Zipper tape and container with zipper tape

Abstract

To provide a container with zipper tape capable of discharging stable steam at the time of heating a content.SOLUTION: Provided is a zipper tape including a first member and a second member. The first member includes in a cross-sectional shape: a first engagement part; a first flange part extending from the first engagement part to a first side of the zipper tape in a width direction; and a second flange part extending from the first engagement part to a second side in the width direction. The second member includes in a cross-sectional shape: a second engagement part engageable with the first engagement part; a third flange part extending from the second engagement part to the first side; and a fourth flange part extending from the second engagement part to the second side. At least any of the first flange part, the second flange part, the third flange part, and the fourth flange part has a portion having a thickness equal to or greater than 170 μm.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a zipper tape and a container with the zipper tape. [Background technology]

[0002] Pouch-shaped containers that can store food and the like and that can be used for cooking have been widely used. Patent Document 1 describes a configuration of such a pouch-shaped container that is provided with a water vapor release mechanism that prevents the pouch from bursting due to excessive expansion during cooking. The pouch-shaped container described in Patent Document 1 has a water vapor release mechanism in which a weakened seal portion is formed, the periphery of which is weakened and sealed to the pouch body so as to cover a circular cutout provided near the side seal portion of the pouch body. When the internal pressure of this water vapor release mechanism increases to a certain level due to steam generated during cooking, the weakened seal portion peels off, allowing water vapor to be released through the cutout, preventing the pouch body from bursting due to excessive expansion.

[0003] However, when weakened seals are used in the water vapor release mechanism as described in Patent Document 1, the internal pressure at which water vapor begins to be released varies depending on the bonding strength of the weakened seals. Furthermore, if the bonding strength of the weakened seals is not uniform, partial peeling of the weakened seals may result in a reduced amount of water vapor being released. Patent Document 2 therefore describes a technology that easily forms a steam outlet that can stably release water vapor by providing a low-bonding strength layer in a portion of the zipper tape bonded to the film that constitutes the bag body, bonding the low-bonding strength layer to the film in a portion of the zipper tape in the longitudinal direction, and bonding the non-low-bonding strength layer to the film in other portions. Patent Document 3 describes a technology that forms such a steam outlet in a section that is eccentrically positioned relative to the longitudinal center of the zipper tape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-46644 [Patent Document 2] International Publication No. 2017 / 119449 [Patent Document 3] Patent Publication No. 2021-024602 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a zipper tape is attached to a bag-shaped container for cooking as described in Patent Document 2, the container may expand due to steam pressure inside the container during cooking, applying a large force to the irregular cross-section of the zipper tape. If this force causes the zipper tape to come loose before a steam outlet is formed, the zipper tape may already be open when the steam pressure drops after cooking is completed, potentially damaging the user's sense of security. Furthermore, Patent Document 3 solved the problem of the zipper tape opening by making the steam outlet eccentric, but there was a risk that steam would not be released stably due to bending of the container.

[0006] Therefore, an object of the present invention is to provide a zipper tape and a container with a zipper tape that can stably release steam when the contents are heated in a container with the zipper tape. [Means for solving the problem]

[0007] [1] A zipper tape comprising a first member and a second member, wherein the first member includes, in a cross-sectional shape, a first engagement portion, a first flange portion extending from the first engagement portion to a first side in a width direction of the zipper tape, and a second flange portion extending from the first engagement portion to a second side in the width direction; and the second member includes, in a cross-sectional shape, a second engagement portion engageable with the first engagement portion, a third flange portion extending from the second engagement portion to the first side, and a fourth flange portion extending from the second engagement portion to the second side; and at least one of the first flange portion, the second flange portion, the third flange portion, and the fourth flange portion has a portion with a thickness of 170 μm or more. [2] The zipper tape according to [1], wherein each of the first flange portion, the second flange portion, the third flange portion, and the fourth flange portion has a portion having a thickness of 170 μm or more. [3] The zipper tape according to [1] or [2], wherein the second member includes an extension portion formed on the second side following the fourth flange portion, and an easy-peel layer is formed on the surface of the extension portion facing the second engagement portion. [4] The zipper tape according to [3], wherein the thickness of the extension portion is greater than that of each of the first flange portion, the second flange portion, the third flange portion, and the fourth flange portion. [5] The zipper tape according to any one of [1] to [4], wherein a rib is formed on at least one of the first flange portion, the second flange portion, the third flange portion, and the fourth flange portion, and the thickness of the first flange portion, the second flange portion, the third flange portion, or the fourth flange portion including the rib is 170 μm or more. [6] The zipper tape according to any one of [1] to [5], wherein the thickness of the first flange portion, the second flange portion, the third flange portion, or the fourth flange portion in the cross-sectional shape is 170 μm or more in a section that is 10% or more of the length of the first flange portion, the second flange portion, the third flange portion, or the fourth flange portion. [7] The zipper tape according to any one of [1] to [6], wherein the maximum value of bending stress in the length-thickness plane of at least one of the first member and the second member is 6.5 N or more. [8] The zipper tape according to any one of [1] to [7], wherein, when the first engagement portion and the second engagement portion are engaged with each other, the maximum value of the bending stress in the length-thickness plane of the entire zipper tape is 12 N or more. [9] The zipper tape according to any one of [1] to [8], wherein when the first engagement portion and the second engagement portion are engaged with each other, the thickness of the entire zipper tape at the first engagement portion and the second engagement portion is 1.30 mm or more.

[10] The zipper tape according to any one of [1] to [9], wherein, when the first engagement portion and the second engagement portion are engaged with each other, the ratio of the overall thickness of the zipper tape at the first engagement portion and the second engagement portion to the larger of the total thickness of the first flange portion and the third flange portion or the total thickness of the second flange portion and the fourth flange portion is 0.11 or more and 2 or less.

[11] A container with zipper tape, comprising the zipper tape according to any one of [1] to

[10] . [Effects of the Invention]

[0008] According to the above configuration, the flange portion of the zipper tape is formed thicker, thereby improving rigidity, thereby effectively preventing the engagement portion from opening or the zipper tape from bending when the contents of a container to which the zipper tape is attached are heated, allowing steam to be released stably. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view of a container with a zipper tape according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 1 is a diagram showing the thickness dimension of a zipper tape according to an embodiment of the present invention. [Figure 4] 10A and 10B are diagrams showing an example in which ribs are formed on a zipper tape. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0011] 1 is a plan view of a container with zipper tape according to one embodiment of the present invention. In a container with zipper tape 100, a zipper tape 120 is joined to a container body formed of a film 110.

[0012] The film 110 is formed, for example, of a single-layer or multi-layer thermoplastic resin film. The thermoplastic resin may be, specifically, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or polypropylene (PP). PP may be homopolypropylene (HPP), random polypropylene (RPP), or block polypropylene (BPP). When the film 110 is formed of a multi-layer film, the surface substrate may be biaxially oriented polypropylene (OPP), biaxially oriented polyethylene terephthalate (OPET), or biaxially oriented nylon (ONy). The film constituting the film 110 may also include a layer of a metal material such as aluminum or a layer of an inorganic material. A resin film containing a desired amount of bioplastic, such as biopolyethylene, may also be used. In the illustrated example, two films are joined together at a side seal portion 112, a top seal portion 113, and a bottom seal portion 114 to form a bag-shaped container body including a first surface 111A and a second surface 111B facing each other. In another example, a similar container body may be formed by folding a single film.

[0013] The zipper tape 120 is a long member formed with a cross-sectional shape as described below, and includes portions to be joined to the first surface 111A and the second surface 111B of the film 110, respectively. The zipper tape 120 includes first and second members having an engaging portion 121 and a flange portion as described below. Examples of resins forming each portion of the zipper tape 120 include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and polypropylene (PP). Examples of PP include homopolypropylene (HPP), random polypropylene (RPP), and block polypropylene (BPP). These may be environmentally friendly bioplastics, or a mixture of a fossil fuel-derived resin and a biomass plastic such as biopolyethylene may be used. Other examples of resins that can be used to form the zipper tape 120 include environmentally friendly biodegradable resins such as polylactic acid (PLA), polybutylene succinate (PBS), poly(butylene adipate / terephthalate) (PBAT), polycaprolactone (PCL), poly(caprolactone / butylene succinate) (PCLBS), poly(butylene succinate / adipate) (PBSA), poly(butylene succinate / carbonate) (PEC), poly(ethylene terephthalate / succinate) (PETS), poly(tetramethylene adipate / terephthalate) (PTMAT), polyethylene succinate (PES), polyvinyl alcohol (PVA-H), polyglycolic acid (PGA), and poly(hydroxybutyrate / hydroxyhexanoate) (PHBH). These biodegradable resins may be derived from biomass. The material of each part of the zipper tape 120 may contain, for example, one or more of the resins exemplified above, and may further contain known additives, such as stabilizers, antioxidants, lubricants, antistatic agents, or colorants, as necessary.

[0014] In the zipper tape-attached container 100, a slit 131 is formed between the zipper tape 120 and the top seal 113 on the side of the container body where the side seal 112 is formed. An opening can be formed in the container by tearing the container body from the slit 131 in the width direction of the container body, i.e., along the length direction of the zipper tape 120. Alternatively, the top seal 113 may not be formed, and the opening may be formed in the container from the beginning. If the opening is formed in the container from the beginning or if other means for forming the opening are provided, the slit 131 does not need to be formed. Note that in FIGS. 1 and 2 , the length direction of the zipper tape 120 is illustrated as the x-direction, the width direction of the zipper tape 120 is illustrated as the y-direction, and the thickness direction of the zipper tape 120 is illustrated as the z-direction.

[0015] FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1 , showing the cross-sectional shape of the zipper tape. As shown, the zipper tape 120 shown in FIG. 1 includes a first member 120A and a second member 120B. In cross-sectional view, the first member 120A includes a first engagement portion 121A, a first flange portion 122A extending from the first engagement portion 121A to a first widthwise side of the zipper tape 120, and a second flange portion 122B extending from the first engagement portion 121A to a second widthwise side. The first member 120A is joined to the first surface 111A of the film 110 at each of the first flange portion 122A and the second flange portion 122B. Here, the first widthwise side of the zipper tape 120 is specifically the opening side formed in the container body as described above, and the second side is the side opposite the opening. Therefore, for simplicity, in the following description, the first side and the second side are also referred to as the opening side and the non-opening side, respectively, but the first side and the second side can be distinguished even before the zipper tape 120 is attached to the film 110, and the above description does not limit the present invention to a state in which the zipper tape 120 constitutes the zipper tape-attached container 100 and an opening is formed in the container body. Also, as described above, the container body may have an opening formed from the beginning, or the opening may be formed later by tearing the container body, but the above description does not limit the present invention to either of these.

[0016] The second member 120B includes, in cross section, a second engaging portion 121B, a third flange portion 122C extending from the second engaging portion 121B toward the opening, and a fourth flange portion 122D extending from the second engaging portion 121B toward the non-opening. The second engaging portion 121B is engageable with the first engaging portion 121A, constituting the pair of engaging portions 121 shown in FIG. 1. Note that while the first engaging portion 121A is illustrated as a combination of a male type and a hook, and the second engaging portion 121B is illustrated as a combination of a female type and a hook, the gender roles may be reversed. Furthermore, various types of engaging portions, such as hooks and knobs, can be used in addition to the male-female type. One or more pairs of various engaging portions can be used, not limited to the male-female type and hook type combination shown in the example. Second member 120B is joined to first surface 111A of film 110 at third flange portion 122C and fourth flange portion 122D, respectively.

[0017] In the illustrated example, the second member 120B includes an extension 122E formed contiguous to the fourth flange 122D on the non-opening side, and an easy-peel layer 123 is formed on the second engaging portion 121B side of the extension 122E, i.e., on the surface facing the first surface 111A of the film 110. The easy-peel layer 123 is formed of, for example, polyethylene or a mixture of polyethylene and polypropylene. Specifically, the easy-peel layer 123 is formed of, for example, linear low-density polyethylene (LLDPE), a mixture of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), or a mixture of low-density polyethylene (LDPE) and polypropylene. As described above, first member 120A and second member 120B of zipper tape 120 are respectively joined to first surface 111A and second surface 111B of film 110. In addition, extension portion 122E of second member 120B is joined to first surface 111A with easy-peel layer 123, thereby preventing, for example, liquid contents from leaking through gaps in engagement portion 121. Easy-peel layer 123 is joined to first surface 111A with lower bonding strength than other portions of zipper tape 120, so that when engagement portion 121 is opened, easy-peel layer 123 can be easily peeled off to allow contents to be inserted or removed.

[0018] The zipper tape-equipped container 100 described above is used, for example, by pouring contents into the container through the opening, sealing the engagement portion 121, and cooking the contents. In this case, a mechanism for forming a steam outlet is provided, for example, at the joint between the zipper tape 120 and either or both of the first surface 111A and the second surface 111B of the film 110. Since any of the mechanisms in the prior art described above can be used for such a mechanism, detailed description and illustrations are omitted. However, whichever mechanism is employed, the zipper tape 120 may be pulled by the expanded film 110, causing the engagement portion 121 to be partially opened or the zipper tape 120 to bend, which may prevent stable release of steam.

[0019] Therefore, in this embodiment, as shown in FIG. 3, the thickness t A , the thickness t of the second flange portion 122B B , the thickness t of the third flange portion 122C C , or the thickness t of the fourth flange portion 122D D At least one of the thicknesses is set to 170 μm or more. This improves the rigidity of the zipper tape 120, and more effectively prevents the engagement portion 121 from opening and the zipper tape 120 from bending, compared to conventional zipper tapes in which the flange thickness is about 145 μm, for example.

[0020] In this embodiment, the thickness t of the flange portion A ,t B ,t C ,t D It is sufficient that any one of the thicknesses is 170 μm or more, but it is preferable that two or more are 170 μm or more, and more preferable that all are 170 μm or more. Furthermore, the thickness of the entire flange portion does not necessarily have to be 170 μm or more, but it is sufficient that the thickness is 170 μm or more in a section of 10% or more of the length of the first flange portion 122A, the second flange portion 122B, the third flange portion 122C, or the fourth flange portion 122D in the cross-sectional shape. The section having a thickness of 170 μm or more is preferably 20% or more, and more preferably 30% or more. Since there is no problem with the entire flange portion being thick, the upper limit is 100%. Furthermore, when the second member 120B includes the extension portion 122E, the thickness t of the extension portion 122E is E The thickness of the flange t A ,t B ,t C ,t D The rigidity of the zipper tape 120 can also be improved by making each of the above larger than the above.

[0021] The improvement in rigidity achieved by configuring the zipper tape 120 as described above can be confirmed, for example, by the bending stress value. Specifically, the maximum bending stress in the length-thickness plane (xz plane in FIGS. 1 and 2) of at least one of the first member 120A and the second member 120B is preferably 6.5 N or more. The maximum bending stress in at least one of the first member 120A and the second member 120B is more preferably 7.2 N or more, and even more preferably 8.4 N or more. The upper limit is not particularly limited, but is, for example, 10 N or less. Furthermore, when the first engaging portion 121A and the second engaging portion 121B are engaged, the maximum bending stress in the length-thickness plane of the entire zipper tape 120 is preferably 12.0 N or more. The maximum bending stress of the entire zipper tape 120 is more preferably 13.5 N or more, and even more preferably 14 N or more. The upper limit is not particularly limited, but is, for example, 20 N or less. In addition, when ribs 124 are formed on the flange portion as shown in FIG. 4, the thickness t of the flange portion including the ribs 124 is A ,t B ,t C ,t D The rib 124 is a locally thickened portion of the flange portion, and the thickness may be made 170 μm or more, for example, by forming the rib 124 in a section that is 10% or more of the length of the first flange portion 122A, the second flange portion 122B, the third flange portion 122C, or the fourth flange portion 122D in the cross-sectional shape.

[0022] When increasing the thickness of the flange portion of the zipper tape 120 to improve rigidity as described above, it is possible to increase the thickness of the entire zipper tape 120, including the engaging portion 121, by increasing the amount of resin used when molding the zipper tape 120 by extrusion molding, for example. On the other hand, it is also possible to change the extrusion mold so that only the flange portion is made thicker while keeping the engaging portion 121 the same size as before. In this case, since the size of the engaging portion 121 is not increased, the amount of resin used can be reduced and a decrease in the crushability of the zipper tape 120 at the side seal portion 112 can be prevented.

[0023] When the engaging portion 121 is formed to have the same size as the conventional one and only the flange portion is made thicker, the total thickness t of the zipper tape 120 at the first engaging portion 121A and the second engaging portion 121B is 1 / 2 inch when the first engaging portion 121A and the second engaging portion 121B are engaged with each other. G The total thickness t is slightly thicker than the conventional thickness, specifically, for example, 1300 μm or more. G is preferably 1400 μm or more, more preferably 1500 μm or more. G The lower limit of the total thickness t is not particularly limited, but is preferably 2800 μm or less, and more preferably 2500 μm or less. G and flange thickness t A ,t B ,t C ,t D Regarding the relationship between the total thickness t G and the total thickness of the flange on the opening side, t A +t C , or the total thickness of the flange on the non-opening side t B +t D The ratio of the larger of (t A +t C ) / t G or (t B +t D ) / t G ) is, for example, 0.11 or more and 2 or less. This ratio is preferably 0.15 or more, more preferably 0.19 or more, even more preferably 0.21 or more, and particularly preferably 0.24 or more. In addition, this ratio is preferably 1.86 or less, more preferably 1.50 or less, and even more preferably 1.20 or less. [Example]

[0024] Next, examples of the present invention will be described. As shown in Table 1, the bending stress in the length-thickness plane was measured for an example of zipper tape in which the flange thicknesses on the opening and non-opening sides of the male side (first member 120A in the above embodiment) and female side (second member 120B) were 170 μm or more, and a comparative zipper tape in which the engaging portion dimensions were similar but the flange thicknesses were less than 170 μm. In Table 1, the thickness dimension of the middle part on the opening side of the male side was the thickness t of the flange shown in Figure 3. A The thickness of the middle part of the non-opening side of the male side is the thickness of the flange part t B The thickness of the middle part of the female opening is the thickness of the flange t C The thickness of the middle part of the non-opening side of the female side is the thickness of the flange part t D , the thickness of the engagement part is the total thickness t G The total thickness t G and total thickness t A +t C or total thickness t B +t D The ratio of the larger of these is (228+198) / 1700=0.25 in the example and (145+150) / 1600=0.18 in the comparative example.

[0025] [Table 1]

[0026] The bending stress of the zipper tape was measured in four tests. Test 1 measured only the male component; Test 2 measured the entire zipper tape with the engaging portion engaged; Test 3 measured the zipper tape from Test 2 with the extension portion cut off; and Test 4 measured the zipper tape from Test 2 bonded to a film (without the easy-peel portion attached). These were then set in a Shimadzu precision universal testing machine (AUTOGRAPHAGS-X 1kN) to measure the maximum bending stress. The bending direction was oriented in the length-thickness plane of the zipper tape, with the male engaging portion facing inward. The test specimens were 100 mm long and 19 mm wide with the extension portion and 12 mm wide without the extension portion. The zipper tape was fabricated by extruding a raw resin composition using an extruder and then water-cooling. The raw resin composition for the flange, engagement portion, and extension portions was homopolypropylene (H-PP). No sealing layer was laminated on the flange portion. The easy-peel layer formed on the extension portion was a blend of polypropylene and polyethylene. The sealing conditions for joining the zipper tape to the film were a sealing pressure of 0.2 MPa, a sealing time of 1 second, and a sealing temperature of 220° C. The results are shown in Table 2.

[0027] [Table 2]

[0028] As shown in Table 2, the zipper tapes according to the examples of the present invention, each having a flange thickness of 170 μm or more, exhibited higher maximum bending stress values ​​than the zipper tapes according to the comparative examples, each having a flange thickness of less than 170 μm, in the cases of only the male component, the entire zipper tape in which the male and female components are engaged with each other, with and without the extension, and the zipper tape joined to a film. [Explanation of symbols]

[0029] 100...container with zipper tape, 110...film, 111A...first surface, 111B...second surface, 112...side seal portion, 113...top seal portion, 114...bottom seal portion, 120...zipper tape, 120A...first member, 120B...second member, 121...engagement portion, 121A...first engagement portion, 121B...second engagement portion, 122A...first flange portion, 122B...second flange portion, 122C...third flange portion, 122D...fourth flange portion, 122E...extension portion, 123...easy peel layer, 124...rib, 131...notch.

Claims

1. A zipper tape comprising a first member and a second member, the first member includes, in a cross-sectional shape, a first engagement portion, a first flange portion extending from the first engagement portion to a first side in a width direction of the zipper tape, and a second flange portion extending from the first engagement portion to a second side in the width direction, the second member includes, in a cross-sectional shape, a second engaging portion engageable with the first engaging portion, a third flange portion extending from the second engaging portion toward the first side, and a fourth flange portion extending from the second engaging portion toward the second side; At least one of the first flange portion, the second flange portion, the third flange portion and the fourth flange portion has a portion with a thickness of 170 μm or more.

2. 2. The zipper tape of claim 1, wherein each of the first flange portion, the second flange portion, the third flange portion, and the fourth flange portion has a portion with a thickness of 170 μm or more.

3. 3. The zipper tape according to claim 1, wherein the second member includes an extension portion formed contiguous to the fourth flange portion on the second side, and an easy-peel layer is formed on a surface of the extension portion on the second engagement portion side.

4. The zipper tape of claim 3 , wherein the extension portion has a thickness greater than each of the first flange portion, the second flange portion, the third flange portion, and the fourth flange portion.

5. 5. The zipper tape according to claim 1, wherein a rib is formed on at least one of the first flange portion, the second flange portion, the third flange portion, and the fourth flange portion has a thickness of 170 μm or more including the rib.

6. 6. The zipper tape according to claim 1, wherein a section of the first flange portion, the second flange portion, the third flange portion, or the fourth flange portion in the cross-sectional shape has a thickness of 170 μm or more over a length of 10% or more of the first flange portion, the second flange portion, the third flange portion, or the fourth flange portion.

7. 7. The zipper tape according to claim 1, wherein at least one of the first member and the second member has a maximum bending stress in the length-thickness plane of 6.5 N or more.

8. 8. The zipper tape according to claim 1, wherein a maximum value of bending stress in a length-thickness plane of the entire zipper tape is 12 N or more in a state in which the first engagement portion and the second engagement portion are engaged with each other.

9. 9. The zipper tape according to claim 1, wherein, in a state in which the first engagement portion and the second engagement portion are engaged with each other, a thickness of the entire zipper tape at the first engagement portion and the second engagement portion is 1.30 mm or more.

10. 10. The zipper tape according to claim 1, wherein, when the first engagement portion and the second engagement portion are engaged with each other, a ratio of an overall thickness of the zipper tape at the first engagement portion and the second engagement portion to a larger one of a total thickness of the first flange portion and the third flange portion or a total thickness of the second flange portion and the fourth flange portion is 0.11 or more and 2 or less.

11. A container with zipper tape, comprising the zipper tape according to any one of claims 1 to 10.

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