Deaeration seal

Abstract

To provide a deaeration seal that prevents the contamination of foreign matter and can easily prevent leakage of liquid contents without using any member other than a seal, in the seal attached to a surface of an air vent provided in a lid of a packaging container for heating in a microwave oven, even if the container is tilted or turned upside down after heating.SOLUTION: A deaeration seal is characterized by comprising: a substrate; an adhesive layer provided on the entire underside of the substrate; a non-adhesive layer provided inside an outer edge of the underside of the adhesive layer; an adhesive permeable layer formed adjacent to the non-adhesive layer; a ventilation portion capable of releasing water vapor provided through the substrate, the adhesive layer and the adhesive permeable layer; and a resin film shrinking due to the heat of water vapor, an outer edge upper side of which is adhered to the underside of the adhesive layer on the underside of the adhesive layer, the non-adhesive layer and the adhesive permeable layer, and the resin film is provided so as to cover the entire underside of the non-adhesive layer and the ventilation portion and not adhered to the entire underside of the non-adhesive layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a deaeration seal, and more particularly to a deaeration seal to be attached to a vent hole provided in the lid of a microwave oven heating container. [Background technology]

[0002] In recent years, the sales volume of so-called microwave-ready products, which can be cooked by simply putting the food in a microwave oven, has been increasing among pre-cooked foods such as boxed lunches sold at convenience stores etc. These microwave-ready products are usually made up of a pre-cooked food, a container body and a lid, and are sold with the pre-cooked food sealed inside the container.

[0003] The above-mentioned prepared foods are generally eaten after being reheated by the purchaser in a microwave at home or at a convenience store, but in the case of products that contain ingredients with a high moisture content, the moisture evaporates inside the container when heated, generating steam. In this case, there is a risk that the generated steam will cause the lid to deform in a sealed container, so lids with U-shaped or V-shaped tongue-shaped ventilation holes are used. In recent years, lids with fine grooves or dots formed by laser processing or the like that open only when heated have also been developed.

[0004] On the one hand, although the exhaust efficiency of the vent hole provided in the lid of the above-mentioned container is good, on the other hand, problems have been pointed out, such as gaps occurring in the tongue-shaped vent hole, through which foreign matter can get in during sales, and liquid contents leaking out from opened slits or holes when the container is tilted or turned upside down after heating.

[0005] To address these problems, the applicant has previously proposed a deaeration seal that is attached to the ventilation hole in the lid of a container and opens only when water vapor is generated to allow water vapor to escape from the container, thereby preventing leakage of water vapor and liquid contents after heating (Patent Document 1).

[0006] This proposed deaeration seal comprises an adhesive layer provided on the entire underside of the substrate, a non-adhesive layer provided inside the outer edge of the underside of the adhesive layer, a ventilation section capable of releasing water vapor provided through the substrate, adhesive layer and non-adhesive layer, and a resin film on the underside of the adhesive layer and non-adhesive layer that shrinks due to the heat of water vapor so as to cover the ventilation section, and as the resin film shrinks due to heating, the ventilation section can be ventilated, and a covering seal is attached after heating. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 7132558 Summary of the Invention [Problem to be solved by the invention]

[0008] Furthermore, with the above-mentioned configuration, the inclusion of foreign matter is prevented by being attached to the surface of the ventilation hole in the lid of a packaging container for microwave heating, and the simplified layer structure facilitates production and reduces costs, and the product is extremely excellent in that it can prevent steam and hot water from leaking from the lid.

[0009] On the other hand, since the ventilation section is covered with a covering seal to prevent steam and hot water from leaking from the lid after heating, there is still room for improvement in that a deaeration seal and a covering seal must be provided as a set, or an attachment process is required.

[0010] The present invention has been made in consideration of the above background, and has as its object to provide a deaeration seal that is affixed to the surface of an air vent in the lid of a packaging container for heating in a microwave oven, which prevents the intrusion of foreign matter and can easily prevent leakage of liquid contents without using any materials other than the seal, even if the container is tilted or turned upside down after heating. [Means for solving the problem]

[0011] According to the present invention, there is provided an evacuation seal as follows. First, the deaeration seal of the present invention comprises a substrate, an adhesive layer provided on the entire lower surface side of the substrate, a non-adhesive layer provided on the inner side of the outer edge of the lower surface of the adhesive layer; an adhesive permeable layer formed adjacent to the non-adhesive layer; a ventilation portion capable of releasing water vapor, the ventilation portion being provided through the base material, the adhesive layer, and the adhesive permeable layer; a resin film that shrinks due to heat of water vapor, the resin film being provided on the lower surfaces of the adhesive layer, the non-adhesive layer, and the adhesive permeable layer such that an outer edge upper surface side of the resin film is adhered to the lower surface side of the adhesive layer, the non-adhesive layer, the adhesive permeable layer, and the ventilation portion are covered, but the resin film is not adhered to the entire lower surface side of the non-adhesive layer, As the resin film shrinks, the upper outer edge side of the resin film peels off from the lower adhesive layer and reaches the area of ​​the non-adhesive layer through the adhesive permeable layer, allowing ventilation through the ventilation section, and the adhesive permeable layer in which the ventilation section is provided retains its adhesiveness. Secondly, in the deaeration seal of the first aspect of the invention, it is preferable that the adhesive permeable layer is formed by perforating a pattern on the outer edge of the non-adhesive layer. Thirdly, in the deaeration seal of the first or second invention, the adhesive permeable layer is preferably formed by pattern coating. Fourthly, in the deaeration seal of the first to third aspects of the invention, it is preferable that a temporary adhesive layer having an adhesive strength weaker than that of the adhesive layer is provided on the lower surface side of the resin film. Fifth, in the deaeration seal of the first to fourth aspects of the invention, it is preferable that a separator is provided on the lower surface side of the adhesive layer and the resin film. Sixthly, in the deaeration seal of the first to fifth aspects of the invention, it is preferable that the ventilation part is formed in any one of a substantially circular shape, a substantially elliptical shape, an arc shape, a cross shape, or a combination of these. Effect of the Invention

[0012] According to the deaeration seal of the present invention, a seal is attached to the surface of an air vent provided in the lid of a packaging container for microwave heating, which prevents the intrusion of foreign matter and also makes it possible to easily prevent leakage of liquid contents without using any materials other than the seal, even if the container is tilted or turned upside down after heating. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a schematic top view of a degassing seal according to an embodiment of the present invention. [Diagram 2] 2 is a schematic cross-sectional view of the degassing seal of the embodiment shown in FIG. 1 along line AA. [Diagram 3] These are schematic cross-sectional diagrams to explain the operating mechanism of the degassing seal. (A) shows the state before heating when attached to a lid, (B) shows the state after heating when water vapor has been released from the ventilation hole in the lid, and (C) shows the state when the resin film has shrunk and water vapor has been released from the surface of the substrate. [Figure 4] 1A and 1B are schematic cross-sectional views to explain the processing procedure for the deaeration seal after heating, in which (A) shows the state in which the deaeration seal is pressed from above after heating, and (B) shows the state in which the adhesive-permeable layer is adhered to the lid. [Diagram 5] FIG. 11 is a schematic top view showing variations in the shape of the base material and the shape of the ventilation portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the evacuable seal according to the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic top view showing the evacuable seal of the embodiment, and Fig. 2 is a schematic AA cross-sectional view of the evacuable seal of the embodiment shown in Fig. 1.

[0015] The deaeration seal of an embodiment of the present invention comprises a substrate 2, an adhesive layer 21 provided on the entire underside of the substrate 2, a non-adhesive layer 22 provided inside the outer edge of the underside of the adhesive layer 21, an adhesive permeable layer 23 formed adjacent to the non-adhesive layer 22, a ventilation section 3 provided through the substrate 2, the adhesive layer 21 and the adhesive permeable layer 23, and a resin film 4 that shrinks due to the heat of water vapor and is provided on the underside of the adhesive layer 21, the non-adhesive layer 22 and the adhesive permeable layer 23 so as to cover the entire underside of the non-adhesive layer 22 and the adhesive permeable layer 23 and the ventilation section 3.

[0016] (base material) The substrate 2 is not particularly limited as long as it has a suitable strength, and may be made of a material such as a resin film or paper used in a normal adhesive tape. Examples of the resin film substrate include resin film substrates made of polyethylene terephthalate (PET), polypropylene (PP), and other synthetic resin film substrates. Examples of the paper substrate include various types of paper such as coated paper, fine paper, and recycled paper, or paper substrates made of laminates thereof. Among these, a polyethylene terephthalate (PET) resin film substrate is preferably used from the viewpoint of strength, handling, and the like. The thickness of the substrate 2 may be appropriately determined within a range in which it is not easily deformed or shrunk by heating.

[0017] (adhesive layer) In the degassing seal 1 of this embodiment, an adhesive layer 21 is provided on the entire lower surface side of the base material 2. The adhesive constituting the adhesive layer 21 is not particularly limited as long as it can strongly adhere to the surface of the lid and is used for ordinary seals. Specifically, an adhesive that has the property of softening when heated is preferable, and examples of such adhesives include acrylic adhesives, rubber adhesives, and hot melt adhesives. Of these, acrylic adhesives are particularly preferable.

[0018] It is preferable to set the adhesive strength of the adhesive layer to be different in parts. For example, in the embodiment of Fig. 1, it is considered to set the adhesive layer 21B part stronger than the adhesive layer 21A part which is the adhesive part with the outer edge part of the resin film 4. This makes it possible to control the state of separation from the adhesive layer 21 when the resin film 4 shrinks due to heat. Specifically, the resin film 4 is peeled off and separated from the adhesive layer 21A which has a weak adhesive strength, shrinks, and is held on the adhesive layer 21B side which has a strong adhesive strength.

[0019] (Non-adhesive layer) Furthermore, in the deaeration seal 1 of this embodiment, a non-adhesive layer 22 is provided on the lower surface side of the adhesive layer 21, in an area inside the outer edge of the adhesive layer 21. The non-adhesive layer 22 is a layer provided as a so-called glue-blocking layer to prevent the adhesive layer 21 from adhering to a resin film 4 described below.

[0020] The material constituting the non-adhesive layer 22 is not particularly limited as long as it satisfies the above conditions, and examples of the material include ink, resin, film, etc. Among these, resin is preferable, and in particular, a UV-curable resin can be suitably used.

[0021] (Adhesive permeable layer) In the degassing seal 1 of this embodiment, an adhesive permeable layer 23 is formed on the lower surface side of the adhesive layer 21, in a region inside the outer edge of the adhesive layer 21, and adjacent to the non-adhesive layer 22, through which the adhesive of the adhesive layer permeates and has an adhesive strength weaker than that of the adhesive layer. The material of the adhesive permeable layer 23 may be the same as that of the non-adhesive layer 22, and the adhesive permeable layer 23 is formed in a form of fine holes penetrating the upper and lower surfaces, or in a mesh shape, and a part of the adhesive forming the adhesive layer 21 penetrates and permeates, and a part of the adhesiveness is exposed on the lower surface side, thereby providing an appropriate adhesiveness. The adhesive strength of the lower surface side can be appropriately adjusted by the size and number of the penetrating fine holes, the shape of the mesh, the coarseness of the mesh, etc. In addition, this appropriate adhesiveness means an adhesiveness to the extent that it does not inhibit the shrinkage of the resin film 4 interposed on the lower surface side. In addition, it is preferable to form the penetrating fine holes or mesh shape by pattern coating.

[0022] (Ventilation section) In the portion where the base material 2, the adhesive layer 21, and the adhesive permeable layer 23 are laminated, a ventilation part 3 is provided that penetrates the upper surface of the base material 2 and the lower surface of the adhesive permeable layer 23. The shape and size of the ventilation part 3 can be appropriately set according to the shape and size of the ventilation hole 71 provided in the lid 7 of the container to be applied, and can be various shapes such as a cut, a slit, a through hole, a mesh, etc. Among these, in consideration of ease of molding, a cut is preferable, and in particular, a cut having a shape including an arc as shown in FIG. 1, a substantially circular shape as shown in FIG. 5(A), a substantially elliptical shape as shown in FIG. 5(B), a circular arc shape as shown in FIG. 5(C), a cross shape as shown in FIG. 5(D), or a combination of these shapes can be used.

[0023] (Resin film) Furthermore, a resin film 4 that shrinks due to the heat of water vapor is provided on the lower surfaces of the adhesive layer 21 and the non-adhesive layer 22. The resin film 4 is adhered to the adhesive layer 21 at the upper surface side of the outer edge, and is provided so as to cover the non-adhesive layer 22, the adhesive permeable layer 23, and the ventilation portion 3 in a state where it is not firmly adhered to the lower surface side of the adhesive permeable layer 23 and in a state where it is not adhered to the lower surface side of the non-adhesive layer 22.

[0024] The resin film 4 is generally called a shrink film, and is not limited as long as it has the property of shrinking due to heat, and examples thereof include heat-shrinkable resin films such as polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC). The resin film 4 used in the present invention is preferably one that shrinks uniformly over the entire surface, as well as one that has different shrinkage rates in the longitudinal and transverse directions. By using a resin film 4 with different shrinkage rates in the longitudinal and transverse directions, the adhesive portion with the adhesive layer 21 remains partially after shrinkage, making it possible to prevent the resin film 4 from falling off.

[0025] The shrinkage rate of the resin film 4 is not particularly limited as long as it is basically greater than that of the base material 2. For example, a shrinkage rate of about 20 to 60%, preferably about 30 to 50%, when heated from room temperature to 100°C is considered.

[0026] Regarding the manufacture of the deaeration seal 1 of the above embodiment, it can be manufactured in a very simple manner and at low cost by only forming the adhesive layer 21, the adhesive permeable layer 23 and the non-adhesive layer 22 in a specified area on the underside of the base material 2 to form the ventilation section 3, and then attaching the resin film 4 to a specified position on the underside of the formed ventilation section 3.

[0027] 1 and 2, in the deaeration seal 1 of this embodiment, a temporary adhesive layer 41 having an adhesive strength weaker than that of the adhesive layer 21 can be provided on the lower surface side of the resin film 4. By providing the temporary adhesive layer 41 on the lower surface side of the resin film 4, it can be stably attached to the lids 7 of containers of various shapes.

[0028] Furthermore, the deaeration seal 1 of this embodiment may be provided in a state where it is already attached to the surface of the ventilation hole 71 provided in the lid 7 of the container, but it may also be provided in the form of a seal so that the purchaser can attach it just before heating. In this case, it is preferable to provide a separator 5 (release paper) on the lower surface side of the adhesive layer 21. By providing the separator 5, when using the deaeration seal 1, it can be peeled off from the separator 5 and attached for use.

[0029] The mechanism of operation of the deaeration seal 1 of this embodiment when in use (when heated) will be described below with reference to Figs. 3(A)-(C), and the processing procedure after heating will be described with reference to Figs. 4(A) and (B). First, as shown in Fig. 3(A), the deaeration seal 1 is attached so as to cover the ventilation hole 71 provided on the surface of the lid 7 of a container for a microwaveable product or the like. At this time, the ventilation hole 71 is attached so as to be located on the underside of the resin film 4. Here, the ventilation hole 71 provided in the lid 7 may be in the form of a tongue-shaped ventilation hole with a slit formed therein, or a groove-shaped or dot-shaped ventilation hole formed by a laser or the like that opens only when heated.

[0030] When the container is heated in a microwave oven in this state, the moisture in the food inside the container evaporates, and as shown in FIG. 3(B), water vapor 6 passes through vent 71 and is released to the upper side of lid 7 and hits the lower side of resin film 4 of deaeration seal 1. This heats resin film 4 and causes it to start shrinking. At this time, adhesive layer 21 fixing the outer edge of resin film 4 is also heated and softened by water vapor 6, so that the outer edge of resin film 4 is detached from adhesive layer 21 due to the shrinkage force. Note that by setting adhesive layer 21B to be stronger than adhesive layer 21A, which is the adhesive portion between the outer edge of resin film 4 and the adhesive layer, resin film 4 is detached from adhesive layer 21A and held by adhesive layer 21B.

[0031] When the shrinkage of the resin film 4 progresses further due to the heat of the water vapor 6, the resin film 4 passes through the adhesive permeable layer 23 and reaches the region of the non-adhesive layer 22, exposing the ventilation portion 3 and allowing ventilation, as shown in Fig. 3(C). The water vapor 6 is then released to the upper surface of the base material 2 through the ventilation portion 3 provided penetrating the base material 2, the adhesive layer 21, and the adhesive permeable layer 23. As a result, the water vapor 6 is released to the outside of the lid 7 for the first time due to heating, from the initial sealed state caused by the attachment of the deaeration seal 1.

[0032] In addition, when heating is completed, for example, if the container is tilted or turned upside down after cooking, there is a risk that the liquid contents will leak from the ventilation part and soil the surroundings, or that the user may be burned by the leaked liquid, etc. Taking such situations into consideration, the deaeration seal 1 of the present invention makes it possible to easily prevent leakage of liquid, etc. without using any member other than the deaeration seal 1. The procedure for preventing leakage is described below.

[0033] First, after heating, when the release of water vapor from the vent has finished, the deaeration seal 1, particularly the vent, is pressed from above in the direction of the arrow as shown in Fig. 4(A). Then, as shown in Fig. 4(B), the adhesive permeable layer 23 with appropriate adhesiveness provided at the bottom of the vent comes into contact with and adheres to the top surface of the lid. This closes the vent 3, making it possible to prevent liquid from leaking out.

[0034] The above describes the evacuation seal of the present invention based on an embodiment, but the evacuation seal of the present invention is not limited to the above embodiment, and various modifications are possible within the scope that does not deviate from the gist of the invention.

[0035] For example, in the embodiment and evacuation seal 1 shown in Figures 1 to 4 above, the shape of the substrate 2 is square when viewed from above, but the shape is not limited to this and can also be, for example, a circle as shown in Figures 5(A), (C), and (D) or an ellipse as shown in Figure 5(B).

[0036] The base material 2 and the resin film 4 may be transparent, but may also be colored transparent or opaque. The surface of the base material 2 may have characters or patterns printed thereon.

[0037] The evacuation seal 1 of the present invention having the above-mentioned configuration not only prevents the inclusion of foreign matter, but also makes it possible to easily prevent leakage of liquid contents without using any components other than the evacuation seal 1, even if the container is tilted or turned upside down after heating. [Explanation of symbols]

[0038] 1 Vacuum seal 2 Base material 21 Adhesive layer 22 Non-adhesive layer 23 Adhesive permeable layer 3 Ventilation section 4. Resin film 41 Temporary adhesive layer 5. Separator 6. Water Vapor 7 Lid 71 Ventilation hole

Claims

1. A substrate, and an adhesive layer provided on the entire lower surface side of the substrate; a non-adhesive layer provided on the inner side of the outer edge of the lower surface of the adhesive layer; an adhesive permeable layer formed adjacent to the non-adhesive layer, through which the adhesive of the adhesive layer permeates and which has an adhesive strength weaker than the adhesive strength of the adhesive layer; a ventilation portion capable of releasing water vapor, the ventilation portion being provided through the base material, the adhesive layer, and the adhesive permeable layer; a resin film that shrinks due to heat of water vapor, the resin film being provided on the lower surfaces of the adhesive layer, the non-adhesive layer, and the adhesive permeable layer such that an outer edge upper surface side of the resin film is adhered to the lower surface side of the adhesive layer, the non-adhesive layer, the adhesive permeable layer, and the ventilation portion are covered, but the resin film is not adhered to the entire lower surface side of the non-adhesive layer, A deaeration seal characterized in that, as the resin film shrinks, the upper outer edge side of the resin film peels off from the lower adhesive layer side, passes through the adhesive permeable layer and reaches the area of ​​the non-adhesive layer, allowing ventilation through the ventilation section, and the adhesive permeable layer in which the ventilation section is provided retains its adhesiveness.

2. 2. The evacuable seal according to claim 1, wherein the adhesive permeable layer is formed by perforating a pattern on the outer edge of the non-adhesive layer.

3. 2. The degassing seal according to claim 1, wherein the adhesive permeable layer is formed by pattern coating.

4. 2. The deaeration seal according to claim 1, wherein a temporary adhesive layer having an adhesive strength weaker than that of the adhesive layer is provided on the lower surface side of the resin film.

5. 2. The deaeration seal according to claim 1, further comprising a separator provided on the lower surface side of the adhesive layer and the resin film.

6. 2. The deaeration seal according to claim 1, wherein the ventilation portion is formed in any one of a substantially circular shape, a substantially elliptical shape, an arc shape, a cross shape, or a combination thereof.

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