening from the opening start seal portion.

[0027] The packaging material according to 6) above can be easily opened.

[0028] According to the method for producing the package according to 7) above, the packages according to 1) to 6) above, which have the above-mentioned effects, can be easily produced.

[0029] According to the manufacturing method of the package described in 8) above, the first sealing plate allows impurities to escape to the outside, so that impurities are less likely to remain in the main seal portion, and sufficient seal strength can be obtained. Furthermore, it is possible to form a ring-shaped pseudo-seal portion in which the heat-sealable resin constituting the container side heat seal layer and the heat-sealable resin constituting the lid side heat seal layer are in close contact with each other so as to have a boundary therebetween.

[0030] According to the manufacturing method of the packaging body 9) above, the first sealing disk has a first annular sealing surface having an inner dimension larger than that of the flange portion of the container and an outer dimension smaller than that of the flange portion, and the first annular sealing surface is a flat surface and the outer shape of the first annular sealing surface is located slightly more inward than the outer peripheral edge of the flange portion of the container, so that an annular pseudo-seal portion can be formed in which the heat-sealable resin constituting the container side heat seal layer and the heat-sealable resin constituting the lid side heat seal layer are in close contact with each other so as to have a boundary therebetween. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view showing a package according to the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the packaging body of FIG. [Diagram 3] FIG. 2 is a plan view of the package of FIG. 1. [Figure 4] 4 is an enlarged view of the line AA in FIG. 3, with the configurations of the container and the lid omitted. [Diagram 5] 4 is an enlarged view of the line BB in FIG. 3, with the configurations of the container and the lid omitted. [Figure 6] 5 is a cross-sectional view of a portion corresponding to FIG. 4, illustrating the configuration of a heat-sealed portion between a flange portion of a container and a lid material in a portion excluding an opening start seal portion of the package in FIG. [Figure 7] 6 is a cross-sectional view of a portion corresponding to FIG. 5, illustrating the configuration of a heat-sealed portion between a flange portion of a container and a lid material at an opening start seal portion of the package in FIG. 1. [Figure 8] FIG. 2 is a schematic diagram of an apparatus for producing the package of FIG. 1. [Figure 9] FIG. 2 is a bottom view of a first sealing disk used to manufacture the package of FIG. 1. [Figure 10] FIG. 2 is a bottom view of a second sealing disk used to manufacture the package of FIG. 1. [Figure 11] 2 is a partially enlarged vertical cross-sectional view showing a state during a first heat-sealing in the method for producing the package shown in FIG. 1. FIG. [Figure 12]2 is a partially enlarged vertical cross-sectional view showing the state of a portion other than the opening start seal portion during a second heat-sealing in the method for producing the package in FIG. 1. FIG. [Figure 13] 2 is a partially enlarged vertical cross-sectional view showing the state of the opening start seal portion during the second heat sealing in the method for producing the package in FIG. 1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0033] Figures 1 to 3 show the overall structure of the package according to the present invention, and Figures 4 to 7 show the structure of the main parts. Figures 8 to 10 show an apparatus used in manufacturing the package, and Figures 11 to 13 show a method for manufacturing the package.

[0034] In Figures 1 to 3, the package (1) consists of a cup-shaped container (2) containing contents and having an outward flange portion (21) around the periphery of the opening, and a lid (3) whose outer periphery is heat-sealed to the flange portion (21) of the container (2) all around so as to cover the opening of the container (2).

[0035] The annular heat seal portion (4) between the flange portion (21) of the container (2) and the lid material (3) comprises an annular main seal portion (41) formed around the entire circumference on the inside of the outer circumferential edge of the flange portion (21) of the container (2) and ensuring the hermeticity of the heat seal portion (4), an opening start seal portion (42) formed in a portion of the circumference of the heat seal portion (4) from the main seal portion (41) to the outer circumferential edge of the flange portion (21) and having a certain length in the circumferential direction, and a pseudo seal portion (43) formed in the portion between the main seal portion (41) and the outer circumferential edge of the flange portion (21) of the container (2) excluding the opening start seal portion (42).

[0036] The entire outer periphery of the lid (3) projects outward beyond the outer periphery of the flange portion (21) of the container (2). An outwardly protruding opening tab (31) is provided at a location on the outer periphery of the lid (3) that corresponds to the opening start seal portion (42). The opening tab (31) is not necessarily required.

[0037] As shown in Figs. 3 to 5, a heat seal mark (5) appears on the entire heat seal portion (4) between the flange portion (21) of the container (2) and the lid member (3) on the upper surface of the lid member (3). It is preferable that the outer end of the heat seal mark (51) appearing on the upper surface of the lid member (3) in the opening start seal portion (42) of the heat seal mark (5) is located outside the outer periphery of the flange portion (21) and extends to the opening tab (31), and that the outer end of the heat seal mark (52) appearing on the upper surface of the lid member (3) in the portion excluding the opening start seal portion (42) is located inside the outer periphery of the flange portion (21). Furthermore, it is preferable that the outer periphery of the lid member (3) protrudes outward by 1 to 3 mm from the outer periphery of the flange portion (21) of the container (2) in the portion excluding the opening tab (31), i.e., in the portion excluding the opening start seal portion (42). In addition, detailed illustration of the structures of the container (2) and the lid (3) is omitted in Figs. 4 and 5.

[0038] The container (2) is cup-shaped and includes a bottom wall portion (22) that is circular in plan view, and a peripheral wall portion (23) that is generally tapered and cylindrical and gradually widens outward from the outer periphery of the bottom wall portion (22) upward. An annular flange portion (21) that extends horizontally outward is provided at the upper end edge (opening periphery) of the peripheral wall portion (23). The bottom wall portion (22) has an annular step (221) at its radially intermediate position, and the inner portion of the annular step (221) is slightly higher than the outer portion. The peripheral wall portion (23) has an annular step (231) at its height intermediate position, and the upper portion of the annular step (231) is slightly larger in diameter than the lower portion. These annular steps (221) and (231) improve the mechanical strength and stackability of the container (2). However, the annular steps (221) and (231) are optional.

[0039] As shown in Figures 6 and 7, the container (2) is formed by deep drawing or bulging on a container laminate (6) including a base layer (61) made of a synthetic resin protective layer (62) and a barrier layer (63) and a container-side heat seal layer (64) made of a heat-fusible resin that covers the barrier layer (63) of the base layer (61), so that the container-side heat seal layer (64) is located on the upper surface side of the flange portion (21) and on the inner surfaces of the bottom wall portion (22) and the peripheral wall portion (23). Note that the heat seal marks (5) are not shown in Figures 6 and 7.

[0040] Considering the formability (particularly the drawability) of the container laminate (6), the protective layer (62) of the base layer (61) is preferably formed of a single layer film having a thickness of 5 to 100 μm made of polyolefin, polyester, polyamide, etc., which has good conformability, or a multilayer film having a thickness of 5 to 100 μm, which is obtained by laminating a plurality of single layer films. These films are used as non-oriented films or biaxially oriented films. Examples of polyolefins include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), homopolypropylene (hPP), propylene-ethylene random copolymer (rPP), and propylene-ethylene block copolymer (bPP). Examples of polyesters include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT). Examples of polyamides include nylon 6 (PA6). In particular, non-oriented polypropylene films are preferable, regardless of whether they are single layer or multilayer.

[0041] The barrier layer (63) of the base layer (61) is a layer for protecting the contents of the package (1) from gas, water vapor, light, etc., and is preferably formed of aluminum foil having a thickness of 50 to 200 μm. As the aluminum foil, 1000 series such as A1N30 and 8000 series such as A8021 and A8079 specified in JIS H4160:1994 are used.

[0042] The container side heat seal layer (64) is a layer that forms the innermost surface of the container (2) and also forms the upper surface of the flange portion (21) of the container (2), i.e., the layer that forms the sealing surface with the lid material (3).

[0043] Considering the formability (particularly the drawability) of the container laminate (6), the container-side heat seal layer (64) is preferably formed of a monolayer film having a thickness of 5 to 100 μm made of polyolefin having good conformability, or a multilayer film having a thickness of 5 to 100 μm made by laminating a plurality of monolayer films. Examples of polyolefin include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), homopolypropylene (hPP), propylene-ethylene random copolymer (rPP), and propylene-ethylene block copolymer (bPP). For example, in the case of polypropylene (PP) resin, it is preferable to use one having MFR of 3 to 15 g / 10 min (230°C) as specified in JIS K7210-1:2014 (ISO1133-1:2011), and in the case of polyethylene (PE) resin, it is preferable to use one having MFR of 3 to 15 g / 10 min (190°C) as specified in JIS K7210-1:2014 (ISO1133-1:2011). As the multilayer film, for example, a coextruded film is used.

[0044] When the container side heat seal layer (64) is made of a multilayer film, a circular notch (211) is formed in a predetermined radial location on the upper surface of the flange portion (21) of the container (2) at the same time as the container (2) is formed from the container laminate (6). The notch (211) is not necessarily required. However, when the container side heat seal layer (64) is made of a single layer film, the notch (211) is not necessarily required.

[0045] The shape of the container 2 is not limited to the illustrated embodiment and can be modified as appropriate. For example, the bottom wall may be elliptical or rectangular with rounded corners in plan view, the peripheral wall may be elliptical or rectangular with rounded corners in cross section, and the flange 21 may be elliptical annular or rectangular annular with rounded corners.

[0046] The lid material (3) is formed by cutting the lid material laminate (7) into a predetermined shape and size, and is circular in plan view, with an opening tab (31) integrally provided on part of the outer periphery protruding radially outward. The shape of the lid material (3) is appropriately changed to match the shape of the flange portion (21) of the container (2).

[0047] The covering laminate (7) comprises a base layer (71) made of a protective layer (72) and a barrier layer (73) made of synthetic resin, and a covering heat seal layer (74) made of a heat-fusible resin covering the barrier layer (73) of the base layer (71), with the protective layer (72) on the outermost side. A printed layer may be interposed between the protective layer (72) and the barrier layer (73) of the base layer (71).

[0048] The protective layer (72) of the base layer (71) may be a film having a thickness of 5 to 30 μm or a coating amount of 0.5 to 1.0 g / m. 2 The resin coating is preferably made of

[0049] As the film, a non-stretched film or a biaxially stretched film made of polyolefin, polyester, polyamide, etc. can be suitably used. Examples of polyolefin include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), homopolypropylene (hPP), propylene-ethylene random copolymer (rPP), propylene-ethylene block copolymer (bPP), etc. Examples of polyester include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT). Examples of polyamide include PA6.

[0050] Examples of coatings include those made of acetate resins (cellulose-based resins) such as soluble nitrocellulose, acrylic resins, epoxy resins, and shellac resins.

[0051] The barrier layer (73) of the base layer (71) is a layer for protecting the contents of the package (1) from gas, water vapor, light, etc., and is preferably made of an aluminum foil having a thickness of 12 to 80 μm or an aluminum vapor-deposited film having a thickness of 0.03 to 0.1 μm.

[0052] The aluminum foil and aluminum vapor-deposited film may be of the 1000 series, such as A1N30, or the 8000 series, such as A8021 or A8079, as specified in JIS H4160:1994. When an aluminum vapor-deposited film is used, the aluminum vapor-deposited film may be used as the film constituting the protective layer (72).

[0053] The heat seal layer (74) on the lid side is preferably formed of a monolayer film made of polyolefin having a thickness of 5 to 100 μm or a multilayer film made by laminating a plurality of monolayer films having a thickness of 5 to 100 μm. Examples of polyolefin include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), homopolypropylene (hPP), propylene-ethylene random copolymer (rPP), and propylene-ethylene block copolymer (bPP). For example, in the case of polypropylene (PP)-based resin, it is preferable to use one having MFR of 3 to 15 g / 10 min (230°C) as specified in JIS K7210-1:2014 (ISO1133-1:2011), and in the case of polyethylene (PE)-based resin, it is preferable to use one having MFR of 3 to 15 g / 10 min (190°C) as specified in JIS K7210-1:2014 (ISO1133-1:2011). As the multi-layer film, for example, a co-extruded film is used.

[0054] The lid material laminate (7) is usually wound into a coil shape with the lid material side heat seal layer (74) facing inward, and is used while being unwound from the coil when manufacturing the package (1). The width of the lid material laminate (7) before being heat sealed to the container (2) is larger than the maximum dimension of the outer shape of the lid material (3) of the manufactured package (1). Alternatively, a lid material laminate (7) cut to a predetermined shape and to a dimension larger than the maximum dimension of the outer shape of the lid material (3) of the manufactured package (1) may be used.

[0055] The main seal portion (41) and the opening start seal portion (42) of the heat seal portion (4) are formed by fusing the heat-sealing resin constituting the uppermost layer of the container-side heat seal layer (64) present in the flange portion (21) with the heat-sealing resin constituting the lowermost layer of the lid material-side heat seal layer (74), and the pseudo seal portion (43) is formed by closely adhering the heat-sealing resin constituting the uppermost layer of the container-side heat seal layer (64) present in the flange portion (21) with the heat-sealing resin constituting the lowermost layer of the lid material-side heat seal layer (74) so ​​that there is a boundary between them. In the main seal portion (41), the joint interface between the container side heat seal layer (64) and the lid side heat seal layer (74) in the flange portion (21) is heated and melted, and further, the molecules in the heat fusion resin of the container side heat seal layer (64) near the joint interface and the molecules in the heat fusion resin of the lid side heat seal layer (74) near the joint interface are melted and become amorphous molecules (non-crystallized) by heating, and the amorphous molecules near the joint interface diffuse into each other, and then become entangled and crystallized by cooling. The pseudo seal portion (43) is formed when the heat fusion resin constituting the lowermost layer of the lid side heat seal layer (74) melts and flows to the outer periphery of the flange portion (21) and solidifies against the uppermost layer of the container side heat seal layer (64).

[0056] Resin pools (8)(9) are formed over the entire circumference between the tip surface of the flange portion (21) of the container (2) and the bottom surface of the lid material (3). The resin pool (8) formed in the opening start seal portion (43) is a resin pool derived from a mixture of the heat fusion resin constituting the uppermost layer of the container side heat seal layer (64) present in the flange portion (21) and the heat fusion resin constituting the lowermost layer of the lid material side heat seal layer (74), and the resin pool (9) formed in the portion excluding the opening start seal portion (43) is a resin pool derived from the heat fusion resin constituting the lowermost layer of the lid material side heat seal layer (74), and the resin pool (8) formed in the opening start seal portion (43) is larger than the resin pool (9) formed in the portion excluding the opening start seal portion (43).

[0057] In the above-mentioned package (1), when a force in the opening direction is applied to the portion of the lid material (3) that protrudes outward from the flange portion (21) except for the portion where the opening tab (31) is provided due to impact or vibration during transportation, the force is weakened by the lid material (3) peeling off from the flange portion (21) at the pseudo seal portion (43). Therefore, the force in the opening direction applied to the outward protruding portion of the lid material (3) is prevented from acting on the main seal portion (41), and the lid material (3) is prevented from peeling off from the flange portion (21) at the main seal portion (41).

[0058] Furthermore, when opening the package (1), when the opening tab (31) of the lid material (3) is picked up with the fingers and pulled up, the container-side heat seal layer (64) forming the opening start seal portion (42) is pulled upward with a relatively strong force together with the lid material (3). If the container-side heat seal layer (64) is made of a multilayer film, the layers are peeled from the outer periphery at the boundary between the adjacent single-layer films, which is the peel-opening position, and when the peeling reaches the notch position, the container-side heat seal layer (64) is divided into upper and lower parts at the peel-opening position. If the container-side heat seal layer (64) is made of a single-layer film, cohesive peeling occurs in the container-side heat seal layer (64), and the container-side heat seal layer (64) is divided into upper and lower parts. Furthermore, when the opening tab (31) is pulled up, the upper portion of the severed container-side heat seal layer (64) remains attached to the lid material (3), and the lid material (3) is separated from the flange portion (21), and the package (1) is opened.

[0059] 8 to 10 show a manufacturing apparatus for the package (1).

[0060] The manufacturing equipment for the packaging body (1) includes a payout roll (100) on which a coil (75) of the lid material laminate (7) is attached, a take-up roll (200) which takes up the remaining material after the lid material (3) is punched out from the lid material laminate (7), and a first sealing plate (300), a second sealing plate (400) and a trimming blade (500) arranged in this order from the payout roll (100) side in the upper part of the movement path of the lid material laminate (7) between the payout roll (100) and the take-up roll (200), and a sealing plate receiver (600) which is arranged below the movement path of the lid material laminate (7) in the part between the payout roll (100) and the take-up roll (200) and which holds and transports the container (2) between the two rolls (100) and (200).

[0061] The first sealing disk (300) has a first annular sealing surface (301) having an outer diameter, for example, about 5 mm larger than the outer diameter of the flange portion (21) of the container (2) and an inner diameter about 1.5 mm larger than the diameter of the annular notch (211). The first annular sealing surface (301) has a predetermined radius of curvature and is partially cylindrical in shape with the center of curvature located on a circumference slightly radially outward from the inner diameter of the first annular sealing surface (301). Therefore, referring to FIG. 11, the cross-sectional shape of the first annular sealing surface (301) is an arc shape in which a portion slightly outer than the inner peripheral edge of the flange portion (21) of the container (2) protrudes most downward and gradually moves upward from the covering material laminate (7) toward the outer peripheral side. The first annular sealing surface (301) has a first portion (302) that is provided on the inner peripheral side and forms a main sealing portion (41), and a second portion (303) that is provided contiguous to the outer peripheral side of the first portion (302) and moves the heat-fusible resin of the lid material side heat seal layer (74) toward the outer peripheral side and forms a pseudo sealing portion (43).

[0062] Although not shown in the figures, the first sealing disk may be provided with a first annular sealing surface having an inner diameter larger than the inner diameter (inner dimension) of the flange portion of the container and an outer diameter smaller than the outer diameter (outer dimension) of the flange portion, the first annular sealing surface being a flat surface and the outer shape of the first annular sealing surface being located slightly inward from the outer circumferential edge of the flange portion of the container.

[0063] The second sealing disk (400) is provided with a second annular sealing surface (401) having an inner diameter equal to that of the first annular sealing surface (301). The second annular sealing surface (401) has an outer dimension smaller than the outer diameter of the first annular sealing surface (301) and is composed of a first sealing portion (402) having a major arc shape as viewed from the bottom surface, which presses a portion of the lid material laminate (7) within the range inside and outside the main sealing portion (41) except for a portion that will become the opening start seal portion (42), and a second sealing portion (403) having a minor arc shape as viewed from the bottom surface, which is located between both ends in the longitudinal direction of the first sealing portion (402) and has an outer end located outside the outer end of the flange portion (21) of the container (2) and presses a portion that will become the opening start seal portion (42) of the lid material laminate (7). The circumferential length of the first sealed portion (402) is equal to the circumferential length of the heat sealed portion (4) of the package (1) excluding the opening start seal portion (42), and the circumferential length of the second sealed portion (403) is equal to the circumferential length of the opening start seal portion (42) of the heat sealed portion (4) of the package (1).

[0064] Referring to Fig. 12, the first seal portion (402) of the second annular seal surface (401) is a semicylindrical surface located on a circumference with the center of curvature located at the center between the outer peripheral edge and the inner peripheral edge of the first seal portion (402). Therefore, the cross-sectional shape of the first seal portion (402) is a semicircle whose inner end is connected to the inner peripheral surface of the second seal plate (400) and whose inner and outer central portions protrude most toward the covering material laminate (7). Also, referring to Fig. 13, the second seal portion (403) of the second annular seal surface (401) is a flat surface, and the inner peripheral edge of the flat surface is connected to the inner peripheral surface of the second seal plate (400) via a roundness having the same curvature radius as the first seal portion (402). Therefore, the cross-sectional shape of the second seal portion (403) is a straight line whose inner end is connected to the inner peripheral surface of the second seal disk (400) via a roundness having the same curvature as the cross-sectional curvature of the first seal portion (402).

[0065] The packaging body (1) is manufactured by the method described below.

[0066] A coil (75) of the lid material laminate (7) having a width wider than the outer diameter of the lid material (3) to be manufactured is previously attached to a pay-out roll (100), and a container (2) is attached to a sealing disk receiver (600).

[0067] In this state, the lid material laminate (7) is unwound from the coil (75) and placed on the flange portion (21) of the container (2) so that both widthwise edge portions extend outward beyond the outer peripheral edge of the flange portion (21) of the container (2). After that, the first heat seal is performed in a portion that is inner than the outer peripheral edge of the flange portion (21) of the container (2) and outer than the notch (211), by heating while pressing the lid material laminate (7) and the flange portion (21) of the container (2) all around with the first annular sealing surface (301) of the first sealing disk (300).

[0068] By performing the first heat sealing, the first part (302) of the first annular sealing surface (302) forms an annular main seal portion (41) in the portion inside the outer circumferential edge of the flange portion (21) of the container (2) by fusing the heat-sealable resin constituting the container side heat seal layer (64) with the heat-sealable resin constituting the lid material side heat seal layer (74) and ensuring the sealing performance of the heat seal portion (4), and the second part (303) forms an annular pseudo seal portion (43) in the portion between the main seal portion (41) and the outer circumferential edge of the flange portion (21) of the container (2) by closely adhering the heat-sealable resin constituting the container side heat seal layer (64) and the heat-sealable resin constituting the lid material side heat seal layer (74) so ​​that there is a boundary between them. Furthermore, the first seal portion (301) of the first annular seal surface (301) moves the heat-fusible resin that constitutes the lid material side heat seal layer (74) radially outward, forming a resin reservoir (9) outside the outer circumferential edge of the flange portion (21).

[0069] After the first heat seal, the sealing disk receiver (600) is moved to the right, and a second heat seal is performed by heating the covering material laminate (7) and the flange portion (21) of the container (2) while pressing them all around with the second annular sealing surface (401) of the second sealing disk (400) in the portion that is inner than the outer periphery of the flange portion (21) of the container (2) and outer than the notch (211).

[0070] By performing the second heat sealing, even if an unsealed portion remains in the main seal portion (41) formed during the first heat sealing due to the influence of foreign matter, the first seal portion (402) of the second annular seal surface (401) reliably seals the unsealed portion in the main seal portion (41) excluding the portion that will become the opening start seal portion (42). As a result, peeling at the heat seal portion (4) is suppressed even if unexpected large vibrations or impacts are applied during transportation. At the same time, the second seal portion (403) of the second annular seal surface (401) fuses the heat-sealing resin constituting the container side heat seal layer (64) and the heat-sealing resin constituting the lid material side heat seal layer (74) in the range from the inner peripheral edge of the main seal portion (41) in the portion that becomes the opening start seal portion (42) to the outer peripheral edge of the portion where the opening start seal portion (42) is to be formed, thereby forming the opening start seal portion (42).In addition, the heat-sealing resin constituting the container side heat seal layer (64) and the heat-sealing resin constituting the lid material side heat seal layer (74) are moved radially outward in the opening start seal portion (42), forming a resin reservoir (8) outside the outer peripheral edge of the flange portion (21).

[0071] After the second heat seal, the sealing disk receiver (600) is moved to the right, and only the lid material laminate (7) is trimmed using a trimming blade (500), thereby forming a lid material (3) whose entire outer peripheral edge protrudes outward beyond the outer peripheral edge of the flange portion (21) of the container (2).

[0072] In this manner, the package (1) is produced. EXAMPLES

[0073] Next, examples of the present invention will be described together with comparative examples, but the present invention is not limited to the following examples. [Example 1] <Preparation of laminate for container> The aluminum foil, which is made of JISA8021-O material as specified in JIS H4160:1994 and has a thickness of 120 μm and forms the barrier layer (63), is treated on both sides with a chemical conversion solution consisting of phosphoric acid, polyacrylic acid, a chromium (III) salt compound, water, and alcohol so that the amount of chromium deposition is 5 mg / m per side. 2 The chemical conversion coating was formed so that

[0074] Next, a polyester polyurethane adhesive was applied to one side of the aluminum foil on which the chemical conversion coating was formed to a thickness of 3 μm to form an adhesive layer, and a 30 μm-thick unstretched polypropylene film was laminated on top of the adhesive layer to form a protective layer (62).

[0075] In addition, a polyester polyurethane adhesive of 3 μm was applied to the other side of the aluminum foil on which the chemical conversion coating was formed to form an adhesive layer, and a 300 μm thick co-extruded film (HDPE layer 50 μm / PE layer with a small amount of PE mixed in 250 μm) was attached on top of the adhesive layer with the HDPE layer on the outside to form a container side heat seal layer (64).

[0076] Thereafter, the laminate was subjected to a heat aging treatment at 40° C. for 8 days to obtain a laminate for a container (6). <Preparation of container> Next, the container laminate (6) was punched into a circular blank of a predetermined size, and the blank was deep-drawn in a press molding device so that the protective layer (62) side was on the outer side of the container (2) (the upper side of the flange portion (21)), thereby producing a cup-shaped container (2).

[0077] The dimensions of the container (2) were as follows: opening diameter: 66 mm, diameter of bottom wall portion (22): 57.38 mm, height: 26.0 mm, radius of curvature of the roundness formed between the upper end of the peripheral wall portion (23) and the inner peripheral edge of the flange portion (21): 2 mm, width of the flat portion of the flange portion (21): 7 mm, and outer diameter of the flange portion (21): 80 mm.

[0078] In addition, a circular notch (211) was formed on the upper surface of the flange portion (21) of the container (2) on a circumference with a diameter of 71 mm centered at the center of the outer periphery of the flange portion (21) and reaching the base layer (61). <Preparation of Laminate for Lid Material> The aluminum foil was made of JISA1N30-O material specified in JIS H4160:1994 and had a thickness of 12 μm. A polyethylene terephthalate film having a thickness of 12 μm was dry-laminated on one side of the aluminum foil forming the barrier layer (73) using a two-component curing polyester polyurethane resin-based adhesive to form a protective layer (72). On the other side of the aluminum foil, a linear low-density polyethylene film having a thickness of 50 μm was dry-laminated using a two-component curing polyester polyurethane resin-based adhesive to form a heat-seal layer (74) for the lid material.

[0079] Thereafter, the laminate was subjected to a heat aging treatment at 40° C. for 8 days to prepare a covering material laminate (7).

[0080] The resulting laminate for lid material (7) was cut into pieces measuring 100×100 mm to obtain test pieces for lid material. <Shapes of the first and second seal plates> The first seal disk (300) used had a first annular seal surface (301) with an outer diameter of 85 mm and an inner diameter of 74 mm. The first annular seal surface (301) was a partial cylindrical surface with a radius of curvature of 30 mm centered on a circumference with a diameter of 76 mm.

[0081] The second seal disk (400) used had a second annular seal surface (401) including a first seal portion (402) whose outer periphery is located on a circumference with a diameter of 78 mm and whose inner periphery is located on a circumference with a diameter of 74 mm, and a second seal portion (403) whose outer periphery is located on a circumference with a diameter of 90 mm and whose inner periphery is located on a circumference with a diameter of 74 mm. The first seal portion (402) is a semi-cylindrical surface with a radius of curvature of 2 mm centered on a circumference located at the center between the outer periphery and inner periphery of the first seal portion (402), and the second seal portion (403) is a flat surface whose inner periphery is connected to the inner periphery of the second seal disk (400) via a curve with the same radius of curvature as the first seal portion (402). <Creating packaging> A lid material specimen was placed on the upper surface of the flange portion (21) of the container (2) with the lid material heat seal layer (74) side in contact, and a first heat seal was performed by pressing the first annular seal surface (301) of a first sealing disk (300) heated to 200°C against the portion of the laminated surfaces from a position 1.5 mm outside the notch (211) to a portion radially outside the outer periphery of the flange portion (21) with a pressure of 160 kgf for 2 seconds.

[0082] Next, a second heat seal was performed by pressing the first seal portion (402) and the second seal portion (403) of the second annular seal surface (401) of the second seal plate (400) heated to 200°C against the overlapping surfaces of the flange portion (21) and the covering material laminate (7) with a pressure of 160 kgf for two seconds. In the second heat seal, the main seal portion (41) formed by the first heat seal was heated while being pressed by the first seal portion (402), and the part radially outward from the outer periphery of the flange portion (21) from the main seal portion (41) formed by the first heat seal was heated while being pressed by the second seal portion (403).

[0083] Finally, the lid material specimen was trimmed using a trimming blade (500) at a portion 2 mm radially outward from the flange portion (21) so that only the lid material laminate (7) remained, with the outermost end being located 47 mm away from the center point of the opening of the container (2), thereby obtaining the package (1). [Example 2] The lid material specimen was heat-sealed to the flange portion (21) of the container (2), and then the lid material specimen was trimmed using a trimming blade (500) at a portion 2 mm radially outward from the outer peripheral edge of the flange portion (21) so that only the lid material laminate (7) was left, with the outermost end being positioned 50 mm away from the center point of the opening of the container (2). Except for this, a package (1) was obtained in the same manner as in Example 1. [Example 3] The first sealing disk (300) used had an outer diameter of 79 mm, an inner diameter of 74 mm, and a first annular sealing surface that was entirely flat and had the same width over the entire circumference. In the first heat seal, the first annular sealing surface of the first sealing disk heated to 200°C was pressed against the flange portion (21) with a pressure of 160 kgf for 2 seconds so that the outer peripheral edge of the first annular sealing surface was positioned 0.5 mm radially inward from the outer peripheral edge of the flange portion (21). Otherwise, the package (1) was obtained in the same manner as in Example 1. [Comparative Example 1] A package was obtained in the same manner as in Example 1, except that the second sealing disk used had an outer diameter of 90 mm, an inner diameter of 74 mm, and a second annular sealing surface that was generally flat and had the same width around its entire circumference. [Comparative Example 2] A package was obtained in the same manner as in Example 1, except that the second sealing disk used had a second annular sealing surface having an outer diameter of 78 mm, an inner diameter of 74 mm, and a second annular sealing surface that was generally flat and had the same width around its entire circumference. <Evaluation test> The ten packages obtained in Examples 1-3 and Comparative Examples 1-2 were subjected to an appearance observation, a transportation test, and an opening test.

[0084] The appearance was observed by observing whether there was any upward bulging in the area of ​​the flange at the periphery of the lid. If there was any bulging, it was determined that impurities had become mixed in between the flange and the lid.

[0085] In the opening test, for the package of the embodiment, the lid material was peeled off by pinching the opening tab and pulling it upward, and it was checked whether the peeling could be done smoothly to the end.For the package of the comparative example 1-2, the lid material was peeled off by pinching an appropriate part of the periphery of the lid material and pulling it upward, and it was checked whether the peeling could be done smoothly to the end.

[0086] For the transportation test, 10 packages were stacked in pairs with the lids facing each other and transported as freight from Hikone City, Shiga Prefecture to Isehara City, Kanagawa Prefecture and back, to check whether any leakage occurred.

[0087] These results are summarized in Table 1.

[0088] [Table 1] In the column of appearance observation in Table 1, ○ indicates that all of the 10 packages had no bulging and were problem-free, △ indicates that bulging was observed in 1 to 3 packages out of the 10 packages, and × indicates that bulging was observed in 4 or more packages out of the 10 packages. In the column of transportation test in Table 1, ○ indicates that no leakage occurred in all of the 10 packages, △ indicates that leakage occurred in 1 to 3 packages out of the 10 packages, and × indicates that leakage occurred in 4 or more packages out of the 10 packages. In the column of opening property test in Table 1, ○ indicates that the lid material could be opened smoothly without resistance when opened in all of the 10 packages, and × indicates that there was resistance in all of the 10 packages when opening the lid material.

[0089] From the results shown in Table 1, the 10 packages of Example 1 obtained good results in all of the appearance observation, the transportation test, and the opening test. In contrast, the package of Comparative Example 1 did not obtain good results in the transportation test, and the package of Comparative Example 2 did not obtain good results in the opening test. [Industrial Applicability]

[0090] The packaging body according to the present invention is suitably used for sealing and packaging food, medicines, electronic parts, industrial products, and the like. [Explanation of symbols]

[0091] (1):Packaging (2): Container (21): Flange (211):Notch (3): Lid material (31): Opening tab (4): Heat seal section (41): Main seal part (42): Opening start seal (43): Pseudo seal part (5): Heat seal marks (51): Heat seal mark at the beginning of the opening seal (52): Heat seal marks excluding the seal area where the opening started (6): Laminated body for containers (61): Base material layer (64): Heat seal layer on container side (7): Laminated body for lid material (71): Base material layer (74): Heat seal layer on the lid side (300): First seal plate (301): First annular seal surface (400): Second seal plate (401): Second annular seal surface (402): First seal part (403): Second seal part

Claims

1. A package comprising a cup-shaped container having an outward flange around the periphery of the opening and containing contents, and a lid material whose outer periphery is heat-sealed to the flange of the container so as to cover the opening of the container, the container comprising a base layer and a container-side heat seal layer made of a heat-sealable resin provided on one side of the base layer and covering an upper surface of the flange, the lid material comprising a base layer and a lid material-side heat seal layer made of a heat-sealable resin provided on one side of the base layer and covering an underside of the lid material, the flange of the container and the lid material being heat-sealed using the container-side heat seal layer and the lid material-side heat seal layer, an opening start seal portion being provided at a portion of the circumferential direction of the heat seal portion between the flange and the lid material, and the entire outer periphery of the lid material protruding outward beyond the outer periphery of the flange of the container, A package in which a heat-sealing resin constituting the container-side heat seal layer and a heat-sealing resin constituting the lid material-side heat seal layer are fused together in a portion inside the outer peripheral edge of a flange portion of a container, and a ring-shaped main seal portion that ensures the hermeticity of the heat seal portion is formed around the entire circumference, an opening start seal portion is formed from the main seal portion to the outer peripheral edge of the flange portion, and a ring-shaped pseudo seal portion is formed in the portion between the main seal portion and the outer peripheral edge of the flange portion of the container, excluding the opening start seal portion, in which the heat-sealing resin constituting the container-side heat seal layer and the heat-sealing resin constituting the lid material-side heat seal layer are in close contact with each other so that there is a boundary between them.

2. 2. The package according to claim 1, wherein the outer peripheral edge of the lid material protrudes outwardly by 1 to 3 mm from the outer peripheral edge of the flange portion of the container in a portion other than the opening start seal portion.

3. 2. The package according to claim 1, wherein an outwardly protruding opening tab is provided on the outer periphery of the lid at a location corresponding to the opening start seal portion.

4. The package described in claim 1, wherein in the opening start seal portion, the outer end of the heat seal mark between the flange portion of the container and the lid material, which appears on the upper surface of the lid material, is located at a position coincident with the outer peripheral edge of the flange portion or at a position outer than the outer peripheral edge of the flange portion, and in the portion excluding the opening start seal portion, the outer end of the heat seal mark is located at a position inner than the outer peripheral edge of the flange portion.

5. The package described in claim 1, wherein a resin pool is formed around the entire circumference between the tip surface of the flange portion of the container and the underside of the lid material, the resin pool formed in the opening start seal portion is a resin pool derived from a mixture of the heat-sealing resin constituting the container side heat seal layer and the heat-sealing resin constituting the lid material side heat seal layer, the resin pool formed in the portion excluding the opening start seal portion is a resin pool derived from the heat-sealing resin constituting the lid material side heat seal layer, and the resin pool formed in the opening start seal portion is larger than the resin pool formed in the portion excluding the opening start seal portion.

6. 2. The package according to claim 1, wherein a notch is formed around the entire periphery of the upper surface of the flange of the container, in a portion inside the main seal portion.

7. A method for producing a package according to any one of claims 1 to 6, comprising the steps of: a container comprising a laminate for a container, the laminate comprising a base layer and a container-side heat seal layer made of a heat-fusible resin provided on one side of the base layer, the upper surface of an outward flange portion provided on the periphery of an opening being covered with the container-side heat seal layer, and containing contents; and a lid material laminate comprising a base layer and a lid material-side heat seal layer made of a heat-fusible resin provided on one side of the base layer, the lower surface being covered with the lid material-side heat seal layer, and having an outer shape larger than the outer shape of the flange portion of the container, a first heat seal is performed by placing the lid material laminate on the flange portion of the container so that the outer peripheral edge of the lid material laminate projects outward beyond the outer peripheral edge of the flange portion of the container, and then applying heat to the lid material laminate and the flange portion of the container while pressing the lid material laminate over the entire circumference using an annular first sealing plate, thereby forming an annular main seal portion in a portion inside the outer peripheral edge of the flange portion of the container, in which the heat fusion resin constituting the container side heat seal layer and the heat fusion resin constituting the lid material side heat seal layer are fused together and which ensures the hermeticity of the heat seal portion, and forming an annular pseudo seal portion in a portion between the main seal portion and the outer peripheral edge of the flange portion of the container, in which the heat fusion resin constituting the container side heat seal layer and the heat fusion resin constituting the lid material side heat seal layer are in close contact with each other so as to have a boundary therebetween; After the first heat seal, a ring-shaped second sealing disk is used to press and heat the entire widthwise range of the main seal portion between the lid material laminate and the flange portion of the container, and a second heat seal is performed by pressing and heating a portion of the entire circumference of the flange portion from the main seal portion to the outer periphery of the flange portion, and an opening start seal portion is formed in a portion of the outer periphery side of the main seal portion by fusing the heat-sealing resin constituting the container side heat seal layer and the heat-sealing resin constituting the lid material side heat seal layer, from the main seal portion to the outer periphery of the flange portion; and after the second heat sealing, trimming only the lid material laminate with a trimming blade to form a lid material whose outer periphery protrudes outward beyond the outer periphery of the flange portion of the container. A method for producing a package comprising the steps of:

8. the first sealing disk is provided with a first annular sealing surface having an inner dimension larger than that of a flange portion of the container and an outer dimension larger than that of the flange portion, the cross-sectional shape of the first annular sealing surface is an arc shape in which a portion slightly outer than the inner peripheral edge of the flange portion of the container protrudes furthest toward the lid material laminate and gradually moves away from the lid material laminate toward the outer peripheral side, the first annular sealing surface has a first portion provided on the inner peripheral side and forming a main seal portion, and a second portion provided continuous with the outer peripheral side of the first portion and moving the heat-fusible resin of the lid material side heat seal layer to the outer peripheral side and forming a pseudo seal portion, 8. A method for manufacturing a package as described in claim 7, wherein the second sealing plate has a second annular sealing surface having the same inner dimension as the first annular sealing surface, the second annular sealing surface has an outer dimension smaller than the outer dimension of the first annular sealing surface, and comprises a first sealing portion that presses a portion of the lid material laminate except for a portion that will become the opening start seal portion within the inner and outer range of this seal portion, and a second sealing portion that is located between both longitudinal ends of the first sealing portion and has an outer end that is located outside the outer end of the flange portion of the container, and presses a portion that will become the opening start seal portion of the lid material laminate, wherein the cross-sectional shape of the first sealing portion is a semicircle whose inner end is connected to the inner peripheral surface of the second sealing plate and whose inner and outer central portions protrude most toward the lid material laminate, and the cross-sectional shape of the second sealing portion is a straight line whose inner end is connected to the inner peripheral surface of the second sealing plate via a roundness having the same curvature as the cross-sectional curvature of the first sealing portion.

9. The first sealing disk is provided with a first annular sealing surface having an inner dimension larger than that of a flange portion of the container and an outer dimension smaller than that of the flange portion, the first annular sealing surface being a flat surface, and the outer shape of the first annular sealing surface is located slightly inward from the outer circumferential edge of the flange portion of the container.

8. A method for manufacturing a package as described in claim 7, wherein the second sealing plate has a second annular sealing surface having the same inner dimension as the first annular sealing surface, the second annular sealing surface has an outer dimension smaller than the outer dimension of the first annular sealing surface, and comprises a first sealing portion that presses a portion of the lid material laminate except for a portion that will become the opening start seal portion within the inner and outer range of this seal portion, and a second sealing portion that is located between both longitudinal ends of the first sealing portion and has an outer end that is located outside the outer end of the flange portion of the container, and presses a portion that will become the opening start seal portion of the lid material laminate, wherein the cross-sectional shape of the first sealing portion is a semicircle whose inner end is connected to the inner peripheral surface of the second sealing plate and whose inner and outer central portions protrude most toward the lid material laminate, and the cross-sectional shape of the second sealing portion is a straight line whose inner end is connected to the inner peripheral surface of the second sealing plate via a roundness having the same curvature as the cross-sectional curvature of the first sealing portion.

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