JPH076127Y2 - Easy-to-open sealed container - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a container composed of a plastic cup body having a flange portion and a lid member, in which the lid can be easily opened. Regarding the container.

[Conventional technology]

As a packaging container for foods, an easy-open plastic sealed container whose lid can be easily opened is widely used.

The most common easy-open method that has been performed in the past is to control the sealing strength with the container appropriately by changing the composition of the resin that constitutes the sealing layer of the lid material (for example, 600 to 1000 g / mm), The peeling is performed by peeling the interface between the material and the container. However, the seal strength is easily affected by the sealing conditions, environmental temperature, adhesion of contents, etc.
Variations in strength often occur. If this variation is biased toward the weak side, there is a risk of leaking the seal. Conversely, if it is biased toward the strong side, the peeling property deteriorates and opening becomes difficult.
However, since seal leakage is a fatal defect, in order to avoid this phenomenon and ensure safety, it is necessary to set a high seal temperature and pressure even if the easy open property is sacrificed. In order to solve such a problem, a method of opening the seal layer by delamination between the seal layer and an adjacent layer has been attempted (for example, Japanese Patent Publication No. 50-37598). Does not break well and the contents are difficult to remove.

Further, a structure in which a notch is provided in the flange portion to facilitate the separation between the release layer and the adjacent layer has also been proposed (JP-A-62-251363, JP-A-63-78, and JP-A-63-25037). etc). However, in the case of the container having these structures, the peripheral edge of the container of the cut portion has to be sealed from the outside in the manufacturing stage, so there is a manufacturing problem that strict control is required for position setting at the time of sealing. . In addition, in the method of peeling the main container seal layer and the seal layer, it is necessary to start peeling from the peripheral edge of the flange because it seals up to the peripheral edge of the flange. There is a drawback to receive.

As a measure to solve this point, there is an example in which a peeling start cut and a peeling stop cut are installed in the flange portion as described in JP-A-63-96060. However, there is an inconvenience in the manufacturing process in that the seal position accuracy of must be set strictly.

[Problems to be solved by the device]

The present invention solves the above-mentioned conventional problems by providing the flange portion with an annular recess of a specific shape, and therefore there is no risk of seal leakage, and easy and stable unsealing can be obtained regardless of the sealing conditions. The present invention provides an openable sealed container.

A structure in which a concave portion is formed in the flange portion by heat-sealing the container body and the lid material with a convex sealing plate has been known for a long time, and it is advantageous that stable sealing can be performed even when the contents overflow into the flange portion. Although the surface is recognized, in the case of opening with interfacial peeling between the seal layer of the container body and the cover material seal layer, both seal layers undergo complicated plastic deformation in the sealing process, so the pressure resistance is improved There is a difficulty in retreating in terms of opening property.

An object of the present invention is to improve the structure to solve this problem.

[Means for Solving the Problems]

An easily openable hermetic container according to the present invention for achieving the above object comprises a flange portion of a container body in which a seal layer and an adjacent layer opposite to the seal layer are laminated, and a seal layer of the same quality as the seal layer of the container body. In the hermetically sealed container in which the lid material is sealed, the flange portion is provided with a seal layer formed by an annular pressing recess from the top surface of the lid material to at least the groove bottom reaching the adjacent layer surface of the flange portion, and both ends of the boundary between the seal portion and the non-seal portion A lump-shaped resin reservoir is formed by the constituent resins of the seal layer and the adjacent layer, and at the time of opening, cut at two points of the seal layer located below the lump-shaped resin reservoir to form the seal layer and the adjacent layer. The structural feature is to have a mechanism for peeling at the interface.

Therefore, the structural feature of the present invention is that the groove bottom is formed in the form of an annular pressing recess so as to be deeper than or equal to the surface of the adjacent layer, and a bump is formed at both ends of the boundary between the seal portion and the non-seal portion. A resinous puddle is formed, and if this requirement is not met, effective achievement of the objective cannot be achieved.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing the entire sealed container, in which 1 is a container body, 2 is a lid, and 3 is a flange portion.

The material of the container body 1 is a multilayer sheet having at least a sealing layer and an adjacent layer facing the sealing layer. For example, a simple two-layer sheet having a polyethylene resin in the sealing layer and a polypropylene resin in the adjacent layer may be used. It may be a 6-layer sheet in which a barrier layer of a saponified product of an ethylene vinyl acetate copolymer or a polyvinylidene chloride resin, an adhesive layer and an outermost layer of polypropylene are arranged in each layer via an adhesive layer. In some cases, other materials such as metal and paper may be laminated on the outside of the multilayer plastic sheet. However, the multilayer sheet has a laminate strength between the seal layer and the adjacent layer of 300 to 2000 g / 25 mm (at a peeling angle of 180 ° and a peeling speed of 200 mm / min), and the thickness of the sealing layer is 10
It is desirable to set in the range of ~ 70μ. The reason for this is
When the laminating strength is less than 300 g / 25 mm and the sheet layer thickness is less than 10 μ, sufficient sealing performance cannot be secured, while the laminating strength exceeds 2000 g / 25 mm and the sealing layer thickness exceeds 70 μ. This is because when it is rotated, the peel strength when opening is increased and the smooth peeling property is impaired.

The lid member 2 is formed of a multi-layer film having a homogenous seal layer that is in close contact with and firmly bonded to the seal layer of the container body 1. The most preferable mode is to form a multilayer film having a sealing layer made of the same material as the sealing layer of the container body 1. For example, in the case where the seal layer of the container body 1 is polyethylene and the adjacent layer is polypropylene, the combination using the lid material in which the seal layer is polyethylene is optimal. Further, the film of the lid material may be a multilayer film containing aluminum foil, polypropylene or the like having a good barrier property.

FIG. 2 is an enlarged cross-sectional view showing the flange portion 3 constituting the present invention. The annular pressing recess 4 formed has a groove bottom T which is deeper than the adjacent layer surface S of the flange portion 3 or more. . And, at both ends of the boundary between the seal part and the non-seal part,
Bump-shaped resin reservoirs 7, 7 ′, 8, 8 ′ made of the constituent resins of the seal layer 5 and the adjacent layer 6 are formed.

There is no particular restriction on the shape of the pressing recess, and for example, a V-shape, U
It may be a suitable shape such as a letter shape.

The pressing recess 4 and the resin pools 7, 7 ', 8, 8'
In order to form the heat-sealing means, a heat-sealing means is used in which the lid member 2 is placed on the flange portion 3 of the container body 1 and press-fitted by using a sealing plate having a concave heat portion. At this time, due to the press-fitting of the convex heat part, the sealing layer 9 of the lid member 2, the sealing layer 5 of the container 1, and the constituent resin of the adjacent layer 6 near the bottom of the pressing surface are plastically deformed to cause the boundary between the sealing part and the non-sealing part. Extruded on both ends. When the press-fitting of the convex heat portion is further advanced and press-fitting is performed until the groove bottom T reaches at least the adjacent layer surface S, the resin swelling further increases, and the bump-shaped resin pool 7,
7'and 8, 8 '. At this time, the lid material 2
The sealing layer 9 is also attached to form resin reservoirs 10 and 10 '. However, the press-fitting of the convex heat portion needs to be performed under the condition that the sealing layer 5 and the sealing layer 9 of the lid material are not entirely pushed out to the bump-shaped resin reservoir portion by pressing, and are interposed as a thin sealing layer portion. .

In the seal portion, the lid material 2 and the container body 1 are completely adhered to each other because the mutual seal layers are of the same quality.
The resin is mixed in the boundary surface between the seal layer 5 and the container. In this state, the sealing strength is higher than the laminating strength between the sealing layer of the container and the adjacent layer.

[Action]

Since the easily openable hermetically sealed container of the present invention has the above-mentioned structure, when the lid material 2 is flipped over from the peripheral edge portion when opening, the third
A force X as shown in the figure is applied, and the sealing layer 9 of the lid member 2 is separated from the sealing layer 5 of the container 1. This peeling is the second
When the point A in the figure is reached, the seal layer 5 is cut and the seal layer 5 is cut.
And the peeling of the adjacent layer 6 occurs. At this time, the presence of the large resin reservoirs 7 and 8 at the point A exerts a resistance force against the sealing layer 5 in the opposite direction to the pressing force X to assist the cutting.

The peeling between the seal layer 5 and the adjacent layer 6 continues to the resin reservoir portion on the container side, but in the process up to this stage, the force X functions only for peeling. Then, when the peeling reaches the point B in FIG. 2, the force X acts on both sides of the peeling and the cutting of the sealing layer 5, but since the resin reservoirs 7 ′, 8 ′ are formed in a large bump-like shape, Is expended as a force to tear off the seal layer 5. Due to such distribution of the force X, cutting and peeling action are combined, and finally the state of FIG. 4 is easily opened.

In a mode in which the groove bottom T of the pressing recess 4 does not reach the adjacent layer surface S, the resin pool is not large, so that the peeling force is always dominant rather than the cutting, and the sealing layer 5 becomes difficult to cut.

〔Example〕

 Examples of the present invention will be described below.

The overall thickness is 850μ, the material of the sealing layer is density 0.955, high density polyethylene (HDPE) with melt index (MI) 5g / 10min, and the adjacent layer (also serving as the outer layer) is polypropylene with melt index (MI) 0.5 / min ( A two-layer seal made of PP) was prepared by coextrusion. Then, this sheet was vacuum-formed to obtain a container body having an inner diameter of 70 mm, a flange outer diameter of 82 mm, and a height of 30 mm. The flange thickness of this container body is 800
μ, the thickness of the seal layer was 20 μ, and the laminating strength between the seal layer and the adjacent layer was 800 g / 25 mm.

Biaxially stretched 6-6,6Ny (ONY) 25 on the flange of the container
Using a sealing board 5 with a U-shaped convex heating part 4 by stacking a lid material consisting of μ / HDPE 60μ, temperature 180 ° C, pressure 10 kg / cm ²
Under the conditions described above, the tip of the convex heating portion (groove bottom T) was press-fitted and sealed so as to reach the adjacent layer surface S.

With this seal, bump-shaped resin reservoirs 7, 7 ', 8, 8'as shown in FIG. 2 are formed at both ends of the boundary between the sealed portion and the non-sealed portion.
Was formed.

When the lid of the above-mentioned sealed container is opened, A and B in FIG.
Cutting of the sealing layer 5 and interlayer peeling at the points are performed very smoothly, and its peel strength (JIS K6854) is 800 g /
It had a good easy-opening property of 15 mm and a cutting strength of 1000 g / 15 mm.

For comparison, when the lid of the sealed container having the resin reservoir formed under the press-fitting condition in which the tip of the convex heating portion (groove bottom T) does not reach the adjacent layer surface S is opened, points A and B, especially point B The cutting of the seal layer in Example 2 was not performed smoothly. That is, the peel strength in this case was 800 g / 15 mm, which was a good unsealing strength, but the sealing layer 5 did not pass after the point B.
The peeling was continued, and the seal layer 5 was peeled and separated from the adjacent layer 6 even if it was finally cut and opened, and the appearance was unsightly.

[Effect of device]

Since the safety and the easy-open property of the seal in the hermetically sealed container are contradictory to each other, it has been difficult to achieve both in the conventional sealing method.

On the other hand, in the structure of the easily openable sealed container according to the present invention, the interface for sealing and the interface for peeling are different, so that the smooth peeling property is given without being controlled by the sealing strength and the resin accumulation Due to the action of the portion, the cutting and opening of the seal layer can be performed very easily. Therefore, the perfect sealing property and the easy-open property are always guaranteed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing the entire sealed container, FIG. 2 is an enlarged sectional view showing a flange portion of the present invention, FIG. 3 is a sectional view showing the direction of force required to open the seal portion, and FIG. The figure is a cross-sectional view showing a state when the package is opened. 1 ... Container body, 2 ... Lid material, 3 ... Flange portion, 4 ...
... Pressing recess, 5 ... Seal layer, 6 ... Adjacent layer, 7,
7 ', 8,8', 10,10 '... resin reservoir, 9 ... seal layer of lid material, A, B ... cutting point, S ... adjacent layer surface, T
…… Groove bottom, X …… force

Claims (1)

[Scope of utility model registration request] 1. A hermetically sealed container comprising a flange portion of a container body, which is formed by laminating a seal layer and an adjacent layer opposite to the seal layer, and a lid member, the seal layer having the same quality as the seal layer of the container body. At (3), a seal portion is provided by an annular pressing concave portion (4) from the upper surface of the lid material, at least the groove bottom (T) reaches the adjacent layer surface (S) of the flange portion, and both end portions of the boundary between the seal portion and the non-seal portion are provided. A lump-shaped resin reservoir (7, 7 ', 8, 8') made of the constituent resins of the sealing layer (5) and the adjacent layer (6) is formed on the bottom of the ridge-shaped resin reservoir when opened. An easily openable sealed container comprising a mechanism of cutting at two points (A, B) of the positioned seal layer (5) and peeling at the interface between the seal layer (5) and the adjacent layer (6).