JP3813235B2 - Easy-open lid material and container using the lid material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for easily opening a container used for packaging retort food or the like.
[0002]
[Prior art]
For example, in the case of a container such as a container for retort foods that is required to have both the sealing property before opening and the easy opening property at the time of opening, the container body shall have a flange portion at the periphery of the top opening, Uses a laminated film with a heat-adhesive resin layer on the back side of the base material layer, and heat-seals the heat-adhesive resin layer against the flange part of the container body, and the back side of the base material layer of the lid A release agent layer wider than the seal portion is provided at the portion corresponding to the seal portion, and when the lid is picked up by holding the knob at the periphery of the cover material, the seal portion of the heat-adhesive resin layer is peeled off from the base material layer. Conventionally, the lid material is peeled off while leaving a part.
[0003]
In addition, as an easy open method, the container body and the flange portion at the periphery of the opening are formed by a laminated sheet composed of a base material layer and a release layer so that the release layer is on the surface side of the flange portion. The release layer located on the inner side of the seal part of the flange part is provided with a notch over the entire circumference, or the release layer of the same part is thinned over the entire circumference, so that the release layer is a lid material at the peripheral part when opened. In some cases, the peeling layer is cut off at the part that is lifted and cut out or thinned so that the lid material is peeled off. Japanese Utility Model Publication No. 6-47773 describes a container which is provided with an easy open property by such a method. In addition, Japanese Utility Model Publication No. 6-96263 describes a method for manufacturing such a container.
[0004]
Japanese Patent Laid-Open No. 62-208375 and Japanese Patent Laid-Open No. 2-219769 disclose that a substrate having an inner surface having heat sealability and an outer surface peeling layer are laminated through an adhesive layer and a resin layer having a weak adhesive force. However, the opening portion does not go through the resin layer having a weak adhesive force, and the outer surface peeling layer is laminated with the base material by the adhesive layer, and at least the base sheet penetrates the base material so as to surround the opening portion. Pull out the adhesive and hold the part that was used as an opening tab to cause the outer surface peeling layer, and pulling upward, the outer surface peeling layer was peeled off from the base material, and only the opening part was the base material Is lifted together with the outer surface release layer, and is broken along the cut line to form an opening.
[0005]
Japanese Utility Model Laid-Open No. 55-139073 discloses a cut in which a metal foil is completely cut from the surface side of the base material in a cover material provided with a heat seal layer on one side of the base material containing a metal foil such as aluminum. It is provided that an opening portion that is continuous with the tab is formed by this cut.
[0006]
[Problems to be solved by the invention]
In the case where the release agent layer is provided in the part corresponding to the seal part on the back surface of the base material layer of the lid material, if the grip part on the peripheral part of the lid material is pulled up, the seal part of the heat-adhesive resin layer is at the interface. Although it peels off, the heat-adhesive resin layer tears diagonally inside the part, and the peeled surface becomes dirty, or a part of the peeled off part is left behind, so that inconveniences such as inability to open can easily occur.
[0007]
Also, in the case where a release layer is provided on the container body side and the release layer is provided with a notch or a thin wall portion, the container body needs to have a laminated structure of a base material layer and a release layer, and the flange portion is formed after the container is formed. It is necessary to form a notch or a thin portion in a ring shape in the release layer, which causes high costs. Such cutouts and thin-walled parts must be formed in a separate process by forming a laminated sheet into a container shape, punching it into individual containers, and pressing it with a hot plate, making the process complicated and cumbersome. This increases the cost. It is not impossible to form notches and thin-walled parts in a multi-faceted state before individually punching the molded containers, but if this is done, the degree of expansion and contraction will be adjusted between the center and edges of the sheet by pressing with a hot plate. As a result, the registration becomes difficult.
[0008]
Further, in the case where discontinuous cuts are provided on the base material, it is necessary to provide an external surface peeling layer such as a synthetic resin film or metal foil having its own strength on the base material whose inner surface has heat-sealing properties, which increases costs.
[0009]
In addition, what has been provided with a cut that completely cuts the metal foil from the surface side of the base material including the metal foil has a problem in barrier properties, and cannot be used for those that are subject to internal pressure. Is limited.
[0010]
Therefore, it is a problem to improve the easy openability of the lid member by means that is easy to process and does not cost, to maintain the barrier property, and to be used for applications where internal pressure is applied. The present invention aims to solve this problem.
[0011]
[Means for Solving the Problems]
The present invention comprises a base material layer and a heat-adhesive resin layer laminated on the back side of the base material layer, and the heat-adhesive resin layer is applied to the flange portion of the container body and melt-sealed at a predetermined seal portion. And a container using the lid material, wherein the lid material is set on the heat-adhesive resin layer at positions separated from the outer circumference and the inner circumference of the seal portion corresponding to the outer circumference and the inner circumference of the seal portion, respectively. The ring-shaped cut formed from the flange contact surface side is provided on the back surface of the base material layer, and the inner ring-side cut from the position corresponding to the outer ring-shaped cut of the thermal adhesive resin layer is provided on the back surface of the base material layer. A release agent layer having at least the same width as the interval between both ring-shaped cuts was provided so as to cover at least the position between the ring-shaped cuts on the outer circumferential side and the position of the ring-shaped cuts on the inner circumferential side over the corresponding positions. It is characterized by.
[0012]
Here, after the base material layer and the heat-adhesive resin layer are bonded together, the ring-shaped cut is formed in a half-cut shape by, for example, laser or fusing.
[0013]
According to the present invention, when the lid member is pulled up with a predetermined portion on the periphery, the laminating strength of the release agent layer is weaker than the sealing strength, so that the outer ring ring cut and the inner ring cut The base material layer is peeled off along the release agent layer in the form of leaving the heat-adhesive resin layer on the container side, and the lid is thermally bonded to the base material layer on the inner side of the inner ring-shaped cut. The functional resin layer opens again as a unit. In this case, the heat-adhesive resin layer is surely and easily separated at the half-cut cut portions on both sides of the seal portion. For this reason, the lid material can be peeled cleanly, leaving only the portion sandwiched between the two cuts without causing the peeling surface to become dirty or cause delamination. Further, since the cut can be prevented from reaching the base material layer, the barrier property is not hindered, and the strength against the internal pressure does not cause a problem.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
FIG. 1 is a sectional view of a container showing an embodiment of the present invention, and FIG. 2 is a plan view of the container. FIG. 3 is a schematic cross-sectional view of the seal portion in the sealed state of the container, and FIG. 4 is a schematic cross-sectional view of the seal portion when the container is opened.
[0016]
In the figure, 1 is a circular cup-shaped container body, and 2 is a sheet-shaped lid. The container main body 1 is a molded product of polypropylene and has a flange portion 1a on the periphery of the top opening. The lid 2 is covered with the top of the container main body 1 after filling the contents, and the peripheral edge is melt sealed to the flange 1a of the container main body 1 and corresponds to the outer shape of the flange 1a of the container main body 1. And has a knob 2a for opening at one place on the peripheral edge. In FIG. 1, a portion with vertical hatching is a seal portion 3. Further, the seal portion 3 corresponds to a portion marked with fine dots in FIG.
[0017]
For example, the lid material 2 is formed by bonding a polyester film 11 having a thickness of 12 μm and an aluminum foil 12 having a thickness of 7 μm by dry lamination, and a pattern printing layer 13 is formed on the surface of the polyester film 11 side by double-sided printing. A release agent layer 14 is provided at a predetermined position on the surface, and a polyester stem film 15 having a thickness of 12 μm is bonded to the surface of the pattern printing layer 13 as a protective layer. It is constituted by a laminated sheet in which an unstretched polypropylene film 16 having a thickness of 70 μm is bonded to the back surface of the aluminum foil 12 (the back surface of the release agent layer 14 at the position of the release agent layer 14). Further, the lid member 2 has a flange portion at a position slightly separated from the seal portion 3 on the outer peripheral side and the inner peripheral side of the seal portion 3 with respect to the unstretched polypropylene film 16 constituting the heat-adhesive resin layer. Ring-shaped cuts 4 and 5 formed from the contact surface side with 1a are provided.
[0018]
Both ring-shaped cuts 4 and 5 are formed by laser or fusing (the illustrated example is a cross-sectional shape when formed by fusing). At this time, both the ring-shaped cuts 4 and 5 are preferably set at positions separated from the outer circumference and the inner circumference of the seal portion 3 so that the registration error can be absorbed. About the cut 4, about 2 mm is good. Further, the ring-shaped cut 5 on the inner peripheral side should be further separated from the outer peripheral side in order to facilitate registration and prevent peeling due to internal pressure. The release agent layer 14 is provided wider than the distance between the ring-shaped cuts 4 and 5 so as to cover at least the position of the ring-shaped cut 4 on the outer peripheral side to the position of the ring-shaped cut 5 on the inner peripheral side. . The release agent layer 14 needs to have at least the same width as the interval between the ring-shaped cuts 4 and 5, and actually, a little across the ring-shaped cuts 4 and 5 so as to absorb the registration error. Set to protrude.
[0019]
The lid 2 is melt-sealed by a seal bar 7 at a predetermined seal portion, with the surface of the unstretched polypropylene film 16 facing the flange portion 1a of the container body 1. As a result, the seal portion 3 is formed. 3 and 4 is a complete seal portion indicated by 3a.
[0020]
This container can be neatly opened as shown in FIG. 4 by holding the knob 2a of the lid 2 and pulling it up. That is, when the knob part 2a is pulled up, the laminating strength (300 g / 15 mm width to 800 g / 15 mm width) of the release agent layer 14 is weaker than the sealing strength (about 1000 to 1500 g / 15 mm width). In the seal portion between the ring-shaped cut 4 and the ring-shaped cut 5 on the inner peripheral side, the base material is formed along the release agent layer 14 in such a manner that the unstretched polypropylene film 16 that is a heat-adhesive resin layer is left on the container 1 side. Layer p is peeled off. And from the ring-shaped cut 5 on the inner peripheral side, the lid 2 is opened while the base material layer p and the unstretched polypropylene film 16 are integrated. At that time, the portion of the unstretched polypropylene 16 that is the heat-adhesive resin layer is reliably and easily separated by the half-cut-like cut portions 4 and 5 on both sides of the seal portion 3 and is sandwiched between the cut portions 4 and 5. The lid 2 is peeled off beautifully leaving the left part. Further, since the cuts 4 and 5 formed by laser or fusing are stopped by the aluminum foil 12, the base material layer p cannot be scratched, barrier properties are ensured, and strength against internal pressure is ensured.
[0021]
Although the said container is suitable as a container for retort foods and a container for boiled foods, it is applicable also to various other containers.
[0022]
【The invention's effect】
According to the present invention, the heat-adhesive resin layer of the lid can be easily and cleanly opened by linear tearing at the inner peripheral edge of the seal portion of the container body, and easy openability is improved. In addition, since there is no need to process the container body, the processing is simple, the cost can be reduced, the barrier property can be maintained, and the container can be applied to applications where internal pressure is applied.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a container showing an embodiment of the present invention.
FIG. 2 is a plan view of the container of FIG.
3 is a schematic cross-sectional view of a seal portion in a sealed state of the container of FIG.
4 is a schematic cross-sectional view of a seal portion when the container shown in FIG. 1 is opened. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Container main body 1a Flange part 2 Lid material 3 Seal part 3a Complete seal part 4 Ring-shaped cut | disconnection (periphery side)
5 Ring-shaped cut (inner circumference side)
11 Polyester film 12 Aluminum foil 13 Pattern printing layer 14 Release agent layer 15 Polyester film 16 Unstretched polypropylene film (thermal adhesive resin layer)
p Base material layer

Claims (2)

A cover material comprising a base material layer and a heat-adhesive resin layer laminated on the back surface side of the base material layer, wherein the heat-adhesive resin layer is applied to the flange portion of the container body and melt-sealed at a predetermined seal portion, The heat-adhesive resin layer has an outer ring shape formed from the flange contact surface side at a position away from the outer periphery and inner periphery of the seal portion corresponding to the outer periphery and inner periphery of the seal portion. provided with a cut and the inner periphery-side ring-shaped cut, the back surface of the base layer, so as to cover up to the position of the inner peripheral side ring-shaped cut from a position on the outer peripheral side ring-shaped cut of the heat-adhesive resin layer, the rings A release agent layer is provided so as to extend slightly across the width of the gap between the ring-shaped cuts or between the ring-shaped cuts, and in the limited region between the ring-shaped cuts, the thermoadhesive resin layer and the base material layer Between is the thermal adhesive tree Lid material having easy-open properties, characterized in that it is configured to weak laminate strength than the seal strength between the flange portion of the layer and the container body. A container body having a flange portion at the periphery of the top opening, and a base material layer and a heat adhesive resin layer laminated on the back surface side of the base material layer. A container made of a lid material that is melt-sealed by a predetermined seal portion, and the thermal adhesive resin layer is separated from the outer periphery and inner periphery of the seal portion corresponding to the outer periphery and inner periphery of the seal portion, respectively. An outer peripheral ring-shaped cut and an inner peripheral ring-shaped cut formed from the flange contact surface side at each position are provided, and an outer peripheral ring-shaped cut of the thermal adhesive resin layer is provided on the back surface of the base material layer. A stripping agent layer is provided so as to cover from the position to the position of the inner ring-shaped cut, the same width as the distance between the two ring-shaped cuts or slightly protruding across both ring-shaped cuts, and the limitation between the two ring-shaped cuts In the area There are, characterized in that between the heat-adhesive resin layer and the base layer is formed on the weak laminate strength than the seal strength between the flange portion of the heat-adhesive resin layer and the container body A container using an easy-open lid.

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