Microwave-safe containers

Abstract

To provide a low-cost microwave oven compatible container capable of releasing internal pressure by heating, and to prevent a packaging material from catching fire or being burnt due to excessive exposure to microwaves. [Solution] A conductive heat-generating ink layer 5 that can generate heat by microwaves is provided at the contact point of the lid 1, which is thermally bonded to the flange 3 of the container body 2 by heat sealing, and the flange of the container body.In this microwave-safe container, the sealant layer near the heat-generating ink is heated and melted when microwaves are irradiated in a microwave oven, thereby releasing the internal pressure that increases when food inside the container is heated.A tab 4 for opening is protruded from one side of the lid, and a heat-generating ink layer is provided at the contact point between the tab and the flange facing the tab.

Description

[Technical field]

[0001] The present invention relates to a microwaveable container that is used when distributing food in a microwaveable container. [Background technology]

[0002] Containerized foods are well known in which food is placed in a cup- or tray-shaped container that is microwave-safe and distributed with a lid on and sealed. In this case, consumers who purchase the food heat the food in a microwave oven with the lid on and sealed, but the internal pressure of the container increases due to the evaporation of moisture from the food as it is heated, causing the container to deform or burst, creating a risk of accidents in which food and other items are scattered inside the microwave oven.

[0003] To prevent this accident, it is necessary to attach a valve to the container in advance to release the pressure generated by the heating, but the labor, process, and cost required for attachment make it difficult to put into practical use in packaging containers that are disposable after one use. Therefore, a microwave-safe container has been proposed in which a conductive heating part capable of generating heat by microwaves is provided at the contact point between the lid, which is sealed to the container body by heat sealing, and the container body, thereby heating and melting the sealant layer near the conductive heating part when irradiated with microwaves by a microwave oven, thereby releasing the internal pressure that rises due to the heating of the food inside the container (Patent Documents 1 and 2). [Patent Document 1] Publication No. 6-15881 [Patent Document 2] JP 2007-119064 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] In the above-mentioned conventional technology, since there is no need to attach a valve as a structure for releasing the internal pressure that increases when food is heated, a microwave-safe container can be realized at low cost. However, if the heating time in the microwave oven is incorrect and microwaves are irradiated for a long period of time, the conductive heating part may become too hot, causing the packaging material to catch fire or burn, resulting in an unpleasant odor.

[0005] This invention has been made with the objective of providing a microwave-safe container that solves the above-mentioned problems of the prior art. [Means for solving the problem]

[0006] The present invention has been created with the objective of providing a microwaveable container that solves the above problems.

[0007] In other words, the microwave-safe container of the present invention is characterized in that it has a conductive heat-generating ink layer that can generate heat by microwaves at the contact point between the lid, which is thermally bonded to the flange of the container body by heat sealing, and the sealant layer near the heat-generating ink is heated and melted when microwaves are irradiated in a microwave oven, thereby releasing the internal pressure that increases due to the heating of the food inside the container, and has a protruding tab for opening on one side of the lid, and a heat-generating ink layer consisting of an aggregate of linear pieces with a width of 0.1 to 1.5 mm arranged in succession at intervals at the contact point between the tab and the flange facing the lid.

[0008] The invention described in claim 2 is characterized in that in the microwave-safe container, the lid body is made of at least two layers, a base layer and a sealant layer.

[0009] The invention described in claim 3 is characterized in that, in the microwave-safe container, the sealant layer is an easy-open film.

[0010] The invention described in claim 4 is characterized in that in the microwave-compatible container, the sealant layer, which is an easy-open film, has a seal strength that decreases to 1 / 2 to 1 / 3 of that at room temperature in an atmosphere of 80°C. Effect of the Invention

[0011] According to the present invention, by providing an electrically conductive heat-generating ink layer facing the opening, even if the heat-generating ink layer generates heat and causes the lid and container to soften or become partially embrittled due to heat, it is possible to prevent the lid from breaking during opening.

[0012] By applying a conductive heat-generating ink layer, the sealant film that makes up the lid and the resin container can be partially heated, creating a difference in seal strength between the area where the conductive heat-generating ink layer is applied and other areas (due to the nature of resin, it softens at high temperatures and the seal temperature drops), allowing steam to escape from any location without bursting.

[0013] Conventionally, conductive heat-generating ink layers have been applied in a solid pattern, but because the amount of heat generated depends on two factors, the area of ​​the pattern and the amount of heat-generating ink applied, the size of the heat-generating ink area varies depending on the size of the product, and the increased amount of heat generated can melt the film or container flange.

[0014] In contrast, in the case of the present invention, the conductive heat-generating ink layer is applied continuously as a thin line of about 1 mm, making it possible to easily accommodate flange shapes whose area varies depending on the container shape.

[0015] In addition, the sealant film is highly heat-dependent, and by using 1 / 2 to 1 / 3 of the amount used at 80°C compared to at room temperature, it is easy to create a strong seal between the conductive heat-generating ink layer and its surrounding area, making it possible to supply a stable product as a vapor-transmitting package. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a plan view of the microwaveable container of the present invention. BEST MODE FOR CARRYING OUT THEINVENTION

[0017] A specific embodiment of the present invention will be described below with reference to the accompanying drawings. Figure 1 shows an example of a microwaveable container according to the present invention. Reference numeral 2 in the figure denotes a container body in which food (not shown) is stored. Here, a cup-shaped container body is shown, but the shape is not limited to this, and it can of course be a tray-shaped one. A flange-shaped protruding portion 3 is provided around the opening of the container body 1, and this protruding portion becomes the contact portion with the lid.

[0018] In the figure, reference numeral 1 denotes a lid. The lid has a tab 4 protruding from one side for opening, but since the container body 2 is rectangular in this example, it is located at a corner. The lid is made up of at least two layers, a base layer and a sealant layer, and in this example, the sealant layer is an easy-open film.

[0019] In the figure, the reference numeral 5 denotes the heat-generating ink layer, which is made up of a collection of linear pieces with a width of 0.1 to 1.5 mm arranged in succession at intervals. The heat-generating ink layer 5 is disposed at the contact point with the flange portion 3 that faces the knob portion (diagonally here), but here it extends to an area further toward the center than the contact point with the flange portion. Here, the lines that make up the heat-generating ink layer 5 are arranged vertically so as to face the center of the lid, but they may also be arranged horizontally.

[0020] In addition, the sealant layer, which is an easy-open film, has a seal strength that decreases to 1 / 2 to 1 / 3 of that at room temperature in an 80°C atmosphere, making it easier to create a seal strength between the conductive heat-generating ink layer and its surrounding areas, making it possible to supply a stable product as a vapor-transmitting package.

[0021] In addition, there are sealant films that are not suitable for the present invention, such as films that have low temperature dependency, high heat resistance, and maintain strong sealing strength even at high temperatures. If such films are used, steam cannot escape stably from the area where the conductive heat generating ink layer is provided, and problems occur such as the container packaging swelling and exploding before the steam escapes, or the shape deforming even after the steam is released. [Explanation of symbols]

[0022] 1 Lid 2 Container body 3 Flange 4 Knob 5 Heat-generating ink layer

Claims

1. This microwave-safe container has a conductive heat-generating ink layer that can generate heat when exposed to microwaves at the contact point between the lid, which is thermally attached to the flange of the container body by heat sealing, and a sealant layer near the heat-generating ink is heated and melted when exposed to microwaves in a microwave oven, thereby releasing the internal pressure that increases when food inside the container is heated.The microwave-safe container is characterized in that it has a protruding tab for opening on one side of the lid, and a heat-generating ink layer consisting of a collection of linear shapes with a width of 0.1 to 1.5 mm arranged in succession at intervals at the contact point between the lid and the flange facing the tab.

2. 3. The microwave-safe container according to claim 1, wherein the lid comprises at least two layers: a base layer and a sealant layer.

3. 3. The microwave-safe container of claim 2, wherein the sealant layer is an easy-open film.

4. 4. The microwave-safe container according to claim 3, wherein the sealant layer which is an easy-open film has a seal strength which decreases in an atmosphere at 80° C. to 1 / 2 to 1 / 3 of that at room temperature.

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