JP4719411B2 - Easy-open packaging body and method for producing easy-open packaging body - Google Patents

Description

The present invention relates to an easy- open packaging body and a method for producing an easy-open packaging body .

  Conventionally, as a packaging form for foods, after the foods are stored in the inside of the container, the container body is provided with a container body provided with a flange portion at the periphery of the opening of the container body and a film-like lid member. Containers with lids that are hermetically sealed by heat-sealing the flange portions and lid materials are widely used.

  Such a lidded container heat-seals the flange part provided in the container main body and the material to be the lid material from the viewpoint of safely storing food stored in the container. The seal part formed by the above is required to have high sealing properties such as making it difficult to peel off, and in the case of opening the lid material, the lid material can be easily peeled off from the container body, It was necessary to have the contradictory property of easy opening at the same time.

On the other hand, in order to have such contradictory characteristics as easy opening and sealing, the interlayer adhesive strength of the container body having a multilayer structure is set to be weaker than the adhesive strength of the flange portion and the lid material, and the flange portion and the lid material A container with a lid is known in which a notch is formed in the inner layer of the flange portion inside the sealed portion where heat sealing is performed, and the inner layer of the container body is delaminated from the outer edge of the flange portion to the notch at the time of opening. It was.
For example, there has been a demand for providing a container with a lid having a skirt flange with a flange body having a container body having a shape such as a tray and the like having improved flange rigidity.

  In addition, as a container with a lid having such a skirt flange, for example, circumferential cuts are provided on the outer side and the inner side of a part to be melt-sealed with a lid material, and a melt-sealed part located at an opening start part is provided. There is provided an easy-open container that is sealed so as to protrude outward from the outer cut position, and a recess is formed in the inner layer of the outer edge of the protruding seal part via a lid (for example, a patent) Reference 1).

Japanese Patent No. 2724355 ([Claims], [FIG. 1] to [FIG. 4])

However, in the above-described conventional technology, a concave portion is formed on the inner layer of the outer edge portion of the protruding seal portion via a lid member. However, if the concave portion is not sufficiently formed, the inner layer is not torn at the time of opening. There was a problem that it was difficult to open the lid.
On the other hand, if the concave portion is formed so deeply, there is a problem that the lid member breaks in the concave portion forming portion.
Furthermore, in order to enable good easy-openability in such an easy-open container, there are various restrictions on the material and thickness of the inner layer of the container and the types of lid materials that can be used.

  In addition, when the conventional technology as described above or the general method of matching the outer end of the heat seal member such as a heat seal ring at the opening start portion with the outer notch, the sealing accuracy of the heat seal machine is poor. In the case where the heat seal member protrudes too much outward from the position of the outer notch, the area of the protruded heat seal portion becomes large, and the inner layer is torn off at the time of opening. It was difficult to open.

Therefore, an object of the present invention is an easy-open packaging body having both easy-openability and sealing performance, and for example, even when the sealing conditions such as the sealing pressure and the sealing temperature, especially the sealing position etc. fluctuate, An object of the present invention is to provide an easy- open packaging body capable of always obtaining a stable easy-openability and a method for producing the easy-open packaging body .

In order to solve the above-described problems, an easy-open packaging body according to the present invention includes an easy-open packaging body including a multilayer container in which a flange portion is disposed on the periphery of an opening portion, and a lid member that is heat-sealed to the flange portion. The layer including at least the inner layer of the container is formed so as to be peelable, and the upper surface of the flange portion is provided with an opening start portion and two circumferential cuts, and the two circumferential shapes cut by concatenating the notch outside of the said are formed lower portion than the upper surface of the flange portion, a lower portion than the upper surface of the flange portion, the shallower than the outer cut portion, in the open seal initiation section The heat seal portion of the lid member is formed in a shape projecting in a mouth shape toward the outer cut and protruding from a portion lower than the upper surface of the flange portion, Do Than is.

The multilayer container of the present invention is a container that can constitute an easy-open packaging body, and, as described above, has a flange portion at the periphery of the opening, and the layer including at least the inner layer of the multilayer structure is peeled off It is made possible. Here, in order to form a layer including at least the inner layer in a detachable manner, for example, a configuration may be adopted in which the inner layer and a next layer in contact with the inner layer are formed in a detachable manner.
Here, the “inner layer” is a layer existing on the innermost surface of the multilayer container and refers to a layer that is heat-sealed with a lid material described later, and the “next layer” refers to a layer in contact with the inner layer. Say. And in order to form these in a peelable manner, for example, when the cover material is to be peeled after heat sealing the inner layer and the cover material, the inner layer and the next layer are peeled from the peel strength of the inner layer and the cover material. What is necessary is just to make intensity | strength small.
Further, “the layer including the inner layer is peelable” means that the peel strength is 1 to 20 N / 15 mm, preferably 3 to 10 N / 15 mm.

  Furthermore, the multilayer container of the present invention may have a configuration in which a cohesive failure layer capable of cohesive failure and separation is formed between the inner layer and the next layer. Here, in order to form a cohesive failure layer capable of cohesive failure and peeling, for example, when the inner cover and the cover material are heat-sealed and then the cover member is peeled off, the cohesive failure is caused between the inner surface and the next layer. It is only necessary to form a layer (cohesive failure layer) in which peeling proceeds by causing In addition, in such a structure, since the cohesive failure layer which becomes an above-described aspect exists between an inner layer and a next layer, an inner layer and a next layer do not contact | connect.

The multilayer container of the present invention is not limited to the above-described configuration, and as will be described later, the inner layer, the next layer, and the cohesive failure layer are basically made of the same material. In addition, between the inner layer and the cohesive failure layer, or the next layer may be a multi-layer structure, delamination may occur between the layers, and the next layer may become a cohesive failure layer so that cohesive failure occurs. Also good. That is, there is no problem as long as the layer including the inner layer to be heat-sealed with the lid is formed so as to be peelable.
And you may make it form other layers, such as a gas barrier layer mentioned later, and an oxygen absorption layer with respect to the interlayer of a multilayer container.

  As a material constituting the multi-layer container, first, the inner layer is preferably heat-sealed because it is heat-sealed with the lid material. For example, polypropylene (PP) resin, polyethylene (PE) resin It is preferable to use polyolefin resins such as resins, and these polyolefin resins may be a single material or a blend. Further, a rubber resin such as ethylene-propylene rubber (EPR) or a thermoplastic elastomer such as styrene elastomer (SEBS) may be added to these polyolefin resins. A low crystalline or amorphous polyethylene terephthalate (PET) resin may also be used. In addition, it is preferable to use the heat resistant resin which can endure the temperature of 100 degreeC or more as a material which comprises an inner layer.

Next, as the next layer, a material similar to the material constituting the inner layer can be suitably used. For example, when the inner layer is a polypropylene resin, high density polyethylene (HDPE) is 50 to 100% by mass. A blend of 0 to 50% by mass of low density polyethylene (LDPE) can be used. Further, an inorganic filler such as talc may be added to these materials.
Such a next layer may have a single layer structure made of the above-described material, but may have a structure in which another layer is further laminated in order to improve the oxygen gas barrier property. Examples of the oxygen gas barrier material include resins such as ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), nylon (polyamide) resin, and the like. These layers may be laminated or used as an intermediate layer.

  In the next layer, as an oxygen absorption layer, for example, pure iron (for example, 20 to 50 parts by weight with respect to the entire layer) with respect to a polyolefin resin such as a polypropylene (PP) resin or a polyethylene (PE) resin. A layer made of a material containing a trace amount of a metal halide salt may be laminated. In this case, the polyolefin resin may be formed from a blended material such as a polypropylene (PP) resin and a polyethylene (PE) resin. Other examples of the oxygen-absorbing layer include organic oxygen-absorbing polymers such as materials comprising a mixture of a polymer containing a cyclohexene functional group and a transition metal, and polymers having a carbon-carbon unsaturated double bond. Etc.

  Further, in the case of forming a cohesive failure layer between the inner layer and the next layer, as a material constituting the cohesive failure layer, the material constituting the inner layer can be applied, for example, A blend of 40 to 100% by weight of homopolypropylene (HPP), 0 to 60% by weight of a low density polyethylene (LDPE) resin, and 0 to 40% by weight of an ethylene special copolymer can be used.

In order to obtain a multi-layer container, in addition to the usual co-extrusion molding method, various molding materials described above are commonly used for laminating, for example, extrusion laminating (extrusion laminating), hot melt laminating, dry laminating. It can be easily produced by thermoforming a sheet-like laminate obtained by means such as a method or a wet lamination method.
As the thermoforming method, various thermoforming methods such as a vacuum forming method, a pressure forming method, a vacuum pressure forming method, and a plug assist vacuum forming method can be employed.

  In general, the thickness of the laminate is preferably in the range of 200 to 3000 μm, and more preferably in the range of 500 to 1500 μm. By setting the thickness of the laminate within such a range, it is possible to provide a multilayer container excellent in strength, workability, and the like.

  The shape of the multilayer container can be various shapes such as a so-called tray shape and cup shape. Moreover, the shape of the opening part of a multilayer container can also be made into various shapes, such as circular shape, square shape, and ellipse shape.

At the periphery of the opening of the multilayer container formed by the above-mentioned means, a flange-like flange portion for heat sealing with the lid member is disposed. As the shape of the flange portion, a skirt flange having a U-shaped cross section formed by extending in the horizontal outer direction from the surface to which the opening belongs and hanging from the outermost edge, or in the horizontal outer direction from the surface to which the opening belongs. Examples thereof include a flat flange that is formed to extend, a curling flange that extends in the horizontal outer direction with the surface to which the opening belongs, and hangs down at the outermost edge to have a curled end portion.
Here, for example, when the shape of the opening has a corner such as a square shape, at least one corner of the opening can be used as the opening start portion, and the opening start portion Then, the lid material described later may be peeled off to open the container.

  Further, the width of the flange formed in the multilayer container may be appropriately determined depending on the size of the multilayer container, but is preferably in the range of 4 to 50 mm, and more preferably in the range of 8 to 20 mm. . By making the width of the flange within such a range, a multilayer container having a flange portion excellent in rigidity and unsealing property is obtained, which is preferable.

  In the easy-open container of the present invention, two circumferential cuts are provided on the upper surface of the flange portion. In this cut, the lid material is heat-sealed to the flange portion of the multilayer container, and at the time of opening the lid material, the layer including at least the inner layer between the inner cut and the outer cut is cut and peeled, and the inner layer is separated from the lid material side. It is possible to move to.

  Among the circumferential cuts, the inner cut may have various cross-sectional shapes such as a V shape, a U shape, and a rectangular shape. Further, the depth of the cut may reach the inner layer without reaching the next layer (or the cohesive failure layer), but if the depth reaches the next layer (or the cohesive failure layer), the peeling can be reliably performed.

Further, a portion that is lower than the upper surface of the flange surface (hereinafter, may be simply referred to as “low portion”) is formed in connection with the outer cut.
Such a low part is formed in connection with the outer cut and is formed at the position of the opening start portion. In this case, what is necessary is just to make it the same shape as the above-mentioned inside cut about the part which is in the outside cut and the said low part is not formed.

  On the other hand, when the opening of the container is circular or oval and can be opened from an arbitrary position of the opening, the lower part may be formed over the entire circumference of the flange of the container opening. preferable.

  In addition, if the said low part is formed with respect to the upper surface of a flange part, even if it is a case where the seal ring which performs a heat seal is located in the outer side of a flange part rather than an outer notch, it is such a low with a cover material Since the outer portion of the flange portion is not heat-sealed from the notch including the portion, or even if it is heat-sealed, the sealing strength is weak, so that the substantial opening starts from the outer notch.

The relationship between the depth of the outer notch and the depth of the lower portion may be the same, but if the depth of the lower portion is shallower than the depth of the outer notch, heat sealing At this time, it is preferable because the amount of resin extruded around the low portion can be reduced, and adverse effects on heat sealing can be suitably prevented.
In this case, the difference in depth between the low portion and the outer cut may be about 10 to 200 μm.

  The shape of the low portion is not particularly limited as long as it is formed so as to be connected to the outer cut, but is preferably a concave shape formed so as to be connected to the outer cut. It is preferable to make the shape of the low portion a concave shape because the outer end of the heat seal portion of the opening start portion can be more reliably aligned with the outer cut position and heat sealed. In addition, processing of the multilayer container is facilitated.

Further, the bottom surface of the recess may be in a smooth state, but if the surface of the bottom surface is provided with irregularities, the lid material is temporarily heat-sealed at the bottom surface of the recess. However, since the bonding area is reduced and the bonding force is also weakened, it is preferable because the lid member and the concave portion can be suitably peeled off.
Here, in order to provide unevenness, the bottom surface is not limited to an appropriate protrusion shape, for example, a triangular shape with a fine cross section, for example, a hemispherical shape with a fine cross section or a cross section. However, a large number of fine cross-shaped protrusions may be provided.

  In order to form a recess connected to the notch and the outer notch with respect to the flange portion, for example, a blade for forming the inner notch and a member for forming the recess are provided on the entire circumference or the opening start portion of the flange portion. You may make it form a cut | notch by pressing these blades to a flange part using the blade which forms the outer cut | notch provided in the located part. By using such means, it is possible to form an inner cut and an outer cut with adjacent recesses at a time. In the case of using such a cutting blade, the temperature of the blade or member may be in a normal temperature state or in a heated state.

  Note that the depth of cut can be adjusted by the area and height of the blade forming the recess, and the depth of cut is controlled by pressure and time. In addition, when processing, a stopper that has a constant depth may be attached to the periphery of the blade by hitting a container flange or a pedestal holding the container.

When heat-sealing the flange portion of the multilayer container and the lid material to be described later, it takes into account that the belt-shaped portion between the inner cut and the outer cut formed on the upper surface of the flange is the heat seal portion. In general, the interval between the two circumferential cuts is preferably about 3 to 40 mm.
The distance between the inner cut and the inner edge of the multilayer container is preferably about 0.5 to 10 mm, and the distance between the outer cut and the outer edge of the multilayer container is preferably about 0.5 to 10 mm.

  Next, as a resin material constituting the lid member that is placed in the opening of the multilayer container and seals the opening by heat-sealing the flange on the periphery of the opening, a single layer or a multilayer structure Or a film (hereinafter, sometimes referred to as “film or the like”) can be used.

  The material constituting the film is not particularly limited as long as it is in the shape of a film or the like, but is not limited to polypropylene (PP) resin, polyethylene (PE) resin, nylon (polyamide) resin, polyethylene terephthalate ( A single layer or a laminated film may be formed by using a known molding method using one or more materials such as polyester resin such as PET), aluminum foil, paper, and adhesive resin.

  Since the lid material is heat-sealed with respect to the flange portion provided at the periphery of the opening of the multilayer container described above, it is preferable to provide a sealant layer, and as such a sealant layer, heat sealability with the lid material, It can be formed of a resin material such as a resin having high adhesive strength, such as a polypropylene (PP) resin, a polyethylene (PE) resin, or a polyethylene terephthalate (PET) resin.

  In addition, it is preferable to provide a gas barrier layer on the lid material in order to improve gas barrier properties. For example, ethylene-vinyl alcohol copolymer (EVOH) resin, nylon (polyamide) resin, aluminum oxide, etc. A metal oxide vapor deposition layer and a gas barrier layer formed of an aluminum foil can be provided.

In addition, when making the film etc. which form a cover material into a laminated film, it can be set as a structure as shown to following (1)-(5), for example.
(1) Stretched polyethylene terephthalate (PET) layer / metal oxide coating layer / stretched nylon (polyamide) layer / polypropylene sealant (2) Stretched polyethylene terephthalate (PET) layer / metal oxide coating layer / stretched nylon (polyamide) layer / Polyethylene sealant (3) Stretched nylon (polyamide) layer / ethylene-vinyl alcohol copolymer (EVOH) layer / polypropylene sealant (4) Stretched nylon (polyamide) layer / ethylene-vinyl alcohol copolymer (EVOH) layer / polyethylene sealant (5) Stretched polyethylene terephthalate (PET) layer / metal oxide coating layer / stretched nylon layer / amorphous polyethylene terephthalate (PET) sealant

  Moreover, it is preferable that the thickness of the film etc. which comprise a cover material exists in the range of 20-150 micrometers, and it is more preferable that it exists in the range of 40-80 micrometers. By setting the thickness of the film constituting the lid within the above range, it is preferable because the lid is excellent in strength, sealability, and easy-openability.

  In order to heat-seal the lid material on the flange portion formed on the periphery of the opening of the multilayer container, first, the lid material is placed on the upper surface of the flange portion, and the surface of the flange portion upper surface and the lid material May be heat sealed with a known heat sealing machine or the like.

  Here, the heat seal part is preferably formed in a belt-like part between the inner cut and the outer cut provided on the upper surface of the flange part of the multilayer container. In this case, a non-fused portion of about 0.5 to 10 mm is formed between the inner cut and the inner edge of the heat seal portion, and between the outer cut and the outer edge of the heat seal portion. Is preferred.

When providing an opening start part with respect to a container, let the outside notch | incision in an opening start part be the shape which protruded outside, for example in the shape of a crow mouth.
In addition, a heat seal member such as a seal ring used for forming the heat seal portion forms a protruding portion that protrudes outward from the outer notch, and the tip of the protruding portion is the outer notch of the flange portion. Heat sealing is performed so as to protrude from a lower portion of the upper surface of the flange surface formed in a connected manner. As a result, even when the heat seal member is displaced inward or outward from the portion to be heat sealed during heat sealing, the lid member can be reliably heat sealed so that stress is concentrated on the surface of the upper surface of the flange portion. Become. Moreover, although the shape of the said protrusion part can select arbitrary shapes, It is more preferable to form so that it may become thin as it goes to a front-end | tip.

  Further, in the case where the lower portion of the flange surface formed by connecting to the outer notch is formed over the entire circumference of the flange portion of the container opening, the container is opened at an arbitrary position. Preferably, the heat seal member such as a seal ring is formed such that the tip of the protruding portion protruding outward from the outer notch protrudes from the low portion. Such a tip portion may protrude only from a portion (opening start portion) that is assumed to be opened beforehand in the entire circumference of the container. As described above, it is possible to freely select whether the flange portion formed in the container opening is provided at an arbitrary position. In this case, 0.2 to 10 mm from the position corresponding to the outer notch formed in the flange portion of the multilayer container to the portion other than the position to be the opening start portion of the heat seal member. A degree of non-fused portion (a portion where the lid material and the flange are not heat-sealed even if they come into contact with the lid material) may be provided, and by providing the non-fused portion, from other than the opening start portion Will be prevented from opening.

And as a means to heat-seal the lid | cover material and the flange part upper surface of a multilayer container, what is necessary is just to heat-seal using the seal ring etc. which can form an above described strip | belt-shaped heat seal part.
Here, in order to form the protruding portion described above with respect to the seal ring or the like, for example, a seal blade capable of forming the protruding portion may be installed on the seal ring or the like.
Further, the heat seal temperature may be appropriately determined depending on the type of material to be heat sealed, but generally may be about 150 ° C to 250 ° C.

In the multilayer container of the present invention thus obtained, a flange portion is provided at the periphery of the opening, and the layer including at least the inner layer of the container is formed so as to be peelable. And two circumferential cuts are provided, and a portion lower than the upper surface of the flange portion is formed in connection with the outer cuts of the two circumferential cuts, and is lower than the upper surface of the flange portion. The portion is configured to be shallower than the outer cut portion . Therefore, the lid member to the flange portion of the multilayer container, in the open seal initiation unit, heat-sealed portion of the lid is, the lower portion than the upper surface of the shape and the flange portion protruding to the mouth shape from outward of the notch Even when a container with a lid is formed by heat-sealing so that it protrudes, the outer end of the heat-sealing part at the opening start part always coincides with the position of the outer notch, and the sealing performance and easy opening It is possible to provide a multi-layer container that constitutes an easy-open packaging body excellent in. With this configuration, easy-open packaging such as easy-open containers with stable easy-openability even when the heat-sealing conditions such as seal strength and seal pressure, and especially the position to be heat-sealed fluctuate. Since a body can be obtained, the range of heat sealing conditions and the like can be expanded. Therefore, for example, when the heat sealing machine has poor sealing accuracy, even if the heat seal member (seal ring) slightly fluctuates in the inner and outer directions at the lower part of the opening start portion, the opening performance is maintained constant, Heat sealing will be performed without problems.

The multilayer container of the present invention is preferably configured such that the multilayer container includes an inner layer and a next layer in contact with the inner layer, and the inner layer of the multilayer container and the next layer in contact with the inner layer are detachable. .
According to the present invention, since the inner layer of the multilayer container and the next layer are formed so as to be peelable from each other, even when the multilayer container is applied to an easy-open packaging body, The delamination between the next layers is preferable because the packaging body is preferably opened.

In the multilayer container of the present invention, the multilayer container preferably includes a cohesive failure layer between the inner layer and the next layer, and the cohesive failure layer is preferably formed so as to be capable of cohesive failure peeling.
According to the present invention, since the multilayer container has a cohesive failure layer formed between the inner layer and the next layer, the cohesive failure layer is formed. Even when the multilayer container is applied to an easy-open packaging body, The cohesive failure layer is preferably peeled off by cohesive failure, so that the package is preferably opened.

Easy-open packaging body of the present invention, it is preferable that the lower portion than the upper surface of the flange portion is formed at a position of the open trigger.
According to the present invention, since the low portion is formed at the position of the opening start portion provided in the container flange portion, the effect of the above-described invention can be obtained when the lid material is opened from the container at the opening start portion. It can enjoy even more suitably.

In the multilayer container according to the present invention, it is preferable that a portion lower than the upper surface of the flange portion is formed over the entire circumference of the flange portion of the container opening.
According to the present invention, since the low portion is formed over the entire circumference of the flange portion of the container opening, the opening start portion of the container can be arbitrarily set, and the container is covered with the lid at any arbitrary position. Even when the material is opened, the effects of the above-described invention can be more suitably enjoyed.

In the multilayer container of the present invention, it is preferable that a portion lower than the upper surface of the flange surface has a concave shape.
According to the present invention, since the low portion has a concave shape, the outer end of the heat seal portion can be more reliably aligned with the outer cut position, and heat sealing can be performed more favorably. can do. In addition, the processing of the lower portion of the multilayer container is facilitated.

In the easily openable container of the present invention, it is preferable that the depth of the concave portion described above is shallower than the depth of the outer cut.
According to the present invention, since the depth of the recess is formed so as to be shallower than the depth of the outer cut, it is possible to reduce the amount of resin removed around the recess when forming the recess by pressing, An adverse effect on heat sealing can be suitably prevented.

In the easily openable container of the present invention, it is preferable that irregularities are provided on the bottom surface of the recess.
According to the present invention, by providing irregularities on the bottom surface of the recess, even if the lid material is heat-sealed at the bottom surface of the recess, the bonding area is reduced and the adhesive force is also reduced. Since it becomes weak, since a peeling with a cover material and the said recessed part can be performed suitably, it is preferable.

The easy-open packaging body according to the present invention includes an inner cut and heat in the two circumferential cuts except for the heat seal part obtained by heat-sealing the flange part and the lid material of the multilayer container and the opening start part. It is preferable that a non-fused portion of 0.5 to 10 mm is provided between the inner edge and / or outer notch of the seal portion and the outer edge of the heat seal portion.
According to the present invention, a non-fused portion in a specific range is provided between the heat-sealed portion where the flange portion of the multilayer container and the lid material are heat-sealed, and the two circumferential cuts excluding the opening start portion. Since it is provided, opening from other than the opening start portion is prevented.

The manufacturing method of the easy-open packaging body according to the present invention is to form two circumferential cuts provided on the upper surface of the flange portion disposed at the peripheral edge of the multilayer container, and a recess connected to the outer cut. The blade that forms the inner cut and the blade that forms the outer cut provided with a recess forming member on the entire circumference or a portion located at the opening start portion of the flange portion is pressed against the flange portion and cut. And forming the concave portion, and then heat-sealing the lid material to the flange portion by a heat seal member having a protruding portion protruding into the concave portion , and the heat seal portion of the lid material at the opening start portion It has a shape that protrudes in a mouth shape toward the cut and protrudes into the recess .

According to the manufacturing method of the easy-open packaging body of the present invention, the inner notch is formed in forming the two circumferential cuts provided on the upper surface of the flange part and the recess connected to the outer cut. The blade and the blade that forms the outer cut provided with a recess forming member on the entire circumference or a portion located at the opening start portion of the flange portion are pressed against the flange portion to form the cut. Therefore, the inner notch and the outer notch provided with adjacent recesses can be formed in one step by a simple means.
Furthermore, since the cover material is heat sealed to the flange portion by the heat seal member provided with a protruding portion protruding from the lower surface of the flange portion, the heat seal member is displaced inward and outward from the portion to be heat sealed. Even if it exists, it can heat-seal by the outer end of a heat-sealing part always coinciding with the position of an outside notch.

In the method for producing an easy-open packaging body according to the present invention, it is preferable that the height of the recess forming member is shallower than the height of the blade forming the outer cut.
According to this invention, even when the depth of the recess provided on the upper surface of the flange is shallower than the depth of the outer cut, while enjoying the effect of the manufacturing method of the easy-open packaging body described above, 2 It is possible to easily form a recess connected to the circumferential cut and the outer cut.

Embodiments of the present invention and reference embodiments related to the present invention will be described below with reference to the drawings.
First reference Embodiment
FIG. 1 is a schematic view showing one reference mode (first reference embodiment) of an easy-open packaging body 1 related to the present invention , and FIG. 1 (B) has shown the state which opened the cover material 3 from the opening start part 4, respectively.

The easy-open packaging body 1 shown in FIG. 1 includes a multilayer container 2, and the multilayer container 2 includes an inner layer 21 and a next layer 22 in contact with the inner layer 21, and is formed so that both can be peeled. It consists of a laminated body.
The multi-layer container 2 has a substantially rectangular tray shape having a predetermined depth, and has a substantially rectangular opening 24, and a flange protrudes outward from the periphery of the opening 24. A portion 25 is provided.

Here, in this reference embodiment, the inner layer 21 and the next layer 22 can be made of a polyolefin resin or the like. For example, the inner layer 21 is made of a high-density polyethylene (HDPE) resin, and the next layer 22 is made of a resin. Polypropylene (PP) resin can be used, but the present invention is not limited to this, and polypropylene (PP) resin is used as the inner layer 21 and high density polyethylene (HDPE) resin is used as the next layer 22. Thus, both may be reversed.

In the easy-open packaging body 1 of this reference embodiment , two circumferential cuts of an inner cut 251 and an outer cut 252 are formed on the upper surface of the flange portion 25 disposed in the opening 24 of the multilayer container 2. Is provided.
Moreover, the multilayer container 2 mounts the lid | cover material 3 with respect to the opening part 24, and heat-seals the flange part 25 and the lid | cover material 3 which were arrange | positioned at the periphery of the opening part 24 of the multilayer container 2. FIG. 1 (A
), The inside of the easy-open packaging body 1 is sealed.
On the other hand, in order to open the easy-open packaging body 1 in a sealed state, as shown in FIG. 1 (B), the lid material 3 is placed at the top in the opening start portion 4 provided at the corner of the easy-open packaging body 1. The easy-open packaging body 1 can be easily opened. In this case, the inner layer 21 between the inner cut 251 and the outer cut 252 formed in the flange portion 25 is peeled off from the multilayer container 2 and moved to the lid 3 side to be opened.

  2 to 4 are partially enlarged views around the opening start portion 4 in the easy-open packaging body 1 shown in FIG. 1, FIG. 2 is a plan view, and FIG. 3 is a sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

As described above, the flange portion 25 of the multilayer container 2 constituting the easy-open packaging body 1 according to this reference embodiment has two circumferential cuts 251 and 252 are formed, the present reference embodiment , A recess 253 (hereinafter sometimes simply referred to as “recess 253”) is formed, which is connected to the outer cut 252 at the position of the opening start portion 4 and is lower than the upper surface of the flange portion.

Here, the distance a from the inner edge of the flange portion 25 of the inner cut 251 shown in FIG. 2 is preferably about 0.5 to 10 mm, and the distance b from the outer edge of the flange portion 25 of the outer cut 252. Is preferably about 0.5 to 10 mm.
The distance c between the inner cut 251 and the outer cut 252 is preferably about 3 to 40 mm. A heat seal portion is formed between the inner cut 251 and the outer cut 252.

A recess 253 is formed on the outer cut 252 at the position of the opening start portion 4 so as to be connected. In this reference embodiment, the planar shape of the concave portion 253 is a substantially crescent shape as shown in FIG. 2, and the maximum width d can be, for example, about 1 to 30 mm.

Moreover, the cross-sectional shape of the concave portion 253 is substantially trapezoidal as shown in FIG. 3 which is a partial cross-sectional view of the opening start portion 4.
In the reference embodiment, the depth of the recess 253 and the depth of the outer cut 252 are substantially equal, and the depth t is about 30 to 300 μm. And the aspect by which the bottom face part 253a of the recessed part 253 was made substantially smooth is shown.

  Furthermore, as shown in FIG. 4, the cross section of the flange portion 25 other than the opening start portion 4 is such that the distance c between the inner cut 251 and the outer cut 252 is about 3 to 40 mm as described above. It forms so that it may become a space | interval.

The two cuts 251 and 252 including the concave portion 253 are, for example, a blade that forms the inner cut 251 and the entire circumference or a portion of the flange portion 25 located at the opening start portion 4 of the concave portion 253. It can be suitably formed by pressing a blade forming the outer cut 252 provided with a forming member against the flange portion 25. In this case, it is preferable to use the blade or member in a room temperature state or heated to about 50 to 300 ° C.
Here, as a member for forming the concave portion 253, a stamping die having a shape similar to the concave portion 253 may be used.

5-7 is the schematic which showed the opening start part 4 periphery at the time of mounting the cover material 3 in the opening part 24 of the multilayer container 2, and heat-sealing, FIG. 5 is a partially expanded view, FIG. 6 is a sectional view taken along line VI-VI in FIG. The present in the reference embodiment, the lid member 3 (shown in Figure 5 the two-dot chain line) has been shown embodiment of the laminated body of three layers, for example, oriented polyethylene terephthalate (PET) layer / A configuration such as an ethylene-vinyl alcohol (EVOH) copolymer layer / polypropylene (PP) resin layer can be employed.

  As shown in FIGS. 5 and 7, the heat seal portion 255 is formed in a band shape between the inner cut 251 and the outer cut 252 at a place other than the opening start portion 4. Further, it is preferable to form a non-fused portion 256 of about 0.5 to 20 mm between the inner cut 251 and the inner edge of the heat seal portion 255 and between the outer cut 252 and the outer edge of the heat seal portion 255. .

Further, the seal ring 260 (indicated by a two-dot broken line in FIGS. 6 and 7), which is a heat seal member in the opening start portion 4, in the reference embodiment, as shown in FIG. A protruding portion 260a is formed by protruding outward from 252 (the angular direction of the flange portion 25), and a tip portion 260b of the protruding portion 260b protrudes into the recess 253 during heat sealing. The length 1 protruding from the outer cut 252 can be set to 1 to 30 mm, for example. In addition, this protrusion part 260a becomes the shape which became thin and sharp, so that it became a front-end | tip (it goes to the angular direction of the flange part 25). As shown in FIG. 6, the outer end portion 255 a of the heat seal portion 255 always coincides with the position of the outer cut 253.

In order to heat-seal the lid member 3 and the flange portion 25 of the multilayer container 2, for example, the container opening start portion 4 may be heat-sealed using the seal ring 260 having the protruding portion 260a.
Here, the heat seal temperature may be appropriately determined depending on the type of material to be heat sealed, but generally may be about 150 ° C to 250 ° C.

And in order to open the easy-open packaging body 1 of this reference embodiment from the opening start part 4, in the place where opening of the cover material 3 reached the outer cut 252, the peeling strength of the cover material 3 and the inner layer 21 Since the peel strength between the inner layer 21 and the next layer 22 is weaker, delamination occurs between the inner layer 21 and the next layer 22. Then, when the lid 3 is pulled up, delamination between the inner layer 21 and the next layer 22 proceeds, and the multilayer container 2 and the lid 3 in the easy-open packaging body 1 are preferably opened. Become.

According to the easy-open packaging body 1 of the first reference embodiment as described above, the following effects can be achieved.
(1) The easy-open packaging body 1 is formed so that the inner layer 21 and the next layer 22 constituting the multilayer container 2 can be peeled, and two circumferential cuts 251 are formed on the upper surface of the flange portion 25 of the multilayer container 2. 252 is provided and is connected to the outer cut 252 of the cuts 251 and 252 to form a concave portion 253 that is lower than the upper surface of the flange portion. Therefore, the outer end portion 255a of the heat seal portion 255 is always It coincides with the position of the outer notch 253, and even when the package 1 is opened, the stress is concentrated on the layer end portion between the inner layer 21 and the next layer 22 so that delamination can be easily performed. Thus, opening of the package 1 is suitably performed. Therefore, in addition to the easy-open packaging body 1 having excellent sealability and easy-openability, it is stable even when the heat-sealing conditions such as the sealing strength and the sealing pressure, especially the heat-sealing position fluctuate. The easy-open packaging body 1 having easy openability can be provided, and the range of heat seal conditions and the like can be widened. For this reason, for example, even when the heat sealing member (seal ring) 260 fluctuates in the inner and outer directions of the recess 253 when the sealing accuracy of the heat sealing machine is poor, the heat sealing is performed without any problem.

(2) Since the low portion has a concave shape, the outer end portion 255a of the heat seal portion 255 can be more reliably aligned with the position of the outer cut 252 and heat sealed. In addition, processing for the multilayer container 2 is facilitated.

(3) Since the concave portion 253 is formed at the position of the opening start portion 4 formed in the flange portion 25 provided in the multilayer container 2, the lid material 3 is opened from the multilayer container 2 by the opening start portion 4. In this case, the easy-open packaging body 1 can be suitably opened.

(4) In the heat seal portion 255 heat-sealing the flange portion 25 of the multilayer container 2 and the lid member 3 and the two circumferential cuts 251 and 252 excluding the opening start portion 4, the inner cut 251 and heat Since a non-fused portion 256 of 0.5 to 10 mm is provided between the inner edge and / or the outer notch 252 of the seal portion 255 and the outer edge of the heat seal portion 255, opening from other than the opening start portion 4 Is preferably prevented.

First Embodiment
In the easy-open packaging body 1 of the first reference embodiment described above, the outer notch 252 provided on the upper surface of the flange portion 25 at the periphery of the opening 24 of the multilayer container 2 is the outer notch 252 in the opening start portion 4. The depth of the recessed part 253 formed adjacent to the outer notch 252 and the outer cut 252 is substantially equal.
In contrast, the easy-open packaging body 1 of the first embodiment is different in that the depth of the recess 253 is shallower than the depth of the outer cut 252 as shown in FIG.
In the present embodiment, the same structure and the same members as those of the first reference embodiment described above are denoted by the same reference numerals, and the description thereof is omitted or simplified.

FIG. 8 is a partial cross-sectional view showing an opening start portion 4 disposed in the easy-open packaging body 1 according to the first embodiment of the present invention, and (A) is a state where the lid 3 is not placed, (B ) Shows a state where the lid 3 is heat sealed.
In the present embodiment, as described above, the depth t1 of the recess 253 provided to be connected to the outer cut 252 in the opening start portion 4 is formed shallower than the depth t2 of the outer cut. However, t1 may be, for example, about 10 to 150 [mu] m, and the depth difference may be, for example, about 10 to 200 mm.

  In addition, the incision including the shallow concave portion 253 is formed, for example, on the blade that forms the inner notch 251 and the portion of the flange portion 25 that is located at the opening start portion 4, and the height of the blade is outside. What is necessary is just to press the blade which forms the outer cut 252 provided with the member for forming the recessed part 253 shallower than the height of the blade which forms the notch 252 with respect to the flange part 25.

Then, the lid 3 is heat-sealed to the upper surface of the flange portion 25 of the multilayer container 2 having such a configuration as shown in FIG. 8B by the same means as in the first reference embodiment. By doing, the easily openable package 1 of this invention can be obtained.

According to the easy-open packaging body 1 of the first embodiment as described above, in addition to the effects achieved by the first referential embodiment (1) to (4), can be obtained the following effects .
(5) In the opening start portion 4 of the easy-open packaging body 1, the depth of the concave portion 253 formed adjacent to the outer cut 252 provided on the upper surface of the flange portion 25 of the multilayer container 2 is the outer side. Since the depth of the notch 252 is shallower, the amount of resin removed to the periphery of the recess 253 can be reduced when the recess is formed by pressing. Therefore, it is possible to suitably prevent the heat seal from being adversely affected, and it is possible to further improve the unsealing property when the lid material 3 is peeled off and the unsealing start portion 4 is unsealed.
(6) In forming the notches 251 and 252 provided on the upper surface of the flange portion 25 and the concave portion 253 having a shallower depth than the outer notch 252, the blade that forms the inner notch 251 and the opening start portion 4 of the flange portion 25 are positioned. The blades that form the outer cuts 252 provided with a member for forming the recesses 253 that are shallower than the blades that form the outer cuts 252 are pressed against the flange portion 25 to cut the cuts 251 and 252. Even if the depth of the recess 253 provided on the upper surface of the flange portion 25 is shallower than the depth of the outer cut 252, the two circumferential cuts 251 and 252 and the outer cut 252 The connected recesses 253 can be easily formed.

[ Second Embodiment]
In the easy-open packaging body 1 of the first reference embodiment and the first embodiment described above, the laminate constituting the multilayer container 2 is composed of the inner layer 21 and the next layer 22 in contact with the inner layer 21 so that both can be peeled off. It was formed.
On the other hand, as shown in FIG. 9, the easy-open packaging body 1 of the second embodiment is capable of cohesive fracture peeling between the inner layer 21 and the next layer 22 in the laminated body constituting the multilayer container 2. The difference is that the cohesive failure layer 23 is provided.
In the present embodiment, the same structure and the same members as those in the first reference embodiment and the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

FIG. 9: is a fragmentary sectional view which shows the opening start part 4 arrange | positioned at the easy-open packaging body 1 in 2nd Embodiment of this invention, (A) is the state which does not mount the cover material 3, (B ) Shows a state where the lid 3 is heat sealed.
In the present embodiment, the laminate constituting the multilayer container 2 is provided with a cohesive failure layer 23 capable of cohesive failure and separation between the inner layer 21 and the next layer 22.
As for the configuration of the outer cut 252 and the recess 253 formed to be connected to the cut 252, the depth of the recess 253 is greater than the depth of the outer cut 252, as in the first embodiment. What is formed shallowly is adopted.

  Further, in order to open the easy-open packaging body 1 of the present embodiment from the opening start portion 4, when the opening reaches the outer cut 252, cohesive failure occurs before delamination of the lid 3 and the inner layer 21 occurs. Since the cohesive failure of the layer 23 occurs, the cohesive failure of the cohesive failure layer 23 progresses as the lid member 3 is pulled up, and the multi-layer container 2 and the lid member 3 in the easy-open packaging body 1 are preferably opened. It will be defeated.

According to the easy-open packaging body 1 of the second embodiment as described above, the effects exhibited by the easy-open packaging body 1 of the first reference embodiment and the first embodiment (excluding (1)) In addition, the following effects can be achieved.
(1-a) The easy-open packaging body 1 has a cohesive failure layer 23 formed between the inner layer 21 and the next layer 22 of the multilayer container 2, and a flange portion of the multilayer container 2. Two circumferential cuts 251 and 252 are provided on the upper surface, and the recess 25 is connected to the outer cut 252 of the two circumferential cuts 251 and 252 and is lower than the upper surface of the flange portion.
3 is formed, the outer end of the heat seal portion 255 always coincides with the position of the outer cut 253, and even when the package 1 is opened, the cohesive failure layer is peeled off at the time of opening. As a result, the packaging body 1 is suitably opened. Therefore, in the same manner as the first reference embodiment described above, in addition to providing the easy-open packaging body 1 excellent in sealing performance and easy-openability, the easy-open packaging body 1 has a sealing strength, a sealing pressure, etc. Even when the heat sealing conditions and especially the position for heat sealing fluctuate, it becomes stable and easy to open, and the range of heat sealing conditions and the like can be widened.

[ Third Embodiment]
In the easy-open packaging body 1 of the first reference embodiment , the first embodiment, and the second embodiment described above, the multilayer container 2 has a substantially rectangular tray shape having a predetermined depth, and is substantially rectangular. The mode which has the shape-like opening part 24 was shown.
Further, in the outer cut 252 provided on the upper surface of the flange portion 25 formed on the periphery of the opening 24 of the multilayer container 2, the recess 253 provided in connection with the cut 252 is formed at the corner of the easy-open packaging body 1. It was formed in the provided opening start part 4.

On the other hand, the easy-open packaging body 1 of 3rd Embodiment employ | adopts the cup-shaped multilayer container 2 which made the shape of the bottom face part 26 and the opening part 24 circular as shown in FIGS. And the recess 253 provided in connection with the outer notch 252 provided on the upper surface of the flange portion 25 formed on the periphery of the circular opening 24 is the entire circumference of the flange portion 25 of the container opening 24. It is different about the point provided over.
Also in this embodiment, the same reference numerals are given to the same structures and members as those in the first reference embodiment , the first embodiment, and the second embodiment, and the description thereof is omitted or simplified.

FIG. 10 is a schematic view showing the easy-open packaging body 1 according to the third embodiment of the present invention. FIG. 10 (A) is a state where the lid 3 is sealed, and FIG. 10 (B) is an opening start portion. The state which opened the cover material 3 from 4 is shown, respectively.
The easy-open packaging body 1 shown in FIG. 10 includes a multilayer container 2 having a layer configuration common to that of the first reference embodiment. The multi-layer container 2 is a cup-shaped container in which the shape of the bottom surface part 26 and the opening part 24 is circular, and a flange part 25 is disposed on the periphery of the opening part 24 so as to project outward. Yes.

11A and 11B are schematic views of the flange portion 25 formed on the peripheral edge of the multilayer container 2, wherein FIG. 11A is a plan view and FIG. 11B is a cross-sectional view taken along line BB in FIG.
As shown in FIGS. 11A and 11B, two circumferential cuts 251 and 252, an inner cut 251 and an outer cut 252, are provided on the upper surface of the flange portion 25. Yes. The distance c ₁ between the inner cut 251 and the outer cut 252 in this embodiment may be about 3 to 40 mm, for example.

In addition, the outer cut 252 is formed with a recess 253 that is connected and is lower than the upper surface of the flange portion 25. In this embodiment, the recess 253 is formed over the entire circumference of the container opening 24. ing.
In the present embodiment, as to the configuration of the outer cut 252 and the recess 253 formed to be connected to the cut 252, the depth of the recess 253 is the same as that of the first embodiment described above. What is formed shallower than the depth of the cut 252 is employed.

FIG. 12 is a plan view showing the flange portion 25 of the easy-open packaging body 1 in which the lid 3 is heat-sealed with respect to the container opening 24.
As shown in FIG. 12, in the present embodiment, the heat seal portion is formed between the inner cut 251 and the outer cut 252 as in the first reference embodiment described above. However, with respect to the upper, lower, left and right four locations from the center of the container opening 24 of the heat seal portion 255, the outer end portion 255a of the heat seal portion 255 is formed so as to coincide with the outer cut 252 and these four locations are the opening start portion. 4a. And the easy-open packaging body 1 of this embodiment will be suitably opened from the said four opening start parts 4a.

  13 is a cross-sectional view taken along the line XIII-XIII of FIG. 12, and the seal ring 260 at the opening start portion has a protruding portion 260a with respect to the recessed portion 253 formed adjacent to the outer cut 252 as described above. Is formed so as to protrude. Further, the length l1 protruding from the outer cut 252 may be about 1 to 30 mm, for example. Also in the present embodiment, the outer end portion 255a of the heat seal portion 255 always coincides with the position of the outer cut 253.

  14 is a cross-sectional view taken along the line XIV-XIV in FIG. 12. In this way, the heat seal portion 255 that is not the opening start portion 4a is provided between the inner cut 251 and the outer cut 252. Become.

According to the easy-open packaging body 1 of the third embodiment as described above , the effects (provided that the easy-open packaging body 1 of the first reference embodiment , the first embodiment, and the second embodiment (however, ( In addition to 1-a) and (3), the following effects can be obtained.
(3-a) Since the recess 253 is formed over the entire circumference of the flange 25 of the container opening 24, any position of the container opening 24 can be set as the opening start portion 4a, and the opening start portion 4a. Even when the lid 3 is opened from the container, the easy-open packaging body 1 can be opened appropriately.

  Note that 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, in the above-described embodiment, the bottom surface portion 253a of the recess 253 formed to be connected to the outer cut 252 provided in the flange portion 25 of the multilayer container 2 constituting the easy-open packaging body 1 of the present invention is substantially smooth. However, the present invention is not limited to this. For example, as shown in FIG. 15, unevenness may be provided on the bottom surface portion 253 a of the recess 253.

FIG. 15 shows an aspect in which a large number of triangular projections having a fine cross section are formed on the bottom surface portion 253a of the concave portion 253 provided to be connected to the outer cut. By making the bottom surface portion 253a of the concave portion 253 in this way, the lid member 3 and the concave portion 253 can be suitably peeled off.
In addition, in order to provide unevenness on the bottom surface portion 253a of the concave portion 253, the shape of the protrusion formed on the bottom surface portion 253a is limited to that having a fine triangular cross section as shown in FIG. Instead, for example, a plurality of protrusions having a hemispherical shape with a fine cross section or a cross shape with a fine cross section may be provided to form irregularities on the bottom surface portion 253a.

In the first reference embodiment described above, the concave portion 253 has an aspect in which the cross section has a substantially rectangular shape or a quadrangular shape such as a trapezoidal shape, but is not limited to this. For example, as shown in FIG. In addition, the cross section of the recess 253 may be semi-elliptical.

In the above-described embodiment, the outer notch 252 provided in the flange portion 25 of the multilayer container 2 has a mode in which the recess 253 is formed by connecting the notch 252 to the portion where the opening start portion 4 is provided. However, the present invention is not limited to this, as shown in FIGS.
As long as the part 253 lower than the upper surface of the flange part 25 is formed, the shape may be arbitrary.

FIG. 17 shows that in the third embodiment described above, a lower portion 253 connected to the outer end of the flange portion 25 is formed over the entire circumference with respect to the outer cut 252 provided in the flange portion 25 of the multilayer container 2. It is a fragmentary sectional view showing the mode which did. FIG. 18 is a partial cross-sectional view showing a mode in which a lower portion 253 connected to the outer end of the flange portion 25 is formed in the second embodiment as described above, instead of a concave shape with respect to the opening start portion 4. is there. Thus, if the part 253 lower than the upper surface of the flange part 25 is formed, the effect of the above-mentioned this invention can be enjoyed.

  In the above-described embodiment, the structure of the laminate forming the multilayer container 2, the structure of the laminate forming the lid member 3, the positional relationship between the two cuts 251 and 252, etc. Although numerical values and the like have been shown, there is no problem even if any of these materials is adopted.

In the above-described third embodiment, an embodiment in which four opening start portions 4a are provided has been described. However, the present invention is not limited to this, and the number of opening start portions 4a is arbitrary, and may be one, for example. .
Further, a non-cohesive failure layer (a layer that does not cohesive failure) of about 5 to 50 μm may be provided between the inner layer 21 and the next layer 22. Moreover, as a manufacturing method of the multilayer container 2 of this invention, the method by the change of the flange clamp at the time of thermoforming of the multilayer container 2, the shape change of a flange receiver, etc. is also employable.
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.

EXAMPLES Next, although an Example , a reference example, and a comparative example are given and this invention is demonstrated in more detail, this invention is not restrict | limited at all to description content, such as these Examples.

[ Reference Example 1]
Using the following materials and methods, an easy-open packaging (easy-open container) related to the present invention shown in FIGS. 1 to 7 (first reference embodiment) was produced.

A laminate (multilayer sheet) composed of the following inner layer / next layer was formed by coextrusion molding.
Inner layer: High density polyethylene (HDPE) resin [Idemitsu polyethylene 440M (manufactured by Idemitsu Petrochemical Co., Ltd.), density 0.96 g / cm ³ , MFR (abbreviation of melt flow rate, the same shall apply hereinafter) 0.9 g / 10 min] 100 μm
Next layer: polypropylene resin (PP) layer [polypropylene resin: Idemitsu Polypro E-10 5GM (manufactured by Idemitsu Petrochemical Co., Ltd.), MFR 0.6 g / 10 min, 80% by weight, low density polyethylene (LDPE) resin: [FZ-038 (Nippon Polychem
(Made by Co., Ltd.), MFR 0.3 g / 10 min, 20 mass% mixture] Thickness
900 μm

  Using this multilayer sheet, a flanged multilayer container of 150 mm × 100 mm × 30 mm was formed by plug-assisted vacuum forming. The multilayer container has a flange portion having a width of 8 mm with respect to the opening, and is formed in a substantially rectangular tray shape. Moreover, the flange part employ | adopts the skirt flange by which the skirt as the bending part which goes to the main body bottom part side is formed in the outer edge.

Next, two circumferential cuts as shown in FIG. 2 were formed using a blade heated to 200 ° C. at 1 mm from the outer edge of the flange portion of the multilayer container and 1 mm from the inner edge.
According to FIG. 3, these cuts are formed so as to cut the inner layer safely, and the interval between the two circumferential cuts is 6 mm. Further, the opening start portion has an outer cut inwardly convex shape, and is connected to the concave portion, which is a lower portion than the upper surface of the flange portion, and has a depth of 150 μm. The cut is provided in a substantially crescent shape with a maximum width of 2 mm.

  The opening of the multilayer container thus obtained is composed of stretched nylon (polyamide) / ethylene-vinyl alcohol copolymer (EVOH) resin layer / polyethylene (PE) layer (thickness 15 μm / 12 μm / 50 μm). An easy-open container of the present invention was obtained by placing the multilayer film and heat-sealing the lid material to the flange portion using the following heat-sealing conditions.

(Heat seal condition)
Sealing temperature 195 ° C
Sealing pressure 10kg / cm ²
Time 2 seconds Number of heat seals 1 time

  Here, the heat sealing is performed such that the lid member and the flange portion are sealed in a band shape according to FIG. 5 between the two cuts. Further, heat sealing is performed so that the distance between the inner cut and the inner edge of the heat seal portion is 2 mm, and the distance between the outer cut and the outer edge of the seal portion is 1 mm.

  In addition, although the part which seals the initial opening position of the used seal ring protrudes in the outer direction of a container flange part rather than an outer notch according to FIG. 6, the recessed part provided in connection with the said outer notch Therefore, the outer end portion of the heat seal portion always coincides with the outer notch position.

[Example 1 ]
The easy-open container of the present invention was manufactured using the same method as in Reference Example 1 except that the cross-section of the opening start portion of the multilayer container had the cross-sectional shape shown in FIG. 8 ( first embodiment).
In FIG. 8, the depth of the outer cut was 150 μm, and the depth of the recess formed adjacent to the outer cut was 100 μm.

[Example 2 ]
Using the following materials and methods, an easy-open container of the present invention shown in FIGS. 10 to 14 ( third embodiment) was manufactured.

Using a sheet with the same specifications as the sheet used in Reference Example 1, a multi-layer container with a flange of φ100 mm (opening outer diameter) × 30 mm (height) shown in FIG. 10 is formed using plug-assisted vacuum forming. did.
This multilayer container has a flange portion having a width of 8 mm at the container opening, and the bottom surface and the opening of the container are formed in a substantially circular cup shape. Moreover, the flange part employ | adopts the skirt flange by which the skirt as the bending part which goes to the main body bottom part side is formed in the outer edge.

Next, in the place of 1 mm from the outer edge of the flange portion of the multilayer container and 1 mm from the inner edge, two circumferential cuts as shown in FIG. 11 were formed using a blade heated to 200 ° C.
Further, according to FIG. 11B, the cut is formed with a depth of about 120 μm so that the inner layer can be safely cut, and the interval between the two circumferential cuts is 6 mm.
And the recessed part which is a part lower than the upper surface of a flange part with respect to the perimeter of a flange part is provided in cyclic | annular form with the depth of 50 micrometers, and the width | variety of 3 mm adjacent to an outer notch.

  A multilayer film serving as a lid made of stretched nylon / ethylene vinyl alcohol copolymer resin layer / polyethylene resin layer (thickness 15 μm / 12 μm / 50 μm) is placed on the opening of the multilayer container thus obtained. Then, the easy-open container of the present invention was obtained by heat-sealing the lid material to the flange portion using the following heat-sealing conditions.

(Heat seal condition)
Sealing temperature 195 ° C
Sealing pressure 10kg / cm ²
Time 2 seconds Number of heat seals 1 time

  Here, according to FIG. 12, the heat seal is heat-sealed in a band shape between the two cuts and the lid member and the flange portion. Further, heat sealing is performed so that the distance between the inner cut and the inner edge of the heat seal portion is 2 mm, and the distance between the outer cut and the outer edge of the heat seal portion is 1 mm.

  In addition, in the seal ring used for heat sealing, the portions that seal the four opening start portions shown in FIG. 12 protrude outward from the notches on the outer side of the flange portion, and the outer width is 1 mm. A seal ring was installed so that the semicircular tip was within the range, and heat sealing was performed. Such a leading end protrudes 0.5 mm outward from the outer cut, but in the heat seal at the opening start portion, the outer end of the heat seal portion always coincides with the outer cut position.

[Example 3 ]
The easy-open container of the present invention was manufactured using the same method as in Reference Example 1 except that the opening start section had the cross-sectional shape shown in FIG.

[Example 4 ]
An easy-open container of the present invention shown in FIG. 9 ( second embodiment) was produced using the same method as in Reference Example 1 except that materials having the following specifications were used as the configuration of the multilayer sheet.

A laminate (multilayer sheet) composed of the following inner layer / cohesive failure layer / next layer was formed by coextrusion molding.
Inner layer: Polypropylene resin (PP) layer [Idemitsu Polypro F744NP (manufactured by Idemitsu Petrochemical Co., Ltd., density 0.9 g / cm ³ , MFR 7 g / 10 min) thickness 100 μm
Cohesive failure layer: polyolefin resin layer [homopolypropylene resin (Idemitsu Polypropylene E-105GM: manufactured by Idemitsu Petrochemical Co., Ltd., MFR 0.6 g) 70% by mass, low density polyethylene (LDPE) resin (FZ-038 : Nippon Polychem Co., Ltd., MFR 0.3 g) 10% by mass, and Treks Pearl ET182: Nippon Polyolefin Co., Ltd., MFR 8 g) 20% by mass] Thickness 150 μm
Next layer: Polypropylene resin (PP) layer [Idemitsu Polypro E-170GM (Idemitsu Petrochemical Co., Ltd., MFR 0.6 g / 10 min)] Thickness 900 μm

[Comparative Example 1]
An easy-open container was manufactured using the same method as in Example 1 except that a portion (concave portion) lower than the upper surface of the flange portion was not formed adjacent to the outer cut.

[Comparative Example 2]
An easy-open container was manufactured using the same method as in Example 3 except that a portion (concave portion) lower than the upper surface of the flange portion was not formed adjacent to the outer cut.

[Test Example 1]
The initial opening strength, the internal pressure strength, and the opening feeling during opening of Examples 1 to 5 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.

(Initial opening strength)
The opening start portion was cut to a width of 15 mm to obtain a sample, and the sample was measured using an autograph tensile tester at 180 ° peeling and 300 mm / min.

(Internal pressure strength)
The pressure (MPa) was measured according to “8. Burst strength test of container” defined in JIS Z0238.

(Open feeling)
The feel at the time of opening was determined according to human feeling.

(result)

As can be seen from the results in Table 1, the easy-open containers of the present invention obtained in Examples 1 to 4 and Reference Example 1 have an appropriate initial opening strength and excellent internal pressure strength. It was confirmed that this was an easily openable container having both properties and sealability.
On the other hand, the easy-open containers obtained in Comparative Example 1 and Comparative Example 2 were unsuitable as easy-open containers because of their high initial opening strength and poor openability.

  The multilayer container, the easy-open packaging body and the multilayer container manufacturing method of the present invention are, for example, a multilayer container, an easy-open packaging body and a multilayer that can be widely used as packaging containers for various foods such as retort foods and medicines. A method for manufacturing a container is provided.

It is the figure which showed the easy-open packaging body of 1st reference embodiment relevant to this invention , Comprising: (A) is the state sealed with the cover material, (B) is the state which opened the cover material from the opening start part. FIG. It is the elements on larger scale (plan view) around the opening start part of the easy-open packaging body shown in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is IV-IV sectional drawing of FIG. It is the elements on larger scale which show the opening start part periphery which heat-sealed the cover material. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. It is VII-VII sectional drawing of FIG. It is a figure which shows the opening start part arrange | positioned at the easy-open packaging body in 1st Embodiment of this invention, Comprising: (A) is a state which does not mount a cover material, (B) heat-sealed the cover material. It is a fragmentary sectional view of a state. It is a figure which shows the opening start part arrange | positioned in the easy-open packaging body in 2nd Embodiment of this invention, Comprising: (A) is a state which does not mount a cover material, (B) heat-sealed the cover material. It is a fragmentary sectional view of a state. It is the figure which showed the easy-open packaging body in 3rd Embodiment of this invention, Comprising: (A) is the state sealed with the cover material, (B) is the outline which shows the state which opened the cover material from the opening start part. FIG. Is a schematic view of the flange portion constituting the easy-open packaging body shown in FIG. 1 0 a B-B sectional view of (A) is a plan view, (B) is (A). It is a top view which shows the flange part of the easy-open packaging body which heat-sealed the cover material. It is XIII-XIII sectional drawing of FIG. It is XIV-XIV sectional drawing of FIG. It is the fragmentary sectional view which showed the other aspect of the recessed part provided in connection with an outer notch. It is the fragmentary sectional view which showed another reference aspect of the recessed part provided in connection with an outer notch. In 3rd embodiment, it is the fragmentary sectional view which showed the aspect formed so that the part lower than a flange part upper surface might be extended to a flange outer end. In a 1st embodiment, it is the fragmentary sectional view which showed the aspect formed so that the part lower than a flange part upper surface might be extended to a flange outer end.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Easy-open packaging body, 2 ... Multilayer container, 3 ... Cover material, 4 and 4a ... Opening start part, 21 ... Inner layer, 22 ... Next layer, 23 ... Cohesive failure layer, 24 ... Opening part, 25 ... Flange part , 26: bottom portion, 251 ... inside cut, 252 ... outside cut, 253 ... recessed portion (low portion), 253a ... bottom portion, 255 ... heat seal portion, 255a ... outer end portion, 256 ... non-fused portion, 260 ... Seal ring, 260a ... Projection, 260b ... Tip

Claims (9)

A multi-layer container in which a flange is disposed around the periphery of the opening;
It is an easy-open packaging body provided with a lid material heat-sealed to this flange portion,
The layer including at least the inner layer of the container is formed to be peelable,
On the upper surface of the flange portion, an opening start portion and two circumferential cuts are provided,
Of the two circumferential cuts, connected to the outer cut, a portion lower than the upper surface of the flange portion is formed,
A portion lower than the upper surface of the flange portion is shallower than the outer cut,
Characterized in that in the open sealing start portion, the heat seal portion of the lid member is formed to protrude to the lower portion than the upper surface of the shape and the flange portion protruding to the mouth shape from toward the notch of the outer Easy-open packaging. In the easy-open packaging body according to claim 1,
The multilayer container includes an inner layer and a next layer in contact with the inner layer,
An easily openable packaging body, wherein an inner layer of the multilayer container and a next layer in contact with the inner layer are formed to be peelable. In the easy-open packaging body according to claim 1,
The multilayer container includes a cohesive failure layer between an inner layer and a next layer,
An easy-open packaging body, wherein the cohesive failure layer is formed so as to be capable of cohesive failure peeling. In the easy-open packaging body according to any one of claims 1 to 3,
The easy-open packaging body, wherein a portion lower than the upper surface of the flange portion is formed over the entire circumference of the flange portion of the container opening. In the easy-open packaging body according to any one of claims 1 to 4 ,
The easy-open packaging body characterized in that a portion lower than the upper surface of the flange portion has a concave shape. In the easy-open packaging body according to claim 5 ,
An easy-open packaging body, wherein unevenness is provided on the bottom surface of the recess. In the easy-open packaging body according to any one of claims 1 to 6 ,
In the two circumferential cuts excluding the heat seal part heat-sealing the flange part and the lid of the multilayer container, and the opening start part,
An easy-open packaging body characterized in that a non-fused portion of 0.5 to 10 mm is provided between the inner cut and the inner edge of the heat seal portion and / or the outer cut and the outer edge of the heat seal portion. . A method for producing the easy-open packaging body according to any one of claims 5 to 7 ,
In forming the two circumferential cuts provided on the upper surface of the flange portion disposed on the peripheral edge of the multilayer container, and the recesses connected to the outer cuts,
A blade that forms an inner cut;
A blade that forms an outer cut provided with a member for forming a recess in the entire circumference or a portion located at an opening start portion of the flange portion is pressed against the flange portion to form the cut and the recess.
Then, the heat seal member provided with a protruding portion protruding into the recess , heat-sealing the lid material to the flange portion,
A method for producing an easy-open packaging body, wherein the heat-sealing portion of the lid material is formed in a shape protruding in a mouth shape toward the outer cut and protruding into the concave portion at the opening start portion. . In the method of manufacturing the easy-open packaging body according to claim 8 ,
A method for producing an easy-open packaging body, characterized in that the height of the recess forming member is shallower than the height of the blade forming the outer cut.