JP2013212843A - Container and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container that is made from a multilayer sheet, and can be used repeatedly without being cleansed, and to provide a method for manufacturing the same.SOLUTION: A container 1 is a container made from a multilayer sheet 15 including at least three layers, and having a flange part 13. The multilayer sheet 15 has a first inter-layer 161 and a second inter-layer 162 which are peelable, and an outer peripheral edge 130 of the flange part 13 is provided with non-bonded parts 131A and 131B to which the first inter-layer 161 and the second inter-layer 162 are not bonded.

Description

  The present invention relates to a container and a manufacturing method thereof.

  Conventionally, as a container, a container obtained by molding a multilayer sheet formed by laminating a plurality of layers according to the purpose is known. Patent Document 1 discloses a container having a structure in which an EVOH layer made of a styrene resin layer and an ethylene-vinyl alcohol copolymer resin is laminated via an adhesive layer. This container is excellent in transparency, and has high rigidity and high impact resistance.

JP-A-10-1003008

  However, the container described in Patent Document 1 is disposable once in spite of having high rigidity and impact resistance, and reuse is desired from the viewpoint of effective use of resources. Although cleaning and reuse can be considered, cleaning is costly and labor-intensive, and is difficult to clean in places where water use is limited, such as campsites and disaster-stricken areas. There was no problem.

  An object of the present invention is to provide a container made of a multilayer sheet, which can be used repeatedly without washing, and a method for producing the same.

  The container of the present invention is a container comprising a multilayer sheet including at least three layers and having a flange portion, wherein the multilayer sheet has a plurality of peelable layers, and the outer peripheral edge of the flange portion includes An unbonded portion in which a peelable interlayer is unbonded is provided.

  In the present invention, the container has a plurality of peelable layers, and the interlayer includes an unbonded portion that is not bonded at the outer peripheral edge of the flange portion. This layer can be removed by delamination by peeling off the non-bonded portion as a trigger. Therefore, the inner surface of the container can be changed to another new layer, and can be newly used as a container.

In the container of the present invention, it is preferable that the non-bonded portions are separated from each other.
According to this configuration, since the unbonded portion is separated from the outer peripheral edge of the flange portion, the unbonded portion can be easily pinched, and the inner sheet of the multilayer sheet can be easily picked up by using the pinched unbonded portion. The surface side layer can be peeled off. Therefore, the inner surface of the container can be changed to another new layer more easily.

Further, in the container of the present invention, the outer peripheral edge of the flange portion of the layer located on the inner surface side of the container extends outward from the outer peripheral edge of the flange portion of the layer facing the layer. It is preferable to take out.
According to this configuration, since the outer peripheral edge of the flange portion of the layer located on the inner surface side extends to the outside from the outer peripheral edge of the flange portion of the facing layer, the outer peripheral edge of the layer located on the inner surface side is It can be easily pinched with a finger, and the layer located on the inner surface side of the container can be easily peeled off.

  In the container of the present invention, it is preferable that the delamination strength between the peelable layers is 2.94 N / 25 mm or more and 11.76 N / 25 mm or less.

  Since the delamination strength is 2.94 N / 25 mm or more and 11.76 N / 25 mm or less, delamination can be easily caused by picking each layer with a finger and peeling off, and each layer can be peeled off naturally. Can be prevented.

  In the container of the present invention, each of the layers constituting the peelable layers is composed mainly of a polypropylene resin, and the other is a resin mainly composed of at least one of polyethylene, polyethylene terephthalate, nylon, and ethylene-vinyl alcohol. It is preferable to become.

  One of the layers constituting the peelable layers is mainly made of polypropylene resin, and the other is made of resin mainly composed of at least one of polyethylene, polyethylene terephthalate, nylon, and ethylene-vinyl alcohol. This container can be used as a container for containing food.

In the container of the present invention, it is preferable that the delamination strength between the plurality of layers is smaller toward the inner surface side of the container.
Since the delamination strength is smaller toward the inner surface side of the container, when delamination is performed, the layers can be peeled in order from the layer on the inner surface side, and the other layers located on the outer side are not peeled off.

In the container of the present invention, the multilayer sheet preferably includes at least one three-layer structure including a first base material layer, an adhesive layer, and a second base material layer.
According to this configuration, either the first base material layer or the second base material layer is provided on the inner surface side of the container, and any one layer that comes into contact with the content stored in the container is treated as a property of the content. The other layer can be a layer having rigidity and delamination strength necessary for the container, and the container can be made to meet the needs.

In the container of the present invention, each layer in the multilayer sheet is preferably composed of one layer.
According to this structure, since a multilayer sheet can be made into a simple structure, the structure of a container can also be made into a simple structure and manufacturing cost can be held down.

  On the other hand, the container manufacturing method of the present invention includes a thermoforming step of thermoforming a multilayer sheet including at least three layers and having a plurality of peelable layers between adjacent layers, and the multilayer sheet after the thermoforming is punched out with a punching blade. A non-adhered portion forming step of forming a non-adhered portion on the outer peripheral edge of the flange portion by causing separation between the layers when punching and forming the flange portion;

Sectional drawing of the container which concerns on embodiment of this invention. Sectional drawing of the multilayer sheet which comprises the container which concerns on embodiment of this invention. Sectional drawing of the container which concerns on the modification of this invention. Sectional drawing of the container which concerns on the modification of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The container described in the present embodiment can be used as a tableware such as a tray or a dish for storing food.

[Container configuration]
As shown in FIG. 1, the container 1 is a container in which the contents are stored.
Hereinafter, a specific configuration of the container 1 will be described.

  As shown in FIG. 1, the container 1 includes a recess 11 in which contents are stored, and a flange portion 13 formed on the periphery of the opening 12 of the recess 11. The container 1 is formed of a multilayer sheet 15 in which a first sheet 151, a second sheet 152, and a third sheet 153 are laminated in this order from the inner surface side of the container 1. An interlayer between the first sheet 151 and the second sheet 152 is referred to as a first interlayer 161, and an interlayer between the second sheet 152 and the third sheet 153 is referred to as a second interlayer 162.

  The recess 11 includes a bottom 111 that forms the bottom of the container 1 and a wall 112 that is formed by being raised from the bottom 111.

The flange portion 13 protrudes from the periphery of the opening portion 12 to the radially outer side of the opening portion 12 and is formed in a flat shape so that the surface direction thereof is parallel to the surface direction of the bottom portion 111. The first sheet 151 at the outer peripheral edge 130 of the flange portion 13 is provided with an unbonded portion 131A in which the first interlayer 161 is not bonded, and the second sheet 152 at the outer peripheral edge 130 of the flange portion 13 is provided on the second sheet 152. An unbonded portion 131B is provided in which the second interlayer 162 is not bonded.
The unbonded portions 131A and 131B may be in contact with the opposing sheets, but are preferably separated from each other. Here, unbonded means that the sheets 151, 152, and 153 are separated from each other, or that the sheets 151, 152, and 153 are in contact with each other to such an extent that the layers can be easily separated with a finger.

  In the multilayer sheet 15, the first sheet 151 is provided to be peelable from the second sheet 152, and the second sheet 152 is provided to be peelable from the third sheet 153. That is, the first sheet 151 and the second sheet 152 can be separated by the first interlayer 161, and the second sheet 152 and the third sheet 153 can be separated by the second interlayer 162.

  The delamination strength between the first interlayer 161 and the second interlayer 162 is preferably set in the range of 2.94 N / 25 mm to 11.76 N / 25 mm. If the delamination strength between the first interlayer 161 and the second interlayer 162 is less than 2.94 N / 25 mm, there is a risk of spontaneous separation without applying force, and it exceeds 11.76 N / 25 mm. Then, there is a possibility that the first interlayer 161 and the second interlayer 162 cannot be easily separated. A more preferable range of the delamination strength is 3.92 N / 25 mm or more and 8.82 N / 25 mm or less, more preferably 5.88 N / 25 mm or more and 7.84 N / 25 mm or less.

In the present embodiment, the first sheet 151, the second sheet 152, and the third sheet 153 are each a three-layered sheet.
As shown in detail in FIG. 2, the first sheet 151 is the innermost layer of the container 1, and includes a first base material layer 201A on the inner surface side of the container 1, and an adhesive layer 202A on the first base material layer 201A. The second base material layer 203A is adhered to the intermediate layer.
The second sheet 152 is located outside the first sheet 151 and is bonded to the first base material layer 201B facing the second base material layer 203A and the first base material layer 201B via the adhesive layer 202B. 2 base material layers 203B.
The third sheet 153 is located outside the second sheet 152 and is bonded to the first base material layer 201C facing the second base material layer 203B and the first base material layer 201C via the adhesive layer 202C. 2 base material layers 203C.

  In the present embodiment, the first sheet 151, the second sheet 152, and the third sheet 153 are composed of the same sheet. That is, the first base material layers 201A, 201B, and 201C of the sheets 151, 152, and 153 are the same, the adhesive layers 202A, 202B, and 202C are the same, and the second base material layers 203A, 203B, and 203C are the same. is there.

  The first base material layers 201A, 201B, and 201C are layers mainly made of polypropylene resin. Examples of the polypropylene resin include homopolypropylene (HPP), random polypropylene (RPP), and block polypropylene (BPP).

The adhesive layers 202A, 202B, 202C have a peel strength greater than the peel strength of the first interlayer 161 and the second interlayer 162. That is, the peel strength of the adhesive layers 202A, 202B, and 202C is preferably set to 11.76 N / 25 mm or more. Thereby, when peeling each sheet | seat 151,152,153, between 1st base material layer 201A, 201B, 201C and 2nd base material layer 203A, 203B, 203C will not peel.
Examples of the constituent material of the adhesive layers 202A, 202B, and 202C include urethane-based elastomers, styrene-based elastomers, maleic anhydride-modified polypropylene, and ethylene vinyl acetate (EVA).

The second base material layers 203A, 203B, and 203C are made of a resin mainly composed of at least one of polyethylene, polyethylene terephthalate (PET), nylon, and ethylene-vinyl alcohol.
In the present embodiment, the first interlayer 161 is between the second base material layer 203A and the first base material layer 201B, and the second base material 201C is between the second base material layer 203B and the first base material layer 201C. Interlayer 162. Therefore, the adhesive strength between the first base material layers 201A, 201B, and 201C and the second base material layers 203A, 203B, and 203C is adjusted so as to be peelable by the thickness of each layer, resin selection, blending ratio, and the like.

  As a method for producing the multilayer sheet 15 before forming to be the container 1, a method such as co-extrusion, dry lamination, extrusion lamination, extrusion coating, or a combination of these methods can be employed.

[Method for producing container 1]
Although the container 1 is not specifically limited, For example, a manufacturing method provided with the thermoforming process of thermoforming the multilayer sheet 15, and the flange part formation process of punching the multilayer sheet 15 after thermoforming with a punching blade, and forming the flange part 13 Etc. can be manufactured.
In the thermoforming step, the multilayer sheet 15 is thermoformed by a known method such as direct hot plate heating, plug assist vacuum forming, or plug assist pressure forming.
In the flange portion forming step, the multilayer sheet 15 after thermoforming is punched out so that the container 1 includes the flange portion 13. At this time, since each layer of the multilayer sheet 15 has the above-described peel strength, when pressure is applied by the punching blade, the sheets 151, 152, and 153 are peeled off at the outer peripheral edge 130 of the flange portion 13, and the unbonded portion 131A. And 131B are formed. In addition, since unbonded part 131A and 131B are formed simultaneously by formation of the flange part 13, a flange part formation process turns into an unbonded part formation process of this invention.

[How to use container 1]
When the container 1 is used repeatedly, after using the first sheet 151 on the inner surface side, the unbonded portion 131A is pinched with a finger, and the first sheet 151 is peeled off from the second sheet 152 toward the concave portion 11 of the container 1. . Thereby, the 2nd sheet | seat 152 is newly exposed to the inner surface of the container 1, and the container 1 can be used.
After use of the second sheet 152, the unbonded part 131 </ b> B is pinched with a finger, and the second sheet 152 is peeled off from the third sheet 153 toward the recess 11 of the container 1. Thereby, the 3rd sheet | seat 153 is newly exposed to the inner surface of the container 1, and the container 1 can be used.
Thus, by peeling off the first sheet 151 and the second sheet 152 in order, in the present embodiment, it can be used repeatedly three times.

(Effect of this embodiment)
According to this embodiment as described above, the following effects can be achieved.

  Since the container 1 has a peelable first interlayer 161 and a second interlayer 162 and is provided with unbonded portions 131A and 131B on the outer peripheral edge of the flange portion 13, the sheet on the inner surface side of the container 1 is attached to the unbonded portion 131A. Alternatively, it can be removed by delamination by peeling 131B as a trigger. Therefore, the inner surface of the container 1 can be easily changed in the order of the second sheet 152 and the third sheet 153 from the first sheet 151 and can be newly used as the container 1.

Since the unbonded portions 131A and 131B are separated from the second sheet 152 and the third sheet 153, respectively, the unbonded portions 131A and 131B can be easily pinched, and the pinched unbonded portions 131A and 131B are used as a trigger. The first sheet 151 and the second sheet 152 can be easily peeled off. Therefore, the inner surface of the container 1 can be more easily changed from the first sheet 151 to the second sheet 152 and the third sheet 153 in this order.
Since the delamination strength between the first interlayer 161 and the second interlayer 162 is 2.94 N / 25 mm or more and 11.76 N / 25 mm or less, the first sheet 151 and the second sheet 152 are grasped with a finger and peeled off, It is possible to easily perform delamination, and it is possible to prevent the first sheet 151 and the second sheet 152 from being naturally peeled off.

The first base material layers 201A, 201B, and 201C are mainly made of polypropylene resin, and the second base material layers 203A, 203B, and 203C are mainly composed of at least one of polyethylene, polyethylene terephthalate, nylon, and ethylene-vinyl alcohol. Since it consists of resin, the container 1 can be used as a container which accommodates food.
In addition, since the first sheet 151, the second sheet 152, and the third sheet 153 have a three-layer structure, the first base material that is provided on the inner surface side of the container 1 and contacts the contents stored in the container 1 The layers 201A, 201B, and 201C can be layers that match the properties of the contents, and the second base material layers 203A, 203B, and 203C can be layers having rigidity and peel strength necessary for the container. Therefore, the container 1 can be provided with properties according to needs.

[Modification]
The aspect described above shows one aspect of the present invention, and the present invention is not limited to the above-described embodiment, and has the configuration of the present invention and can achieve the object and effect. It goes without saying that modifications and improvements within the scope are included in the content of the present invention. In addition, the specific structure and shape in carrying out the present invention may be used as other structures and shapes within the scope of achieving the object and effect of the present invention. The present invention is not limited to the above-described embodiments, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention.

  For example, as shown in FIG. 3, the flange portion 13 extends outside the outer peripheral edge of the sheet facing the outer peripheral edge of the sheet located on the inner surface side of the container 1 at the outer peripheral edge 130 of the flange portion 13. May be. That is, the outer peripheral edge of the first sheet 151 extends to the outside rather than the outer peripheral edge of the second sheet 152, thereby forming an unbonded portion 132A in which the first interlayer 161 is not bonded. Further, the outer peripheral edge of the second sheet 152 extends to the outside rather than the outer peripheral edge of the third sheet 153, thereby forming an unbonded portion 132B in which the second interlayer 162 is not bonded. Also in this configuration, the first sheet 151 or the second sheet 152 can be peeled off by pinching the unbonded portion 132A or 132B with a finger.

Further, the first sheet 151, the second sheet 152, and the third sheet 153 constituting the multilayer sheet 15 may not be the same sheet.
In particular, the second base material layer 203A of the first sheet 151 and the second base material layer 203B of the second sheet 152 are different layers, and the delamination strength of the first interlayer 161 is greater than the delamination strength of the second interlayer 162. It is preferable to reduce the size. That is, the delamination strength between the second base material layer 203 </ b> A of the first sheet 151 and the first base material layer 201 </ b> B of the second sheet 152 is set to be the first of the second base material layer 203 </ b> B of the second sheet 152 and the third sheet 153. It is made smaller than the delamination strength with the base material layer 201C. As a result, the first interlayer 161 can be more easily peeled than the second interlayer 162, and the second sheet 152 peels from the third sheet 153 at the same time when the first sheet 151 is peeled off from the second sheet 152. Can be prevented.

Further, the container 1 is not limited to the one having the three sheets 151, 152, 153 and having the two layers 161, 162, and may be made of four or more sheets and having two or more layers. .
Furthermore, each of the first sheet 151, the second sheet 152, and the third sheet 153 is not limited to a sheet having a three-layer structure, and a sheet having a one-layer structure, a two-layer structure, or a four-layer structure or more can be used. Each sheet may have a different number of layer structures.
For example, as shown in FIG. 4, the container 1 may be a container 1 </ b> A including five sheets of a first sheet 151 </ b> A, a second sheet 152 </ b> A, a third sheet 153 </ b> A, a fourth sheet 154, and a fifth sheet 155. Each sheet in the container 1A is a sheet having a single layer structure. In this case, for example, the first sheet 151A, the third sheet 153A, and the fifth sheet 155 may be mainly made of polypropylene, and the second sheet 152A and the fourth sheet 154 may be made of polyethylene terephthalate.

  In addition, the shape of the container 1 is not limited to that illustrated in FIGS. 1 and 3 and may be a shape obtained by thermoforming a multilayer sheet. Examples of these shapes include trays, dishes, and balls.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these examples.

[Example 1]
A container of the present invention whose overall shape is shown in FIG. 1 was produced using the following materials and methods.
First, the multilayer sheet 15 which laminated | stacked the sheet | seat shown below three layers was shape | molded using the distributor system coextrusion multilayer sheet manufacturing apparatus.
Sheet: a layer composed of 80% by mass of polypropylene (product name “E-105GM” manufactured by Prime Polymer Co., Ltd.) and 20% by mass of polyethylene (product name “R-300” manufactured by Ube Maruzen Polyethylene Co., Ltd.) / A sheet comprising an adhesive resin (maleic anhydride-modified polypropylene, manufactured by Mitsubishi Chemical Corporation, product name “Modic AP (registered trademark) P604”) / a layer composed of polyethylene terephthalate (PET) in this order.

  Next, the multilayer sheet 15 is used for hot plate thermoforming, and the recess 11 has a substantially circular bottom 111 and opening 12. And the container 1 which has the flange part 13 of the width dimension 5mm was punched out with the punching blade so that the flange part 13 might be arrange | positioned so that it might protrude outside from the periphery of the opening part 12. FIG.

[Evaluation of container]
The delamination strength between the first interlayer 161 and the second interlayer 162 in the container 1 was measured. The measurement was performed 5 times and the average value was taken.
Further, as a peeling test, the possibility of peeling from the flange portion 13 was confirmed by peeling the layers on the inner surface side of the container 1 in order with a finger. The case where it was easy to peel with a weak force was evaluated as “◯”, and the case where it was difficult to peel off because it was able to be peeled off but a strong force was required was indicated as “Δ”. The results are shown in Table 1.

[Example 2 and Comparative Example 1]
In Example 1, containers were manufactured in the same manner as in Example 1 except that the second base material layers 203A, 203B, and 203C of the sheets 151, 152, and 153 were changed to the resins shown in Table 1. The evaluation results are shown in Table 1.

  The container of the present invention can be used as a tray for storing food or the like, tableware such as a plate, and a storage container.

DESCRIPTION OF SYMBOLS 1,1A ... Container 13 ... Flange part 15 ... Multilayer sheet 130 ... Outer peripheral edge 131A, 131B, 132A, 132B ... Unbonded part 151, 151A ... First sheet (layer)
152, 152A ... second sheet (layer)
153, 153A ... Third sheet (layer)
154 ... Fourth sheet (layer)
155 ... Fifth sheet (layer)
161: First interlayer (interlayer)
162 ... second interlayer part (interlayer)
201A, 201B, 201C ... first base material layer 202A, 202B, 202C ... adhesive layer 203A, 203B, 203C ... second base material layer

Claims (9)

A container comprising a multilayer sheet including at least three layers and having a flange portion,
The multilayer sheet has a plurality of peelable layers,
The outer peripheral edge of the flange portion includes an unbonded portion in which the peelable interlayer is unbonded.
A container characterized by that. The container according to claim 1,
The non-adhered portion is spaced apart. In the container according to claim 1 or 2,
Between the peelable layers, the outer peripheral edge of the flange portion of the layer located on the inner surface side of the container extends to the outside from the outer peripheral edge of the flange portion of the layer facing the layer. container. In the container according to any one of claims 1 to 3,
The delamination strength between the peelable layers is 2.94 N / 25 mm or more and 11.76 N / 25 mm or less. In the container according to any one of claims 1 to 4,
Each of the layers constituting the peelable layers is mainly composed of a polypropylene resin, and the other is composed of a resin mainly composed of at least one of polyethylene, polyethylene terephthalate, nylon, and ethylene-vinyl alcohol. container. In the container according to any one of claims 1 to 5,
The container, wherein the delamination strength between the plurality of layers is smaller toward the inner surface side of the container. In the container according to any one of claims 1 to 6,
The multilayer sheet includes at least one three-layer structure including a first base material layer, an adhesive layer, and a second base material layer. In the container according to any one of claims 1 to 6,
Each layer in the multilayer sheet consists of one layer. It is a manufacturing method of the container given in any 1 paragraph of Claims 1-8,
A thermoforming step of thermoforming a multilayer sheet including at least three layers and having a plurality of peelable layers between adjacent layers;
A non-adhered portion forming step of forming a non-adhered portion on the outer periphery of the flange portion by causing peeling between the layers when punching the multilayer sheet after thermoforming with a punching blade to form a flange portion. A method for producing a container characterized by the above.