Heat shrinkable film and packaging container

Abstract

To provide a heat shrinkable film allowing easy removal from a container when attached as a cylindrical label to the container.SOLUTION: A heat shrinkable film is to be attached as a cylindrical label to a container. The heat shrinkable film includes a film main body having a perforation. The perforation extends so as to allow a removal of the cylindrical label by breaking the cylindrical label along the perforation when the heat shrinkable film is attached onto the container as the cylindrical label. In a target portion of the film main body, a detachability improvement layer is laminated in a vicinity of the perforation. The target portion is a portion to be an edge part in an axial direction of the cylindrical label when removing the cylindrical label.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a heat-shrinkable film and a packaging container.

Background Art

[0002] Conventionally, a heat-shrinkable film formed in a tubular shape has been used as a label and attached to the body of a container, a cap, or the like. Such a heat-shrinkable label may have perforations from the viewpoint of facilitating peeling of the label (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] A heat-shrinkable label attached to a container adheres strongly to the container and usually has almost no gap with the container. Therefore, even if perforations are formed, it is not always easy to peel the label from the container. This is because it is difficult for fingertips or nails to enter the gap between the container and the label, and it is difficult to start peeling the label along the perforations. In this regard, in Patent Document 1, in addition to the perforations, a cut is made at the end of the label. In Patent Document 2, in addition to the perforations, a tab portion is provided at the end of the label. However, from the viewpoint of peelability or other viewpoints such as design and productivity, the conventional methods are not always sufficient. Therefore, a new method for providing a heat-shrinkable label with high peelability is required.

[0005] An object of the present invention is to provide a heat-shrinkable film that can be easily peeled off from a container when attached to the container as a cylindrical label, and a packaging container packaged with the same.

Means for Solving the Problems

[0006] Item 1. A heat-shrinkable film attached to a container as a cylindrical label, comprising a film body with perforations formed therein, wherein the perforations extend so that when the heat-shrinkable film is attached to the container as the cylindrical label, the cylindrical label can be peeled off from the container by breaking the cylindrical label along the perforations, in a target portion of the film body, a peelability improvement layer is laminated in the vicinity of the perforations, wherein the target portion is a portion that becomes an axial end of the cylindrical label when the cylindrical label is peeled off, Heat-shrinkable film.

[0007] Item 2. The peelability improvement layer is a printing layer or a coating layer, The heat-shrinkable film according to Item 1.

[0008] Item 3. The peelability improvement layer is intermittently laminated along the entire circumference of the target portion in the target portion, The heat-shrinkable film according to Item 1 or 2.

[0009] Item 4. The peelability improvement layer is laminated in the target portion so as to overlap the perforations, The heat-shrinkable film according to any one of Items 1 to 3.

[0010] Item 5. A cylindrical label formed of the heat-shrinkable film according to any one of Items 1 to 4, and a container to which the cylindrical label is attached A packaging container comprising.

Effects of the Invention

[0011] According to the present invention, it is possible to provide a heat-shrinkable film that can be easily peeled off from a container when it is attached to the container as a cylindrical label.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0013] Hereinafter, a heat-shrinkable film and a packaging container according to an embodiment of the present invention will be described with reference to the drawings.

[0014] <1. Overall Configuration of the Packaging Container> Figures 1 and 2 show two side views of the packaging container 1 according to this embodiment viewed from different angles, and Figure 3 shows a plan view of the packaging container 1. Figure 1 is a side view viewed from the direction of arrow A1 shown in Figure 3, and Figure 2 is a side view viewed from the direction of arrow A2 shown in Figure 3. The packaging container 1 includes a container 2 and a cylindrical label L attached to the container 2. The cylindrical label L is a shrink label and is formed of a heat-shrinkable film 3. Figure 4 shows a developed view of the heat-shrinkable film 3 before being processed into the cylindrical label L. In the description of this embodiment, unless otherwise specified, up and down (vertical direction) and left and right (horizontal direction) are defined as shown in Figure 4. The heat-shrinkable film 3 is planar in the state of Figure 4, and is formed into a cylindrical shape by overlapping its left end portion and right end portion to become the cylindrical label L. Then, the container 2 is disposed inside the cylindrical label L so that the cylindrical label L surrounds the container 2, and heat is applied to the cylindrical label L in that state. Thereby, the cylindrical label L contracts and deforms along the outer shape of the container 2 and adheres closely to the outer surface of the container 2. In this way, the heat-shrinkable film 3 is attached to the container 2 as the cylindrical label L.

[0015] The container 2 according to this embodiment has a main body portion 20 and a cap 25. The main body portion 20 has a bottom surface portion 21, a body portion 22, and a cap attachment portion 23. The portions 20, 22, 23, 25 are covered with the cylindrical label L and are at least partially not visible from the outside. However, for the sake of explanation, in Figures 1 to 3, the positions of the portions hidden by the cylindrical label L are indicated by reference numerals 20, 22, 23, 25. The bottom surface portion 21 according to this embodiment is circular in plan view. The body portion 22 rises from the outer peripheral edge of the bottom surface portion 21 and is generally cylindrical although the diameter of the cross section varies along the vertical direction. A cap attachment portion 23 is provided at the upper portion of the body portion 22. The cap 25 is attached to the cap attachment portion 23. The cap 25 according to this embodiment is circular in plan view. The cap 25 may be configured to be openable and closable, and in this case, a screw type, a hinge type, etc. can be considered. The cap 25 may be configured such that it cannot be closed again once it is opened.

[0016] The material of the main body 20 is not particularly limited. However, the main body 20 according to this embodiment is made of resin. As a preferable example, it can be made of a polyester resin such as polyethylene terephthalate (PET), or a polyolefin resin. As other examples, the main body 20 can be made of glass, paper, or the like. The material of the cap 25 is also not particularly limited. However, the cap 25 according to this embodiment is made of resin. As a preferable example, it can be made of a polyolefin resin or a polyester resin. Further, although not limited thereto, in this embodiment, the main body 20 is configured to be transparent or translucent (hereinafter, may be expressed as clear) so that the contents of the container 2 can be visually recognized, and the cap 25 is configured to be opaque.

[0017] The cylindrical label L according to this embodiment is mounted so as to cover the body portion 22, the cap attachment portion 23, and the cap 25. As shown in FIGS. 1 and 2, the body portion 22 is covered with the cylindrical label L except for its lower portion. The cap attachment portion 23 is also covered with the cylindrical label L. The bottom surface portion 21 is not covered with the cylindrical label L. As shown in FIG. 3, the cap 25 has its side surface portion 25S and the outer peripheral portion of its top surface portion 25T covered with the cylindrical label L, but the central portion of the top surface portion 25T is not covered.

[0018] From the above, the heat-shrinkable film 3 according to this embodiment does not cover the entire outer surface of the clear main body 20 in the state of being mounted on the container 2, and the bottom surface portion 21 and the lower portion of the body portion 22 are exposed. Therefore, the heat-shrinkable film 3 according to this embodiment is not a so-called light-shielding film, and the contents can be visually recognized through the exposed portion of the clear main body 20. Although details will be described later, since a clear portion is formed in the heat-shrinkable film 3 according to this embodiment, the contents can also be visually recognized through this portion.

[0019] The use of the container 2 is not particularly limited. As a preferable example, it can be a container for food such as dressing, soy sauce, and noodle sauce, or a beverage container.

[0020] <2. Heat-Shrinkable Film> Next, the details of the heat-shrinkable film 3 will be described. FIG. 5A is a cross-sectional view taken along line B1-B1 of FIG. 4, and FIG. 5B is a cross-sectional view taken along line B2-B2 of FIG. 4. As shown in FIGS. 4, 5A, and 5B, the heat-shrinkable film 3 includes a film body 4 and a printing layer 5 laminated on the film body 4. In the figures, the printing layer 5 is shown in dark gray, and the portion of the film body 4 where the printing layer 5 is not laminated is shown in light gray.

[0021] In this embodiment, the film body 4 is configured to be clear, and the printing layer 5 is configured to be opaque. The printing layer 5 constitutes a decorative surface with a pattern for decorating the container 2 when the heat-shrinkable film 3 wraps the container 2. The pattern applied to the decorative surface may include characters explaining various information about the contents of the container 2. Note that the film body 4 can also be configured to be opaque.

[0022] The material of the film body 4 only needs to have heat-shrinkability and is not particularly limited. As a preferred example, the film body 4 can be formed of a polyester-based resin, a polystyrene-based resin (including hybrid polystyrene), or a polyolefin-based resin, or a mixture or laminate thereof.

[0023] The material of the printing layer 5 is also not particularly limited, and the printing layer 5 can be configured using various inks suitable for laminating on the film body 4. The material of the printing layer 5 is typically a colored (opaque) ink, but at least partially clear ink can also be used. In the latter case, a part or all of the printing layer 5 can be configured to be clear instead of opaque by using clear ink for part or all of the printing layer 5.

[0024] Of the two sides of the film body 4, when the heat-shrinkable film 3 wraps the container 2, the surface facing the container 2 side (inside) is called the back surface, and the surface facing the outside is called the front surface. The printing layer 5 may be formed on either the back surface or the front surface of the film body 4, or may be formed on both surfaces. However, when the film body 4 is a clear film, from the viewpoint of appearance, it is preferable to form the printing layer 5 on the back surface. The printing layer 5 according to the present embodiment is disposed on the back surface of the film body 4. Note that FIG. 4 is a view of the heat-shrinkable film 3 viewed from the front surface side, and the printing layer 5 on the back surface can be seen through the clear film body 4.

[0025] In the present embodiment, perforations L1 to L8 are formed in the film body 4 included in the heat-shrinkable film 3. In the examples of FIGS. 5A and 5B, the perforations L1 to L6 penetrate the film body 4 and the printing layer 5. The same applies to the perforations L7 and L8. The perforations L1 to L8 are formed to facilitate breaking of the tubular label L attached to the container 2 and to facilitate peeling of the tubular label L from the container 2. Therefore, the perforations L1 to L8 extend at positions where breaking is expected when the tubular label L is peeled from the container 2 in the heat-shrinkable film 3. Thereby, when the heat-shrinkable film 3 is attached to the container 2 as the tubular label L, the tubular label L can be easily peeled from the container 2 by breaking the tubular label L along the perforations L1 to L8.

[0026] The perforations L1 to L4 are perforations for peeling off the upper film portion 31 of the tubular label L, which mainly covers the cap 25, from the container 2 when the packaging container 1 is opened. The heat-shrinkable film 3 is separated into an upper film portion 31 and a lower film portion 32 with the perforations L3 and L4 as boundaries. The perforations L3 and L4 extend in the horizontal direction (left-right direction) from the left edge to the right edge of the heat-shrinkable film 3. The perforations L3 and L4 run parallel in the horizontal direction with a slight distance in the vertical direction. The perforations L1 and L2 extend from the upper edge of the heat-shrinkable film 3 to the perforation L3. The perforation L3 is located above the perforation L4. The perforations L1 and L2 according to the present embodiment extend so that the distance gradually approaches the perforation L3 from the upper edge of the heat-shrinkable film 3. An opening portion 31A surrounded by the perforations L1 to L3 is formed in the upper film portion 31.

[0027] A method for opening the packaging container 1 will be described. First, the user hooks a nail, fingertip, etc. on the portion of the tubular label L surrounded by the circle C1 in FIGS. 1 and 3, and pulls the above-described opening portion 31A downward. The portion surrounded by the circle C1 is a portion near the perforations L1 and L2 among the portions covering the outer peripheral portion of the top surface portion 25T of the cap 25 included in the upper film portion 31. Thereby, the upper film portion 31 is broken along the perforations L1 and L2. Subsequently, by pulling the opening portion 31A in the horizontal direction along the perforations L3 and L4, the portion between the opening portion 31A and the lower film portion 32 is broken along the perforations L3 and L4, and the opening portion 31A is separated from the lower film portion 32. Thereby, the opening portion 31A is peeled off from the container 2 and removed. Subsequently, the remaining portion 31B of the upper film portion 31 other than the removed opening portion 31A (hereinafter referred to as the remaining portion) is pinched, and the remaining portion 31B is pulled in the horizontal direction along the perforations L3 and L4. Thereby, the portion between the remaining portion 31B and the lower film portion 32 is broken along the perforations L3 and L4, and the remaining portion 31B is separated from the lower film portion 32. As a result, the remaining portion 31B is peeled off from the container 2 and removed. Note that the remaining portion 31B may be removed before the opening portion 31A. As described above, the entire upper film portion 31 is removed from the packaging container 1, and the cap 25 is exposed. The user opens the cap 25 in this state.

[0028] As described above, the container 2 is in a state where only the lower film portion 32 of the cylindrical label L is attached. Without being limited to this, as a typical usage method, the container 2 is used with only the lower film portion 32 attached until the contents are used up (until the removal of the contents is completed). During this period, by opening and closing the outlet of the container 2 with the cap 25, the contents can be taken out little by little from the main body portion 20 or the remaining contents in the main body portion 20 can be stored.

[0029] After the contents are used up, the container 2 is discarded. At the time of discarding, typically for recycling purposes, the lower film portion 32 attached to the container 2 is also peeled off from the container 2 and removed. The perforations L5 and L6 are mainly perforations for peeling the lower film portion 32 covering the main body portion 20 of the container 2 from the container 2. In the examples of FIGS. 2 and 4, the perforations L5 and L6 extend in the vertical direction from the lower end edge to the upper end edge of the heat-shrinkable film 3. The perforation L5 is formed near the left end portion of the heat-shrinkable film 3 in the unfolded state, and the perforation L6 is formed near the right end portion of the heat-shrinkable film 3 in the unfolded state. As a result, in the cylindrical label L formed by overlapping the left end portion and the right end portion of the heat-shrinkable film 3, the perforations L5 and L6 run parallel in the vertical direction with a slight distance in the horizontal direction (see FIG. 2). In FIGS. 2 and 3, the overlapped portion O1 of the heat-shrinkable film 3 is indicated by diagonal hatching.

[0030] Next, a method for peeling the lower film portion 32 of the cylindrical label L from the container 2 will be described. Typically, there are two methods. As the first method, the user hooks a claw or fingertip on the portion of the cylindrical label L surrounded by the circle C2 in FIG. 2 and pulls the portion upward from the lower end edge to the upper end edge of the lower film portion 32. The portion surrounded by the circle C2 is a portion near the perforations L5 and L6 at the lower end portion of the lower film portion 32. Thereby, the lower film portion 32 is broken along the perforations L5 and L6, and the lower film portion 32 is peeled off from the container 2 and removed.

[0031] As a second method, the user hooks a claw, fingertip, etc. on the portion of the cylindrical label L surrounded by the circle C3 in FIG. 2, and pulls this portion downward from the upper edge to the lower edge of the lower film portion 32. The portion surrounded by the circle C3 is a portion near the perforations L5 and L6 at the upper end of the lower film portion 32. Thereby, the lower film portion 32 is broken along the perforations L5 and L6, and the lower film portion 32 is peeled off from the container 2 and removed.

[0032] The perforations L7 and L8 are perforations for assisting the breaking of the cylindrical label L along the perforations L5 and L6. The perforation L7 is formed so as to run parallel to the perforation L5 in the vicinity of the perforation L5. The perforation L8 is formed so as to run parallel to the perforation L6 in the vicinity of the perforation L6. In the examples of FIGS. 2 and 4, the perforations L7 and L8 extend slightly upward from the lower edge of the heat-shrinkable film 3 and do not reach the upper edge of the heat-shrinkable film 3 or the upper edge of the lower film portion 32. However, one or both of the perforations L7 and L8 may reach the upper edge of the heat-shrinkable film 3 or the upper edge of the lower film portion 32. Also, one or both of the perforations L7 and L8 can be omitted.

[0033] As shown in FIGS. 2 and 4, the perforations L5 and L6 are also formed in the upper film portion 31. Therefore, the perforations L5 and L6 also function as perforations for peeling the upper film portion 31 from the container 2 when the packaging container 1 is opened. In this case, the user hooks a nail or fingertip on the portion of the cylindrical label L surrounded by the circle C4 in FIGS. 2 and 3, and pulls the portion downward from the upper edge to the lower edge of the upper film portion 31. The portion surrounded by the circle C4 is a portion near the perforations L5 and L6 among the portions covering the outer peripheral portion of the top surface portion 25T of the cap 25 included in the upper film portion 31. Thereby, the upper film portion 31 is broken along the perforations L5 and L6. Subsequently, the upper film portion 31 is pinched, and the upper film portion 31 is pulled horizontally along the perforations L3 and L4. Thereby, the upper film portion 31 is separated from the lower film portion 32 along the perforations L3 and L4, and the upper film portion 31 is peeled off from the container 2 and removed. Thereafter, the user opens the exposed cap 25.

[0034] As described above, the portions surrounded by the circles C1 to C4 shown in FIGS. 1 to 4 can be the break start points of the cylindrical label L. Therefore, hereinafter, these portions are referred to as break start points C1 to C4.

[0035] <3. Peeling property improving layer> In the above manner, the cylindrical label L can be peeled off from the container 2. The cylindrical label L is provided with peeling property improving layers D1 to D7 for improving the peeling property of the cylindrical label L. In the present embodiment, a part of the printing layer 5 laminated on the film body 4 constitutes the peeling property improving layers D1 to D7.

[0036] As shown in FIG. 4, the printing layer 5 includes an upper portion 5U and a lower portion 5D. In this embodiment, both the upper portion 5U and the lower portion 5D are rectangular on the film body 4. The upper edge of the upper portion 5U extends horizontally downward from the upper edge of the film body 4 with a slight gap. The lower edge of the upper portion 5U extends horizontally downward from the perforation L4 with a gap. The left and right edges of the upper portion 5U extend vertically downward from the left and right edges of the film body 4 with a slight gap to the right and left, respectively. The upper edge of the lower portion 5D extends horizontally downward from the lower edge of the upper portion 5U with a gap. The lower edge of the lower portion 5D extends horizontally upward from the lower edge of the film body 4 with a slight gap. The left and right edges of the lower portion 5D extend vertically downward from the left and right edges of the film body 4 with a slight gap to the right and left, respectively.

[0037] The film body 4 includes an upper end portion 4U, a middle portion 4M, a lower end portion 4D, a left end portion 4L, and a right end portion 4R where the upper portion 5U and the lower portion 5D of the printing layer 5 are not laminated. However, in the upper end portion 4U and the lower end portion 4D, the printing layer 5 is partially laminated as the peelability improvement layers D1 to D5 and the layer of the region D8 described later.

[0038] Hereinafter, in the film body 4, a portion that becomes the axial end of the cylindrical label L when the cylindrical label L is peeled from the container 2 is referred to as a target portion. As shown in FIG. 4, the film body 4 according to this embodiment includes three target portions T1 to T3. The target portions T1 to T3 included in the cylindrical label L are each formed in a ring shape. In this example, the target portion T1 coincides with the upper end portion 4U of the film body 4, and the target portion T2 coincides with the lower end portion 4D of the film body 4. The target portion T3 is included in the lower film portion 32 and is a portion along the perforation L4 at a position below the perforation L4. That is, the target portion T3 is a portion that becomes the axial end (upper end) of the lower film portion 32 (cylindrical label L) when the upper film portion 31 is peeled along the perforations L3 and L4 from the container 2 and then the lower film portion 32 is further peeled.

[0039] The peelability improving layers D1 to D7 are laminated in the vicinity of the perforations L1 to L8 in the target portions T1 to T3. More specifically, in the target portion T1, the peelability improving layer D1 is laminated in the vicinity of the perforations L1 and L2, the peelability improving layer D4 is laminated in the vicinity of the perforation L5, and the peelability improving layer D5 is laminated in the vicinity of the perforation L6. In the target portion T1, the printing layer 5 does not exist in the portions where the peelability improving layers D1, D4, and D5 are not laminated. Therefore, the printing layer 5 including the peelability improving layers D1, D4, and D5 is intermittently laminated along the entire circumference (entire width) of the target portion T1 in the target portion T1.

[0040] In the target portion T2, the peelability improving layer D2 is laminated in the vicinity of the perforations L5 and L7, and the peelability improving layer D3 is laminated in the vicinity of the perforations L6 and L8. Also, in the target portion T2, the printing layer 5 is laminated at the position of the region D8. The region D8 occupies the same position as the peelability improving layer D1 in the lateral direction. In the target portion T2, the printing layer 5 does not exist except for the layer of the region D8 and the peelability improving layers D2 and D3. Therefore, the printing layer 5 including the layer of the region D8 and the peelability improving layers D2 and D3 is intermittently laminated along the entire circumference (entire width) of the target portion T2 in the target portion T2.

[0041] In the target portion T3, the peelability improving layer D6 is laminated in the vicinity of the perforation L5, and the peelability improving layer D7 is laminated in the vicinity of the perforation L6. The peelability improving layers D6 and D7 are included in the upper portion 5U of the printing layer 5. Therefore, in the target portion T3, the printing layer 5 exists also in the portions where the peelability improving layers D6 and D7 are not laminated, except for the positions of the left end portion 4L and the right end portion 4R. The printing layer 5 including the peelability improving layers D6 and D7 is continuously laminated along substantially the entire circumference (entire width) of the target portion T3 in the target portion T2.

[0042] When the heat-shrinkable film 3 is formed into the cylindrical label L, the peelability improvement layer D1 constitutes the fracture initiation point C1 in FIGS. 1 and 3. Further, the peelability improvement layers D2 and D3 are overlapped with each other to constitute the fracture initiation point C2 in FIG. 2. Further, the peelability improvement layers D4 and D5 are overlapped with each other to constitute the fracture initiation points C4 in FIGS. 2 and 3. Further, the peelability improvement layers D6 and D7 are overlapped with each other to constitute the fracture initiation point C3 in FIG. 2.

[0043] In the heat-shrinkable film 3, the portion where the printing layer 5 is laminated is thicker than the other portions. Therefore, when the cylindrical label L is heat-shrunk and attached to closely adhere to the container 2, the portions (fracture initiation points C1 to C4) where the peelability improvement layers D1 to D7 are laminated are in a state of slightly floating from the container 2. In particular, the fracture initiation points C1, C2, and C4 located at the ends of the cylindrical label L during heat shrinkage can be warped with respect to the container 2. This is because the fracture initiation points C1 to C4 are thicker and harder than the portions where the printing layer 5 is not laminated, and heat shrinkage is suppressed. Further, as described above, the peelability improvement layers D1 to D7 are present at positions that become the ends of the cylindrical label L when the cylindrical label L is peeled off. Therefore, when the cylindrical label L is peeled off, it becomes easy to catch claws, fingertips, etc. in the slight gap between the portions (fracture initiation points C1 to C4) where the peelability improvement layers D1 to D7 are present and the container 2. Then, by pinching and pulling the portion (fracture initiation points C1 to C4) where the claws, fingertips, etc. are caught, the cylindrical label L can be easily torn.

[0044] Here, for comparison, consider the case of tearing the cylindrical label L starting from a portion where the printing layer 5 is not laminated in the target portions T1 to T3 (for example, the portion surrounded by the circle E in FIGS. 2 and 4; hereinafter referred to as portion E). When such a portion E is heat-shrunk to attach the cylindrical label L to the container 2, it curls toward the container 2 side and falls down, adhering more firmly to the container 2. This is because portion E is thinner, softer, and more prone to heat shrinkage than the portion where the printing layer 5 is laminated. Therefore, it is impossible to insert a claw, fingertip, etc. well between portion E and the container 2, and it is impossible to pick up portion E well. If one tries to pick it up forcefully, portion E may turn up and can no longer be picked up. In particular, when portion E adheres to a non-flat portion of the container 2, such as being inclined or curved in a side view, it may become difficult to pick up portion E. Also, in the case of a container 2 with high strength, the same problem may occur. Therefore, even if perforations are formed so as to overlap portion E, it may become difficult to tear the cylindrical label L starting from portion E as the fracture starting point.

[0045] In the present embodiment, the peelability improvement layers D1 to D7 are laminated so as to overlap the perforations L1 to L8 in the target portions T1 to T3. However, at least one of the peelability improvement layers D1 to D7 may be arranged at a position slightly separated from the perforations L1 to L8 without overlapping the perforations L1 to L8. In this case, it is preferable that the peelability improvement layers D1 to D7 are located within a range of a distance of 0.001 mm to 1.0 mm from the perforations L1 to L8.

[0046] In addition, in the present embodiment, the peelability improvement layers D1 to D7 are disposed between the perforations that form a pair in the cylindrical label L. However, at least one of the peelability improvement layers D1 to D7 may be disposed outside the perforations that form a pair instead of being disposed between the perforations that form a pair. Further, at least one of the peelability improvement layers D1 to D7 may overlap only one of the perforations that form a pair. Also, the peelability improvement layer may be disposed over the entire or substantially the entire region slightly separated from the perforations in the target portion. In this case, as the portion where the peelability improvement layer is laminated floats during heat shrinkage, the portion where the peelability improvement layer is not laminated also floats, and as a result, a break start point may be formed near the perforations.

[0047] From the viewpoint of improving the functions of the break start points C1 to C4, the length of the peelability improvement layers D1 to D7 in the breaking direction is preferably 0.5 mm or more, more preferably 1.0 mm or more, still more preferably 2.0 mm or more, and even more preferably 3.0 mm or more.

[0048] From the viewpoint of hardness (and thus from the viewpoint of improving the functions of the break start points C1 to C4), the (average) thickness of the peelability improvement layers D1 to D7 is preferably 0.5 μm or more, more preferably 2.0 μm or more, and still more preferably 5 μm or more. Also, the (average) thickness of the peelability improvement layers D1 to D7 is preferably 10 μm or less. The (average) thickness of the peelability improvement layers D1 to D7 can be measured by a method conforming to JIS K7130. Also, the ratio of the (average) thickness of the peelability improvement layers D1 to D7 to the (average) thickness of the film body 4 is preferably 2% or more, more preferably 5% or more, and still more preferably 10% or more. Also, the ratio is preferably 40% or less, more preferably 30% or less, and still more preferably 25% or less. The (average) thickness of the film body 4 can also be measured by a method conforming to JIS K7130. The numerical values described here also apply to the entire printing layer 5 including the peelability improvement layers D1 to D7.

[0049] As the ink constituting the peelability improving layers D1 to D7, it is preferable to use the same ink as that for the other parts in the printing layer 5. When multicolor inks are used for the other parts in the printing layer 5, it is preferable to use the same ink as one color or a plurality of colors among them. In this case, the peelability improving layers D1 to D7 can be formed simultaneously with the other parts in the printing layer 5, and the cost can be suppressed. Further, as the material of the peelability improving layers D1 to D7, from the viewpoint of hardness (and thus, from the viewpoint of improving the functions of the fracture initiation points C1 to C4), it is preferable to use a colored (opaque) ink, for example, a white ink, but a clear ink may also be used. It is not necessary to use the same ink for all of the peelability improving layers D1 to D7, and different inks may be used for each of them.

[0050] A coating agent may be applied to at least any one of above the printing layer 5, between the film body 4 and the printing layer 5, and on the surface of the film body 4 on the side opposite to the printing layer 5 to form a coating layer. Instead of or in addition to this, an additive may be added to the ink constituting the printing layer 5. The ratio of the additive is preferably about 3 to 12 wt% of the entire ink. The coating agent and the additive may include one or more of a curing agent, an antiblocking agent, a surface protecting agent, and an ultraviolet ray preventing agent. Further, as the coating layer, a peeling layer for deinking can also be formed between the film body 4 and the printing layer 5.

[0051] When the above coating agent and / or additive is used (particularly when a curing agent is used), the thermal shrinkage of the fracture initiation points C1 to C4 can be further suppressed, and the functions of the fracture initiation points C1 to C4 can be further improved. Therefore, the above coating layer can constitute the peelability improving layers D1 to D7 together with the printing layer 5 at the positions of the fracture initiation points C1 to C4. Note that when paying attention to the functions of the fracture initiation points C1 to C4, the coating layer may be formed only in the part constituting the peelability improving layers D1 to D7 in the entire printing layer 5. Similarly, the additive may be added only to the ink constituting the peelability improving layers D1 to D7.

[0052] The printing layer 5 may be a single layer or multiple layers. The coating layer may also be a single layer or multiple layers.

[0053] From the perspective of hardness (and thus from the perspective of improving the functions of the fracture initiation points C1 to C4), the ink constituting the peelability improvement layers D1 to D7 preferably contains a pigment. In this case, the average particle size of the pigment is preferably 0.3 μm or more, more preferably 2 μm or more, and even more preferably 5 μm or more. Also, the average particle size of the pigment is preferably 15 μm or less, and more preferably 10 μm or less. Note that the same numerical range also applies to the average particle size of the particles contained in the above-described coating agent and additive. The average particle size can be measured by a laser diffraction particle size distribution measuring device.

[0054] <4. Manufacturing Method> With reference to FIG. 6, an example of the manufacturing method of the above-described heat-shrinkable film 3 and packaging container 1 will be described. However, the heat-shrinkable film 3 and packaging container 1 can be manufactured by various other methods.

[0055] First, a film roll F1 around which the film body 4 is wound is prepared. The film roll F1 is set in a printing machine 40, and the long film body 4 is fed out from the film roll F1. The film body 4 fed out from the film roll F1 sequentially passes through one or more impression cylinders. At this time, when an impression cylinder is pressed against one surface of the film body 4, the ink of the color corresponding to the impression cylinder is transferred. Thereby, a printing layer 5 with a predetermined decorative design is laminated on one surface of the film body 4. Note that the printing method is not limited to this. Thereafter, the film body 4 (heat-shrinkable film 3) on which the printing layer 5 is laminated is appropriately dried by a dryer and then wound up as a film roll F2. Thus, the above-described heat-shrinkable film 3 is manufactured.

[0056] The heat-shrinkable film 3 wound around the film roll F2 is composed of heat-shrinkable films 3 (hereinafter referred to as unit films) that are continuous vertically and horizontally to form a cylindrical label L (hereinafter referred to as a unit label) for one container 2. The vertical direction of the heat-shrinkable film 3 corresponds to the MD (Machine Direction), and the horizontal direction corresponds to the TD (Traverse Direction). Each unit film included in the heat-shrinkable film 3 wound around the film roll F2 is arranged in the same direction. Therefore, as the next step, the heat-shrinkable film 3 wound around the film roll F2 is cut in the vertical direction according to the width of the unit film. Specifically, the film roll F2 is set on the cutting machine 41, and the heat-shrinkable film 3 fed from the film roll F2 is cut in the vertical direction by a cutter, thereby being divided in the horizontal direction. Note that the cutting method is not limited to this. Thereafter, the multiple rows of heat-shrinkable films 3 divided in the horizontal direction are wound as separate film rolls F3. The heat-shrinkable film 3 wound around each film roll F3 is such that the unit films are continuous vertically in a single row.

[0057] Incidentally, as can be seen by referring to FIG. 4, the horizontal ends (left end 4L and right end 4R) of the unit film are clear without the printing layer 5 formed thereon. Therefore, in the cutting machine 41, in the heat-shrinkable film 3 fed from the film roll F2, the position of the clear portion extending in the vertical direction can be detected by an optical sensor (camera), and the cutting position can be determined.

[0058] Next, the film roll F3 is set on the center sealer 42. In the center sealer 42, the heat-shrinkable film 3 fed from the film roll F3 is sealed in the vertical direction and formed into a cylindrical shape. Specifically, both horizontal ends of the heat-shrinkable film 3 are overlapped, and the overlapped portion is continuously sealed in the vertical direction. Thereby, a cylindrical label L in which the unit labels are continuous vertically in a single row is manufactured and then wound as a film roll F4. The sealing method is not particularly limited, and for example, solvent sealing, heat sealing, ultrasonic sealing, etc. are conceivable.

[0059] The sealed portion in the heat-shrinkable film 3 at least partially overlaps the clear both ends (left end 4L and right end 4R) in the lateral direction of the unit film. Therefore, it becomes easy to check the sealed state.

[0060] In the center sealer 42, perforations can also be formed. In the example here, among the above-mentioned perforations L1 to L8, the perforations L5 to L8 that extend straight in the vertical direction are formed while the heat-shrinkable film 3 is being fed out from the film roll F3 and wound up on the film roll F4. The processing method for the perforations extending in the vertical direction is not particularly limited, and for example, laser processing, processing with a sewing blade, etc. can be considered.

[0061] Also, as can be seen by referring to FIGS. 2 and 4, the perforations L5, L6 are formed continuously along the clear portion (corresponding to the left end 4L and the right end 4R) that extends in the vertical direction in the heat-shrinkable film 3 or the cylindrical label L, near the clear portion. Therefore, here, the position of the clear portion can be detected by an optical sensor (camera), and the formation positions of the perforations L5, L6 can be determined. On the other hand, the perforations L7, L8 also extend in the vertical direction in the vicinity of the perforations L5, L6, but are formed only in the vicinity of the lower end 4D. Therefore, the position of the lower end 4D extending in the lateral direction (more precisely, at this stage, since the lower end 4D is connected to the upper end 4U, the positions of the lower end 4D and the upper end 4U) is detected by an optical sensor (camera), and based on this, the formation positions of the perforations L7, L8 can be determined. Although the lower end 4D (and the upper end 4U) partially includes the printing layer 5, since it includes a clear portion, the position of the lower end 4D (and the upper end 4U) can be detected by detecting the position of the clear portion. In addition or instead of this, the position of the clear middle portion 4M can be detected, and based on this, the formation positions of the perforations L7, L8 can be determined.

[0062] Next, the film roll F4 is set on the labeler 43. At the labeler 43, the cylindrical label L unwound from the film roll F4 is attached to each container 2. Specifically, the cylindrical label L unwound from the film roll F4 is cut transversely at predetermined intervals in the longitudinal direction and divided into unit labels. Then, the divided unit labels are placed so as to cover the container 2 from the outside, and the container 2 is inserted into the space inside the unit label. In that state, the unit label is heat-treated in various ways such as blowing hot air or steam. For example, the container 2 covered with the unit label can be heated in a tunnel while passing through the tunnel. Thereby, the unit label thermally contracts and adheres closely to the outer surface of the container 2 along the outer shape of the container 2. Thus, the packaging container 1 is manufactured.

[0063] At the labeler 43, perforations can also be formed. In the example here, among the above-described perforations L1 to L8, the obliquely extending perforations L1 and L2 and the horizontally straight extending perforations L3 and L4 are formed. The processing method of these perforations L1 to L4 is not particularly limited, and for example, laser processing, processing with a sewing blade, etc. are conceivable. Also, the perforations L1 to L4 are preferably formed before the cylindrical label L is attached to the container 2.

[0064] As shown in FIGS. 1 and 4, the perforations L1 and L2 are formed only at the upper part of the unit film or unit label. Therefore, by detecting the position of the clear portion included in the upper end portion 4U (when the upper end portion 4U and the lower end portion 4D are still connected at this stage, the upper end portion 4U and the lower end portion 4D) with an optical sensor (camera), the longitudinal formation position of the perforations L1 and L2 can be determined based on this. Instead of or in addition to this, the longitudinal formation position of the perforations L1 and L2 may be determined based on detecting the position of the clear middle portion 4M with an optical sensor (camera). Similarly, the longitudinal formation position of the perforations L3 and L4 can also be determined based on the positions of the upper end portion 4U, the lower end portion 4D, and / or the middle portion 4M detected by the optical sensor (camera).

[0065] Also, the lateral formation positions of the perforations L1 and L2 can be determined based on the positions of the clear portions included in the upper end portion 4U and the lower end portion 4D detected by an optical sensor (camera). That is, based on the positions of the clear portions included in the upper end portion 4U and the lower end portion 4D, the position of the peelability improvement layer D1 can be specified, and based on the position of the peelability improvement layer D1, the lateral formation positions of the perforations L1 and L2 can be determined.

[0066] <5. Modification Example> As described above, one embodiment of the present invention has been explained. However, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit thereof. For example, the following modifications are possible.

[0067] <5-1> In the above embodiment, a part of the printing layer 5 constitutes the peelability improvement layers D1 to D7. However, the printing layer 5 may not be included in the peelability improvement layers D1 to D7, and the peelability improvement layers D1 to D7 may be composed only of the coating layers described above. <5-2> In the above embodiment, in the cylindrical label L, two perforations are configured to be paired. However, along one breaking direction, only one perforation may be formed, or three or more parallel perforations may be formed.

[0068] <5-3> In the printing layer 5, the shape of at least any one of the peelability improvement layers D1 to D7 may be made into a stripe, polka dot, character shape, etc., to give a design property.

[0069] <5-4> Prior to heat shrinkage for attaching the cylindrical label L to the container 2, at least one of the break start points C1 to C4 may be preliminarily heat shrunk to thicken and harden the break start point. In this case, the function of the break start point can be improved. Also, in this case, it is preferable to make the total thickness of the break start point after preliminary heat shrinkage about 5 to 20% thicker than before preliminary heat shrinkage.

[0070] <5―5> In the above embodiment, as shown in FIG. 2, the perforations L5 to L8 for peeling the lower film portion 32 were formed near the seal portion O1 of the cylindrical label L. However, alternatively or additionally, for example, as shown in FIG. 7, the perforations L9 to L12 for peeling the lower film portion 32 may be formed outside the vicinity of the seal portion O1 of the cylindrical label L. In the example of FIG. 7, the perforations L9 and L10 are horizontally aligned with the perforations L1 and L2, respectively, in the lower film portion 32 and extend in the vertical direction. In the vicinity of the perforations L9 and L10, a peelability improving layer D8 is formed in the target portion T2, and a peelability improving layer D9 is formed in the target portion T3. Thereby, the fracture initiation points C5 and C6 are formed. On the other hand, the perforations L11 and L12 also extend in the vertical direction in the lower film portion 32, but in the upper film portion 31, no perforations are formed at positions corresponding horizontally to the perforations L11 and L12. In the vicinity of the perforations L11 and L12, a peelability improving layer D10 is formed in the target portion T2, and a peelability improving layer D11 is formed in the target portion T3. Thereby, the fracture initiation points C7 and C8 are formed.

Explanation of Symbols

[0071] 1 Packaging container 2 Container 20 Main body portion 21 Bottom surface portion 22 Body portion 23 Cap attachment portion 25 Cap 25S Side surface portion 25T Top surface portion 3 Heat-shrinkable film 31 Film upper portion 31A Opening portion 31B Remaining portion 32 Film lower portion 4 Film body 4D Lower end portion 4L Left end portion 4M Middle portion 4R Right end portion 4U Upper end portion 5 Printing layer 5D Lower part 5U Upper part 40 Printing machine 41 Cutting machine 42 Center sealing machine 43 Labeler C1 - C8 Breaking start points D1 - D7, D9 - D11 Peelability improvement layer D8 Area (peelability improvement layer) F1 - F4 Film rolls L Tubular label L1 - L12 Perforations O1 Overlapped part (sealing part) T1 - T3 Target parts

Claims

1. A heat-shrinkable film to be attached as a cylindrical label to a container, comprising a film body with perforations formed therein, wherein the perforations extend such that when the heat-shrinkable film is attached to the container as the cylindrical label, the cylindrical label can be peeled off from the container by breaking the cylindrical label along the perforations, a peelability-improving layer is laminated in the vicinity of the perforations in a target portion of the film body, the target portion is a portion that becomes an axial end portion of the cylindrical label when the cylindrical label is peeled off, heat-shrinkable film.

2. The peelability-improving layer is a printing layer or a coating layer, The heat-shrinkable film according to claim 1.

3. The peelability-improving layer is intermittently laminated along the entire circumference of the target portion in the target portion, The heat-shrinkable film according to claim 1 or 2.

4. The peelability-improving layer is laminated in the target portion so as to overlap the perforations, The heat-shrinkable film according to claim 1 or 2.

5. A cylindrical label formed of the heat-shrinkable film according to claim 1 or 2, and a container with the cylindrical label attached thereto comprising a packaging container.

Images