Lid materials and containers with lids

Abstract

To reduce opening defects.SOLUTION: A lid material 3 comprises: a rectangular lid body 33; a grip part 34 which is positioned at a corner part 41 of the lid body 33, and extends in a first direction D1 from the lid body 33; and a rear half-cut line 35 which is cut into the lid body 33 from a rear face 3b of the lid material 3 toward a front face 3a of the lid material 3. The rear half-cut line 35 has: a first rear half-cut main line 55 linearly extending along an outer peripheral part 42; a second rear half-cut main line 56 linearly extending along a second outer peripheral part 43; a first rear half-cut guide line 53 extending from the first outer peripheral part 42 side to the first rear half-cut main line 55 with respect to an extension line EL1 of the first rear half-cut main line 55; and a second rear half-cut guide line 54 extending from a second outer peripheral part 43 side to the second rear half-cut main line 56 with respect to an extension line EL2 of the second rear half-cut main line 56. The first rear half-cut guide line 53 and the second rear half-cut guide line 54 extend in directions separating from each other as moving toward a second direction D2 opposite to the first direction D1.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a lid material joined to a flange formed around an opening of a container and a container with a lid to which the lid material is joined.

Background Art

[0002] Patent Document 1 describes a lid material that seals a flange at the periphery of a rectangular container opening to close the opening. The lid material described in Patent Document 1 is configured by laminating a front layer and a back layer so as to be peelable, and has an opening tab provided at a position corresponding to a corner of the rectangular container opening for opening the lid material, a front half cut line for cutting the front layer, and a back half cut line for cutting the back layer. The front half cut line goes around the rectangular container opening, and both ends thereof reach both sides of the opening tab. The back half cut line goes around the rectangular container opening inside the front half cut line, and both ends thereof reach both sides of the opening tab. Thus, when the opening tab is pulled, delamination can be performed between the front half cut line and the back half cut line to open the lid material.

[0003] However, when the opening tab is pulled, only the front layer may be pulled, and the front layer and the back layer may be erroneously delaminated. Therefore, the lid material described in Patent Document 1 is further provided with auxiliary half cut lines that cut the back layer and connect to two sides sandwiching the opening tab of the back half cut line. Thus, when the opening tab is pulled, even if only the front layer is pulled, delamination between the front layer and the back layer can be stopped at the auxiliary half cut lines.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present inventors conducted an opening test using the lid material described in Patent Document 1, and found that in some cases, only the surface side peeled off thinly, causing interlayer delamination not to stop at the auxiliary half-cut line and the back half-cut line, resulting in a failed opening.

[0006] Therefore, the object of the present invention is to provide a lid material and a container with a lid that can further reduce opening failures. [Means for solving the problem]

[0007] The inventors of this invention conducted intensive research on the above problem and found that when only the surface side of the lid peeled off thinly, the bonding force between the container flange and the lid material became higher than the breaking strength at the back half-cut line of the lid, and interlayer delamination did not stop at the auxiliary half-cut line and the back half-cut line. This invention was made based on the above finding.

[0008] In other words, the lid material according to the present invention is as follows:

[0009] [1] A sheet-like lid material that is joined to the flange of a container having a rectangular opening and a flange formed around the opening to close the opening, comprising: a rectangular lid body that is joined to the flange to close the opening; a gripping portion located at the corner of the lid body and extending in a first direction from the lid body; and a back half cut line cut into the lid body from the back surface toward the front surface of the lid material, wherein the lid body has a first outer peripheral portion and a second outer peripheral portion that extend linearly on either side of the corner, and the back half cut line extends toward the first outer peripheral portion A lid material having a first back half-cut main line extending in a straight line along the second outer peripheral portion, a second back half-cut main line extending in a straight line along the second outer peripheral portion, a first back half-cut guide line extending from the first outer peripheral portion side of the extension of the first back half-cut main line to the first back half-cut main line, and a second back half-cut guide line extending from the second outer peripheral portion side of the extension of the second back half-cut main line to the second back half-cut main line, wherein the first back half-cut guide line and the second back half-cut guide line extend in a direction that separates them from each other as they move toward a second direction opposite to the first direction.

[0010] In this lid material, when the gripping portion is pulled in the second direction to open the lid body, the lid body is pulled by the gripping portion and breaks (tears) in the second direction. The back half-cut line has a first back half-cut guide line that extends from the first outer peripheral area side of the extension of the first back half-cut main line to the first back half-cut main line, and a second back half-cut guide line that extends from the second outer peripheral area side of the extension of the second back half-cut main line to the second back half-cut main line, with the first and second back half-cut guide lines extending in directions that move further apart from each other as the direction toward the second direction progresses. As a result, the distance from the back half-cut line to the first and second outer peripheral areas in the third direction perpendicular to the second direction is shortened compared to when the first and second back half-cut guide lines are not formed in this way. In other words, the bonding force between the container flange and the lid body that prevents the lid body from breaking at the first and second back half-cut guide lines can be reduced. As a result, even if only the surface of the lid body is thinly peeled off, the lid body becomes more likely to break at the first and second back half-break guide lines, and the breakage of the lid body progresses more easily from the first and second back half-break guide lines to the first and second back half-break main lines, thereby reducing opening failures.

[0011] [2] The lid material as described in [1], wherein the first back half-cut guide wire and the second back half-cut guide wire extend in a straight line.

[0012] In this lid material, the first and second back half-break guide lines extend in a straight line, which allows the first and second back half-break guide lines to be shortened, making it easier to guide the breakage of the lid body to the first and second back half-break guide lines.

[0013] [3] The cover material according to [1], wherein the first back half-cut guide wire and the second back half-cut guide wire extend in a curved shape.

[0014] In this lid material, the first and second back half-cut guide lines extend in a curved shape, which allows for a smooth transition of the lid body's fracture from the gripping portion to the first and second back half-cut guide lines, and from the first and second back half-cut guide lines to the first and second back half-cut main lines.

[0015] [4] The first back half-cut guide wire and the second back half-cut guide wire are bent, as described in any one of [1] to [3].

[0016] In this lid material, the first and second back half-cut guide wires are bent, which increases the degree of freedom in the shape of the first and second back half-cut guide wires.

[0017] [5] The gripping portion has a first side portion and a second side portion that extend in the second direction and are arranged in a third direction perpendicular to the second direction, and at least a part of the first side portion is formed by a first full cut line cut from the surface of the lid material to the back surface of the lid material, and at least a part of the second side portion is formed by a second full cut line cut from the surface of the lid material to the back surface of the lid material, as described in any one of [1] to [4].

[0018] In this lid material, at least a portion of the first and second side edges, which extend in the second direction and are arranged in the third direction, are formed by first and second full cut lines that cut from the surface to the back surface of the lid material. This makes the lid body more likely to break in the second direction when the gripping portion is pulled in the second direction. This allows for appropriate control of the direction in which the lid body breaks.

[0019] [6] The cover material according to [5], wherein the first back half-cut guide wire extends from the vicinity of the tip of the first full cut wire in the second direction to the first back half-cut main wire, and the second back half-cut guide wire extends from the vicinity of the tip of the second full cut wire in the second direction to the second back half-cut main wire.

[0020] In this lid material, the first inner half-cut induction line and the second inner half-cut induction line extend from the vicinity of the tip of the first full-cut line in the second direction and the vicinity of the tip of the second full-cut line in the second direction, so that the first full-cut line and the second full-cut line and the first inner half-cut induction line and the second inner half-cut induction line can be formed simultaneously, and the progress of breakage from the first full-cut line and the second full-cut line to the first inner half-cut induction line and the second inner half-cut induction line can be facilitated.

[0021] [7] The lid material further includes a front half-cut line cut into the lid body from the front surface of the lid material toward the back surface of the lid material. In the thickness direction of the lid material, the tip of the front half-cut line is located on the back surface side of the tip of the back half-cut line. The front half-cut line includes a first front half-cut main line extending linearly along the first outer peripheral portion between the first outer peripheral portion and the first inner half-cut main line, a second front half-cut main line extending linearly along the second outer peripheral portion between the second outer peripheral portion and the second inner half-cut main line, a first front half-cut induction line extending from the first outer peripheral portion side of the extension line of the first front half-cut main line to the first front half-cut main line, and a second front half-cut induction line extending from the second outer peripheral portion side of the extension line of the second front half-cut main line to the second front half-cut main line. The lid material according to any one of [1] to [6].

[0022] In this lid material, by providing a front half-cut line cut into the lid body from the front surface of the lid material toward the back surface of the lid material, when the gripping portion is pulled in the second direction, delamination of the lid body can progress from the front half-cut line. Then, in the thickness direction of the lid material, since the tip of the front half-cut line is located on the back surface side of the tip of the back half-cut line, the delamination of the lid body that has progressed from the front half-cut line can be stopped by the back half-cut line. Thereby, defective opening can be reduced.

[0023] Furthermore, by having the front half-cut line include the first front half-cut main line and the second front half-cut main line, as well as the first front half-cut guiding line and the second front half-cut guiding line, the breakage of the lid body can be made to progress from the first front half-cut guiding line and the second front half-cut guiding line to the first front half-cut main line and the second front half-cut main line. At this time, attempting to inhibit the breakage of the lid body along the first back half-cut guiding line and the second back half-cut guiding line results in the bonding force between the flange of the container and the lid body in the region between the back half-cut line and the front half-cut line in the third direction orthogonal to the second direction. And in this lid material, compared to the case where the first back half-cut guiding line and the second back half-cut guiding line are not formed in this way, the distance from the back half-cut line to the front half-cut line in the third direction orthogonal to the second direction becomes shorter. That is, the bonding force between the flange of the container and the lid body that inhibits the breakage of the lid body at the first back half-cut guiding line and the second back half-cut guiding line can be reduced. Thereby, even if only the surface of the lid body is thinly peeled off, the lid body is likely to break at the first back half-cut guiding line and the second back half-cut guiding line, so that defective opening can be reduced.

[0024] [8] The lid material according to [7], wherein the first front half-cut guiding line and the second front half-cut guiding line extend in a direction of separating from each other as they go in the second direction.

[0025] In this lid material, by having the first front half-cut guiding line and the second front half-cut guiding line extend in a direction of separating from each other as they go in the second direction, the breakage of the lid body can be smoothly made to progress from the first front half-cut guiding line and the second front half-cut guiding line toward the first front half-cut main line and the second front half-cut main line.

[0026] [9] The lid material according to [7] or [8], wherein the back half-cut line further has a back half-cut auxiliary line extending from the tip on the corner side of the first back half-cut main line to the tip on the corner side of the second back half-cut main line.

[0027] This lid material has a back half-cut auxiliary line that extends from the corner end of the first back half-cut main line to the corner end of the second back half-cut main line. This allows the progression of peeling to be stopped at the back half-cut auxiliary line, even if only the surface of the lid body peels off in a thin layer.

[0028]

[10] When a line passing through the point on the back half-cut auxiliary line where the distance to the gripping portion is smallest, and extending in a third direction perpendicular to the first direction, is defined as a virtual line, the point where the virtual line intersects the first back half-cut guide line is defined as the first reference point, the point where the virtual line intersects the first front half-cut main line or the first front half-cut guide line is defined as the second reference point, the point where the virtual line intersects the second back half-cut guide line is defined as the third reference point, and the point where the virtual line intersects the second front half-cut main line or the second front half-cut guide line is defined as the fourth reference point, the first distance from the first reference point to the second reference point and the second distance from the third reference point to the fourth reference point are 5 mm or less, the lid material as described in [9].

[0029] In this lid material, the first distance from the first reference point to the second reference point and the second distance from the third reference point to the fourth reference point are 5 mm or less, which reduces the bonding force between the container flange and the lid body that inhibits the lid body from breaking at the first and second back half-break guide lines. As a result, even if only the surface of the lid body peels off thinly, the lid body becomes more likely to break at the first and second back half-break guide lines, thus reducing opening failures.

[0030]

[11] The lid material is the lid material according to any one of [1] to

[10] , having a sealant layer and a paper substrate layer disposed on the surface side of the sealant layer.

[0031] This lid material has a sealant layer, which allows the lid material to be joined to the container flange by heat sealing. Furthermore, since the paper base material layer is placed on the surface side of the sealant layer, various designs can be easily applied to the surface of the lid material.

[0032]

[12] The lid material according to

[11] , wherein the sealant layer is made of polypropylene.

[0033] In this lid material, the heat resistance of the lid material can be improved because the sealant layer is made of polypropylene. Furthermore, when the sealant layer is made of polypropylene, the lid material becomes less likely to break, and because it has a first and second back half-cut guide line, opening failures can be reduced.

[0034] Furthermore, the lidded container according to the present invention is as follows:

[0035]

[13] A container with a lid, comprising: a container having a rectangular opening and a flange formed around the opening; and a lid material according to any one of [1] to

[12] above, which is joined to the flange and closes the opening.

[0036] In this container with a lid, one of the lid materials described above is joined to the flange of the container to seal the opening, thereby reducing the likelihood of opening the container improperly. [Effects of the Invention]

[0037] According to the present invention, the number of opening failures can be reduced. [Brief explanation of the drawing]

[0038] [Figure 1] This is a plan view showing a container with a lid according to an embodiment. [Figure 2] This is a cross-sectional view along the line II-II shown in Figure 1. [Figure 3] This is a plan view showing a cover material according to an embodiment. [Figure 4] This is a magnified plan view of a portion of the surface side of the lid material. [Figure 5] This is a magnified view of the bottom of the lid, showing a portion of the underside. [Figure 6] This is a magnified cross-sectional view of a portion of the lid material. [Figure 7]This is a plan view corresponding to Figure 4, used to explain the back half-cut line and the front half-cut line. [Figure 8] This is a plan view corresponding to Figure 4, used to explain the back half-cut line and the front half-cut line. [Figure 9] This is a cross-sectional view showing a container with a lid before it is opened. [Figure 10] This is a cross-sectional view showing a container with a lid in an opened state. [Figure 11] This is a plan view showing a container with a lid in an open state. [Figure 12] This is a plan view showing the lid material of the comparative example. [Figure 13] This is a cross-sectional view showing the lidded container of the comparative example before it was opened. [Figure 14] This is a cross-sectional view showing the lidded container of the comparative example in its opened state. [Figure 15] This is a plan view showing the lidded container of the comparative example in its opened state. [Figure 16] This table shows the evaluation results for Example 1 and Comparative Example 1. [Modes for carrying out the invention]

[0039] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.

[0040] Figure 1 is a front view showing a lidded container according to this embodiment. Figure 2 is a cross-sectional view taken along line II-II shown in Figure 1. As shown in Figures 1 and 2, the lidded container 1 according to this embodiment comprises a container 2 and a lid material 3.

[0041] Container 2 has a rectangular opening 21 and a flange 22 formed around the opening 21. A rectangular shape is a shape that can be considered substantially rectangular, and for example, a shape in which the four corners of a rectangle are rounded is also included in the rectangular shape. Container 2 is filled with contents 23, such as food. The contents 23 can be removed from the opening 21. The flange 22 is formed in a rectangular shape, similar to the opening 21.

[0042] Figure 3 is a plan view showing a lid material according to an embodiment. Figure 4 is a magnified plan view of a part of the surface side of the lid material. Figure 5 is a magnified bottom view of a part of the back side of the lid material. As shown in Figures 1 to 5, the lid material 3 is a sheet-like member that is joined to the flange 22 of the container 2 and closes the opening 21 of the container 2. The surface 3a of the lid material 3 is the surface that is exposed above the container 1 with a lid, and the back surface 3b of the lid material 3 is the surface that is joined to the flange 22 of the container 2.

[0043] Figure 6 is an enlarged cross-sectional view of a part of the lid material. As shown in Figure 6, the lid material 3 is a laminate in which a sealant layer 31 and a paper base material layer 32 are laminated together.

[0044] The sealant layer 31 forms the back surface 3b of the lid material 3 and is joined to the flange 22 of the container 2. The sealant layer 31 is joined to the flange 22 by, for example, heat sealing. The material of the sealant layer 31 is not particularly limited and can be, for example, polypropylene (PP), polyethylene (PE), etc. From the viewpoint of heat resistance, the sealant layer 31 is preferably made of polypropylene.

[0045] The paper substrate layer 32 is positioned on the surface 3a side of the sealant layer 31. The paper substrate layer 32 may or may not form a surface 3a. For example, another layer, such as a coating layer, may be positioned on the surface 3a side of the paper substrate layer 32, and this other layer may form the surface 3a. The paper substrate layer 32 may have a single-layer structure or a multi-layer structure. By making the paper substrate layer 32 a multi-layer structure, the paper substrate layer 32 can be easily given thickness and rigidity.

[0046] Furthermore, container 2 may be a laminate in which a sealant layer (not shown) and a paper substrate layer (not shown) are laminated, similar to lid material 3. In this case, the lidded container 1 may be constructed such that the sealant layer 31 of lid material 3 is heat-healed to the sealant layer of container 2.

[0047] As shown in Figures 1 to 6, the lid material 3 comprises a lid body 33, a gripping portion 34, a back half-cut line 35, and a front half-cut line 36. The lid body 33 and the gripping portion 34 are each laminates formed by laminating a sealant layer 31 and a paper base material layer 32.

[0048] The lid body 33 is the part that is joined to the flange 22 of the container 2 and closes the opening 21 of the container 2. The lid body 33 is formed in a rectangular shape in order to be joined to the flange 22 and close the opening 21. One of the four corners of the lid body 33 is called the corner portion 41. The lid body 33 has a first outer peripheral portion 42 and a second outer peripheral portion 43 that extend in a straight line on either side of the corner portion 41. The first outer peripheral portion 42 and the second outer peripheral portion 43 are two outer peripheral portions of the lid body 33 that are adjacent to each other on either side of the corner portion 41, among the four outer peripheral portions that extend in a straight line. The first outer peripheral portion 42 and the second outer peripheral portion 43 extend in directions that are perpendicular to each other, for example.

[0049] The gripping portion 34 is the part that is grasped when opening the lid body 33. The gripping portion 34 is located at the corner 41 of the lid body 33 and extends from the lid body 33 in a first direction D1. The first direction D1 can be, for example, a direction perpendicular to the first outer peripheral portion 42, a direction perpendicular to the second outer peripheral portion 43, a direction in which the angles between the first outer peripheral portion 42 and the second outer peripheral portion 43 are the same, or the diagonal direction of the lid body 33 passing through the corner 41. The gripping portion 34 is connected to the lid body 33 at its tip in a second direction D2, which is opposite to the first direction D1.

[0050] The gripping portion 34 has a first side portion 44 and a second side portion 45 that extend in a second direction D2 and are arranged in a third direction D3 perpendicular to the second direction D2. The first side portion 44 and the second side portion 45 form the edge of the gripping portion 34 in the third direction D3 and extend in the second direction D2. At least a portion of the first side portion 44 is formed by a first full cut line 46 cut from the surface 3a of the lid material 3 to the back surface 3b of the lid material 3. At least a portion of the second side portion 45 is formed by a second full cut line 47 cut from the surface 3a of the lid material 3 to the back surface 3b of the lid material 3. The first full cut line 46 and the second full cut line 47 extend from the edge of the lid body 33 in the first direction D1, which forms the boundary with the gripping portion 34, to the second direction D2.

[0051] As shown in Figure 6, the back half-cut line 35 is a half-cut line cut into the lid body 33 from the back surface 3b of the lid material 3 toward the front surface 3a of the lid material 3. The front half-cut line 36 is a half-cut line cut into the lid body 33 from the front surface 3a of the lid material 3 toward the back surface 3b of the lid material 3. Half-cut lines are also called half-cut lines, etc. In the thickness direction D4 of the lid material 3, the tip 36a of the front half-cut line 36 is located on the back surface 3b side than the tip 35a of the back half-cut line 35. Similarly, in the thickness direction D4, the tip 35a of the back half-cut line 35 is located on the front surface 3a side than the tip 36a of the front half-cut line 36. In the plan views of Figures 3 and 4, the front half-cut line 36 is shown as a solid line and the back half-cut line 35 is shown as a dashed line. In the bottom view of Figure 5, the back half-cut line 35 is shown as a solid line and the front half-cut line 36 is shown as a dashed line.

[0052] As shown in Figures 3 to 5, the back half cut line 35 includes a back half cut main line 51, a back half cut auxiliary line 52, a first back half cut guide line 53, and a second back half cut guide line 54.

[0053] The back half-cut main line 51 extends along the outer circumference of the lid body 33, excluding the corner portion 41 of the lid body 33. The back half-cut main line 51 has a first back half-cut main line 55 and a second back half-cut main line 56. The first back half-cut main line 55 extends linearly along the first outer peripheral portion 42. The second back half-cut main line 56 extends linearly along the second outer peripheral portion 43. The back half-cut main line 51 extends from the first back half-cut main line 55, around the corner opposite to the corner portion 41, to the second back half-cut main line 56.

[0054] The back half-cut auxiliary line 52 extends from the tip 55a on the corner 41 side of the first back half-cut main line 55 to the tip 56a on the corner 41 side of the second back half-cut main line 56. In other words, the back half-cut auxiliary line 52 is formed at the corner 41 between the first back half-cut main line 55 and the second back half-cut main line 56, where the back half-cut main line 51 is not formed. The shape of the back half-cut auxiliary line 52 is not particularly limited. For example, the back half-cut auxiliary line 52 may extend in a straight line or in a curved line. Also, the back half-cut auxiliary line 52 may be bent. In the drawing, the back half-cut auxiliary line 52 is formed in an arc shape that is convex in the first direction D1 and smoothly connected to the first back half-cut main line 55 and the second back half-cut main line 56.

[0055] Figure 7 is a plan view corresponding to Figure 4, illustrating the back half-cut line and the front half-cut line. As shown in Figure 7, the first back half-cut guide line 53 extends from the first outer peripheral area 42 side of the extension line EL1 of the first back half-cut main line 55 to the first back half-cut main line 55. The second back half-cut guide line 54 extends from the second outer peripheral area 43 side of the extension line EL2 of the second back half-cut main line 56 to the second back half-cut main line 56. The first back half-cut guide line 53 and the second back half-cut guide line 54 extend in directions that move away from each other as we move towards the second direction D2.

[0056] For example, the first back half-cut guide line 53 extends from the tip 46a of the first full cut line 46 in the second direction D2, or from the vicinity of the tip 46a of the first full cut line 46, to the first back half-cut main line 55. The vicinity of the tip 46a of the first full cut line 46 refers to, for example, the area of ​​a circle with a radius of 7.5 mm centered on the tip 46a. The second back half-cut guide line 54 extends from, for example, the tip 47a of the second full cut line 47 in the second direction D2, or from the vicinity of the tip 47a of the second full cut line 47, to the second back half-cut main line 56. The vicinity of the tip 47a of the second full cut line 47 refers to, for example, the area of ​​a circle with a radius of 9.5 mm centered on the tip 47a. When forming the back half-cut line 35, the front half-cut line 36, the first full cut line 46, and the second full cut line 47 simultaneously, it is difficult to continuously operate the blades that form them without interruption. Therefore, from the viewpoint of ease of manufacturing, it is preferable that the first half-cut guide line 53 extends from the vicinity of the tip 46a of the first full-cut line 46 to the first half-cut main line 55 so that the first full-cut line 46 and the first half-cut guide line 53 are spaced apart. Also, it is preferable that the second half-cut guide line 54 extends from the vicinity of the tip 47a of the second full-cut line 47 to the second half-cut main line 56 so that the second half-cut guide line 54 and the second full-cut line 47 are spaced apart.

[0057] Furthermore, the first half-cut guide wire 53 does not need to extend from the tip 46a of the first fully cut wire 46 or in the vicinity of the tip 46a of the first fully cut wire 46, as long as it extends from the first outer peripheral area 42 side of the extension line EL1 of the first half-cut main wire 55. Also, the second half-cut guide wire 54 does not need to extend from the tip 47a of the second fully cut wire 47 or in the vicinity of the tip 47a of the second fully cut wire 47, as long as it extends from the second outer peripheral area 43 side of the extension line EL2 of the second half-cut main wire 56.

[0058] The shapes of the first back half-cut guide line 53 and the second back half-cut guide line 54 are not particularly limited. For example, the first back half-cut guide line 53 and the second back half-cut guide line 54 may extend in a straight line or in a curved line. Also, the first back half-cut guide line 53 and the second back half-cut guide line 54 may be bent. In the drawing, the first back half-cut guide line 53 extends in an arc from the vicinity of the tip 46a of the first full cut line 46 to the tip 55a of the first back half-cut main line 55. Also, the second back half-cut guide line 54 extends in an arc from the vicinity of the tip 47a of the second full cut line 47 to the tip 56a of the second back half-cut main line 56.

[0059] As shown in Figures 3 to 5, the surface half-cut line 36 has a surface half-cut main line 61, a first surface half-cut guide line 63, and a second surface half-cut guide line 64.

[0060] The front half-cut main line 61 extends along the outer circumference of the lid body 33, excluding the corners 41 of the lid body 33. The front half-cut main line 61 has a first front half-cut main line 65 and a second front half-cut main line 66. The first front half-cut main line 65 extends linearly along the first outer peripheral portion 42 between the first outer peripheral portion 42 and the first back half-cut main line 55. The second front half-cut main line 66 extends linearly along the second outer peripheral portion 43 between the second outer peripheral portion 43 and the second back half-cut main line 56. The front half-cut main line 61 extends from the first front half-cut main line 65, around the corner opposite to the corner 41, to the second front half-cut main line 66.

[0061] As shown in Figure 7, the first half-cut guide wire 63 extends from the first outer peripheral area 42 side to the first half-cut main line 65, beyond the extension line EL3 of the first half-cut main line 65. The second half-cut guide wire 64 extends from the second outer peripheral area 43 side to the second half-cut main line 66, beyond the extension line EL4 of the second half-cut main line 66. Furthermore, the first half-cut guide wire 63 and the second half-cut guide wire 64 extend in directions that move away from each other as we move towards the second direction D2.

[0062] For example, the first half-cut guide wire 63 extends from the tip 46a of the first full-cut wire 46, or near the tip 46a of the first full-cut wire 46, to the first half-cut main wire 65. Similarly, the second half-cut guide wire 64 extends from the tip 47a of the second full-cut wire 47, or near the tip 47a of the second full-cut wire 47, to the second half-cut main wire 66. As described above, from the viewpoint of ease of manufacture, it is preferable that the first half-cut guide wire 63 extends from the vicinity of the tip 46a of the first full-cut wire 46 to the first half-cut main wire 65 so that the first full-cut wire 46 and the first half-cut guide wire 63 are spaced apart. It is also preferable that the second half-cut guide wire 64 extends from the vicinity of the tip 47a of the second full-cut wire 47 to the second half-cut main wire 66 so that the second half-cut guide wire 64 and the second full-cut wire 47 are spaced apart.

[0063] Furthermore, the first half-cut guide wire 63 does not need to extend from the tip 46a of the first fully cut wire 46 or in the vicinity of the tip 46a of the first fully cut wire 46, as long as it extends from the first outer peripheral area 42 side of the extension line EL3 of the first half-cut main wire 65. Also, the second half-cut guide wire 64 does not need to extend from the tip 47a of the second fully cut wire 47 or in the vicinity of the tip 47a of the second fully cut wire 47, as long as it extends from the second outer peripheral area 43 side of the extension line EL4 of the second half-cut main wire 66.

[0064] The shapes of the first half-cut guide line 63 and the second half-cut guide line 64 are not particularly limited. For example, the first half-cut guide line 63 and the second half-cut guide line 64 may extend in a straight line or in a curved line. Also, the first half-cut guide line 63 and the second half-cut guide line 64 may be bent. In the drawing, the first half-cut guide line 63 extends in a straight line from the vicinity of the tip 46a of the first full cut line 46 to the tip 65a on the corner 41 side of the first half-cut main line 65. Also, the second half-cut guide line 64 extends in a straight line from the vicinity of the tip 47a of the second full cut line 47 to the tip 66a on the corner 41 side of the second half-cut main line 66.

[0065] Figure 8 is a plan view corresponding to Figure 4, illustrating the back half-cut line and the front half-cut line. As shown in Figure 8, point P is the point on the back half-cut auxiliary line 52 where the distance to the gripping part 34 is smallest. The line passing through point P and extending in the third direction D3 is defined as the virtual line VL. The point where the virtual line VL intersects with the first back half-cut guide line 53 is defined as the first reference point P1. The point where the virtual line VL intersects with the first front half-cut main line 65 or the first front half-cut guide line 63 is defined as the second reference point P2. The point where the virtual line VL intersects with the second back half-cut guide line 54 is defined as the third reference point P3. The point where the virtual line VL intersects with the second front half-cut main line 66 or the second front half-cut guide line 64 is defined as the fourth reference point P4. In these cases, the first distance L1 from the first reference point P1 to the second reference point P2 and the second distance L2 from the third reference point P3 to the fourth reference point P4 are preferably 5 mm or less, and more preferably 3.5 mm or less. Furthermore, the first distance L1 and the second distance L2 are preferably 1 mm or more, and more preferably 2 mm or more, and more preferably 2.5 mm or more, from the viewpoint of suppressing the opening of the lid material 3 due to the impact of dropping the container 1 with a lid. The first distance L1 and the second distance L2 may be the same or different.

[0066] As shown in Figures 1 and 2, in the container with a lid 1, the lid material 3 is joined to the flange 22 of the container 2 such that the front half-cut line 36 is positioned on the flange 22 and the back half-cut main line 51 is positioned inside the flange 22 (towards the opening 21).

[0067] Now, with reference to Figure 12, the lid material of the comparative example will be described. Figure 12 is a plan view showing the lid material of the comparative example. As shown in Figure 12, the lid material 103 of the comparative example is basically the same as the lid material 3 of this embodiment, but differs from the lid material 3 of this embodiment only in the shape of the first back half-cut guide line and the second back half-cut guide line. The back half-cut line 135 formed on the lid body 133 of the lid material 103 of the comparative example has a back half-cut main line 51, a back half-cut auxiliary line 52, a first back half-cut guide line 153, and a second back half-cut guide line 154.

[0068] The first back half-cut guide line 153 extends in the second direction D2 from the vicinity of the tip 46a of the first full-cut line 46 to the back half-cut auxiliary line 52, so that the first side edge 44 of the gripping portion 34 is extended in the second direction D2. Similarly, the second back half-cut guide line 154 extends in the second direction D2 from the vicinity of the tip 47a of the second full-cut line 47 to the back half-cut auxiliary line 52, so that the second side edge 45 of the gripping portion 34 is extended in the second direction D2. Therefore, the first back half-cut guide line 153 and the second back half-cut guide line 154 do not extend in directions that move away from each other as they move toward the second direction D2, but rather extend in directions that are parallel to each other.

[0069] In the comparative example lid material 103 configured in this way, the distance from the back half-cut line 135 to the first outer peripheral portion 42 and the second outer peripheral portion 43 in the third direction D3, and the distance from the back half-cut line 135 to the front half-cut line 36 in the third direction D3 are long. In other words, the bonding force between the flange 22 of the container 2 and the lid body 133 is large, which prevents the lid body 133 from breaking at the first back half-cut guide line 153 and the second back half-cut guide line 154.

[0070] Therefore, as shown in Figure 13, in a lidded container 101 in which the lid material 103 is joined to the flange 22 of the container 2, when the gripping portion 34 is pulled in the second direction D2 to open the lid body 133, if only the surface 103a of the lid body 133 is thinly peeled off due to delamination within the paper substrate layer 32, the progress of this peeling becomes difficult to stop at the back half-cut auxiliary line 52 and the back half-cut main line 51. Figure 13 is a cross-sectional view showing the state of the comparative example lidded container before opening. As a result, as shown in Figures 14 and 15, the opening 21 of the container 2 is likely to be covered by the back surface 3b of the lid body 133, resulting in an opening failure. Figure 14 is a cross-sectional view showing the state of the comparative example lidded container during opening. Figure 15 is a plan view showing the state of the comparative example lidded container during opening. In Figure 15, the peeled surface 103c of the delaminated lid material 103 is shown with fine dot hatching. Although Figure 15 shows the lid material 103 appearing to break near the back half-cut guideline 52, this breakage occurs because the delamination of the lid body 133 extends beyond the back half-cut guideline 52, and the tensile force causing the delamination of the lid body 133 tears the area near the back half-cut guideline 52. In other words, the lid body 133 was not opened from the back half-cut guideline 52.

[0071] In contrast, in the lid material 3 of this embodiment, the first back half-cut guide line 53 and the second back half-cut guide line 54 extend in a direction that moves away from each other as we move toward the second direction D2. Therefore, compared to the lid material 3 of the comparative example, the distance from the back half-cut line 35 to the first outer peripheral portion 42 and the second outer peripheral portion 43 in the third direction D3, and the distance from the back half-cut line 35 to the front half-cut line 36 in the third direction D3 are longer. In other words, the bonding force between the flange 22 of the container 2 and the lid body 33 that prevents the lid body 33 from breaking at the first back half-cut guide line 53 and the second back half-cut guide line 54 is reduced.

[0072] Therefore, as shown in Figure 9, in a lidded container 1 in which the lid material 3 is joined to the flange 22 of the container 2, when the gripping part 34 is pulled in the second direction D2 to open the lid body 33, even if only the surface 3a of the lid body 33 is thinly peeled off due to interlayer delamination within the paper substrate layer 32, the progress of this peeling is more likely to stop at the back half-cut auxiliary line 52 and the back half-cut main line 51. Figure 9 is a cross-sectional view showing the state of the lidded container before opening. As a result, as shown in Figures 10 and 11, the lid body 33 is more easily opened from the back half-cut auxiliary line 52, the first back half-cut main line 55, and the second back half-cut main line 56. Figure 10 is a cross-sectional view showing the state of the lidded container during opening. Figure 11 is a plan view showing the state of the lidded container during opening. In Figure 11, the peeled surface 3c of the delaminated lid material 3 is shown with fine dot hatching.

[0073] As described above, in the lid material 3 according to this embodiment, when the gripping portion 34 is pulled in the second direction D2 to open the lid body 33, the lid body 33 is pulled by the gripping portion 34 and breaks (tears) in the second direction D2. The back half-cut line 35 has a first back half-cut guide line 53 that extends from the first outer peripheral portion 42 side of the extension line EL1 of the first back half-cut main line 55 to the first back half-cut main line 55, and a second back half-cut guide line 54 that extends from the second outer peripheral portion 43 side of the extension line EL2 of the second back half-cut main line 56 to the second back half-cut main line 56, and the first back half-cut guide line 53 and the second back half-cut guide line 54 extend in directions that move away from each other as they move toward the second direction D2. Therefore, compared to the case where the first back half-cut guide line 53 and the second back half-cut guide line 54 are not formed in this manner, the distance from the back half-cut line 35 to the first outer peripheral portion 42 and the second outer peripheral portion 43 in the third direction D3 is shortened. In other words, the bonding force between the flange 22 of the container 2 and the lid body 33 that inhibits the lid body 33 from breaking at the first back half-cut guide line 53 and the second back half-cut guide line 54 can be reduced. As a result, even if only the surface 3a of the lid body 33 is thinly peeled off, the lid body 33 becomes more likely to break at the first back half-cut guide line 53 and the second back half-cut guide line 54, and the rupture of the lid body 33 progresses more easily from the first back half-cut guide line 53 and the second back half-cut guide line 54 to the first back half-cut main line 55 and the second back half-cut main line 56, thus reducing opening failures.

[0074] Furthermore, in this lid material 3, the first back half-break guide wire 53 and the second back half-break guide wire 54 extend in a straight line, which allows the first back half-break guide wire 53 and the second back half-break guide wire 54 to be shortened, making it easier to guide the breakage of the lid body 33 to the first back half-break guide wire 53 and the second back half-break guide wire 54.

[0075] Furthermore, in this lid material 3, the first back half-cut guide wire 53 and the second back half-cut guide wire 54 extend in a curved shape, which allows for a smooth transition of the lid body 33 from the gripping portion 34 to the first back half-cut guide wire 53 and the second back half-cut guide wire 54, and from the first back half-cut guide wire 53 and the second back half-cut guide wire 54 to the first back half-cut main wire 55 and the second back half-cut main wire 56.

[0076] Furthermore, in this lid material 3, the first back half-cut guide wire 53 and the second back half-cut guide wire 54 are bent, which increases the degree of freedom in the shape of the first back half-cut guide wire 53 and the second back half-cut guide wire 54.

[0077] Furthermore, in this lid material 3, at least a portion of the first side portion 44 and the second side portion 45, which extend in the second direction D2 and are arranged in the third direction D3, are formed by first and second full cut lines 46 and 47, which are cut from the surface 3a to the back surface 3b of the lid material 3. This makes it easier for the lid body 33 to break in the second direction D2 when the gripping portion 34 is pulled in the second direction D2. This allows for appropriate control of the breaking direction of the lid body 33.

[0078] Furthermore, in this lid material 3, the first back half-cut guide line 53 and the second back half-cut guide line 54 extend from the vicinity of the tip 46a of the first full cut line 46 in the second direction D2 and the vicinity of the tip 47a of the second full cut line 47 in the second direction D2, so that the first full cut line 46 and the second full cut line 47 and the first back half-cut guide line 53 and the second back half-cut guide line 54 can be formed simultaneously, and the fracture can be easily propagated from the first full cut line 46 and the second full cut line 47 to the first back half-cut guide line 53 and the second back half-cut guide line 54 into the lid body 33.

[0079] Furthermore, this lid material 3 is provided with a front half cut line 36 cut into the lid body 33 from the front surface 3a toward the back surface 3b of the lid material 3. When the gripping portion 34 is pulled in the second direction D2, the interlayer delamination of the lid body 33 can be advanced from the front half cut line 36. In the thickness direction D4 of the lid material 3, the tip 36a of the front half cut line 36 is located on the back surface 3b side than the tip 35a of the back half cut line 35. As a result, the interlayer delamination of the lid body 33 that has progressed from the front half cut line 36 can be stopped at the back half cut line 35. This reduces the likelihood of opening failures.

[0080] Furthermore, the fact that the surface half-cut line 36 has a first surface half-cut main line 65 and a second surface half-cut main line 66, and a first surface half-cut guide line 63 and a second surface half-cut guide line 64, allows the fracture of the lid body 33 to progress from the first surface half-cut guide line 63 and the second surface half-cut guide line 64 to the first surface half-cut main line 65 and the second surface half-cut main line 66. At this time, the force that tries to prevent the fracture of the lid body 33 along the first back half-cut guide line 53 and the second back half-cut guide line 54 is the bonding force between the flange 22 of the container 2 and the lid body 33 in the region between the back half-cut line 35 and the surface half-cut line 36 in the third direction D3. And in this lid material 3, the distance from the back half-cut line 35 to the surface half-cut line 36 in the third direction D3 is shorter compared to when the first back half-cut guide line 53 and the second back half-cut guide line 54 are not formed in this way. In other words, the bonding force between the flange 22 of the container 2 and the lid body 33, which inhibits the rupture of the lid body 33 at the first back half-break guide wire 53 and the second back half-break guide wire 54, can be reduced. As a result, even if only the surface 3a of the lid body 33 is thinly peeled off, the lid body 33 becomes more likely to rupture at the first back half-break guide wire 53 and the second back half-break guide wire 54, thereby reducing opening failures.

[0081] Furthermore, in this lid material 3, the first surface half-cut guide line 63 and the second surface half-cut guide line 64 extend in directions that move away from each other as they move toward the second direction D2, thereby allowing the fracture of the lid body 33 to proceed smoothly from the first surface half-cut guide line 63 and the second surface half-cut guide line 64 toward the first surface half-cut main line 65 and the second surface half-cut main line 66.

[0082] Furthermore, this lid material 3 has a back half-cut auxiliary line 52 that extends from the tip 55a on the corner 41 side of the first back half-cut main line 55 to the tip 56a on the corner 41 side of the second back half-cut main line 56. This allows the progression of peeling to be stopped at the back half-cut auxiliary line 52, even if only the surface 3a of the lid body 33 is thinly peeled off.

[0083] Furthermore, in this lid material 3, the first distance L1 from the first reference point P1 to the second reference point P2 and the second distance L2 from the third reference point P3 to the fourth reference point P4 are 5 mm or less, or 3.5 mm or less, respectively, which reduces the bonding force between the flange 22 of the container 2 and the lid body 33, preventing the lid body 33 from breaking at the first back half-break guide line 53 and the second back half-break guide line 54. As a result, even if only the surface 3a of the lid body 33 is thinly peeled off, the lid body 33 becomes more susceptible to breaking at the first back half-break guide line 53 and the second back half-break guide line 54, thus reducing opening failures. On the other hand, the first distance L1 and the second distance L2 are 2 mm or more, or 2.5 mm or more, which suppresses the lid material 3 from being opened by the impact of dropping the container 1 with the lid.

[0084] Furthermore, because this lid material 3 has a sealant layer 31, the lid material 3 can be joined to the flange 22 of the container 2 by heat sealing. And, since the paper base material layer 32 is arranged on the surface 3a side of the sealant layer 31, various designs and the like can be easily applied to the surface 3a side of the lid material 3.

[0085] Furthermore, since the sealant layer 31 of this lid material 3 is made of polypropylene, the heat resistance of the lid material 3 can be improved. Although the lid material 3 is less likely to break when the sealant layer 31 is made of polypropylene, the presence of a first back half-cut guide wire 53 and a second back half-cut guide wire 54 reduces opening failures.

[0086] In the container 1 with a lid according to this embodiment, the lid material 3 described above is joined to the flange 22 of the container 2 to seal the opening 21 of the container 2, thereby reducing the likelihood of opening the container improperly.

[0087] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and may be modified or applied to other things without changing the gist of each claim.

[0088] For example, in the above embodiment, it was described that the lid material has a half-cut line on the back and a half-cut line on the front, but the lid material may not have a half-cut line on the front. Also, in the above embodiment, it was described that the lid material has a first full-cut line and a second full-cut line, but the lid material may not have a half-cut line on the front. Even in these cases, having a first half-cut guide line and a second half-cut guide line on the back can reduce opening failures. [Examples]

[0089] Next, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0090] (Example 1) Basis weight: 310 g / m² 2 An anchor coating agent (Arrowbase DC-5010; manufactured by Unitika Ltd.) was applied to the uncoated side of a cup base paper (Mitsubishi Water-Resistant; manufactured by Mitsubishi Paper Mills Ltd.), and then polypropylene resin (FL02T; manufactured by Nippon Polypropylene Co., Ltd.) was laminated using extrude lamination to produce a roll of paper. Paper lid material having the structure shown in Figures 3 to 5 was punched out from the prepared roll using a die-cutting die. The punched-out lid material had a first distance L1 of 4.28 mm from the first reference point P1 to the second reference point P2, and a second distance L2 of 4.13 mm from the third reference point P3 to the fourth reference point P4 (see Figure 8). The basis weight was 320 g / m². 2Fried rice was filled into paper trays constructed by laminating 30 μm polypropylene resin (FL02T; manufactured by Nippon Polypropylene Co., Ltd.) onto cup paper base (H2 cup; manufactured by Hokuetsu Corporation). 50 lidded containers were created by heat-sealing lid material, which was punched out from the paper trays after the contents were filled. An opening test was then conducted on these 50 lidded containers. In the opening test, the lidded containers were stored in a freezer for 24 hours, then heated in a microwave oven at 500W for 5 minutes. Afterward, the gripping portion was pulled in a second direction to open the lid. A rating was given if the lid opened from the back half-cut line, and a rating was given if the lid did not open from the back half-cut line. The evaluation results are shown in Figure 16.

[0091] (Comparative Example 1) A raw material was prepared in the same manner as in Example 1, and a paper lid material having the structure shown in Figure 12 was punched out from the prepared raw material using a die-cutting machine. The punched-out lid material had a first distance L1 of 5.25 mm from the first reference point P1 to the second reference point P2, and a second distance L2 of 6.19 mm from the third reference point P3 to the fourth reference point P4. In addition, a paper tray was prepared in the same manner as in Example 1, and 50 lidded containers were produced by filling the tray with contents and heat-sealing the punched-out lid material onto the paper tray. Then, the same opening test as in Example 1 was performed on the 50 lidded containers produced. The evaluation results are shown in Figure 16.

[0092] (evaluation) As shown in Figure 16, Comparative Example 1 had eight instances of a B rating, while Example 1 had only two. In Comparative Example 1, the first back half-cut guide line 153 and the second back half-cut guide line 154 did not extend in a direction that separated them from each other as they moved toward the second direction D2, and the first distance L1 from the first reference point P1 to the second reference point P2 and the second distance L2 from the third reference point P3 to the fourth reference point P4 were greater than 5 mm. As a result, the bonding force between the flange 22 of the container 2 and the lid body 133, which inhibits the rupture of the lid body 133 at the first back half-cut guide line 153 and the second back half-cut guide line 154, was increased, and it is presumed that in many cases the lid material 103 was not opened from the back half-cut line 135. On the other hand, in Example 1, the first back half-cut guide line 53 and the second back half-cut guide line 54 extend in directions that move away from each other as they move toward the second direction D2, and the first distance L1 from the first reference point P1 to the second reference point P2 and the second distance L2 from the third reference point P3 to the fourth reference point P4 are 5 mm or less. As a result, the bonding force between the flange 22 of the container 2 and the lid body 33 that prevents the lid body 33 from breaking at the first back half-cut guide line 53 and the second back half-cut guide line 54 is reduced, and it is presumed that the number of cases in which the lid material 3 is not opened from the back half-cut line 35 is reduced. [Explanation of symbols]

[0093] 1...Container with lid, 2...Container, 3...Lid material, 3a...Front surface, 3b...Back surface, 3c...Release surface, 21...Opening, 22...Flange, 23...Contents, 31...Sealant layer, 32...Paper substrate layer, 33...Lid body, 34...Grip part, 35...Back half-cut line, 35a...Tip, 36...Front half-cut line, 36a...Tip, 41...Corner, 42...First outer peripheral part, 43...Second outer peripheral part, 44...First side edge, 45...Second side edge, 46...First full cut line, 46a...Tip, 47...Second full cut line, 47a...Tip, 51...Back half-cut main line, 52...Back half-cut auxiliary line, 53...First back half-cut guide line, 54...Second back half-cut guide line, 55...First back half-cut main line, 55a...Tip, 56...Second back half-cut main line Line, 56a...tip, 61...front half-cut main line, 63...first front half-cut guide line, 64...second front half-cut guide line, 65...first front half-cut main line, 66...second front half-cut main line, 101...container with lid, 103...lid material, 103a...surface, 103c...peeling surface, 133...lid body, 135...back half-cut line, 153...first back half-cut guide line, 154...second back half-cut guide line, D1...first direction, D2...second direction, D3...third direction, D4...thickness direction, EL1...extension line, EL2...extension line, EL3...extension line, EL4...extension line, L1...first distance, L2...second distance, P...point, P1...first reference point, P2...second reference point, P3...third reference point, P4...fourth reference point, VL...virtual straight line.

Claims

1. A sheet-like lid material that is joined to the flange of a container having a rectangular opening and a flange formed around the opening, and that seals the opening, A rectangular lid body joined to the flange and closing the opening, A gripping portion located at the corner of the lid body and extending in a first direction from the lid body, A back half cut line is cut into the lid body from the back surface of the lid material toward the front surface of the lid material, The lid material comprises a front half cut line cut into the lid body from the front surface toward the back surface of the lid material, The lid body has a first outer peripheral portion and a second outer peripheral portion that extend in a straight line across the corner portion, The aforementioned back half cut line is, The first back half-cut main line extends in a straight line along the first outer peripheral portion, A second back half-cut main line extends in a straight line along the second outer peripheral portion, A first back half-cut guide line extends from the first outer peripheral side to the first back half-cut main line, which is further than the extension of the first back half-cut main line, It has a second back half-cut guide line that extends from the second outer peripheral side to the second back half-cut main line, which is further than the extension of the second back half-cut main line, The first half-cut guide wire and the second half-cut guide wire extend in directions that move away from each other as they move toward the second direction, which is opposite to the first direction. In the thickness direction of the lid material, the tip of the front half cut line is located on the back side than the tip of the back half cut line. The aforementioned table half-cut line is, Between the first outer peripheral portion and the first back half-cut main line, the first front half-cut main line extends in a straight line along the first outer peripheral portion, Between the second outer peripheral portion and the second back half-cut main line, the second front half-cut main line extends in a straight line along the second outer peripheral portion, A first half-cut guide line extends from the first outer peripheral side to the first half-cut main line, which is further than the extension of the first half-cut main line, The system includes a second half-cut guide line that extends from the second outer peripheral side to the second half-cut main line, which is further than the extension of the second half-cut main line, Lid material.

2. The first back half-cut guide wire and the second back half-cut guide wire extend in a straight line. The lid material according to claim 1.

3. The first and second back half-cut guide wires extend in a curved shape. The lid material according to claim 1.

4. The first half-cut guide wire and the second half-cut guide wire are bent. The lid material according to claim 1.

5. The gripping portion has a first side portion and a second side portion that extend in the second direction and are arranged in a third direction perpendicular to the second direction, At least a portion of the first side edge is formed by a first full cut line cut from the surface of the lid material to the back surface of the lid material, At least a portion of the second side edge is formed by a second full cut line cut from the surface of the lid material to the back surface of the lid material. The lid material according to claim 1.

6. The first back half-cut guide wire extends from the vicinity of the tip of the first full cut wire in the second direction to the first back half-cut main wire. The second back half-cut guide wire extends from the vicinity of the tip of the second full cut wire in the second direction to the second back half-cut main wire. The lid material according to claim 5.

7. The first half-cut guide line and the second half-cut guide line extend in directions that move away from each other as they move toward the second direction. The lid material according to claim 1.

8. The aforementioned back half cut line further includes a back half cut auxiliary line extending from the corner end of the first back half cut main line to the corner end of the second back half cut main line. The lid material according to claim 1.

9. A hypothetical straight line is defined as a line that passes through the point on the aforementioned back half-cut auxiliary line where the distance to the gripping portion is smallest, and extends in a third direction perpendicular to the first direction. The point where the aforementioned virtual line and the first half-cut guide line intersect is defined as the first reference point. The point where the aforementioned virtual line intersects with the first half-cut main line or the first half-cut guide line is designated as the second reference point. The point where the aforementioned virtual line and the aforementioned second half-cut guide line intersect is designated as the third reference point. When the point where the aforementioned virtual line intersects with the aforementioned second table half-cut main line or the aforementioned second table half-cut guide line is designated as the fourth reference point, The first distance from the first reference point to the second reference point and the second distance from the third reference point to the fourth reference point are 5 mm or less. The lid material according to claim 8.

10. The lid material comprises a sealant layer and a paper substrate layer disposed on the surface side of the sealant layer. The lid material according to claim 1.

11. The sealant layer is made of polypropylene. The lid material according to claim 10.

12. A container having a rectangular opening and a flange formed around the opening, A cover material according to any one of claims 1 to 11, which is joined to the flange and closes the opening, A container with a lid.

Images