JPS63294368A - Easy-open hermetically sealed food container - Google Patents

Abstract

PURPOSE:To make manual opening possible, by providing a tight seal part and an easy-open seal part on both sides of an intermediate material and imparting predetermined difference between release strength and the release strength from the outside of a container. CONSTITUTION:A tight seal part 5 is formed between an intermediate material 4 and a lid 3, and an easy-open seal part 6 is formed between the intermediate material 4 and a flange 1. The inner peripheral side end edge 7 of the easy-open seal part 6 is positioned on the center side from the inner peripheral side end edge 8 of the tight seal part 5. At an opening start part 9, the outer peripheral side end edge 10 of the easy-open seal part 6 is present at the same position as the outer peripheral side end edge 11 of the tight seal part 5 or positioned on the center side from said end edge 11. Since the inner peripheral side end edge 7 is positioned on the center side from the inner peripheral side end edge 8 of the tight seal part 5, the breaking force P from the inside acts on the tight seal part 5. Since the outer peripheral side end edge 10 is present at the same position as the outer peripheral side end edge 11 of the tight seal part 5 or positioned on the center side from said side end edge 11, release force P' acts on the easy-open seal part 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an easy-open sealed food container,
More specifically, the peel strength from the center of the container is high enough to withstand, for example, retort sterilization, and the peel strength from the outside of the container maintains an easy-to-open seal so that it can be opened by hand. This invention relates to an easy-open sealed food container that is dripping.

(Prior art) Conventionally, heat-sealed packaging bodies have been widely used in many fields such as food packaging, and those that can be peeled off at the heat-sealed interface are also widely used as easy-to-open or peelable heat-sealed lids. It is used.

Among heat-sealed packages, the seal strength of the heat-sealed part is 2.3 for those whose contents have been subjected to retort sterilization treatment.
kg/width of 15 mm or more, and when the seal strength between the container body and the lid reaches this value, it becomes difficult to manually peel off the heat-sealed interface between the two.

To solve this problem, we provide an easy-to-open, heat-sealable inner material layer on the inner surface of the container body, and make it easy to separate the inner layer from the inner layer. A score is provided on the center side to cut this inner material layer, and the heat seal strength from the center side to the outside is set to 2.
A heat-sealed container has already been proposed which has a width of 3.0 g/15 mm or more and which can be easily opened from the outside.

(Problems to be Solved by the Invention) The above-mentioned easy-to-open heat-sealed container has a sealing strength of 2.
．． This is significant because it provides easy-to-open packaging while maintaining a width of 3 kg/15 mm or more, but there are restrictions on the structure and manufacturing of the container, such as the need to score the container. is the problem. In addition, in order to score the inside of the peripheral area for heat sealing, there are restrictions on the container material that can be used, and the area of the container flange inevitably becomes larger, which increases the amount of container material used and reduces the packaging material. It is also unfavorable from the viewpoint of increased bulk and appearance characteristics.

Therefore, an object of the present invention is to provide a container with a peel strength of at least 2.3 kg/15 mm width from the center side of the container, so that it can withstand increased internal pressure during retort sterilization. To provide an easily openable sealed food container whose peel strength from the outside is maintained at an easy open heat seal strength.

Another object of the present invention is to provide an easily openable sealed food container in which the above-mentioned peel strength anisotropy is achieved without marking the container or container lid with a score.

(Means for Solving Problems) According to the present invention, in a container in which opposing portions of a plurality of container materials are sealed by heat sealing, the sealing portion is inserted between the plurality of container materials. It has a laminated structure with an intermediate material, and the intermediate material and one of the plurality of container materials are a tight seal, and the intermediate material and the other of the plurality of container materials are an easy-to-open seal, and the easy-to-open seal part The inner circumferential edge of is located closer to the center than the inner circumferential edge of the tight seal portion, and the outer circumferential edge of the easy-to-open seal portion is located closer to the center than the inner circumferential edge of the tight seal portion at the opening start position. Provided is an easy-open sealed food container characterized in that the food container is located at the same position as the food container or closer to the center than the food container.

(Function) In FIG. 1 showing an example of the container of the present invention, this container includes a container body 2 having a heat-sealing flange 1 and a lid 3.
It consists of An intermediate member 4 is provided between the flange 1 and M3. In the specific example shown in Figure 1,
A tight seal 5 is formed between the intermediate material 4 and M3, while an easy-to-open seal 6 is formed between the intermediate material 4 and the flange 1.

The inner circumferential edge 7 of the easy-to-open seal portion 6 is the tight seal portion 5
The outer edge 10 of the easy-to-open seal part 6 is located at the same position as the outer edge 11 of the tight seal part 5 in the opening start part 9, or Or it's located closer to the center.

In FIG. 2, which shows a state in which a peeling force is applied from the inside to this sealing part, the inner circumferential edge 12 of the intermediate member 4 is in close contact with the flange 1, and the easily-openable sealing part The inner peripheral edge 7 of 6 is the inner peripheral edge 8 of the tight seal portion 5.
Therefore, the peeling force or destructive force P from the inside acts on the tight seal portion 5,
For example, a large peeling or breaking strength such as 2.3 g/15 mm width or more can be achieved.

On the other hand, in FIG. 3, which shows a state in which a peeling force from the outside is applied to the unsealing curve starting part 9 of this sealing part, the end 1 of the lid 3 is
3 and pull it upward to open the easy-to-open seal part 6.
The outer peripheral edge 10 of is the outer peripheral edge 11 of the tight seal portion 5.
Since the peeling force P' is located at the same position as or closer to the center than that, the peeling force P' acts on the easy-to-open seal part 6, and the peeling strength becomes, for example, 2 kg/15 non width or less, making it difficult to remove by hand. Easy to peel and open.

In the heat seal structure shown in FIG. 1, the intermediate material 4 remains on the lid side after opening, and the flange portion 1 has a clean appearance, but as shown in FIG. A structure may also be adopted in which the seal portion 6 is provided upside down and the intermediate material 4 remains on the cup side after opening.

According to the present invention, the tight seal portion and the easy-to-open seal portion are provided on both sides of the intermediate member 4, and by regulating the positions of the inner and outer edges of the container or It is possible to provide a predetermined difference between the peel strength from the center of the container and the peel strength from the outside of the container without imprinting a score on the lid.

(Description of Preferred Embodiments) In the present invention, in order to provide a tight seal on one side of the intermediate material and form an easy-to-open seal portion on the other side, it is necessary to Utilizing the difference in heat sealing strength.

For example, if the intermediate material is a polypropylene film and the inner surface of the lid or container is made of polypropylene, a tight seal will be formed. Furthermore, if the inner surface of the lid or the inner surface of the container is formed of a blend of polypropylene and other polymers such as polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene rubber, etc., an easy-to-open seal will be formed. In addition, if the intermediate material is made of a laminated structure of a polypropylene layer and the blend layer, and both the inner surface of the lid and the inner surface of the container are made of polypropylene, a tight seal is attached to the polypropylene layer side and an easy-to-open seal is attached to the blend stone side. will be formed.

These examples also apply to heat-sealable resins such as polyethylene, polyester, and polyamide.

It is also known that polyolefin films have heat-sealing properties for certain coating films. That is,
Polyolefin films exhibit superior heat-sealing properties compared to coatings made of oxidized polyethylene or acid-modified olefin resins dispersed therein. By providing this coating on the inner surface of the lid or container and adjusting the amount of polyethylene oxide or acid-modified olefin resin dispersed, a tight seal is formed on one side of the polyolefin film and an easy-to-open seal is formed on the other side. Can be done. This tendency also applies to resins such as polyester and polyamide that exhibit heat sealability with paints.

The positions of the inner and outer edges of the easy-to-open seal portion and the inner and outer edges of the tight seal portion can be controlled by any means. The simplest method is to control the position of the inner and outer edges by controlling the shape and position of the heat seal bar when heat sealing the intermediate material to the lid or container flange. can.

Alternatively, a non-adhesive coating defining the inner and outer edges of the heat-sealed portion may be applied to the flange surface and inner surface of the lid by printing, coating, vapor deposition, welding, or other known thin film forming techniques. Alternatively, it can be applied to an intermediate material to regulate the position of the inner and outer edges of the heat-sealed portion.

The container body and lid may be made of any container-forming material known per se, such as resin, metal, paper, glass, ceramic, or a laminate thereof. Suitable container bodies and lids are made of resin having heat-sealing properties at least on the inner surface, such as low-medium high density polyethylene, tactical polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate copolymer. Olefin resins such as olefin resins graft-modified with polymerized or ethylenically unsaturated carboxylic acids or their anhydrides; polyamide or copolyamide resins with relatively low melting points or low softening points; polyesters with relatively low melting points or low softening points. or copolyester resin.

The container body may be a container formed from these resins alone, or may be a laminated container including a metal foil such as aluminum foil, steel foil, or tin foil as an intermediate layer.

The lid body can be made of metal foil such as aluminum foil, tin foil, steel foil, or tin foil, thermoplastic resin film such as biaxially oriented polyethylene terephthalate film, biaxially oriented nylon film, or polycarbonate film, various compositions, or even these. The base material may be a laminate or the like, and the heat-sealable resin layer described above may be laminated thereon as an inner surface material.

The intermediate material is a film made of one or more layers of the heat-sealable resin described above, and its thickness must be at least resistant to breakage when the package is opened, and generally has a thickness of 15 to 1000 μm, particularly 30 to 100 μm. Preferably within this range.

The present invention is particularly useful for applications in which the contents are sterilized by retort or boiling, or by hot filling.In this case, from the standpoint of heat resistance, the inner material of the container and lid may be made of polypropylene resin. is common. As an intermediate material particularly suitable for this application, the thickness is 15 to 1000 μm.
m, especially in the range from 30 to 100 μm, and a thickness of from 1 to 100 μm, especially from 3 to 50 μm.
Mention may be made of an intermediate material comprising a blend layer of a propylene-ethylene copolymer of m and polyethylene in a ratio of 90:10 to 50:5.

Although the present invention has been described above with respect to a sealed container consisting of a cup-shaped container and a lid, the present invention can also be applied to a container formed by sealing the Yuba pouch constituent material around the circumference by heat sealing. In FIG. 5, which shows an example of this container, pouch constituent materials 2' and 2' are heat-sealed through an intermediate material 4, and a tight seal 5 is attached to one side of the intermediate material, and an easy-open seal 6 is attached to the other side of the intermediate material. Let it form. The positional relationship of the edges of these seal parts is the same as that shown in FIG. The intermediate material 4 may be provided around the entire circumference of the pouch, or may be provided only in the portion of the pouch that is to be opened. By providing an openable seal portion on both sides of the container and regulating the positions of the inner and outer edges thereof, peeling from the center of the container can be achieved without inscribing a score on the container or lid. It becomes possible to provide a predetermined difference between the strength and the peel strength from the outside of the container, thereby providing an easily openable sealed food container that can be opened by hand.

Example 1 The specifications of the lid material, cup-shaped container, and intermediate material used in Example 1 are shown below.

A sealing layer of 70 mm was applied to the aluminum side of the base material, which was made by laminating a 12 μm biaxially stretched polyethylene terephthalate film and a 9 μm soft aluminum foil with a urethane adhesive.
A product made by laminating μm unstretched isotactic polypropylene films with a urethane adhesive.

40 μm on one side of a 75 μm surface-treated steel foil in a cup-shaped container and 7 μm on the other side.
A 0 μm unstretched isotactic polypropylene film is laminated with a urethane adhesive, and this laminate is 70 μm thick.
A round container having a heat-sealing flange with a width of 6 m and 111 mm, which is deep drawn so that the unstretched isotactic polypropylene film side becomes the sealing surface.

Coextrusion of a two-layer system created using a T-die consisting of a 50 μm isotactic polypropylene layer as an intermediate material and a 5 μm blend layer made of a 30% by weight blend of linear low-density polyethylene with ethylene-propylene random copolymer. film.

A sealed container of the type shown in FIG. 1 was produced using these lid materials, cup-shaped containers, and intermediate materials.

Heat-sealing was performed by first sealing the molded container and the intermediate material for easy opening, filling the container with water to about 90% of the total volume, and then tightly sealing the intermediate material and the lid. Table 1 shows the sealing conditions for easy-open seals and tight seals.
Shown below.

In addition, the positions of the inner and outer edges of the easy-to-open seal and the inner and outer edges of the tight seal are as follows:
This was done by regulating the shape and position of the heat seal bar. The seal widths of the easy-open seal part and the tight seal part are 3 mm and 2 m'm, respectively, and the distance between the inner edges is 2IuII+ and the distance between the outer edges is 0.
．． It was set to 5 mm.

The peel strength of the sealed and filled container thus obtained was 12
Measurements were taken before and after retort sterilization at 0°C for 50 minutes. To measure peel strength, cut out a strip 1511 mm wide at right angles to the direction of the seal, put the lid side of the strip in the upper chuck and the side wall of the cup in the lower chuck, and pull it up and down at a speed of 300 mm/min. I did it. Table 1 shows the measurement results from the inside of the container and the measurement results from the outside at the beginning of opening.
Shown below.

Example 2 A sealed container of the type shown in FIG. 4 was produced using the same lid material, cup-shaped container, and intermediate material as in Example 1.

Heat sealing was performed by first tightly sealing the molded container and the intermediate material, filling the container with water to about 90% of the total volume, and then performing an easy-open seal with the intermediate material to seal the container. Table 1 shows the sealing conditions for the easy-open seal and tight seal.

In addition, the positional restrictions of the inner and outer edges of the easy-to-open seal and the inner and outer edges of the tight seal are as follows:
Non-adhesive aluminum films were formed on both sides of the intermediate material by vacuum deposition so that their respective positions were regulated. In addition, as in Example 1, the seal widths of the easy-open seal part and the tight seal part are 3 mm and 2 m+n, respectively, and the distance between the inner edges is 2 nm, and the distance between the outer edges is 0. .5111m.

The peel strength of the thus obtained sealed and filled container was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

Example 3 The specifications of the lid material, cup-shaped container, and intermediate material used in Example 3 are shown below.

Lid material A lid material similar to that used in Example 1.

A 40 μm unstretched isotactic polypropylene film is placed on one side of a 75 μm surface-treated steel foil in a cup-shaped container, and a 5 μm unstretched isotactic polypropylene film is placed on the other side.
A two-layer coextruded film made using a T-die consisting of a 0 μm isotactic polypropylene layer and a 5 μm blend layer made of a 30% by weight blend of linear low-density polyethylene and ethylene-propylene random copolymer is made of urethane. A round container having a heat-sealing flange with a width of 6+ nm, which is laminated with a base adhesive and deep-drawn from this laminate so that the blend layer on the coextruded film side serves as the sealing surface.

An unstretched isotactic polypropylene film with an intermediate material of 50 μm.

A hermetically sealed container of the type shown in FIG. 1 was produced in the same manner as in Example 1 using these lid materials, cup-shaped containers, and intermediate materials. In addition, peel strength measurements were also carried out in the same manner as in Example 1. Table 1 shows the heat sealing conditions and peel strength measurement results.

Example 4 Specifications for the lid material, cup-shaped container, and intermediate material used in Example 4 are shown below.

Lid material 12 μm biaxially stretched polyethylene reterephthalate film and 9 μm soft aluminum foil are laminated with urethane adhesive.On the aluminum side of the base material, a 50 μm isotactic polypropylene layer and a linear ethylene-propylene random copolymer layer are attached. 30% by weight low density polyethylene
A two-layer coextruded film prepared using a T-die consisting of a 5 μm blend layer was laminated with a urethane adhesive so that the blend layer served as a sealing layer.

cup-shaped container A cup-shaped container similar to that used in Example 1.

An unstretched isotactic polypropylene film with an intermediate material of 50 μm.

A hermetically sealed container of the type shown in FIG. 4 was produced in the same manner as in Example 2 using these lid materials, cup-shaped containers, and intermediate materials. Further, peel strength measurement was performed in the same manner as in Example 1. Table 1 shows the heat sealing conditions and peel strength measurement results.

Example 5 The specifications of the lid material, cup-shaped container, and intermediate material used in Example 5 are shown below.

A surface treatment was applied to one side of the 50 μm aluminum foil for the lid to improve the adhesion of the paint film, and a 10 PH maleic anhydride-modified polypropylene layer was applied to that surface as a sealing layer.
Painted and baked with R-containing epoxy/phenol paint to a thickness of 5 μm.

A cup-shaped container 0.2 mm tin plate is coated with epoxy/phenol paint on one side and epoxy/phenol paint containing 7 PHR of maleic anhydride modified polypropylene on the other side to a thickness of 2 μm and 5 μm, respectively. A round container is made by baking and deep drawing the coated plate so that the coating side containing modified polypropylene becomes the sealing surface to form a heat-sealing flange with a width of 6 mm.

An unstretched isotactic polypropylene film with an intermediate material of 50 μm.

A hermetically sealed container of the type shown in FIG. 1 was produced in the same manner as in Example 1 using these lid materials, cup-shaped containers, and intermediate materials. Further, peel strength measurement was also carried out in the same manner as in Example 1. Table 1 shows the heat sealing conditions and peel strength measurement results.

Example 6 The specifications of the lid material, cup-shaped container, and intermediate material used in Example 6 are shown below.

One side of a 50μm aluminum foil cover material is surface-treated to improve paint film adhesion, and a sealing layer of 5μm thick epoxy/phenol paint is baked onto that surface.

On one side of a 0.5 mm polyethylene terephthalate sheet containing a cup-shaped container nucleating agent, 20 μm polyethylene terephthalate/isophthalate, polybutylene terephthalate/
For heat sealing with a width of 6 mm, a three-component blend film of isophthalate and ionomer is thermally bonded using a hot roll, this sheet is pressure-formed so that the blend film side becomes the sealing surface, and heat-treated after molding. A square container with a flange.

Intermediate materials polyethylene terephthalate, polyethylene terephthalate/isophthalate, polybutylene terephthalate/
80μ blend of isophthalate and ionomer
M four-component blend film.

A hermetically sealed container of the type shown in FIG. 4 was produced in the same manner as in Example 2 using these lid materials, cup-shaped containers, and intermediate materials. Moreover, peel strength measurement was performed by the same method as in Example 1. Table 1 shows the heat sealing conditions and peel strength measurement results.

Example 7 A 12 μm biaxially oriented polyethylene terephthalate film and a 9 μm soft aluminum foil were laminated with a urethane adhesive, and on the aluminum side of the base material, a film was applied as a sealing layer.
A pouch shown in FIG. 5 was prepared using a packaging material made of μm unstretched isotactic polypropylene films laminated with a urethane adhesive and the intermediate material used in Example 1.

Heat sealing was performed using an impulse sealer, first performing the tight sealing side and then performing the easy-open sealing side. Seal width of easy-open seal part and tight seal part is 5
mn, and the easy-to-open seal was shifted 2.5 +n+++ to the inside of the pouch with respect to the tight seal so as to have the positional relationship shown in FIG. 6(a).

A 15 mm wide strip was cut out from the opening start part of the pouch thus prepared at right angles to the sealing direction, and the T-beer strength was measured at a pulling speed of 300 II 1 m/min. Table 2 shows the measurement results from the inside and outside of the pouch.

Comparative Example 1.2 In Example 7, the easy-open seal was shifted 2.5 mm to the inside of the pouch compared to the tight seal, and the positional relationship was as shown in Figure 6(a). 6. As shown in Figure (b), place an easy-to-open seal on the outside of the pouch (Comparative Example 1) or a tight seal on the outside of the pouch.
．． A pouch was produced in the same manner as in Comparative Example 2) and Example 7, with the positional relationship shown in FIG. 6(C) shifted by 5 m+n.

The T-peel strength was measured in the same manner as in Example 7. The measurement results are shown in Table 2.

An object of the present invention is to provide a sealed food container that can withstand increased internal pressure during retort sterilization, while being easily opened from the outside of the container. In Examples 1 to 7, the peel strength from the inside of the container is 2.3 g/15 mm or more, which is strong enough to withstand the increase in internal pressure during retort sterilization, and the peel strength from the outside is 2 Kg/15 mm. It is less than the width and has an easy-to-open seal. When the containers of Examples 1 to 7 were actually held and peeled off by hand, they were easily opened. However, in Comparative Example 1.2, the desired effect of the present invention was not observed, and in Comparative Example 2, the package was too difficult to open.

[Brief explanation of the drawing]

1, 4, and 5 are diagrams each showing a cross-sectional structure of an example of an easily open sealed container of the present invention, and FIG. 2 is a diagram showing a sealed container example of the sealed container shown in FIG. FIG. 3 is a cross-sectional view showing a state in which a peeling force from the inside is applied to the sealed container example; FIG. FIG. 6 is a cross-sectional view illustrating the positional relationship between the easy-to-open seal portion and the tight seal portion in the sealed containers of Example 7 and Comparative Example 1.2. Reference number 1 is the heat seal flange, 2 is the container body,
3 is a lid, 4 is an intermediate material, 5 is a tight seal portion, 6 is an easy-to-open seal portion, 7 is an inner edge of the easy-to-open seal portion, 8 is an inner edge of the tight seal portion, 10 Reference numeral 11 indicates the outer circumferential edge of the easy-open seal portion, and 11 indicates the outer circumferential edge of the tight seal portion. Hand Itosale Amendment (self-motivated) November 21, 1986 Director General of the Patent Office Kunio Ogawa Tono 1, Relationship with the case indicated Patent applicant Address 3-3-16 Iwato, Yokosuka City, Kanagawa Prefecture Name
Hiroshi Ueno 4, Agent 〒105 6, Claims of the specification subject to amendment and detailed description of the invention column 7,
Contents of the amendment 9 The scope of claims is corrected as shown in the appendix. ■9 Detailed Description of the Invention Column (1) The statement in lines 4 to 12 of page 3 of the specification is corrected as follows. "To solve this problem, a heat-sealable inner material layer is provided on the inner surface of the container body, and the inner layer and the inner layer are easily peelable, and this layer is placed closer to the center than the heat-sealed part. A score is provided to cut the inner material layer, and the heat seal strength from the center side to the outside is 2.3 Kg/15
Heat-sealed containers have already been proposed that have a width of mm or more and that can be easily opened from the outside. 1 (2) The statements from page 4, line 16 to page 5, line 8 are corrected as follows. r According to the present invention, in a container in which opposing portions of a plurality of container materials are sealed by heat sealing, at least an opening initiation portion of the sealed portions is connected to the plurality of container materials;
It has a laminated structure with an intermediate material inserted between them, the intermediate material and one of the plurality of container materials are a tight seal, and the intermediate material and the other of the plurality of container materials are an easy-to-open seal, The inner edge of the easy-to-open seal part is located closer to the center than the inner edge of the tight-seal part, and the outer edge of the easy-to-open seal part is closer to the center than the inner edge of the tight-seal part, and the outer edge of the easy-to-open seal part is located closer to the center than the inner edge of the tight seal part. Provided is an easily openable sealed food container characterized in that the container is located closer to the center than the outer peripheral edge of the container. (3) The statements from page 5, line 18 to page 6, line 3 are corrected as follows.

[The inner edge 7 of the easy-to-open seal part 6 is located closer to the center than the inner edge 8 of the tight seal part 5, and the outer edge 7 of the easy-to-open seal part 6 is located closer to the center than the inner edge 8 of the tight seal part 5. edge 10
is located closer to the center than the outer peripheral edge 11 of the tight seal portion 5. J (4) The statements from page 6, line 13 to page 7, line 1 are corrected as follows. "On the other hand, in FIG. 3, which shows a state in which a peeling force from the outside is applied to the opening initiation part 9 of this sealing part, when the end part 13 of the lid 3 is grasped and pulled upward, the easy-to-open seal part Since the outer circumferential edge lO of the tight seal portion 5 is located closer to the center than the outer circumferential edge 11 of the tight seal portion 5, the peeling force P′ acts on the easy-to-open seal portion 6, for example, 2 Kg/15.
The peel strength is less than the rafll width, making it easy to peel and open by hand. ] (5) Page 7, lines 7 and 8
Insert the following statement between the lines. The intermediate material 4 may be provided around the entire circumference of the sealed part, but it may also be provided only at the opening start part 9.The opening strength is greatest at the time of opening, where the peeling is widest in the sealed part, and generally speaking. becomes the opening start part 9. Therefore, even if the sealing strength between the container 2 and the lid 3 is strong, for example, 2.3 to 3 K
Even if the width is 15 mm, insert the intermediate material 4 into the unsealing start part 9 and tightly seal one side through the intermediate material 5. By using the easy-to-open seal 6 on the other side and regulating their position, the same effect as described above can be obtained, and the maximum value of the opening strength is reduced, making opening easier. ” (6) On page 14, line 9, the phrase “a two-layer system made using a T-die” should be corrected to “1, a two-layer system made using an rT die.” (7) In the third line of page 18, the phrase “indicates the specifications for the intermediate material” is corrected to “indicates the specifications for the intermediate material, J.” Revised scope of patent claims (1) Plural In a container in which opposing portions of the container materials are sealed by heat sealing, at least the unsealing initiation portion of the sealing portion has a contact structure of the plurality of container materials and an intermediate material inserted therebetween. The intermediate material and one of the plurality of container materials are a tight seal, and the other of the intermediate material and the plurality of container materials are an easy-to-open seal, and the inner peripheral edge of the easy-to-open seal part is a tight seal. The outer circumferential edge of the easy-to-open seal portion is located closer to the center than the outer circumferential edge of the tight seal portion at the opening start position. An easy-open sealed food container characterized by: (2) One of the container materials is a cup-shaped container equipped with a heat-sealing flange, the other container material is a lid, and the cup-shaped container and the intermediate layer are The food container according to claim 1, wherein there is an easy-to-open seal between the lid and the intermediate layer, and a tight seal between the lid and the intermediate layer. (3) The plurality of container materials are two pieces of pouch-constituting materials. A food container according to claim 1.

Claims (3)

[Claims] (1) In a container in which opposing portions of a plurality of container materials are sealed by heat sealing, the sealing portion has a laminated structure of a plurality of container materials and an intermediate material inserted therebetween, and One of the plurality of container materials is a tight seal, and the other of the intermediate material and the plurality of container materials is an easy-to-open seal, and the inner peripheral edge of the easy-to-open seal part is the inner periphery of the tight seal part. It is located closer to the center than the side edges,
An easy-open sealed food container characterized in that, at the opening start position, the outer peripheral edge of the easy-open seal part is located at the same position as the outer peripheral edge of the tight seal part or closer to the center than the outer peripheral edge of the tight seal part. . (2) The food container according to claim 1, wherein one of the container materials is a cup-shaped container equipped with a heat-sealing flange, and the other container material is a lid. (3) The food container according to claim 1, wherein the plurality of container materials are two pieces of pouch-constituting materials.