JPH0194806A - Sealed container for cooking in electronic oven - Google Patents

Abstract

PURPOSE: To rapidly heat the lid of a container to a high temperature and to open the lid of the container by condensing microwave energy by the antenna of a large dimension and converting it into heat at a narrow part. CONSTITUTION: The antenna 4 composed of a conductor is laminated on the lid main body 1 of this container sealed by the lid main body 1 composed of an insulated flexible sheet, and when the container is exposed to microwaves in a microwave oven, the microwave energy is condensing near the opposing tip part of the antenna 4. The energy is converted into the heat and the lid main body 1 is opened by the heat. In such a manner, the lid of the insulated flexible sheet of the sealing container is rapidly heated in a short time by microwave oven heating and a hole for discharging generated steam is automatically opened on the lid of the container.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sealed container for storing food, and in particular, a container for releasing steam generated when cooking food in a microwave oven while the food is stored in the sealed container. The present invention relates to a microwave oven-operated sealed container in which a hole is automatically opened in the lid of the container.

[Conventional technology]

When cooking food in a sealed container made of plastic, paper, etc. in a microwave oven, it is convenient to be able to heat the food while it is packaged in the sealed container. When food in a sealed container is heated in a microwave oven, the pressure inside the container increases due to the generation of water vapor, causing the container to burst. At this time, the food inside the container may scatter to the outside. Furthermore, if the food is heated without the lid of the sealed container removed, a large amount of moisture will escape from the food, resulting in deterioration of the quality of the food. In order to solve the above-mentioned problem, a means has been proposed for automatically opening the lid of a sealed container when the food is heated in a microwave oven. Japanese Patent Publication No. 61-6957
According to the technique proposed in No. 6, an adhesive layer made of non-metallic microwave-absorbing particles is provided on the lid of the container. According to the technique disclosed in U.S. Pat. No. 4,210,674, a conductive material is provided in the lid of the container, and the size and shape of the conductive material are adapted to absorb microwaves. A method has been proposed in which the lid is heated and melted using a microwave absorbing material provided on the lid to open the lid.

[Problem that the invention seeks to solve]

In microwave ovens and microwave cooking cabinets, standing waves occur inside the cabinet, and the microwave intensity within the cabinet is not uniform but has a distribution. In the prior art method using only a pyrogen that absorbs microwaves and generates heat, if the pyrogen is placed in an area where the microwave intensity is weak, the heat generating material may be insufficient and the lid may not be opened. In addition, since it creates openings even in areas where microwaves are weak, if a large exothermic substance is placed in an area where microwave intensity is strong, large holes will be created, causing a large amount of moisture to escape from the food, resulting in deterioration of the quality of the food.

The present invention has been made to solve the problems of the prior art described above, and the lid of the insulating flexible seam 1- of the sealed container is rapidly heated in a short period of time by heating in a microwave oven, thereby ensuring that the lid is properly sized. An object of the present invention is to provide a sealed container for microwave cooking that can be melted and opened.

The insulating flexible sheet herein refers to a single sheet such as a thermoplastic plastic sheet, a thermosetting plastic sheet, or a paper material, or a sheet consisting of two or more thereof.

Thermoplastic plastics include linear polyesters such as polyethylene terephthalate, polyolefin resins such as polyethylene, polypropylene, ethylene-propylene copolymers, ionomers, acrylic resins, polystyrene resins, As resins, ABS resins, polyamide resins,
From polyimide lll'f, polyimine IjAlff, polyvinyl chloride resin, polyvinylidene chloride resin, vinyl chloride-vinyl acetate copolymer, vinylidene copolymer, acetal resin, diallyl phthalate resin, fluorine resin, and multiple combinations thereof Examples include resins such as

Examples of thermosetting plastics include urea resins, phenol resins, epoxy resins, melamine resins, urethane resins, xylene-formaldehyde resins, and resins consisting of a plurality of combinations thereof.

[Means for solving problems]

An antenna made of a conductive material is laminated on the lid body of a container that is sealed by a lid body made of an insulating flexible sheet.
When the container is exposed to microwaves in a microwave oven, microwave energy is collected near the opposing tips of the antenna, the energy is converted into heat, and the heat opens the lid body.

If a heating element is placed in the area where the microwave energy is collected, the heating effect will be further enhanced.

When a heating element is placed, even if the antenna is not placed in opposition, by placing the heating element at the corner of the antenna, the heating element converts microwave energy into heat, which allows the lid body to be opened. .

The heating element herein is not limited to a high-resistance element, but may also be a substance that generates heat by absorbing microwaves, that is, a substance that generates heat not only due to resistance loss but also due to magnetic loss, dielectric loss, or discharge. - Substances that generate heat due to magnetic loss include ferrite represented by MoFe2O3 (where M is a divalent metal ion), and ferromagnetic alloys made of iron, cobalt, nickel, and combinations of multiple thereof. Examples of heating elements due to dielectric loss include polymer compounds such as epoxy resin, neoprene, Bakelite, and nylon, and substances with large dielectric loss such as barium titanate.

Examples of heating elements generated by discharge include vacuum-deposited films made of metal materials such as aluminum, iron, and nickel, vacuum-deposited films made of semiconductor materials such as silicon, and fibrous substances made of these materials.

[Effect]

An alternating current flows in the microwave through the antenna, which is a good conductor, and a high frequency high electric field and high magnetic field are generated at the locations where the antennas face each other and at the corners of the antenna. If a resistor, which is a heating element, is placed at a position where this high electric field and high magnetic field are generated, heat will be generated by the Joule heat of the current flowing through the heating element, and a dielectric material, which is a heating element, will be placed at a position where the high electric field is generated. In this case, heat is generated due to dielectric heating of the electric training body. Furthermore, if a magnetic body serving as a heat generating body is placed at a position where a high magnetic field is generated, heat is generated due to the hysteresis phenomenon of magnetization. Since virtually no heat is generated in the antenna, there is little heat dissipation even if the size is increased, and the large amount of energy collected by the large antenna is converted into heat by the small heating element, which quickly raises the temperature of the lid body. It can be heated to.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are diagrams showing a first embodiment of the present invention. In the figure, 1 is a lid main body made of a thermoplastic plastic sheet, which is heat-sealed to the 7 flange portion of a plastic container 2 containing preserved food. A C-shaped anti-f4 made of a conductive material and a heating element 5 made of a high resistance material are laminated on the lid body 1. The heating element 5 is positioned above the heat-sealed portion of the lid body, and the antenna 4 is positioned across the heating element 5. The antenna is formed by coating with conductive paint containing conductive powder, vacuum evaporation, sputtering, thermal spraying of conductive materials, chemical plating, adhesion of metal foil, etc., and the heating element is made of high-resistance particles. Binder painting and II
It can be formed by gluing plastic sheets together. These may be laminated directly to the lid body, or they may be laminated to a plastic sheet to form a label and the label adhered to the lid body.

If the heating element is formed by coating a binder containing high-resistance particles, when the heating element is heated above a certain temperature, the binder will melt and the heat-generating action will stop, causing abnormal heating of the lid body and thermal decomposition. This can be prevented. A foamable substance 6 is attached to the flange portion of the container 2 at a position facing the heating element 5.

When the package constructed in this way is exposed to microwaves in a microwave oven, the current flowing through the antenna 4 generates a high electric field in the heating element 5, and the current flows inside the heating element 5, causing the heating element 5 to generate heat. The seal portion heated by the heating element 5 melts and opens. After cooking in the microwave, the container and main body can be easily separated by pulling the opened seal. If a foaming material is attached to the opening seal portion as in this embodiment, the lid can be separated more easily.

FIG. 3 is a plan view of a lid used in a sealed container according to a second embodiment of the present invention. In the figure, reference numeral 4 denotes an antenna made of a conductive material, which is provided as a GT layer on the lid body 1 as in the first embodiment. This lid body 1 is heat-sealed to a container in the same manner as in the first embodiment. In this embodiment, a high electric field is generated between the opposing tips of the C-shaped antenna 4 through which a current flows due to microwaves, and the portion 1' of the lid body near the antenna tip is dielectrically heated and melted and opened.

FIG. 4 is a plan view of a lid used in a sealed container according to a third embodiment of the present invention. In the figure, reference numeral 4.4 denotes an antenna made of a conductor, which is laminated on the lid body 1 in the same manner as in the first embodiment. A heating element 5 is connected to both antennas 4.4 and laminated on the lid body.This heating element may be made of the same material as the antenna or a different material, but the resistance value per unit length is the same as that of the antenna. It needs to be large compared to If the antenna and the heating element are made of the same material, the heating element must be smaller in width or thickness than the antenna.

In this embodiment, the heating element is connected to the antenna, but the heating element may be in close proximity to the antenna without being connected. Use a lid like this first
If used in the same manner as in the embodiment described above, a high electric field will be generated between the antennas 4 and 4, and current will flow through the heating element 5, generating heat.

FIG. 5 is a plan view of a lid used in a sealed container according to a fourth embodiment of the present invention. In the figure, reference numeral 4 denotes an antenna made of a conductor, which is laminated on the lid body 1 as in the first embodiment. A heating element connected to the corner of the antenna 4 and made of a material having a higher resistance than the antenna is laminated on the lid 5. In this embodiment, the heating element is connected to the antenna, but the heating element may be in close proximity to the antenna without being connected. When such a lid is used in the same manner as in the first embodiment, a high electric field generated by the antenna 4 is applied to the heating element 5, and the heating element 5 generates heat to melt and open the lid body 4.

FIG. 6 is a plan view of a lid used in a sealed container according to a fifth embodiment of the present invention. In the figure, reference numeral 4.4 denotes an antenna made of a conductive material, which is arranged in 8!1 layers on the lid main body 1 with their tips close to each other in the same way as in the first embodiment. If such a lid is used in the same manner as in the first embodiment, the portion 1' of the lid body adjacent to the antenna 4.4 will be dielectrically heated by the high electric field generated between the antennas 4.4 and will melt and open.

FIG. 7 is a plan view of a lid used in a sealed container according to a sixth embodiment of the present invention. In the figure, 4° 4 is an antenna made of a conductive material, and a heating element 5 made of ferrite BSF-547 manufactured by Toda Kogyo and epoxy resin is placed close to the long side of the antenna in the same manner as in the first embodiment. Lid body 1
Laminated on. If such a lid is used in the same manner as in the first embodiment, the ferrite will generate heat and open linearly.

FIG. 8 is a plan view of a lid used for a sealed container according to a seventh embodiment of the present invention. In the figure, 4゜4 is an antenna made of a conductor, and the tips of each other are! The v4 layer is placed on the lid-main body 1 in the same manner as in the first embodiment, with a heating element 5 made of a metal aluminum vapor-deposited film in between. If such a lid is used in the same manner as in the first embodiment, the deposited film will generate heat due to discharge due to the high electric field generated between the antennas 4 and 41, and the lid will open.

FIG. 9 is a plan view of a lid used in a sealed container according to an eighth embodiment of the present invention. In the figure, 4 is a C-shaped antenna made of a conductor, and 5 is a heating element made of barium titanate and epoxy resin, which is laminated on the lid body 1 in the same way as in the first embodiment in a state close to the antenna. . If such a lid is used in the same manner as in the first embodiment, the barium titanate-epoxy resin will be dielectrically heated by the high electric field generated between the antennas 4, and the lid will open.

〔Effect of the invention〕

As mentioned above, since microwave energy is collected by a large antenna and converted into heat in a narrow area, the lid of the container can be rapidly heated to a high temperature, and the lid of the container can be reliably sealed when cooking in the microwave. The lid can be opened. Furthermore, when the opening/part is provided in the sealing part, the lid and the container can be easily separated.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a sealed container that is a first embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a sealed container that is a second embodiment of the present invention. FIG. 4 is a plan view of a lid used in a sealed container according to a third embodiment of the present invention, and FIG. 5 is a plan view of a lid used in a sealed container according to a fourth embodiment of the present invention. FIG. 6 is a plan view of a lid used in a sealed container according to a fifth embodiment of the present invention. FIG. 7 is a plan view of a lid used in a sealed container according to a sixth embodiment of the present invention, and FIG.
A plan view of a lid used for a sealed container which is an example of
The figure is a plan view of a lid used in a sealed container according to an eighth embodiment of the present invention. 1... Lid body, 2... Container, 3... Preserved food, 4
・・・Antenna, 5...Heating element, 6...Effervescent substance Applicant's agent Hiroshi Fujimoto Mitsugei 1st 2nd Figure Musume 3 Figure 4 Figure 5th item $6 Figure

Claims (1)

[Claims] 1. A container sealed with a lid body made of an insulating flexible sheet, wherein a C-shaped antenna made of a conductive material is laminated on the lid body, and the container is heated in a microwave oven. A sealed container for microwave oven cooking, in which when exposed to microwaves inside the container, microwave energy is collected near the opposing tips of the antenna by the antenna, the energy is converted into heat, and the lid body is opened by the heat. . 2. A heating element that heats with microwaves is stacked close to or connected to the antenna between opposing tip portions of the antenna, and the heating element converts the microwave energy collected by the antenna into heat. A sealed container for microwave cooking according to scope 1. 3. The sealed container for microwave cooking according to claim 1, wherein the position where the lid main body melts and opens is a sealing portion with the container. 4. A container sealed with a lid body made of an insulating flexible sheet, the lid body having a plurality of antennas made of a conductive material stacked thereon, and the container being exposed to microwaves in a microwave oven. A sealed container for cooking in a microwave oven, in which microwave energy is collected by the antenna near the opposing tips of the antenna, the energy is converted to heat, and the lid body is opened by the heat. 5. A heating element that heats with microwaves is stacked close to or connected to the antenna between opposing tip portions of the antenna, and the heating element converts the microwave energy collected by the antenna into heat. A sealed container for microwave cooking according to scope 4. 6. The microwave cooking container according to claim 4, wherein the melt opening position of the lid body is a sealing portion with the container. 7. A container that is sealed with a lid body made of an insulating flexible sheet, and an antenna made of a conductor is laminated on the lid body, and a heating element is close to or connected to a corner of the antenna. A microwave oven in which the antenna collects microwave energy when the container is exposed to microwaves in a microwave oven, the energy is converted into heat by the heating element, and the lid body is opened by the heat. Sealed container for cooking. 8. The sealed container for microwave cooking according to claim 7, wherein the melting opening position of the lid body is a sealing portion with the container.