JP7062872B2 - Sealed resin container - Google Patents

Description

The present invention relates to a closed container including a container and a lid, and more particularly to a resin closed container having easy-opening and resealing properties.

As a packaging container for food use, a closed container in which a flexible lid is sealed with a heat seal on the flange portion of the resin container is widely used.
Such a closed container is required to have a performance contrary to the sealing performance, that is, the lid welded by heat seal can be easily peeled off and opened by hand while ensuring the airtightness of the container. ..

As such a closed container, for example, in Patent Document 1 below, a layer including at least an inner layer of the container is formed so as to be peelable, and an opening start portion and two circumferential cuts are formed on the upper surface of the flange portion of the container. Of these two circumferential notches provided, a portion lower than the upper surface of the flange portion is formed in connection with the outer notch, and the portion lower than the upper surface of the flange portion is shallower than the outer notch. Proposed an easy-to-open container in which the heat-sealed portion of the lid material is formed so as to protrude like a mouth toward the outer notch and protrude below the upper surface of the flange portion at the opening start portion. (Patent Document 1 etc.).

On the other hand, even in a heat-sealed container, it is desired that the lid once peeled off from the container can be re-fitted into the container and resealed (resealed) when the contents remain. A closed container having a resealing property by using the molded lid of No. 2 has also been proposed (Patent Document 2).
As a heat-sealing container that can be resealed, for example, Patent Document 3 below has a resealing function including a surface resin layer, an adhesive resin layer containing a specific styrene-based thermoplastic elastomer as a main component, and a heat-sealing resin layer. A package made of a multilayer film has been proposed.

Japanese Patent No. 4719411 Japanese Unexamined Patent Publication No. 2004-331156 Japanese Unexamined Patent Publication No. 2007-125820

In the easy-to-open container described in Patent Document 1, the outer end of the heat-sealed portion at the opening start portion always coincides with the outer notch, and the two circumferences excluding the heat-sealing portion and the opening start portion are included. Since a non-fused portion is provided between the notch and the shape, it has excellent easy-opening property, but this easy-to-open container cannot be resealed.
Further, the molded lid having a drop lid shape described in Patent Document 2 is thicker and more rigid than the highly flexible sheet-shaped lid, so that the sealing property is inferior and the lid is easily distorted when opened. In some cases.
Further, in the packaging body using the multilayer film with the resealing function described in Patent Document 3, by using a specific adhesive resin layer, the surface resin layer and the adhesive resin layer exposed at the time of peeling are made by hand or finger. Resealing properties are exhibited only by pressure bonding, but they are not yet fully satisfactory in terms of sealing properties when resealed, and the container and lid must have a multi-layer structure, which is economical and production. I'm still not completely satisfied with the sex.

Therefore, an object of the present invention is to provide a closed container which has excellent sealing property and easy opening property, can be resealed, and is also excellent in productivity and economy.

According to the present invention, it is a closed container composed of a container body having at least a bottom portion and a side wall portion, a container composed of a flange member separate from the container body, and a lid member covering the opening of the container. At the time of opening, the upper end of the opening and the side wall of the container body and the flange member are detachably joined to each other, and the flange member can be resealed so as to be joined to the outer surface of the container body. A fitting protrusion is formed, and an engagement recess and an engagement protrusion that are fitted to each other are formed on the joint surface between the fitting protrusion and the outer surface of the container body, and the container body and the flange member are integrally formed by insert molding. By molding, the engaging recess and the engaging protrusion are combined without gaps , and the combination of the container body and the resin constituting the flange member has heat-sealing properties and two or more types of heat that are incompatible with each other. Provided is a closed container which is a combination of plastic resins and in which the thermoplastic resin is selected from an ethylene-based polymer, a propylene-based polymer, or a blend thereof .
In the closed container of the present invention,
1. 1. The flange member has a frame shape that surrounds the entire circumference of the opening of the container body.
2. 2. The container body has a flange portion partially in the opening portion, and the flange member is formed into a shape corresponding to the opening portion of the container excluding the flange portion.
3. 3. The opening force (peeling strength) of the container body and the flange member shall be 0.5 to 2.5 kgf.
4. The container body and the flange member are made of a heat-sealing thermoplastic resin.
5. The container body and the flange member are composed of a blend of an ethylene-based polymer and a propylene-based polymer, and a combination of the propylene-based polymer.
Is preferable.
The present invention also provides a method for manufacturing the closed container, which comprises integrally molding the container body and the flange member by insert molding.

In the closed container of the present invention, the container is formed from the container body and the flange member molded separately from the container body, and the joint surface between the container body and the flange member is peeled off at the time of opening, so that the container is firmly bonded to the lid. The flange member can be easily removed from the container body and opened. That is, the container body and the flange member are molded with a combination of resins having poor adhesion to each other, and the flange member that is inseparably joined to the lid is, for example, a resin constituting at least the inner surface of the lid, as will be described later. By molding from a resin that can be strongly heat-sealed, the flange member integrated with the lid is pulled up following the movement of the lid at the time of opening, and is easily removed from the container body.
In the closed container of the present invention, it is preferable that the flange member is formed with a fitting protrusion that is in close contact with the side wall portion of the container body, and in this case, not only easy-opening property but also resealing property can be exhibited. That is, at the time of resealing, the flange member is fitted to the container body so as to return to the state before opening, and the lid fixed to the flange member covers the container body opening to be resealed. Since the fitting protrusions that are in close contact with the side wall portion of the container are formed, the flange member fits tightly with the side wall portion of the container body, so that the resealability is improved.
Further, in the closed container of the present invention, the fitting protrusion is formed so as to be in close contact with the side surface of the container body as described above, and the fitting protrusion and the joint surface of the side surface of the container body are engaged with each other. It is more preferable that the joint protrusion is formed. In this case, the fitting protrusion and the side surface of the container body engage with each other in the horizontal direction at the time of resealing, so that the opening direction of the lid is unintentionally (in this case). Even if a force (in the vertical direction) is applied, the engagement is not easily released, and it is possible to secure the sealing property at the time of resealing.

In the closed container of the present invention, the flange member has a frame shape that surrounds the entire circumference of the opening of the container body, or the container body has a flange portion partially in the opening and the flange member is the flange portion. It is possible to take an embodiment in which the container is molded into a shape corresponding to the opening of the container excluding the above, and in any embodiment, the container can be easily molded by insert molding or the like.
When the flange member has a frame shape that surrounds the entire circumference of the opening of the container body, the lid integrally fixed to the flange member can be completely separated from the container body and any of the openings of the container body. It can also be opened from the part.
When a flange is partially formed in the opening of the container body, the lid is fixed to both the flange member detachable from the container body and the flange portion integrally formed with the container body. When opening the lid, the part fixed to the flange member separates from the container body to form an opening, while the part fixed to the flange part of the container body does not separate from the container body and the lid is connected to the container body. It is also possible to maintain the state of the container.

It is a figure which shows an example of the closed container of this invention, (A) shows the perspective view, (B) shows the XX side sectional view of (A). It is a figure for demonstrating the opening mechanism of the closed container shown in FIG. It is a figure for demonstrating the aspect of the joint surface of a container body and a flange member in a closed container of this invention. It is a figure which shows another example of the closed container of this invention, (A) is the perspective view, (B) is the XX side sectional view of (A), (C) is the side sectional view at the time of opening. It is a figure for demonstrating the measuring method of the opening force.

(Sealed container)
The closed container of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the closed container 1 of the present invention is located at the opening of the container body 2 and the container body, and is welded to the flange member 3 and the flange member 3 separate from the container body by heat sealing. It consists of a lid 4.
As shown in FIG. 1, the container body 2 is composed of at least a bottom portion 21 and a side wall portion 22. Further, as is clear from FIG. 1B, the flange member 3 abuts on the entire circumference of the opening tip 23 of the container body 2 and extends outward from the opening tip 23 of the container body 2. 31. It is composed of a fitting projection 32 that extends downward from the lower surface of the flange portion 31, is in close contact with the outer surface of the side wall portion 22 of the container body, and is tagged from the outside above the side wall portion of the container body.
Further, in the specific example shown in FIG. 1, the fitting protrusion 32 of the flange member 3 and the side wall portion 22 of the container body have an annular engaging protrusion 33 on the inner surface of the fitting protrusion 32, and the engaging protrusion 33 has a shape. A matching annular engaging recess 24 is formed on the outer surface side of the container body, and not only the flange member 3 is fixed to the container body by the fitting protrusion 32 , but also the engagement between the fitting protrusion 32 and the side wall portion 22 of the container body is engaged. The flange member 3 is further firmly fixed by the combination.
The lid 4 is a sheet-shaped lid having a size substantially the same as the outer diameter of the flange member 3, and is fixed to the upper surface of the flange portion 31 of the flange member 3 by a joining method such as a heat seal so as not to be peeled off. An opening piece 41 extending outward from the outer edge of the flange member 3 is formed.

As described above, in the closed container of the present invention, when the container is opened, the joint surface between the container body and the flange member is peeled off, and the flange member is separated from the container body, so that the lid integrated with the flange member is removed from the container body. And an opening is formed.
FIG. 2 is a diagram for explaining an operation of opening the closed container by enlarging the P portion of the closed container of FIG. 1 described above, and FIG. 2A is a diagram showing a sealed state, and FIG. 2A is a diagram showing a sealed state. (B) is a diagram showing a state in which the opening piece 41 of the lid 4 has begun to be pulled up, and FIG. 2 (C) is a diagram showing a state in which the fitting protrusion of the flange member 3 has come off from the container body.
As described above, in the sealed state, as shown in FIG. 2A, the upper part of the opening tip portion 23 and the side wall portion 22 of the container body 2 is the inner peripheral side of the flange portion 31 of the flange member 3 and the fitting protrusion. The fitting protrusion 32 is joined to the 32 with a peelable seal strength, and the fitting protrusion 32 is tagged from the outside above the side wall portion 22 and further formed on the outer surface of the side wall portion of the container body 2 and the inner surface of the fitting protrusion 32. It is tightly combined by the engaging recesses 24 and the engaging protrusions 33 that fit together. Further, since the lid 4 is joined to the flange member 3 so as not to be peelable by the welded portion 5, the inside of the container is surely maintained in a sealed state.
As shown in FIG. 2B, when the opening piece 41 of the lid 4 is pulled upward for opening, the flange member 3 follows this, and the joint surface between the container body and the flange member begins to peel off, and at the same time, The tag tightening from the outside by the fitting protrusion 32 is loosened, and the engagement between the engaging recess 24 and the engaging protrusion 33 begins to be disengaged. When the opening piece 41 is further pulled up, the flange member 3 is completely separated from the container body and opened, as shown in FIG. 2C.

The closed container of the present invention is not limited to the above-described embodiment. FIG. 3 is an enlarged view showing a joint portion of an upper portion of a container body and a flange member for explaining another aspect of the closed container of the present invention.
In the embodiment shown in FIG. 3A, the annular flange member 3 is joined to the opening tip 23 of the container body 2. In this aspect, since the opening tip 23 and the annular flange member are joined only at the opening tip 23, it is desirable to use a molded lid 4 having a drop lid shape in order to obtain resealability.
Further, in the embodiment shown in FIG. 3B, the flange member 3 does not have a flange portion extending outward from the opening tip 23 of the container body, and only the fitting projection 32 that is in close contact with the outer surface of the side wall portion of the container body is formed. The flange member 3 is formed and is joined to the opening tip 23 of the container body at the upper outer surface of the side wall portion. In this embodiment, since the fitting protrusion 32 is formed on the flange member 3, the fitting protrusion 32 can be fixed by tagging the side wall portion of the container body from the outside at the time of resealing.
Further, in the embodiment shown in FIG. 3C, the flange member 3 is formed with a flange portion 31 extending outward from the opening tip 23 of the container body, and a fitting protrusion that is in close contact with the inner surface of the side wall portion of the container body. 32 is formed, and the flange member 3 is joined to the opening tip 23 of the container body on the inner surface of the upper part of the side wall portion. In this aspect, since the fitting protrusion 32 is formed on the flange member 3, the fitting protrusion 32 can be fixed by pushing the side wall portion of the container body from the inside at the time of resealing.
Furthermore, the aspect shown in FIG. 3 (D) is the same as that in FIG. 3 (C) except that the flange member 3 is not formed with a flange portion extending outward from the opening tip 23 of the container body.
Also in the embodiments shown in FIGS. 3 (B) to 3 (C), the engaging protrusion may be formed on the joint surface between the fitting protrusion and the container body.

In the above-mentioned closed container of the present invention, the flange member is formed with an annular flange member around the entire circumference of the opening tip of the container body, but the flange member is not necessarily annular (frame-shaped). Not limited.
FIG. 4 is a diagram showing another aspect of the closed container of the present invention. The closed container represented by 1 is located at the opening of the container main body 2 and the container main body, and is a flange member separate from the container main body. 3 and the lid 4 to be welded to the flange member 3 by heat sealing are the same as those in FIG. 1, but in this embodiment, the flange is provided at the tip 23a of a part of the opening of the container body. The flange member 3 is formed at a position corresponding to the opening tip 23b in which the portion 25 is formed and the flange portion 25 is not formed, and the flange portion 25 of the container body and the upper surface of the flange member 3 have a uniform flange surface. The lid 4 is fixed to this portion. When the closed container of this aspect is opened, as shown in FIG. 4C, only the portion of the flange member 3 is removed from the container body, so that the lid does not come off from the container body and the lid is partially. It will be opened. Therefore, it is desirable that the flange portion 25a formed on the container body is 180 degrees or less with respect to the entire circumference of the opening from the viewpoint of openness.

(Resin used)
In the present invention, in order to ensure that the container body and the flange member can be reliably maintained in a sealed state and that the container body and the flange member can be easily peeled off at the time of opening, the resin constituting the container body and the resin constituting the flange member are used. It is preferable to adjust the adhesive strength by the combination. As the adhesive strength suitable for satisfying both the sealing performance and the easy-opening performance, as shown in FIG. 5, a push-pull gauge 6 is attached to one end of the lid 4 welded to the flange member 3, and this is attached to the lid 4. It is desirable that the opening force (peeling strength) measured by pulling up in the direction of 45 degrees is in the range of 0.5 to 2.5 kgf.
As described above, in addition to the combination of the resin constituting the container body and the resin constituting the flange member, the sealing performance is enhanced by the fitting protrusion of the flange member and the engagement between the container side wall portion and the fitting protrusion. Can be done.
As such a combination of resins, two or more kinds of thermoplastic resins having a heat-sealing property and having no compatibility can be appropriately combined.
For example, when the container body is made of a propylene-based polymer, the flange member is made of a blend of an ethylene-based polymer and a propylene-based polymer, so that the sealing property can be ensured and the easy-opening property can be maintained. , The peel strength can be adjusted by appropriately changing the blend ratio of the blended product.

Examples of the propylene-based polymer include homopolypropylene, propylene and ethylene, or other α-olefins such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Random copolymers and the like can be mentioned. The ethylene-based polymer may be a homopolymer of ethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium- or high-density polyethylene (MDPE, HDPE), or ethylene, for example, 1-. Other α-oliffins such as butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, Examples thereof include a copolymer with a vinyl-based monomer such as vinyl acetate and styrene, an ionomer and the like.
In addition to the combination of the above olefin polymers, the blend includes thermoplastic polyester resins such as polyethylene terephthalate and polyethylene terephthalate isophthalate copolymers, polycarbonate resins, polyacrylonitrile resins, and the above olefin polymers. Combinations and the like can also be used.

In the present invention, the combination of the resin of the container body, the flange member, and the lid is not limited to this, and the following combinations can be exemplified.
For example, in the embodiment shown in FIG. 1, the container body is molded from a propylene-based polymer, the flange member is molded from a blend of a propylene-based polymer and an ethylene-based polymer, and at least the inner layer of the lid is the same as the flange member. Can be formed from a blend of.
Further, in the embodiment shown in FIG. 4, the container body is molded from a blend of a propylene-based polymer and an ethylene-based polymer having a large compounding ratio of the propylene-based polymer, and the flange member is propylene having a large compounding ratio of the ethylene-based polymer. By molding with a blend of a system polymer and an ethylene polymer and forming at least the inner layer of the lid from a blend similar to the flange member, the joint surface between the container body and the flange member is peeled off at the time of opening, and the container body It is possible to prevent peeling at the joint surface between the flange portion and the lid and the joint surface between the flange member and the lid.

In the present invention, when a propylene-based polymer and an ethylene-based polymer are used as the blend, in order for the flange member made of the blend to exhibit good releasability from the container body made of the propylene-based polymer. , It is preferable to preferably use a blend of a propylene-based polymer and an ethylene-based polymer in a weight ratio of 5: 5 to 9.5: 0.5.
Further, in the present invention, it is particularly preferable that the flange member and the lid, or the container body flange portion and the lid in the embodiment shown in FIG. 4, are joined by heat sealing so as not to be peeled off. It is also possible to bond using an adhesive resin such as an acid-modified olefin resin, or to impregnate the lid or flange member with a material that generates heat by laser irradiation so that it cannot be peeled off by laser welding.

The shape of the container in the closed container of the present invention is not particularly limited, and the shape of the opening may be circular, elliptical, or rectangular. Further, as long as the lid can be joined at the flange portion, a conventionally known shape such as a cup type or a tray type can be adopted. Further, the container body may have a single-layer structure of the resin described above, but may have a multi-layer structure having a gas barrier intermediate layer as long as the joint surface with the flange member satisfies the above-mentioned conditions.
As the lid used for the closed container of the present invention, a conventionally known lid can be used except that the flange member or, in the embodiment shown in FIG. 4, is inseparably joined to the flange portion of the container body.
For example, a flexible single-layer film or multilayer film having at least a layer made of the same resin as the flange member on the flange member side, specifically, a flexible laminate made of the inner layer / gas barrier intermediate layer / outer layer and the like. I can raise my body.
Examples of the material constituting the gas barrier intermediate layer include a metal foil such as an aluminum foil, an inorganic thin-film film, and a gas barrier resin such as an ethylene vinyl alcohol copolymer.
Further, the molded lid may have a drop lid shape having at least a layer made of the same resin as the flange member on the flange member side. Such a molded lid having a drop lid shape can be molded by a conventionally known method such as thermoforming from a sheet, compression molding, or injection molding.

(Production method)
In the closed container of the present invention, the container can be manufactured by various methods as long as it has the above-mentioned configuration. Alternatively, the container body and the flange member can be integrally molded by insert molding, which is inserted into an injection molding die and the container body is molded by compression molding or injection molding. Alternatively, the order may be reversed, that is, the container body may be molded first, and then the resin constituting the flange member may be supplied and integrally molded.
As described above, the container and the lid can be joined by heat sealing or the like.

1 Closed container, 2 Container body, 3 Flange member, 4 Lid, 21 Bottom, 22 Side wall, 23 Opening tip, 24 Engagement recess , 25 Flange, 31 Flange, 32 Fitting protrusion, 33 Engagement protrusion ..

Claims (7)

A closed container composed of a container body having at least a bottom and a side wall, a container composed of a flange member separate from the container body, and a lid member covering the opening of the container.
At the time of opening, the flange member is detachably joined to the upper end of the opening and the side wall of the container body.
A fitting protrusion that enables resealing is formed on the flange member so as to be joined to the outer surface of the container body, and an engaging recess that fits to the joint surface of the fitting protrusion and the outer surface of the container body. And the engaging protrusions are formed, and the engaging recesses and the engaging protrusions are combined without gaps by integrally molding the container body and the flange member by insert molding .
The combination of the resin constituting the container body and the flange member is a combination of two or more kinds of thermoplastic resins having heat-sealing property and incompatibility, and the thermoplastic resin is an ethylene-based polymer or a propylene-based resin. A closed container characterized by being selected from a polymer or a blend thereof . The closed container according to claim 1 , wherein the flange member has a frame shape that surrounds the entire circumference of the opening of the container body. The hermetic seal according to claim 1 or 2 , wherein the container body has a flange portion partially in the opening portion, and the flange member is formed into a shape corresponding to the opening portion of the container excluding the flange portion. container. The closed container according to any one of claims 1 to 3 , wherein the opening force (peeling strength) of the container body and the flange member is 0.5 to 2.5 kgf. The closed container according to any one of claims 1 to 4 , wherein the container body and the flange member are made of a thermoplastic resin having a heat-sealing property. The closed container according to any one of claims 1 to 5 , wherein the container body and the flange member are composed of a blend of an ethylene-based polymer and a propylene-based polymer, and a combination of the propylene-based polymer. The method for manufacturing a closed container according to any one of claims 1 to 6 , wherein the container body and the flange member are integrally molded by insert molding.

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