Laminated container

Abstract

To provide a laminated container that allows for easy separation and sorting of the outer and inner layers.SOLUTION: A laminated container made of synthetic resin includes: an inner layer 6 that holds the contents; and an outer layer 7 that covers the inner layer 6 and is laminated on the outer surface of the inner layer 6. A partition 8 is provided on the outer surface of the inner layer 6, which is formed from a synthetic resin material that is compatible with the inner layer 6 and is incompatible with the outer layer 7. The outer layer 7 is formed from a synthetic resin material that is incompatible with both the inner layer 6 and the partition 8. The laminated container is structured such that the inner layer 6 and the partition 8 are laminated together in a fused state.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a laminated container that can be easily separated into an outer layer and an inner layer.

Background Art

[0002] Generally, high-viscosity contents such as emulsions, mayonnaise, and dressings tend to adhere to the wall surface of the container or accumulate at the bottom, and thus cannot be used up to the end and easily remain as residual liquid in the container. Since the container containing the residual liquid is discarded as garbage, consumers feel that the residual liquid is wasted, and the container may not be recyclable. For this reason, there is a demand for a container that reduces the remaining amount of the content.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a conventional method for reducing the remaining amount, for example, in an extrusion container, a pair of extrusion portions 9 projecting convexly are provided on the inner surface of the shoulder portion where the content is likely to remain, and by pushing in the pair of extrusion portions 9, it is known that the residual content can be effectively extruded (see, for example, Patent Document 1), but there is still room for improvement in completely removing the content adhering to the inner wall and the bottom. Further, in a laminated container in which an inner layer is laminated on the inner wall of the outer layer, since the outer layer does not come into contact with the content and can be recycled, and the inner layer leads to a reduction in the remaining amount by squeezing, a mechanism for separating and sorting the outer layer and the inner layer is required.

[0005] In order to solve the problems in the above-mentioned prior art, an object of the present invention is to create a laminated container that can easily separate and classify the outer layer and the inner layer so as to achieve both a reduction in the remaining amount and an improvement in recyclability.

Means for Solving the Problems

[0006] Among the means for solving the above problems, the first means of the present invention is a laminated container made of synthetic resin in which an inner layer for containing contents and an outer layer covering the inner layer on the outer surface of the inner layer are laminated, a dividing portion formed of a synthetic resin material that is compatible with the inner layer and incompatible with the outer layer is provided on the outer surface of the inner layer, the outer layer is formed of a synthetic resin material that is incompatible with the inner layer and the dividing portion, characterized in that the inner layer and the dividing portion are laminated in a fused state.

[0007] The second means of the present invention is the addition of the means that the dividing portion has a substantially mountain-shaped cross section to the first means.

[0008] The third means of the present invention is the addition of the means that the dividing portion is formed of a synthetic resin obtained by mixing a first synthetic resin material that is compatible with the inner layer and incompatible with the outer layer and a second synthetic resin material that is compatible with the outer layer to the first or second means, and the mixing ratio of the first synthetic resin material and the second synthetic resin material is in the range of 95:5 to 70:30.

[0009] The fourth means of the present invention is the addition of the means that the outer layer is covered with a separable coating layer to the first or second means.

[0010] The fifth means of the present invention is a laminated container made of synthetic resin in which an inner layer for containing contents and an outer layer covering the inner layer on the outer surface of the inner layer are laminated, On the inner surface of the outer layer, there is provided a synthetic resin material that is compatible with the outer layer and incompatible with the inner layer, and a dividing portion formed of a synthetic resin material that is incompatible with the inner layer is provided. The inner layer is formed of a synthetic resin material that is incompatible with the outer layer and the dividing portion. It is characterized in that the outer layer and the dividing portion are laminated in a fused state.

[0011] Further, the sixth means of the present invention is obtained by adding to the first or second means the means of providing a gripping portion or a pushing-in portion that protrudes radially outward on the dividing portion.

Advantages of the Invention

[0012] In the laminated container of the present invention, separation between the outer layer and the inner layer can be prevented during use. Also, after use, since the outer layer and the inner layer can be easily separated, by separating the outer layer and the inner layer, the reduction of the remaining amount of the content and the recyclability can be improved.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a laminated container showing a first embodiment of the present invention, FIG. 2 is a bottom view of the laminated container, and FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1. In FIGS. 1 and 2, for convenience of explanation, the outer layer 7 is shown colored in black, and the divided portion 8 is shown without coloring (uncolored). In the following, the direction along the container axis O will be referred to as the axial direction, the vertical direction, or the height direction, the direction orthogonal to the container axis O will be referred to as the radial direction, and the direction of orbiting around the container axis O will be referred to as the circumferential direction for explanation.

[0015] The laminated container 1 of the present invention is a container suitable for containing relatively high-viscosity contents such as paste-like or paste-like foods such as mayonnaise, ketchup, and dressing, or creamy cosmetics and facial cleansers, but is not limited thereto and may contain low-viscosity contents. The laminated container 1 is a bottomed cylindrical container made of synthetic resin in which a cylindrical body portion 4 is continuously provided via a diameter-expanded shoulder portion 3 at the lower end of a short cylindrical mouth portion 2, and a bottom portion 5 that closes the lower end of the body portion 4 is provided. A neck ring 2A is provided around the mouth portion 2. When discharging the contents, it is used with a discharge cap or the like (not shown) attached to the mouth portion 2.

[0016] As shown in FIG. 3, the laminated container 1 has an inner layer 6 and an outer layer 7 covering the outer surface thereof, and is formed in a state where the outer layer 7 is laminated on the outside of the inner layer 6. Further, at least one position in the circumferential direction of the outer surface of the inner layer 6, a dividing portion 8 having a substantially mountain-shaped cross section that protrudes into the outer layer 7 toward the radially outer side is fusion-bonded and disposed, and a slit 7A having a substantially valley-shaped cross section into which the dividing portion 8 can be inserted is formed to open on the inner surface of the outer layer 7 facing this. The protruding dimension of the dividing portion 8 in the radial direction is set to the same dimension as the wall thickness of the outer layer 7. Further, as shown in FIG. 1, both the dividing portion 8 and the slit 7A are arranged in a longitudinal strip shape along the axial direction, and an outer end portion 8a provided on the radially outer side of the dividing portion 8 is exposed to the outside through the slit 7A. And in this state, the outer end portion 8a and the outer surface of the outer layer 7 are in a flush state without a step. That is, the slit 7A and the outer end portion 8a of the dividing portion 8 exposed from the slit 7A constitute a part of the outer surface of the outer layer 7. Such a dividing portion 8 and slit 7A are formed, for example, between the upper opening end 2a of the mouth portion 2 and the center of the bottom portion 5. Incidentally, the dividing portion 8 only needs to penetrate the outer layer 7, and its cross-sectional shape is not limited to the substantially mountain shape as described above. Also, the "substantially mountain shape" mentioned here means a shape in which the width dimension in the circumferential direction gradually decreases from the inner side to the outer side in the radial direction.

[0017] The dividing portion 8 has a function as a starting point for peeling between the inner layer 6 and the outer layer 7 during separation after use. However, when the circumferential width of the outer end portion 8a is less than 0.5 mm, the starting point for peeling becomes thin and it becomes difficult to divide, and when it exceeds 50 mm, there is a concern that unexpected separation may occur between the inner layer 6 and the outer layer 7 during use. For this reason, the width of the outer end portion 8a constituting the dividing portion 8 is appropriately in the range of 0.5 mm or more and 50 mm or less, and more preferably in the range of 3 to 15 mm.

[0018] Here, the inner layer 6 and the dividing part 8 are formed in a fused state by using the same kind of compatible material, while the outer layer 7 is formed by using a different kind of material that is incompatible with the inner layer 6 and the dividing part 8 and is difficult to fuse. Thus, when the outer end 8a of the dividing part 8 exposed from the slit 7A of the outer layer 7 is pressed radially inward, the inner layer 6 and the outer layer 7 can be separated starting from the dividing part 8. After separation, a longitudinal strip-shaped slit 7A remains on the outer surface of the outer layer 7. By pushing the outer layer 7 open in the circumferential direction with this slit 7A as the boundary, the outer layer 7 can be split into two. Therefore, after the contents are used up, by pressing the dividing part 8 radially inward to separate the inner layer 6 and the outer layer 7, and then forcibly expanding the slit 7A in the circumferential direction, the inner layer 6 can be pulled out from the outer layer 7 to separate the inner layer 6 and the outer layer 7. Thereby, for the inner layer 6, the residual amount reduction property can be improved by squeezing out the contents until the end, and for the outer layer 7 that the contents do not directly touch, it can be recycled. In addition, the inner layer 6 separated from the outer layer 7 may be separated by pulling it out through the mouth part 2.

[0019] On the other hand, the dividing part 8 is basically formed of the same kind of resin material that is compatible with the inner layer 6, but it may also be configured to add and mix a small amount of the incompatible resin material that forms the outer layer 7 to this resin material. When the resin material that forms the outer layer 7 is mixed in a small amount in the dividing part 8 in this way, it becomes possible to increase the fusing force (adhesive force) between the dividing part 8 and the slit 7A of the outer layer 7 facing it, so that the dividing part 8 and the slit 7A do not easily peel off during use. Therefore, for example, even if an impact such as dropping is applied to the laminated container 1, the initial form in which the dividing part 8 fits into the slit 7A can be maintained, so that it is possible to prevent the appearance of the laminated container 1 from being damaged. Also, after use when the contents are used up, it is possible to separate the inner layer 6 and the outer layer 7 in the same manner as described above.

[0020] In the above, as the synthetic resin material used for manufacturing the laminated container 1, for example, the inner layer 6 can be formed of polypropylene (PP) resin, and the outer layer 7 can be formed of polyethylene terephthalate (PET) resin. In this case, if the adhesive force between the dividing portion 8 and the slit 7A is too weak, it is likely to peel off, and if it is too strong, it will not peel off and separation will be difficult. For this reason, the dividing portion 8 is preferably formed using a synthetic resin material obtained by mixing a first synthetic resin material having compatibility with the inner layer 6 and non-compatibility with the outer layer 7, and a second synthetic resin material having compatibility with the outer layer 7. In this case, it is preferable to use the same resin material as the inner layer for the first synthetic resin material and the same resin material as the outer layer for the second synthetic resin material. And in this case, the amount of the second synthetic resin material added is appropriately in the range of 1% to 30%. If it is less than 1%, it is likely to separate during use, and if it exceeds 30%, it will be difficult to separate when discarded. That is, the mixing ratio of the first synthetic resin material to the second synthetic resin material (first synthetic resin material: second synthetic resin material) is preferably in the range of 95:5 to 70:30. Also, the amount of the second synthetic resin material added is more preferably in the range of 5% to 20%. In addition, as examples of other combinations (outer layer / inner layer) of the outer layer 7 and the inner layer 6, there can be polyamide (PA, nylon) / PP, polyethylene (PE) / ethylene vinyl alcohol copolymer resin (EVOH), PP / EVOH, EVOH / PE, EVOH / PP, PA / PET, etc.

[0021] In addition, in FIGS. 1 and 2, the outer layer 7 is colored black and the dividing portion 8 constituting the dividing portion 8 is described as uncolored (not colored). However, the outer layer 7, the dividing portion 8, and the inner layer 6 may be formed of a colored synthetic resin material, or may be formed of a transparent or translucent synthetic resin material. Of course, as shown in FIGS. 1 and 2, the inner layer 6 and the dividing portion 8 may be formed of a transparent synthetic resin material, and a configuration having a function (window function) of visually recognizing the inside of the laminated container 1 through these may be provided. Furthermore, in order to suppress the separation between the inner layer 6 and the outer layer 7, the outer peripheral surface of the laminated container 1 may be configured to be covered with a coating layer made of a separable shrink label or the like.

[0022] The laminated container 1 having the above-described configuration can be manufactured by, for example, extrusion blow molding using a tubular laminated parison, or biaxial stretch blow molding using an injection-molded laminated preform, but is not limited thereto. Also, when using the extrusion blow molding method, regarding the molding of the mouth part 2, it is preferable to adopt a known UPI (Upper Plug In) molding method (see Japanese Patent No. 3796587) and fold back the upper end part of the inner layer 6 so as to be positioned on the upper end surface of the outer layer 7. In this configuration, the inner layer 6 is configured to be folded back radially outward at the upper opening end 2a of the mouth part 2. When a cap (not shown) is attached to the mouth part 2, the folded-back portion of the inner layer 6 can be sandwiched between the lower surface of the cap and the upper opening end 2a. Therefore, it is possible to prevent the inner layer 6 from being displaced when the laminated container 1 is subjected to an impact such as dropping, and further, since the initial forms of the dividing part 8 and the slit 7A can be maintained, it can contribute to preventing the appearance of the laminated container 1 from being damaged.

[0023] FIG. 4 is a perspective view of a laminated container showing a second embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along line V-V of FIG. 4. The difference between the second embodiment and the first embodiment described above is that a gripping part is provided, and the other configurations and effects are the same as those of the first embodiment. Note that the same parts as those in the first embodiment are denoted by the same reference numerals and will be described. As described above, when the resin material forming the outer layer 7 is mixed with the dividing part 8, it is possible to increase the melting adhesion force between the dividing part 8 and the outer layer 7 (slit 7A). However, if there is variation in the mixing amount, an overly strong melting adhesion force (adhesive force) may be exhibited, and as a result, there is a possibility that the inner layer 6 and the outer layer 7 may not peel off even when the dividing part 8 is pushed in.

[0024] Therefore, in the second embodiment, as shown in FIGS. 4 and 5, a gripping portion 8b that protrudes radially outward is integrally provided on the side surface of the body portion 4, more specifically, at the outer end portion 8a of the dividing portion 8. To form such a gripping portion 8b on the side surface of the body portion 4, in a known flash molding (see, for example, Japanese Patent No. 5146930) in which a flash is formed when a part of the laminated parison or laminated preform is pinched by a split mold, by appropriately setting the opposing interval of the pinch-off portion provided in the split mold, when the dividing portion 8 is pinched, it is possible to form the gripping portion 8b integrally connected to the outside of the outer end portion 8a of the dividing portion 8. Note that the width (circumferential size) of the outer end portion 8a may be a narrow slit shape as shown in FIG. 4, or may be widened to a semicircular shape. As another forming method, by providing a concave portion having the same shape as the gripping portion 8b on the inner surface of the mold, it is possible to form the gripping portion 8b having a shape corresponding to the concave portion during blow molding without pinching a part of the laminated parison or laminated preform by the split mold.

[0025] Thus, in the second embodiment, when the gripping portion 8b is provided on the dividing portion 8, during the separation operation, since it becomes easy to perform operations such as pulling radially outward or pushing radially inward while pinching the gripping portion 8b, a large shearing force can be applied to the interface between the slit 7a and the dividing portion 8. Therefore, even when a large fusing force (adhesive force) acts between the dividing portion 8 and the slit 7A, it is possible to reliably separate and separate between the inner layer 6 and the outer layer 7.

[0026] The position where the gripping portion 8b is provided is not limited to the body portion 4 near the bottom portion 5 as shown in FIG. 4, and may be any position of the center of the body portion 4, the shoulder portion 3, or the bottom portion 5. Furthermore, it may be provided over the entire body portion 4 or over the entire body portion 4 from the shoulder portion 3. Moreover, a configuration in which a concave portion is formed on the surface of the gripping portion 8b or a configuration in which a through hole is formed to form a substantially U-shape is preferable. In such a configuration, the concave portion and the through hole function as finger-hooking portions, so that the operability during pulling can be further improved.

[0027] Also, as shown by the dashed line in FIG. 5, it is preferable that the gripping portion 8b is configured to be foldable in the circumferential direction along the body portion 4 with the base end portion (connection portion with the outer end portion 8a) as a fulcrum. In this case, in order to facilitate folding, the entire gripping portion 8b may be formed to be thin, or only the connection portion with the outer end portion 8a may be formed to be thin. Furthermore, a configuration in which the body portion 4 is covered with a covering layer made of a shrink label or the like is preferable in that the folded posture of the gripping portion 8b can be maintained. With these configurations, since the height dimension of the gripping portion 8b protruding radially outward from the body portion 4 can be kept low, it is possible to prevent the gripping portion 8b from getting in the way during distribution or use.

[0028] FIG. 6 is a cross-sectional view of a laminated container showing a third embodiment of the present invention. The difference between the third embodiment and the above-described first embodiment is that a pushing portion is provided, and the other configurations and effects are the same as those of the first embodiment. Note that the same reference numerals are given to the same parts as those in the first embodiment and will be described.

[0029] As shown in FIG. 6, the third embodiment has a configuration in which a convex pushing portion 8c protruding radially outward from the outer end portion 8a is provided at the outer end portion 8a exposed to the outside through the slit 7A. The pushing portion 8c may be provided at any one position on the outer end portion 8a, or may be provided at a plurality of positions on the outer end portion 8a, or may be configured to be provided along the axial direction over the entire outer end portion 8a. Also, the amount of protrusion of the pushing portion 8c radially outward from the outer end portion 8a is preferably such that it does not get in the way during distribution or use.

[0030] In the configuration in which the pushing portion 8c is provided in the dividing portion 8 as the third embodiment in this way, since the amount of pushing when the pushing portion 8c is pushed radially inward during the sorting operation can be increased more than before, even when a large fusing force (adhesive force) acts between the dividing portion 8 and the slit 7A, it is possible to surely separate and sort between the inner layer 6 and the outer layer 7.

[0031] The configuration and the operation and effects of the present invention have been described above along with the embodiments. However, the embodiments of the present invention are not limited to the above embodiments. For example, in the first embodiment described above, the configuration in which the dividing portion 8 is provided on the outer surface of the inner layer 6 and the slit 7A is provided in the outer layer 7 has been described. However, a configuration in which this is reversed, that is, the dividing portion 8 is provided on the inner surface of the outer layer 7 and the slit 7A is provided in the inner layer 6 may also be used.

Industrial Applicability

[0032] The present invention can further expand the application development in the field of laminated containers in a wider area.

Explanation of Signs

[0033] 1: Laminated container 2: Mouth part 2a: Upper opening end 2A: Neck ring 3: Shoulder part 4: Body part 5: Bottom part 6: Inner layer 7: Outer layer 7A: Slit 8: Dividing portion 8a: Outer end portion 8b: Gripping portion 8c: Pushing-in portion O: Container axis

Claims

1. A laminated container made of synthetic resin in which an inner layer (6) for containing the contents and an outer layer (7) covering the inner layer (6) on the outer surface of the inner layer (6) are laminated, a dividing portion (8) formed of a synthetic resin material having compatibility with the inner layer (6) and incompatibility with the outer layer (7) is provided on the outer surface of the inner layer (6), the outer layer (7) is formed of a synthetic resin material having incompatibility with the inner layer (6) and the dividing portion (8), The laminated container is characterized in that the inner layer (6) and the dividing portion (8) are laminated in a fused state.

2. The laminated container according to claim 1, wherein the dividing portion (8) has a substantially mountain-shaped cross section.

3. The dividing portion (8) is formed of a synthetic resin obtained by mixing a first synthetic resin material having compatibility with the inner layer (6) and incompatibility with the outer layer (7) and a second synthetic resin material having compatibility with the outer layer (7), and the mixing ratio of the first synthetic resin material and the second synthetic resin material is in the range of 95:5 to 70:

30. The laminated container according to claim 1 or 2, characterized in that

4. The laminated container according to claim 1 or 2, characterized in that the outer layer (7) is covered with a separable coating layer.

5. A laminated container made of synthetic resin in which an inner layer (6) for containing the contents and an outer layer (7) covering the inner layer (6) on the outer surface of the inner layer (6) are laminated, a dividing portion formed of a synthetic resin material having compatibility with the outer layer (7) and incompatibility with the inner layer (6) is provided on the inner surface of the outer layer (7), the inner layer (6) is formed of a synthetic resin material having incompatibility with the outer layer (6) and the dividing portion, The laminated container is characterized in that the outer layer (7) and the dividing portion are laminated in a fused state.

6. The laminated container according to claim 1 or 2, characterized in that a gripping portion (8b) or a pushing portion (8c) protruding radially outward is provided on the dividing portion (8).

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