Layered container

Abstract

To propose a laminated container capable of facilitating recycling while suppressing an environmental load.SOLUTION: A laminated container 1 comprises: a trunk part 10 for storing a content; a mouth part 30 continued with an upper end of the trunk part 10; a synthetic resin container layer 50 having a bottom part 40 for closing a lower end of the trunk part 10; and a synthetic resin label layer 60 for covering at least a part of the trunk part 10 from an outer side. In an area where the label layer 60 is formed, the container layer 50 is thicker in thickness than the label layer 60, an outermost face of the container layer 50 and an innermost face of the label layer 60 each are formed of a peelable material, one of the container layer 50 and the label layer 60 is larger in specific gravity than liquid used for specific gravity separation, and the other one of the container layer 50 and the label layer 60 is smaller in specific gravity than the liquid used for the specific gravity separation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laminated container. [Background technology]

[0002] Due to social demands such as reducing the burden on the environment, there is a demand for recycling synthetic resin containers. On the other hand, containers are widely used that have been decorated on the body of the container by printing, transferring, vapor deposition, painting, or other means to enhance their appearance, or that display a trademark, product name, manufacturer name, or description of the contents (for example, Patent Document 1). When trying to recycle these containers, it is difficult to completely remove the ink, etc. used for printing, making it difficult to separate and recycle the containers.

[0003] To address these problems, for example, Patent Document 2 proposes a container that is made easier to recycle by wrapping a shrink label displaying the product name and a description of the contents around the body and cap of the container and removing the shrink label from the container body when recycling. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-149910 A [Patent Document 2] JP 2012-176760 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the shrink-labeled container described in Patent Document 2, it is necessary to prepare a shrink label separately from the container body, and if attempts are made to thin the container body in consideration of the burden on the environment, it can become difficult to attach the shrink label, and there is room for improvement in this regard.

[0006] The present invention is intended to solve these problems, and has an object to propose a laminated container that can be easily recycled while reducing the burden on the environment. [Means for solving the problem]

[0007] The laminated container of the present invention comprises a synthetic resin container layer having a body for accommodating contents, a mouth connected to the upper end of the body, and a bottom for closing the lower end of the body, and a synthetic resin label layer laminated on the outside of the container layer so as to cover the entire container layer, wherein in the region where the label layer is formed, the thickness of the container layer is greater than the thickness of the label layer, and the outermost surface of the container layer and the innermost surface of the label layer are formed of materials which can be peeled off from each other, The label layer has an easy-to-tear layer that is in contact with the outermost surface of the container layer and a difficult-to-tear layer that is provided outside the break layer, and the label layer has an easy-to-tear portion that does not have the difficult-to-tear layer and extends from the bottom to the upper end of the mouth, The present invention is characterized in that the specific gravity of one of the container layer and the label layer is greater than the specific gravity of the liquid used for gravity separation, and the specific gravity of the other of the container layer and the label layer is smaller than the specific gravity of the liquid used for gravity separation.

[0008] In the laminated container of the present invention having the above-mentioned configuration, the label layer is preferably decorated.

[0010] In the laminated container of the present invention having the above configuration, it is preferable that the difference in specific gravity between the container layer and the label layer based on the liquid, when the liquid is water, is 0.07 or more.

[0011] In the stacked container of the present invention having the above configuration, the liquid used for gravity separation is preferably water. Effect of the Invention

[0012] According to the present invention, it is possible to propose a laminated container that can be easily recycled while suppressing the burden on the environment. [Brief description of the drawings]

[0013] [Figure 1]1 is a partially cutaway front view of a stacked container according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the laminated container shown in FIG. [Diagram 3] FIG. 2 is a bottom view of the laminated container shown in FIG. [Figure 4] FIG. 2 is an enlarged cross-sectional view of part A in FIG. [Diagram 5] 2 is a cross-sectional view of the easy-tear portion shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a laminated container 1 according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0015] As shown in Figures 1, 2, and 3, the stacked container 1 has a bottle shape including a cylindrical body 10 that is approximately elliptical in a plan view and forms a storage space S for storing the contents, a mouth 30 that is connected to the upper end of the body 10 via a shoulder 20 and supplies and discharges the contents, and a bottom 40 that closes the lower end of the body 10.

[0016] The outer circumferential surface of the mouth portion 30 is integrally provided with a male thread portion 31 to which a cap, a pump, etc. can be attached by threaded engagement.

[0017] The bottom 40 has a peripheral edge 41 and a recess 42 that is raised from the peripheral edge 41, and a knob 43 extending in the left-right direction of the figure is formed in the recess 42. The knob 43 is provided along a pinch-off portion 44 on the bottom 40 that extends in the left-right direction of the figure.

[0018] In the laminated container 1, the entire area of ​​the body 10, shoulder 20, mouth 30 and bottom 40 is formed by a container layer 50 made of synthetic resin, which is shown partially in cross section in FIG.

[0019] In this specification and claims, "upper" and "lower" respectively refer to "upper" and "lower" when the stacked container 1 is in an upright position with the mouth 30 facing upward relative to the body 10 as shown in Fig. 1. In addition, in describing the layer structure of the stacked container 1, the side of the storage space S is defined as the inside, and the opposite side is defined as the outside.

[0020] 1 and 4, the laminated container 1 includes a synthetic resin label layer 60 laminated on the outside of the container layer 50 so as to cover at least a portion of the body 10 of the container layer 50 from the outside. In this embodiment, the label layer 60 is laminated on the outside of the container layer 50 so as to cover not only the body 10 of the container layer 50 but the entire container layer 50.

[0021] The label layer 60 can be decorated by, for example, printing, transfer, vapor deposition, painting, or the addition of a coloring material. For example, a master batch to which a pigment has been added can be used as a coloring material for decorating the label layer 60. The decoration applied to the label layer 60 can be, for example, a design that evokes an aesthetic feeling in the user, a trademark, a product name, a manufacturer name, or an explanation of the contents.

[0022] The thickness of the container layer 50 is greater than the thickness of the label layer 60 in the entire area where the label layer 60 is laminated. That is, the container layer 50 has a body 10, a shoulder 20, a mouth 30, and a bottom 40, and forms the skeleton of the laminated container 1.

[0023] The outermost surface of the container layer 50 and the innermost surface of the label layer 60 are formed of materials that can be peeled off from each other. That is, the label layer 60 laminated on the outside of the container layer 50 can be removed from the container layer 50 and separated by peeling it off from the container layer 50. This allows the label layer 60, which has been decorated by printing or the like, to be removed from the container layer 50 when recycling the laminated container 1, and the container layer 50 and the label layer 60 can be separated and recycled separately.

[0024] The laminated container 1 having the above configuration is formed into a laminated structure in which the label layer 60 is peelably laminated on the outside of the container layer 50 by extrusion blow molding a laminated parison having a synthetic resin layer corresponding to the container layer 50 and a synthetic resin layer corresponding to the label layer 60. Therefore, the laminated container 1 having the label layer 60 removably provided on the outside of the container layer 50 can be easily and inexpensively manufactured without performing a task of attaching a removable shrink label as a post-process on the outside of the container body formed by blow molding.

[0025] The specific gravity of one of the container layer 50 and the label layer 60 is greater than that of the liquid used for gravity separation, and the specific gravity of the other is less than that of the liquid used for gravity separation. In this embodiment, it is assumed that water is used as the liquid used for gravity separation, and the container layer 50 has a specific gravity of less than 1 based on water, and the label layer 60 has a specific gravity of more than 1 based on water. As described above, by setting the specific gravity of the container layer 50 and the specific gravity of the label layer 60 to be such that gravity separation can be performed using water, the container layer 50 and the label layer 60 can be easily separated from each other using equipment that uses water as the liquid for gravity separation, which is currently used in many recycling facilities.

[0026] The laminated container 1 is configured so that the label layer 60 can be removed from the container layer 50, and the container layer 50 and the label layer 60 can be separated and recycled separately. However, if the laminated container 1 is recycled as is without peeling the label layer 60 from the container layer 50, there is a risk that the synthetic resin material constituting the container layer 50 will be mixed with the synthetic resin material constituting the label layer 60 and the master batch for decoration, resulting in a decrease in the purity of the synthetic resin material after recycling.

[0027] In contrast, in the laminated container 1 of this embodiment, one of the container layer 50 and the label layer 60 has a specific gravity greater than that of the liquid used for the specific gravity separation, and the other has a specific gravity less than that of the liquid used for the specific gravity separation. Therefore, even if the laminated container 1 is recycled as is without peeling the label layer 60 from the container layer 50, in the specific gravity separation using the liquid, one of the container layer 50 and the label layer 60 sinks in the liquid and the other floats in the liquid, so that the container layer 50 and the label layer 60 can be easily separated by the specific gravity separation. This can increase the recyclability of the laminated container 1 or the purity of the synthetic resin material after recycling. In addition, the separation by specific gravity separation of the laminated container 1 is performed after the laminated container 1 is finely crushed, so that the label layer 60 can be peeled off and separated from the container layer 50 by the specific gravity separation.

[0028] In the stacked container 1 of this embodiment, the difference between the specific gravity of the container layer 50 and the specific gravity of the label layer 60 is preferably 0.07 or more. This allows the container layer 50 and the label layer 60 to be separated more easily and reliably in gravity separation, thereby improving the recyclability of the stacked container 1, and also allows equipment that uses water as the liquid for gravity separation, which is currently used in many recycling facilities, to be more easily used as equipment for separating the container layer 50 and the label layer 60 by gravity separation.

[0029] The container layer 50 is preferably formed of a single synthetic resin material. With this, the separation of the container layer 50 can be completed by peeling off the label layer 60, and the container layer 50 can be used as a single material for recycling. This further enhances the recyclability of the laminated container 1.

[0030] In addition, it is preferable that the container layer 50 does not contain a coloring material. Since the container layer 50 does not contain a coloring material, the container layer 50 can be used as a recyclable material that does not contain a coloring material. Therefore, the recyclability of the laminated container 1 can be further improved.

[0031] The container layer 50 may be formed from a mixture of the above-mentioned synthetic resin material with recycled material of the synthetic resin material, or may be formed only from the recycled material, or may be configured by laminating a layer formed from the above-mentioned synthetic resin material and a layer formed from the recycled material.

[0032] As shown in Fig. 4, the label layer 60 may be configured such that a fracture layer 61, an adhesive layer 62, and a fault-resistant layer 63 are laminated from the inside to the outside. The fracture layer 61 is made of a synthetic resin material with a tensile fracture strain of 5% or less, and is configured so that a sorter can easily fracture it. In contrast, the fault-resistant layer 63 is made of a synthetic resin material with a tensile fracture strain of 50% or more, and is configured so that a sorter cannot easily fracture it. The adhesive layer 62 is made of a synthetic resin material that can bond the fracture layer 61 and the fault-resistant layer 63 together.

[0033] As shown in Fig. 1, the label layer 60 is provided with two easy-to-tear portions 64 extending in a substantially vertical direction. In this embodiment, the two easy-to-tear portions 64 each extend in a substantially vertical direction from the gripping portion 43 of the bottom portion 40 to the upper end of the mouth portion 30. As shown in Fig. 5, the adhesive layer 62 and the hard-to-fracture layer 63 are not provided in the portion of the label layer 60 where the two easy-to-tear portions 64 are provided, and the label layer 60 is formed only by the fracture layer 61. In this embodiment, the easy-to-tear portions 64 are provided laterally from the center position on the front side, but are not limited to this aspect and may be provided at any circumferential position.

[0034] The pinch-off portion 44 is formed by cutting off the label layer 60 with the blow molding die when the laminated container 1 is extrusion blow molded, so that the label layer 60 is not fused at the pinch portion 43. Therefore, the sorter can peel the part sandwiched between the two easy-to-tear portions 64 of the label layer 60 upward along the two easy-to-tear portions 64 from the pinch portion 43 of the bottom portion 40, and the part can be peeled upward from the container layer 50 while being separated from the other parts of the label layer 60. At this time, since the hard-to-fracture layer 63 is provided in the other parts of the label layer 60, the part sandwiched between the two easy-to-tear portions 64 of the label layer 60 can be peeled off without deviating from the two easy-to-tear portions 64. Then, when the part sandwiched between the two easy-to-tear portions 64 of the label layer 60 is removed, the label layer 60 is in a state where a part of its circumferential direction is cut out, so that the sorter can easily remove the label layer 60 from the container layer 50 and separate it.

[0035] Thus, in this embodiment, the label layer 60 has an easy-to-tear break layer 61 abutting the outermost surface of the container layer 50, and a difficult-to-tear layer 63 located on the outside of the break layer 61 and difficult to break, and the label layer 60 in a part of the body 10 is provided with an easy-tear portion 64 that does not have the difficult-to-tear layer 63, making it possible to easily separate the label layer 60 from the container layer 50.

[0036] In the laminated container 1 having the above-mentioned configuration, the container layer 50 can be formed, for example, from polypropylene resin (PP) having a specific gravity of 0.91 to 0.92.

[0037] Meanwhile, in the laminated container 1 having the above configuration, the label layer 60 can be configured by laminating two layers formed of, for example, two types of polystyrene resin (PS) having different tensile breaking strains. By using polystyrene resin as the synthetic resin material forming the label layer 60, the label layer 60 can be configured to be easily peeled off from the container layer 50 formed of polypropylene resin, while having an overall specific gravity of greater than 1. In addition, by laminating two layers formed of two types of polystyrene resin having different tensile breaking strains, the label layer 60 can be configured to be easily separated from the container layer 50 by providing an easy-tear portion 64.

[0038] Specifically, the label layer 60 can be configured by laminating a fracture-resistant layer 63 formed of a polystyrene resin layer having a tensile fracture strain of 50% or more (e.g., "SGP10" manufactured by PS Japan Co., Ltd., specific gravity 1.05, tensile fracture strain 3%) mixed with a colored master batch (MB) on the outside of a fracture layer 61 formed of a polystyrene resin layer having a tensile fracture strain of 50% or more (e.g., "475-D" manufactured by PS Japan Co., Ltd., specific gravity 1.04, tensile fracture strain 50%) without sandwiching an adhesive layer 62. This configuration makes it easy to peel the label layer 60 from the container layer 50, and also makes it possible to easily separate the label layer 60 from the container layer 50 by providing an easy-to-tear portion 64, while making the label layer 60 highly aesthetically colored when viewed from the outside.

[0039] The label layer 60 may also be configured such that a fracture-resistant layer 63 formed of a polystyrene resin layer having a tensile fracture strain of 50% or more (e.g., "SGP10" manufactured by PS Japan Co., Ltd., specific gravity 1.05, tensile fracture strain 3%) mixed with a glossing agent and having a tensile fracture strain of 50% or more (e.g., "475-D" manufactured by PS Japan Co., Ltd., specific gravity 1.04, tensile fracture strain 50%) is laminated on the outside of a fracture layer 61 formed of a polystyrene resin layer having a tensile fracture strain of 5% or less (e.g., "SGP10" manufactured by PS Japan Co., Ltd., specific gravity 1.05, tensile fracture strain 3%) without sandwiching an adhesive layer 62. This configuration makes it easy to peel the label layer 60 from the container layer 50, and also makes it possible to easily separate the label layer 60 from the container layer 50 by providing an easy-to-tear portion 64, while giving the label layer 60 a glossy and aesthetically pleasing appearance when viewed from the outside.

[0040] Furthermore, the label layer 60 may be configured such that a fracture-resistant layer 63 formed of a polystyrene resin layer having a tensile fracture strain of 50% or more (e.g., "SGP10" manufactured by PS Japan Co., Ltd., specific gravity 1.05, tensile fracture strain 3%) mixed with a light-shielding master batch (MB) is laminated on the outside of the fracture layer 61 formed of a polystyrene resin layer having a tensile fracture strain of 50% or more (e.g., "475-D" manufactured by PS Japan Co., Ltd., specific gravity 1.04, tensile fracture strain 50%) without sandwiching an adhesive layer 62. This configuration makes it easy to peel the label layer 60 from the container layer 50, and also provides the label layer 60 with light-shielding properties while providing an easy-tear portion 64 to easily separate the label layer 60 from the container layer 50.

[0041] Furthermore, the label layer 60 may be configured such that a fracture-resistant layer 63 formed of a polystyrene resin layer (e.g., "475-D" manufactured by PS Japan Co., Ltd., specific gravity 1.04, tensile fracture strain 50%) having a tensile fracture strain of 50% or more is laminated on the outside of a fracture layer 61 formed of an ethylene-vinyl alcohol copolymer resin (e.g., EVOH "DC3203RB" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., specific gravity 1.19) via an adhesive layer 62 (e.g., "SE800" manufactured by Mitsui Chemicals, Inc., specific gravity 0.90). This configuration makes it easy to peel the label layer 60 from the container layer 50, and also provides the label layer 60 with gas barrier properties while providing an easy-to-tear portion 64 to make the label layer 60 easily separable from the container layer 50. Since the lower the ethylene content of an ethylene-vinyl alcohol copolymer resin, the higher its specific gravity, by using an ethylene-vinyl alcohol copolymer resin with a lower ethylene content as the rupture layer 61, the label layer 60 can be more easily separated from the container layer 50 in gravity separation.

[0042] Regardless of the layer structure, the label layer 60 is set to have an overall specific gravity of greater than 1, and therefore can be easily separated from the container layer 50 by gravity separation.

[0043] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention.

[0044] For example, the container layer 50 is not limited to the polypropylene resin described above, but may also be formed primarily from synthetic resin materials such as high density polyethylene resin (HDPE) with a specific gravity of 0.95 to 0.97, low density polyethylene resin (LDPE) with a specific gravity of 0.92 to 0.93, linear low density polyethylene resin (LLDPE) with a specific gravity of 0.92 to 0.94, or ionomer resin with a specific gravity of 0.94 to 0.96.

[0045] Since all of these materials have a specific gravity of less than 1, the container layer 50 can be configured to be separable from the label layer 60 by gravity separation using water.

[0046] Furthermore, when the container layer 50 is formed mainly from a high-density polyethylene resin, it is possible to impart high water vapor barrier properties, chemical resistance, and impact resistance to the laminated container 1. Furthermore, when the container layer 50 is formed mainly from a low-density polyethylene resin or a linear low-density polyethylene resin, it is possible to impart high flexibility and impact resistance to the laminated container 1. Furthermore, when the container layer 50 is formed mainly from an ionomer resin, it is possible to impart high transparency, impact resistance, and flexibility to the laminated container 1.

[0047] Instead of the polystyrene resin described above, the label layer 60 may be made of, for example, polyamide resin (nylon 6, specific gravity 1.12), polycarbonate resin (PC, specific gravity 1.20), polyethylene terephthalate resin (PET) with a specific gravity greater than 1, PCTG resin (specific gravity 1.27), PET-G resin (specific gravity 1.27), PCTA resin (specific gravity 1.25), etc.

[0048] Since all of these materials have a specific gravity greater than 1, the label layer 60 can be configured to be separable from the container layer 50 by gravity separation using water.

[0049] Furthermore, the label layer 60 is not limited to a configuration that covers the entire container layer 50, but may be a configuration that covers at least a portion of the container layer 50 in the body portion 10.

[0050] Furthermore, in the above embodiment, a male thread portion 31 is provided on the outer peripheral surface of the mouth portion 30 so that an attachment cap, pump, etc. can be attached by threaded engagement, but instead of the male thread portion 31, the mouth portion 30 may be provided with an annular protrusion for attaching an attachment cap, pump, etc. by plugging engagement.

[0051] Furthermore, in the above embodiment, the laminated container 1 is formed by extrusion blow molding, but this is not limited to the above. The laminated container 1 may be formed, for example, by two-color molding, or may be formed by setting a preform assembly combining an inner preform corresponding to the container layer 50 and an outer preform corresponding to the label layer 60 in a mold and performing stretch blow molding.

[0052] Furthermore, the laminated container 1 is not limited to a bottle shape, and may be a rectangular container, a pouch container, a cup container, or the like. [Explanation of symbols]

[0053] 1. Layered container 10. Torso 20 Shoulder 30 Mouth 31 Male thread 40 bottom 41 Periphery 42 Recess 43 Knob 44 Pinch-off section 50 container layer 60 Label Layers 61 Fracture Layer 62 Adhesive layer 63 Difficult Fault 64 Easily tearable part S Storage space O center axis

Claims

1. a synthetic resin container layer having a body portion for accommodating contents, a mouth portion connected to an upper end portion of the body portion, and a bottom portion closing a lower end portion of the body portion; A label layer made of a synthetic resin is laminated on the outside of the container layer so as to cover the entire container layer, In the region where the label layer is formed, the thickness of the container layer is greater than the thickness of the label layer, The outermost surface of the container layer and the innermost surface of the label layer are formed of materials that can be peeled off from each other, The label layer has an easy-to-break breakable layer that abuts against the outermost surface of the container layer, and a hard-to-break layer that is provided outside the breakable layer, The label layer has an easy-tear portion that does not have the difficult-to-fracture layer and extends from the bottom portion to the upper end of the mouth portion, A stacked container characterized in that one of the container layer and the label layer has a specific gravity greater than the specific gravity of the liquid used for gravity separation, and the other of the container layer and the label layer has a specific gravity less than the specific gravity of the liquid used for gravity separation.

2. The laminated container according to claim 1 , wherein the label layer is decorated.

3. 3. The laminated container according to claim 1, wherein the difference in specific gravity between the container layer and the label layer is 0.07 or more.

4. The laminated container according to any one of claims 1 to 3, wherein the liquid used for gravity separation is water.

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