JP2014198429A - Multilayer structure, processed product, container, packaging container, method of manufacturing multilayer structure, and method of manufacturing container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer sheet whose surface layer can be delaminated.SOLUTION: Since a second substrate layer of the multilayer sheet contains at least one adhesive, bonding strength between the second substrate layer and a first substrate layer can be increased. The adhesive is at least one selected from the group consisting of a urethane-based elastomer, a styrene-based elastomer, a maleic anhydride-modified polyethylene, a maleic anhydride-modified polypropylene, and an ethylene-vinyl acetate (EVA). In the case of using the multilayer sheet for a container body 2 of an easily unsealable container 1, the first substrate layer and a surface layer can be appropriately delaminated when unsealing a lid 3, thereby allowing the easily unsealable container 1 to be easily unsealed. Furthermore, high sealability can be obtained without requiring a decrease in bonding strength between the surface layer and the first substrate layer.

Description

  The present invention relates to a multilayer structure having a laminated structure including a surface layer and a base material layer, a processed product, a container, a packaging container, a multilayer structure sealing method, and a container manufacturing method.

As a packaging form of foods, there is a container with a lid configured to include a container body provided with a food storage part inside the container, a flange part at the periphery of the opening of the container body, and a film-like lid. Widely used (see, for example, Patent Document 1).
The lidded container described in Patent Document 1 is formed so that the interlayer adhesive force of the container body is smaller than the adhesive force between the flange portion and the lid member. The container body is formed from a multilayer sheet of a surface layer and a base material layer obtained by co-extrusion of a mixture of polypropyne resin and low density polyethylene resin and low density polyethylene on the surface layer. The surface of the layer made of polyethylene is heat sealed.

JP 63-44467 A

  However, in the container with a lid described in Patent Document 1, by making the interlayer adhesion of the container body smaller than the adhesion between the flange portion and the lid, high sealing performance cannot be obtained, and when external force is applied, There is a risk of inconvenience such as peeling and accidental opening.

  An object of the present invention is to provide a multilayer structure, a processed product, a container, a packaging container, a method for producing a multilayer structure, and a method for producing a container, which can achieve high sealing performance and can be opened well by delamination. And

The multilayer structure of the present invention is a multilayer structure including a surface layer and a base material layer, and the material constituting the base material layer has a loss tangent tan δ value at 165 ° C. of less than 0.18. It is characterized by that.
In this invention, since the value of the loss tangent tan δ at 165 ° C. is less than 0.18 as a material constituting the base material layer laminated on the surface layer, for example, the base material layer flows and heat seals when heat sealing is performed. It is possible to prevent the resin pool from being formed at the edge of the resin, to prevent the delamination due to the resin pool, and to appropriately set the adhesive strength of the heat seal that can appropriately delaminate and obtain high sealing properties.
Here, delamination is a state in which peeling occurs between layers constituting the multilayer structure, for example, a state in which peeling occurs between a surface layer and a base material layer directly adjacent to the critical layer.
When the value of the loss tangent tan δ at 165 ° C. of the material constituting the base material layer is 0.18 or more, for example, when the heat seal is performed, the base material layer flows and a resin pool is generated at the edge of the heat seal. This causes the inconvenience that the openability deteriorates. For this reason, the value of the loss tangent tan δ at 165 ° C. is set to less than 0.18.
The measuring method and measuring device for the loss tangent tan δ is a dynamic viscoelasticity measuring device (DMS). The loss tangent tan δ of the resin as the constituent material can be controlled by blending the raw materials used.

Further, in the present invention, the value of the loss tangent tan δ at 165 ° C. may be 0.01 or more and less than 0.18.
In this invention, by setting the value of the loss tangent tan δ at 165 ° C. to 0.01 or more and less than 0.18, for example, when heat sealing, the base material layer flows and a resin pool is formed at the edge of the heat seal. It is possible to prevent the occurrence of delamination due to the resin pool, and it is possible to suitably set the adhesive strength of the heat seal that can appropriately delaminate and obtain high hermeticity.
There is no particular problem if the value of the loss tangent tan δ at 165 ° C. is less than 0.18, but it can be suitably used if it is, for example, 0.01 or more.

And in this invention, it is preferable to set it as the structure by which the said surface layer and the said base material layer are laminated | stacked directly adjacent.
In this invention, the surface layer and the base material layer are laminated directly adjacent to each other, thereby preventing the formation of a resin pool by the base material layer, and appropriate delamination between the surface layer and the base material layer. The setting for carrying out and obtaining high sealing property is easily obtained.

Moreover, in this invention, it is preferable that the said base material layer sets it as the structure which consists of at least any 1 type chosen from the group of an olefin resin, a polystyrene resin, and a polyester-type resin.
In this invention, by using the predetermined material as the base material layer, it is possible to easily form a layer for obtaining appropriate delamination without forming a resin reservoir.

Furthermore, in the present invention, the material constituting the base material layer includes a polymer containing at least a part of a propylene unit (hereinafter referred to as a polypropylene-based resin and appropriately expressed as PP) and a polymer containing at least a part of an ethylene unit. A structure in which a resin composition blended with PP: PE = 30% by mass or more and 99% by mass or less: 1% by mass or more and 70% by mass or less is used. It is preferable to do.
In this invention, a base material layer is comprised by comprising a base material layer using the resin composition mix | blended by PP: PE = 30 mass% or more and 99 mass% or less: 1 mass% or more and 70 mass% or less. The value of the loss tangent tan δ at 165 ° C. of the material can be easily made less than 0.18.
Here, if the mass ratio PP / PE is less than 0.429, rigidity may be insufficient, and if the mass ratio PP / PE is more than 99, flexibility may be insufficient.

In the present invention, the base material layer includes a second base material layer, a first adhesive layer, a barrier layer, a second adhesive layer, a third base material layer, and a fourth base material layer. And are preferably laminated.
In this invention, the second base material layer, the first adhesive layer, the barrier layer, the second adhesive layer, the third base material layer, and the fourth base material layer are laminated on the base material layer. Therefore, for example, it can be suitably used as a container or bag for satisfactorily storing various articles such as foods, pharmaceuticals, and industrial articles.

The processed product of the present invention is formed by using the multilayer structure of the present invention.
In the present invention, for example, when the heat sealing is performed, the base material layer flows to prevent the resin pool from being formed at the edge of the heat seal, and thus the multilayer structure of the present invention is used. It is possible to provide a workpiece that can be prevented from being peeled off and can be appropriately separated from each other and have high sealing properties.

In the present invention, the multilayer structure is preferably formed by heating.
In the present invention, by using heating for forming the multilayer structure of the present invention, it can be easily formed into various shapes such as a deep drawn cup shape or a bottom tray shape.

The container of the present invention is formed using the multilayer structure of the present invention.
In the present invention, for example, when the heat sealing is performed, the base material layer flows to prevent the resin pool from being formed at the edge of the heat seal, and thus the multilayer structure of the present invention is used. It is possible to provide a container that can prevent delamination and can be appropriately delaminated and have high sealing properties.

And in this invention, it is preferable to set it as the structure provided with the container main body which has the flange part protrudingly provided by the outer side from the opening part periphery of packaged goods, and was shape | molded using the said multilayer structure.
In the present invention, a container body having a flange portion projecting outward from the periphery of the opening for storing an object to be packaged is molded using the multilayer structure of the present invention, so that a lid sealed, for example, on the flange portion When the body is opened, since a resin reservoir is not formed between the surface layer and the base material layer, it is possible to provide a container that can be satisfactorily delaminated and obtain high sealing performance.

Moreover, in this invention, it is preferable to set it as the structure by which the said surface layer of the said flange part is provided with the notch groove surrounding the said opening part.
In this invention, by providing a notch groove in the surface layer of the flange portion so as to surround the opening portion, for example, when opening the lid sealed to the flange portion, the delamination between the surface layer and the base material layer is excellent. Then, the opening can be satisfactorily opened by peeling between the lid and the surface layer by the cutout groove.

And in this invention, it is preferable that the said notch groove is set as the structure provided in the depth more than the thickness dimension of the said surface layer.
In this invention, since the notch groove is provided at a depth greater than the thickness dimension of the surface layer, for example, when the sealed lid is opened, the surface layer is delaminated with the first base material layer. Thereafter, the delamination of the surface layer is reliably released on the opening side by the cutout groove, and the separation is performed between the lid and the surface layer, so that the opening can be reliably opened.

Furthermore, in the present invention, the shape of the container body is preferably a cup shape or a tray shape.
In this invention, heat sealing can be performed using a general apparatus by making the shape of the container body into a cup shape or a tray shape.

The packaging container of the present invention is a packaging container in which a lid is bonded to a flange portion of the container body, and the container body is a container body of the container of the present invention.
In this invention, by using the container main body of the container of the present invention for the container main body to which the lid body is bonded at the flange portion, it is possible to achieve satisfactory delamination between the surface layer and the base material layer, and high sealing performance. The resulting packaging container can be provided.

The method for sealing a multilayer structure of the present invention is formed by using the multilayer structure of the present invention, and a container body having a flange portion disposed on the periphery of the opening and a lid member using a sealing disk. A method for sealing a multilayer structure in which heat sealing is performed at the flange portion, wherein the seal disc has a base portion and an annular seal portion on one surface thereof, and the seal portion is on the outer peripheral side of the annular shape. A separation surface that is separated from the heat-sealed surface according to the outer peripheral edge, and a plane that is provided on the inner peripheral edge side of the annular shape from the separation surface and is parallel to the heat-sealed surface. It heat-seals by pressing against the flange portion through a material.
In this invention, when the lid body is heat-sealed to the container main body using the multilayer structure, the sealing disk has a sealing surface having a separation surface on the outer peripheral edge side of the annular shape and a flat surface on the inner peripheral edge side from the separation surface. As a result, the heat seal with a flat and highly adhesive property can be obtained, and the pressing force decreases along the outer peripheral edge side of the separation surface, so that the resin moves slowly, and the resin pools on the inner peripheral edge side of the heat sealed portion. Can be prevented from being formed. For this reason, while being able to peel well between a surface layer and a base material layer, high sealing performance is obtained.

The multilayer structure manufacturing method of the present invention is a manufacturing method for manufacturing a multilayer structure including a surface layer and a base material layer, and uses a material having a loss tangent tan δ value at 165 ° C. of less than 0.18. Forming the base material layer.
In this invention, it expands to the manufacturing method which manufactures the multilayer structure of this invention, and there exists an effect similar to the multilayer structure of this invention.

The container manufacturing method of the present invention is characterized by forming the multilayer structure of the present invention.
In this invention, for example, since the base material layer flows when heat-sealed and the resin pool is prevented from being formed at the edge of the heat seal, molding is performed using the multilayer structure of the present invention. Therefore, it is possible to provide a container that can prevent delamination appropriately and can achieve high sealing performance.

  According to the present invention, since the value of the loss tangent tan δ at 165 ° C. is less than 0.18 as the material constituting the base material layer laminated with the surface layer facing the surface, the base material layer is, for example, when heat-sealed. It is possible to prevent the resin pool from being formed at the edge of the heat seal by flowing, and to prevent the delamination due to the resin pool from being prevented. It can set suitably.

Sectional drawing of the multilayer sheet which concerns on one Embodiment of the multilayer structure of this invention. It is the figure which showed the easily openable container using the said multilayer sheet, Comprising: The schematic which shows the state which opened the cover body from the opening start part. It is IX-IX sectional drawing of FIG. 2, Comprising: (A) is a state before opening, (B) is a figure which shows the state after opening. The schematic diagram which showed the sealing process of the said easily openable container.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In this embodiment, although the structure shape | molded in the container main body of a packaging container is illustrated as a multilayer sheet of this invention, it is not this limitation.

[Configuration of multilayer sheet]
In FIG. 1, 10 is a multilayer sheet, and the multilayer sheet 10 is a laminate in which two layers of a surface layer 11 and a base material layer 12 adjacent to the surface layer are sequentially laminated.

The surface layer 11 is a layer that comes into contact with the contents and is heat-sealed with the sealant of the lid when the multilayer sheet 10 is molded into the shape of a container body, for example. Then, as will be described in detail later, the lid and the heat-sealed portion are peeled off from the container body together with the lid, like the opening of the easy-open container that is used as the container body of the easy-open container.
As the surface layer 11, for example, a material heat-sealed with the lid, preferably a polyolefin-based resin is suitably used. Specifically, polypropylene resins such as homopolypropylene (HPP), random polypropylene (RPP) and block polypropylene, polyethylene resins such as high density polyethylene (HDPE) and low density polyethylene (LDPE), linear ethylene- An α-olefin copolymer or the like is used.

The base material layer 12 constitutes a lower layer of the surface layer 11 adjacent to the surface layer 11, and is delaminated with the surface layer 11 when the easy-open container described later is opened.
The base material layer 12 is made of a material having a loss tangent tan δ value at 165 ° C. of less than 0.18, preferably 0.10 or less, particularly preferably 0.07 or less.
Here, when the value of the loss tangent tan δ at 165 ° C. of the material constituting the base material layer 12 becomes 0.18 or more, for example, when the heat seal is performed, the base material layer flows and a resin pool is generated at the edge of the heat seal. As a result, the inconvenience that the openability deteriorates is caused. Therefore, the value of the loss tangent tan δ at 165 ° C. is set to less than 0.18. There is no particular problem if the value of the loss tangent tan δ is less than 0.18, but for example, it can be suitably used if it is 0.01 or more.
And the measuring method and measuring device of loss tangent tan-delta are dynamic viscoelasticity measuring devices (DMS). The loss tangent tan δ of the resin as the constituent material can be controlled by blending the raw materials used.

As a specific material constituting the base material layer 12, for example, it is preferable that the material is made of at least one selected from the group of olefin resin, polystyrene resin, and polyester resin.
As the olefin resin, specifically, polypropylene, polyethylene, and the like are used. In particular, polypropylene is preferably used because it is widely distributed and easily available, is inexpensive, and has high strength.
Specific examples of the polystyrene-based resin include general-purpose transparent and rigid GP grade polystyrene and impact-resistant HI grade polystyrene, and particularly required when HI grade polystyrene is used as a container. It is preferably used from the viewpoint of impact resistance.
As the polyester resin, specifically, amorphous polyester, crystalline polyester, or the like is used, and amorphous polyester is particularly preferably used for reasons of processability.

In particular, as the base material layer 12, a polymer containing at least part of a propylene unit (hereinafter referred to as a polypropylene resin, and appropriately referred to as PP) and a polymer containing at least part of an ethylene unit (hereinafter referred to as a polyethylene resin). It is preferable to use a resin composition in which PP: PE = 30 mass% or more and 99 mass% or less: 1 mass% or more and 70 mass% or less.
Here, if the mass ratio PP / PE is smaller than 0.67, there is a possibility that a resin pool is generated during heat sealing, resulting in inconvenience that unsuccessful opening occurs. In particular, when the mass ratio PP / PE is less than 0.429, rigidity may be insufficient, and when the mass ratio PP / PE is more than 99, flexibility may be insufficient.
The polypropylene resin is specifically selected from any of four types of homopolypropylene, random polypropylene, block polypropylene, and mixtures thereof. And when heat resistance is considered, it is preferable in order of a homo polypropylene, a block polypropylene, and a random polypropylene. Moreover, when considering the sealing properties with other layers, random polypropylene, block polypropylene, and homopolypropylene are preferable in this order.
Specific examples of the polyethylene-based resin include high-density polyethylene and low-density polyethylene. Particularly, low-density polyethylene is preferably used for reasons of molding process stability.

Note that an inorganic filler such as talc may be added to the base material layer 12.
Further, the base material layer 12 is laminated and formed directly adjacent to the surface layer 11, but does not flow or hardly flows between the surface layer 11 and the base material layer 12 due to heat sealing such as an adhesive layer. A relatively thin layer may be provided.

[Configuration of easy-open container]
Next, the structure of the easily openable container using the said multilayer sheet 10 is demonstrated with reference to drawings.
2 is a schematic view showing an embodiment of the easy-open container 1 of the present invention, FIG. 3 is a cross-sectional view taken along the line IX-IX in FIG. 2, and (A) is a state before opening, (B) These are figures which show the state after opening.

The easy-open container 1 includes a container body 2 and a lid 3. The container body 2 is formed by molding the multilayer sheet 10, specifically, by heating. The surface layer 11 of the multilayer sheet 10 corresponds to the release layer 21, and the base material layer 12 corresponds to the front and lower layer 22. It is a laminated body in which two layers of the peeling layer 21 and the front lower layer 22 are laminated in this order.
The container main body 2 has a substantially rectangular tray shape having a predetermined depth, and has a substantially rectangular opening 24, and a flange 25 is formed on the periphery of the opening 24 so as to project outward. It is arranged. In the easy-open container 1, the flange portion 25 and the lid 3 placed on the flange portion 25 with respect to the opening portion 24 are heat sealed to form an annular heat seal portion 26 (see FIG. 3). The inside of the easy-open container 1 is sealed. Further, the container body 2 is provided with a notch 27 as a circumferential notch groove in the state where the release layer 21 is cut into the inside of the heat seal portion 26.

Here, the notch 27 is cut at the position of the notch 27 when the lid 3 is opened, even when a part of the thickness of the release layer 21 in the position of the notch 27 remains. The depth is not particularly limited as long as the depth does not cause delamination to the release layer 21 on the opening 24 side. In particular, it is preferable that the depth reaches the surface lower layer 22, that is, a depth equal to or greater than the thickness dimension of the release layer 21. Note that the notches 27 are formed in series by a molding operation using a claw-like member provided on the mold when the container body 2 is molded from the multilayer sheet 10, for example, or notched after the container body 2 is molded. May be.
And in order to open the easily openable container 1 of a sealing state, as shown to FIG. 3 (A), the cover body 3 is pulled up in the opening start part 4 provided in the corner of the easy openable container 1. Then, as shown in FIG. 3 (B), the easy-open container 1 is easily opened.

The thickness of the flange portion 25 of the container body 2 is preferably 200 μm or more and 2000 μm or less, more preferably 250 μm or more and 600 μm or less, and particularly preferably 300 μm or more and 500 μm or less.
Here, if the thickness of the flange portion 25 is less than 200 μm, there is a possibility that the rigidity of the container is lowered. If the thickness is greater than 2000 μm, many materials are required and the manufacturing cost (raw material cost) increases. Therefore, the above range is set.

In this embodiment, the lid 3 has an outer layer 32 as a base material layer that appears outside the easy-open container 1, and a seal layer 31 that is a sealant layer that is heat-sealed with the release layer 21 of the container body 2. It is the laminated body which consists of.
As the outer layer 32 constituting the lid 3, a polyethylene terephthalate (PET) film, a biaxially stretched nylon film (O—Ny) or the like can be used. The seal layer 31 can be made of a resin composition such as linear low density polyethylene (LLDPE).
Then, by heat-sealing the container body 2 and the lid 3, the release layer 21 and the seal layer 31 are fused to form the heat seal portion 26, and the container that is weak against stress at the time of opening. The peeling layer 21 of the main body 2 is peeled from the surface lower layer 22 on the outer peripheral side from the notch 27.

Here, in manufacturing the easy-open container 1, a seal device 70 including an annular seal disc 7 as shown in FIG. 4 is used. In order to fuse the flange portion 25 of the container body 2 and the lid body 3 so that the easily openable container 1 is in a sealed state, the lid body 3 is overlaid on the flange portion 25 of the container body 2. Heat sealing is performed by pressing the heated annular sealing disk 7 of the sealing device 70 from the upper surface.
That is, as shown in FIG. 4, the heat seal between the flange portion 25 of the container body 2 and the lid body 3 is performed by superimposing the lid body 3 on the flange portion 25 of the container body 2 and heating from the upper portion of the lid body 3. This is performed by pressing the annular seal disc 7 in the state of FIG. 4 in the direction of the arrow, whereby the release layer 21 that appears on the flange portion 25 of the container body 2 and the seal layer 31 of the lid 3 are fused. .

  An annular seal disc 7 used for manufacturing the easy-open container 1 of the present embodiment includes an annular seal portion 7A and a flat base portion 7B. Although the material which comprises the cyclic | annular sealing board 7 is not specifically limited, For example, it can select suitably from metals which have heat conductivity, such as aluminum, iron, copper, or these alloys. The thickness and shape of the base portion 7B are not particularly limited, and those appropriately changed according to the sealing device can be suitably used.

The seal portion 7A is not particularly limited, but can be appropriately changed according to the flange shape of a target container, such as a circular shape, an elliptical shape, a polygonal shape, a gourd shape, and a tear shape.
The seal portion 7A is provided with a flat surface portion 7A1, which is a plane parallel to the upper surface of the flange portion 25, on the inner peripheral side. The flat surface portion 7A1 is continuous with the flat surface portion 7A1 toward the outer peripheral side. A spacing portion 7A2 that is inclined in a direction away from the upper surface of the flange portion 25 is provided. In addition, although the convex curved surface 7A3 by the R process for chamfering is provided in the inner periphery of plane part 7A1, it does not need to provide.

Among these, in the separation portion 7A2 formed on the outer peripheral edge side of the annular seal disc 7, an inclination angle that is formed from the inner peripheral edge toward the outer peripheral edge with respect to the upper surface of the flange portion 25, that is, the heat-sealed surface 26A. The angle (θ) of the separating portion 7A2 with respect to the horizontal plane varies depending on the distance H, which is the width of the annular seal disc 7, but is 2 ° to 20 °, preferably 3 ° to 15 °, more preferably 6 ° to 12 °. It is preferable to set it to be less than °.
If the angle of the separating portion 7A2 is smaller than 2 °, the space between the sealed surface 231 and the separating portion 12 is not sufficient even when the sealing portion 1A is pressed during heat sealing, and the plane portion 11 is delayed. There is a possibility that the separation portion 12 presses the surface to be sealed 231 almost simultaneously and the resin cannot flow to the heat seal portion 23 corresponding to the separation portion 12. On the other hand, when the angle of the separating portion 7A2 exceeds 20 °, the periphery of the boundary with the flat surface portion 7A1 is gently pointed, and the lid 3 may be cut at the time of sealing or opening. May be damaged.

The spacing portion 7A2 is preferably formed with a width of 0.2H or more and 0.8H or less, and more preferably 0.4H or more and 0.6H or less with respect to the width H of the cross section of the seal portion 7A. If the width of the separation portion 7A2 is smaller than 0.2H, the amount of resin that is pressed by the flat portion 7A1 and flows to the outer peripheral side increases, and the width of the separation portion 7A2 that comes into contact with the flat portion 7A1 is too narrow. It becomes difficult to gently move the resin to the heat seal portion 26 corresponding to the separation portion 7A2. As a result, a resin reservoir is easily formed in the vicinity of the outer peripheral edge of the heat seal portion 26, the resin reservoir is caught when the obtained easily openable container 1 is opened, and the resistance increases outside the heat seal portion 26, It may be difficult to smoothly open the easy-open container 1. Further, when the width of the separation portion 7A2 is larger than 0.8H, the width of the flat portion 7A1 parallel to the heat seal surface 26A becomes narrow, and the heat seal surface 26A cannot be sufficiently pressed, and the container body 2 and the lid There is a risk that heat sealing with the body 3 is not sufficient, and the sealing performance of the easy-open container 1 is insufficient. Further, since the separation distance between the outer peripheral end of the separation portion 7A2 and the heat-sealed surface 26A is increased, if the heat sealing is attempted to the position corresponding to the outer peripheral end, the pressing force at the flat portion 7A1 becomes too strong, and the container body 2 Or the lid 3 may be damaged.
The width H is not particularly limited, and for example, 0.8 mm to 3.0 mm, more preferably 0.9 mm to 2.5 mm, and particularly preferably 1 mm to 2 mm are preferably used.

  Further, the R processing applied to the convex curved surface 7A3 formed on the inner peripheral edge side of the annular seal disc 7 varies depending on the width H of the annular seal disc 7, but the periphery of the boundary with the flat surface portion 7A1 is gentle without being sharp. R processing that is so-called chamfering that the lid 3 is not cut at the time of sealing or opening is preferable.

[Effect of the embodiment]
According to the embodiment, the value of the loss tangent tan δ at 165 ° C. is less than 0.18 as the material constituting the base layer 12 (surface lower layer 22) laminated on the surface layer 11 (peeling layer 21).
For this reason, for example, when heat-sealing, it is possible to prevent the base material layer 12 (surface lower layer 22) from flowing to form a resin pool at the edge of the heat seal, and to prevent delamination due to the resin pool. Suitable for heat-seal adhesive strength that can provide appropriate delamination, and does not require a reduction in the adhesive strength between the surface layer 11 (peeling layer 21) and the base material layer 12 (surface lower layer 22). Can be set.

And in the said embodiment, it is set as the structure which laminates | stacks the surface layer 11 (peeling layer 21) and the base material layer 12 (surface lower layer 22) directly adjacently.
For this reason, while preventing formation of the resin pool by the base material layer 12 (surface lower layer 22), while performing appropriate delamination of the surface layer 11 (peeling layer 21) and the base material layer 12 (surface lower layer 22), Easy setting for high sealing performance.

Moreover, in the said embodiment, at least any 1 type chosen from the group of an olefin resin, a polystyrene resin, and a polyester-type resin is used as the base material layer 12 (surface lower layer 22).
Therefore, it is possible to easily form a layer for obtaining appropriate delamination without forming a resin reservoir.

Furthermore, in the said embodiment, the base material layer 12 (surface lower layer 22) is formed using the resin composition mix | blended by PP: PE = 30 mass% or more and 99 mass% or less: 1 mass% or more and 70 mass% or less. ing.
For this reason, the value of the loss tangent tan δ at 165 ° C. of the material constituting the base material layer 12 (the lower surface layer 22) can be easily made less than 0.18.

And the container main body 2 is formed using the multilayer sheet 10 which has the base material layer 12 (surface lower layer 22) of predetermined loss tangent tan-delta.
For this reason, the easy-open container 1 which can obtain favorable delamination and high sealing performance can be provided.

In addition, the container body 2 made of the multilayer sheet 10 has a flange portion 25 that protrudes outward from the periphery of the opening 24 for storing an object to be packaged.
For this reason, when unsealing the lid 3 sealed on the flange portion 25, for example, the surface layer 11 (peeling layer 21) and the base material layer 12 (surface lower layer 22) can be delaminated well, and high An easily openable container 1 that can provide sealing performance can be provided.

Further, a notch 27 is provided in the surface layer 11 of the flange portion 25 so as to surround the opening 24.
For this reason, for example, when the lid 3 sealed by the flange portion 25 is opened, after the surface layer 11 (peeling layer 21) and the base material layer 12 (surface lower layer 22) are delaminated well, the notch 27, the opening 3 can be satisfactorily opened by peeling between the lid 3 and the surface layer 11 (peeling layer 21).

Further, the depth of the notch 27 is at least equal to or greater than the thickness dimension of the release layer 21 formed from the surface layer 11.
For this reason, when the sealed lid 3 is opened, the delamination layer 21 is delaminated between the upper and lower layers 22, and then the delamination of the delamination layer 21 is reliably released on the opening 24 side by the notch 27. Thus, the opening 3 can be reliably unsealed by peeling between the lid 3 and the peeling layer 21.

And the shape of the container main body 2 is made into tray shape.
For this reason, heat sealing can be performed using a general apparatus.

[Modification]
Although the best configuration for carrying out the present invention has been disclosed in the above description, the present invention is not limited to this. That is, the present invention has been described primarily with reference to specific embodiments, but with respect to the above-described embodiments without departing from the scope of the technical idea and object of the present invention, the material, quantity, and other details. In this configuration, those skilled in the art can make various modifications.
Accordingly, the description of the materials, layer structures, and the like disclosed above is exemplary for easy understanding of the present invention, and does not limit the present invention. Descriptions with names excluding some or all of the limitations are included in the present invention.

For example, in the said embodiment, although 2 layer structure was illustrated as the multilayer sheet 10, it can be set as the multilayer structure of 3 layers or more. Further, the base material layer 12 (surface lower layer 22) having a predetermined loss tangent tan δ of the present invention is not limited to one layer, and may be a plurality of layers.
That is, the layer configuration of the multilayer sheet 10 (container body 2) may be, for example, the following layer configuration.
(A) Surface layer 11 (peeling layer 21) / base material layer 12 (surface lower layer 22) / barrier layer (b) surface layer 11 (peeling layer 21) / base material layer 12 (surface lower layer 22) / second base material Layer / barrier layer (c) surface layer 11 (release layer 21) / base material layer 12 (surface lower layer 22) / barrier layer / base material layer 12 (surface lower layer 22)
(D) Surface layer 11 (peeling layer 21) / base material layer 12 (surface lower layer 22) / barrier layer / base material layer 12 (surface lower layer 22) / outer surface layer (surface layer 11)
(E) Surface layer 11 (peeling layer 21) / base material layer 12 (surface lower layer 22) / second base material layer / barrier layer / second base material layer (f) surface layer 11 (peeling layer 21) / base material Layer 12 (surface lower layer 22) / second substrate layer / barrier layer / second substrate layer / substrate layer 12 (surface lower layer 22)
(G) Surface layer 11 (peeling layer 21) / base material layer 12 (surface lower layer 22) / second base material layer / barrier layer / second base material layer / base material layer 12 (front surface lower layer 22) / outer surface layer ( Surface layer 11)
(H) Surface layer 11 (peeling layer 21) / base material layer 12 (surface lower layer 22) / second base material layer / first adhesive layer / barrier layer / second adhesive layer / second base material layer / group Material layer 12 (surface lower layer 22) / outer surface layer (surface layer 11)
And the like.

Here, the surface layer 11 is a layer heat-sealed with another film or the like. For example, when the multilayer structure (multilayer sheet 10) of the present invention is formed into the shape of the container body 2, the surface layer 11 is in contact with the contents. It becomes a layer to be heat sealed with the sealant of the lid 3. And like the opening of the easy-open container 1 described above, the lid 3 and the heat-sealed portion are peeled from the container body 2 together with the lid 3.
The base material layer 12 constitutes a lower layer of the surface layer 11. For example, when the container body 2 molded using the multilayer structure of the present invention is heat-sealed with the lid body 3 and the lid body 3 is opened. In addition, it is a layer that delaminates between the surface layer 11 and is a main layer of the multilayer structure (multilayer sheet 10). There are layers to compose. In addition, the base material layer 12 does not need to function as a main layer, when the following 2nd base material layers are laminated | stacked.
Furthermore, the second base material layer is provided as a main layer of the multilayer structure (multilayer sheet 10), and is a layer that is a main component of the container body 2 formed using the multilayer structure of the present invention, for example. .

  The adhesive layer is a layer that bonds the second base material layer and the barrier layer. For example, urethane elastomer, styrene elastomer, maleic anhydride modified polyethylene, maleic anhydride modified polypropylene, ethylene vinyl acetate (EVA). A material such as can be suitably used. The thickness of the adhesive layer is preferably 10 μm or more and 50 μm or less, and more preferably 20 μm or more and 40 μm or less.

  Further, the barrier layer is a layer using a resin that blocks oxygen, and by providing the barrier layer, a multilayer structure (multilayer sheet 10) having an oxygen permeation blocking property can be provided. As the barrier layer, for example, materials such as ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN) can be preferably used. The layer thickness of the barrier layer is preferably 10 μm or more and 210 μm or less, and more preferably 20 μm or more and 170 μm or less.

  The outer surface layer as the fourth base material layer is made of a material that is compatible with the adjacent layers. For example, the outer surface layer is formed on the outer surface of the container body 2 of the easy-open container 1 formed using the multilayer structure of the present invention. In the facing layer, the same material as that used in the base material layer 12, the second base material layer, or the surface layer can be suitably used. Further, a material different from the material used for the base material layer 12, the second base material layer, or the surface layer 11 may be used.

As in the structures (c) to (h) above, a plurality of layers may be repeatedly provided in the layer structure. Among these, the structure (h), which is a cross-sectional target structure, is preferable for the reason of film formation stability.
In addition, in the laminated structure as said (h), it can utilize as a container and a bag which accommodates various articles | goods, such as foodstuffs, a pharmaceutical, and an industrial article favorably.
Similarly, not only the layer configuration of the lid 3 (outer layer 32 / sealing layer 31) but also the configuration of the outer layer 32 / barrier layer / sealing layer 31, or the first outer layer 32 / second outer layer 32 / sealing layer 31 and the like. It is done.

  And although the multilayer sheet 10 was shape | molded and demonstrated to the tray shape as the container main body 2, you may shape | mold to cup shape and other shapes. Moreover, you may shape | mold not only the case where the container main body 2 is shape | molded from the multilayer sheet 10, but various processed materials.

Further, when the lid 3 is fused, the annular seal disk 7 having the seal portion 7A having a predetermined shape is used. However, the present invention is not limited to this configuration, and a generally used seal disk may be used.
In addition, the specific structure, shape, and the like in the implementation of the present invention may be other structures as long as the object of the present invention can be achieved.

Next, the present invention will be described more specifically based on examples.
The present invention is not limited by the following examples and comparative examples.

[Example 1]
As shown below, the container body 2 of the easy-open container 1 is molded using a multilayer sheet 10 having the following layer structure, the overall shape is shown in FIG. 2, and the cross-sectional structure of the opening start portion 4 is shown in FIG. The indicated easy-open container 1 was produced.

(Manufacture of multilayer sheet 10)
By coextrusion molding, the following surface layer / first substrate layer (substrate layer) / second substrate layer / first adhesive layer / barrier layer / second adhesive layer / third substrate layer / fourth substrate A multilayer sheet 10 having a thickness of 400 μm composed of a layer (outer surface layer) was formed.
Surface layer: Polypropylene (100% by mass) (80 μm)
First base material layer: polypropylene (80% by mass) + low density polyethylene (16% by mass) + high density polyethylene (4% by mass) (120 μm) (tan δ = 0.10)
Second base material layer: polypropylene (80% by mass) + polyethylene (10% by mass) + maleic anhydride-modified polypropylene copolymer (10% by mass) (205 μm)
First adhesive layer: maleic anhydride-modified polypropylene (20 μm)
Barrier layer: ethylene-vinyl alcohol copolymer (30 μm)
Second adhesive layer: maleic anhydride modified polypropylene (20 μm)
Third substrate layer: polypropylene (80% by mass) + polyethylene (10% by mass) + maleic anhydride-modified polypropylene copolymer (10% by mass) (205 μm)
Fourth base material layer: laminate of polypropylene (80% by mass) + low density polyethylene (16% by mass) + high density polyethylene (4% by mass) (120 μm)

(Configuration of container body 2)
Next, a container body 2 with a flange of 45 mm × 60 mm × 25 mm was formed by plug-assisted vacuum forming using the multilayer sheet 10. The container body 2 has a flange portion 25 having a width of 5 mm with respect to the opening 24 and is formed to have a substantially rectangular tray shape. Furthermore, the flange portion 25 is provided with a notch 27 having a depth reaching the lower surface layer 22.
A multilayer film having the following configuration is placed as the lid 3 on the flange portion 25 at the periphery of the opening 24 of the container body 2 obtained in this way, and the following sealing conditions are used. As the board 7, an annular seal board (seal ring) 7 shown in FIG. 4 in which the separating part 7 A 2, the flat part 7 A 1 and the convex curved surface 7 A 3 are formed on the entire circumference is used. It heat-sealed with respect to the flange part 25, and manufactured in the shape similar to the easy-open container 1 of the said embodiment.
In addition, when the container main body 2 and the lid 3 having this configuration are used, delamination between the surface layer 11 and the base material layer 12 of the container main body 2 is performed at the time of opening.

(Configuration of lid 3)
Seal layer 31: polyethylene (60 μm)
Outer layer 32: polyethylene terephthalate (PET) (12 μm) / polyamide (nylon) (15 μm) (in order of PET / Ny / PE)

(Sealing conditions)
Sealing temperature: 200 ° C
Sealing pressure: 1960N (200kgf / piece)
Time: 1.1 seconds Number of heat seals: Once

(Specifications of annular seal panel)
Seal width H: 3mm
Inclination angle θ (separating part 7A2): 6 °
R processing from the lower end of the separation part 7A2: 0.9 mmR

[Example 2]
In Example 1, using the same method as Example 1 except that the structure of the 1st base material layer (base material layer 12) of the multilayer sheet 10 (container main body 2) was as follows, it was easy to open. Container 1 was manufactured.
In addition, when the container main body 2 and the cover body 3 of this structure are used, the delamination of the container main body 2 is performed at the time of opening like Example 1.
(Configuration of the first base material layer)
Polypropylene (80% by mass) + Polyethylene (200% by mass) (100 μm) (tan δ = 0.17)

[Example 3]
In Example 1, using the same method as Example 1 except that the structure of the 1st base material layer (base material layer 12) of the multilayer sheet 10 (container main body 2) was as follows, it was easy to open. Container 1 was manufactured.
In addition, when the container main body 2 and the cover body 3 of this structure are used, the delamination of the container main body 2 is performed at the time of opening like Example 1.
(Configuration of the first base material layer)
Polypropylene (100% by mass) (100 μm) (tan δ = 0.15)

[Comparative Example 1]
In Example 1, the container was manufactured using the same method as Example 1 except having made the structure of the 1st base material layer (base material layer 12) of the multilayer sheet 10 (container main body 2) as follows. .
(Configuration of the first base material layer)
Polypropylene (block PP 85% by mass) + polyethylene (15% by mass) (100 μm) (tan δ = 0.32)

[Comparative Example 2]
In Example 1, the container was manufactured using the same method as Example 1 except having made the structure of the 1st base material layer (base material layer 12) of the multilayer sheet 10 (container main body 2) as follows. .
(Configuration of the first base material layer)
Polypropylene (Block PP 100% by mass) (100 μm) (tan δ = 0.24)

[Test example]
The opening strength, opening feeling, and internal pressure strength of Examples 1 to 3 and Comparative Examples 1 and 2 obtained as described above were compared and evaluated according to the following criteria. The results are shown in Table 1.

(Openability)
The corner of the lid 3 of the easy-open container 1 having the above shape was gripped with a chuck, and the opening strength when the lid 3 was pulled at an angle of 45 ° with the top surface of the lid 3 was measured. For the measurement of the opening strength, a digital force gauge manufactured by Imada Co., Ltd. was used. The measurement was carried out five times, the average value was calculated, and evaluated in the following two stages.
A: Opening strength is 4.9 N or more and less than 9.8 N (0.5 kgf / opening port or more and 1.0 kgf / opening port or less)
○: Opening strength is 9.8 N to 14.7 N (1.0 kgf / opening port to 1.5 kgf / opening port)
X: Opening strength is greater than 14.7N

(Internal pressure strength)
Pressurized air was injected into the easy-open container at 1.0 ± 0.2 liter / min, and the pressure (MPa) when the container burst was measured. The test was performed with n = 5 using a burst strength tester (manufactured by Sun Kagaku Co., Ltd.). The internal pressure strength was evaluated in the following four stages.
A: The internal pressure strength is very high. (0.100 MPa or more)
○: Internal pressure strength is high. (0.060 MPa to 0.099 MPa)
Δ: The internal pressure strength is slightly low. (0.030 to 0.059 MPa)
X: The internal pressure strength is low. (Less than 0.03 MPa)

  As shown in Table 1, from the result that the resin pool of the first base material layer after heat sealing is large and leads to unsuccessful opening, it is possible to obtain a consideration that a resin blend that does not cause resin pool is necessary.

  The multilayer structure of the present invention has both high sealing properties and easy opening properties by heat sealing, and can be widely used as packaging containers for various foods such as retort foods, medicines, cosmetics, and the like.

DESCRIPTION OF SYMBOLS 1 ......... Easily-openable container as a container 2 ......... Main body as a container that is a processed product 3 ......... Cover body 7 ......... Annular seal board that is a seal board 7A ... Seal part 7A1 ... in a plane A certain flat surface portion 7A2 ... a separation portion 7B which is a separation surface ... a base portion 10 ... a multilayer sheet as a multilayer structure 11 ... a surface layer 12 a base material layer 24 an opening portion 25 a flange portion 27 …… Notch as a notch

Claims (16)

A multi-layer structure having a laminated structure including a surface layer, a first substrate layer that can be peeled between the surface layer, and a second substrate layer adjacent to the first substrate layer,
The multilayer structure according to claim 1, wherein the second base material layer contains at least one adhesive. The multilayer structure according to claim 1,
The adhesive is at least one selected from the group of urethane elastomers, styrene elastomers, maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, and ethylene vinyl acetate (EVA). Multilayer structure. The multilayer structure according to claim 1 or 2, wherein
Said 2nd base material layer consists of at least any 1 sort (s) chosen from the group of an olefin resin, a polystyrene-type resin, and a polyester-type resin. The multilayer structure characterized by the above-mentioned. A multilayer structure according to any one of claims 1 to 3, wherein
The first base material layer is composed of polypropylene and polyethylene. A multilayer structure according to any one of claims 1 to 4, wherein
The adhesive is contained in an amount of 1% by mass to 50% by mass. A multilayer structure according to any one of claims 1 to 5,
A first adhesive layer adjacent to the second substrate layer;
A barrier layer adjacent to the first adhesive layer;
A second adhesive layer adjacent to the barrier layer;
A third substrate layer adjacent to the second adhesive layer;
A multilayer structure comprising a fourth base material layer adjacent to the third base material layer. A workpiece obtained by molding using the multilayer structure according to any one of claims 1 to 6. The workpiece according to claim 7,
A processed product obtained by forming the multilayer structure by heating. A container formed by using the multilayer structure according to any one of claims 1 to 6. A container according to claim 9,
A container comprising a container body having a flange projecting outward from a periphery of an opening for storing an object to be packaged and formed using the multilayer structure. A container according to claim 10,
The surface layer of the flange portion is provided with a notch groove surrounding the opening. A container according to claim 11,
The notch groove is provided at a depth equal to or greater than the thickness dimension of the surface layer. A container according to any one of claims 10 to 12,
The container body has a cup shape or a tray shape. A packaging container having a lid bonded to the flange of the container body,
A packaging container, wherein the container body is a container body of the container according to any one of claims 10 to 13. Production method for producing a multilayer structure having a laminated structure including a surface layer, a first substrate layer that can be peeled between the surface layer, and a second substrate layer adjacent to the first substrate layer Because
Said 2nd base material layer is formed with the resin composition containing the at least 1 sort (s) of adhesive agent. The manufacturing method of the multilayer structure characterized by the above-mentioned. A method for producing a container, comprising molding the multilayer structure according to any one of claims 1 to 6.