JPH079805Y2 - Inner seal material for container mouth sealing - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner seal material for sealing a container mouth.

[0002]

2. Description of the Related Art A so-called inner seal, which is attached to the mouth of a container of instant coffee or the like to protect the contents from moisture, has been generally known. Such an inner seal is usually formed by a laminated body of a reseal layer mainly made of cardboard and a seal layer mainly made of metal foil, and when the cap of the container is removed during use, the reseal layer is Remains on the inside of the cap, and the sealing layer is in close contact with the mouth of the container body to protect the contents from moisture.

By the way, when the inner seal is sealed at the mouth of the container, a high frequency induction heating method as described in, for example, Japanese Patent Publication No. 56-35544 and Japanese Utility Model Publication No. 50-32540 is known. There is. That is, in this method, an aluminum foil layer is provided on the upper surface side of the seal layer, a thermoplastic resin layer is provided on the lower surface side, and a plastic film layer is provided on the lower surface side of the reseal layer, and between the seal layer and the reseal layer. An inner seal material is constructed by interposing a surfactant on the inner surface of the container, and a cap with the inner seal material inserted is attached to the container body while applying a high frequency wave from above to match the ring shape of the container mouth. By heating the aluminum foil in the layers, the thermoplastic resin on the lower surface of the seal layer is melted to adhere the inner seal material to the mouth of the container.

[0004]

However, in the above conventional inner seal material, since the seal layer and the reseal layer are adhered to each other through the surfactant, when the high frequency induction heating is performed, the gap between these layers is increased. There has been a problem that the peel strength is increased and the reseal layer and the seal layer are not reliably peeled off when the cap of the container is opened.

The present invention has been made in view of the above problems, and it is difficult for the reseal layer and the seal layer to be peeled off until the inner seal material is sealed at the mouth of the container, and these can be easily opened when the container is opened. The purpose is to be able to peel off.

[0006]

In order to achieve the above object, an inner seal material for sealing a container mouth portion according to the present invention comprises:
In an inner seal material that has a laminated structure of a reseal layer and a seal layer and is heat-sealed to the mouth of a container by high-frequency induction heating, an absorbent material such as paper is laminated on the lowermost surface of the resealing layer and the uppermost surface of the sealing layer. At the same time, the reseal layer and the seal layer are laminated via a hot melt adhesive layer.

[0007]

In the present invention, absorbent materials such as paper are laminated on the lowermost surface of the reseal layer and the uppermost surface of the seal layer, respectively.
Since these are adhered to each other via the hot melt adhesive, the reseal layer and the seal layer are securely adhered and are not peeled off until the inner seal material is sealed to the container mouth portion. When heat seal bonding is applied to the mouth of the container by heating, the hot melt adhesive is melted and absorbed by the absorbent material of the adjacent reseal layer and seal layer, so that the peel strength between the reseal layer and the seal layer in the high frequency heating part is increased. Since these are almost zero, both layers can be easily peeled off.

[0008]

Embodiments Embodiments will be described below with reference to the drawings.

FIG. 1 is a layer diagram of an inner seal material for sealing a container mouth according to an embodiment of the present invention.

In this embodiment, the inner seal material 1
Is composed of a seal layer 2 and a reseal layer 3.
Among them, the seal layer 2 is formed by attaching an aluminum foil 6 having a thickness of 30 μ to the upper surface of a Surlyn 4 having a thickness of 50 μ via a dry laminate layer 5, and providing a printed pattern layer 7 on the upper surface of the aluminum foil 6. Then, on the upper surface thereof, a basis weight of 16 g / m is provided through a 15 μm-thick polyethylene extrusion coating layer 8.
² is formed by providing pure white, high-quality thin paper (carbon sandwich paper) 9. On the other hand, the reseal layer 3 has a basis weight of 52.3 on the upper surface of the cardboard 10 having a basis weight of 230 g / m ² via the extrusion coating layer 11 of polyethylene having a thickness of 15 μm.
It is formed by laminating g / m ² thin paper 12. A hot melt adhesive layer 13 is provided between the thin papers 9 and 12 laminated on the uppermost surface of the seal layer 2 and the lowermost surface of the reseal layer 3. As this hot melt adhesive, a wax mainly composed of paraffin wax and containing several percent of ethylene-vinyl acetate copolymer (EVA) resin is used. The softening point of this wax can be changed depending on the EVA content. Specifically, Nippon Seiro's "Neoparax 3240" (normal time) or the same "Neoparax 345"
5 ”(when the temperature is high such as in summer) is used. Here, "Neoparax 3240" has a softening point of 70 ° C and a viscosity (120 ° C) of 1350 CPS, and "Neoparax 3455" has a softening point of 75 ° C and a viscosity (120 ° C).
It is 1800 CPS.

The inner seal material 1 having the above structure is
It is punched into a circular shape having a predetermined size and is inserted into the cap so that the seal layer 2 is on the container mouth side. Then
After mounting the cap on the container body, a ring-shaped high frequency wave is applied from above the cap by a high frequency generator so as to follow the shape of the container mouth. Then, the aluminum foil 6 in the seal layer 2 is inductively heated to melt the Surlyn 4 on the lowermost surface of the seal layer 2 and the inner seal material 1 is attached to the mouth portion of the container.

At this time, since the thin papers 9 and 12 are laminated on both sides of the hot melt adhesive layer 13,
The hot melt adhesive heated at a high frequency is melted and absorbed by each of these thin papers 9 and 12, and the peel strength between the reseal layer 3 and the seal layer 2 in the heating portion becomes almost zero.
Therefore, the reseal layer 3 and the seal layer 2 can be easily peeled off during use. Although the heating by the high frequency is applied only to the peripheral portion of the inner seal material 1, the peeling of the reseal layer 3 is performed from the peripheral portion, so that the peel strength between the reseal layer 3 and the seal layer 2 in the central portion is somewhat large. Can be peeled off smoothly.

In the above-mentioned embodiment, the thin paper is laminated on both sides of the hot melt adhesive layer. However, these are not necessarily limited to the thin paper and may be those capable of absorbing wax. However, other materials may be used.

[0014]

Since the present invention is constructed as described above, the reseal layer and the seal layer are firmly adhered and are not easily peeled off until the inner seal material is sealed to the container mouth.
Further, these can be easily peeled off when the container is opened, and furthermore, when the reseal layer and the seal layer are peeled off, the adhesive does not remain on the surface and a poor appearance does not occur.

[Brief description of drawings]

FIG. 1 is a layer configuration diagram of an inner seal material for sealing a container mouth according to an embodiment of the present invention.

[Explanation of Codes] 1 inner seal material 2 seal layer 3 reseal layer 9, 12 thin paper (absorbent material) 13 hot melt adhesive layer

Claims (1)

[Scope of utility model registration request] 1. An inner seal material having a laminated structure of a reseal layer and a seal layer, which is heat-sealed to a container opening portion by high frequency induction heating, wherein paper or the like is provided on the lowermost surface of the resealing layer and the uppermost surface of the sealing layer. An inner seal material for sealing the mouth of a container, characterized in that the absorbent material is laminated, and the reseal layer and the seal layer are laminated via a hot melt adhesive layer.