JP4968442B2 - Sealed container for microwave oven heating - Google Patents

Description

  The present invention increases when the contents are heated and cooked using a microwave oven in a state where the contents such as food are stored in a sealed container, due to water vapor caused by the moisture in the contents or expansion of air in the container. The present invention relates to a sealed container for heating a microwave oven in which an opening for automatically releasing the internal pressure is automatically formed so that the internal pressure is smoothly released to the outside and the contents are not blown out or the sealed container is not deformed or ruptured.

  There are commercially available sealed containers for heating a microwave oven that can be cooked in a microwave oven while containing contents such as food. When these microwave-heated sealed containers are cooked using a microwave oven, the internal pressure in the container increases, and the container is deformed or ruptured, so various measures have been made to prevent this. Yes. For example, 1) A hermetic packaging container is disclosed in which a cut piece or a small hole is provided in paper or a synthetic resin, and a cover piece coated with a hot melt adhesive on the back is attached to the opening of the package (for example, Patent Document 1). If the container disclosed in Patent Document 1 is used, the hot-melt adhesive is softened by heating, and the internal pressure of the container can open a cut or small hole in the lid piece to reduce the internal pressure, thereby preventing the container from bursting. It can be done. However, when a low melting point hot melt is used, the hot melt melted during cooking may come into contact with the contents, which is not preferable for safety and health.

  Further, for example, 2) a container is disclosed in which a thin part having a thinner thickness than other parts is provided in a part of the lid of the container, or a small hole closed with a thin film is provided in a part of the lid (for example, Patent Document 2). In the container disclosed in Patent Document 2, the thin part is destroyed by the internal pressure that is increased by cooking, and the internal pressure of the container is decreased. May be damaged, and is not preferable for safety and hygiene as in Patent Document 1.

As a solution to the above problem, the container is sealed by heat sealing, and a heat-bonding part of a specific shape protruding in the inner direction of the container is provided on the heat-seal band, resulting from the moisture of food produced by heating There is disclosed a sealed cooking container for heating and cooking that can automatically open the protruding heat-bonded portion due to an increase in internal pressure due to, for example, expansion of water vapor or air in the container, and prevent the container from bursting or deforming (for example, And Patent Document 3). The container disclosed in Patent Document 3 can release the increased internal pressure from the projecting heat-bonded portion that is opened by cooking with a microwave oven, and can prevent the contents from being blown out or the container bursting or deforming. However, when the internal pressure suddenly rises, such as when the contents suddenly boil or when cooked in a commercial microwave oven, etc. There was a case that the contents were blown out by the momentum when doing.
Japanese Utility Model Publication No.59-31590 Japanese Utility Model Publication No. 51-37402 Japanese Patent Publication No. 08-25583

  Accordingly, the present invention is a sealed container for heating a microwave oven containing contents such as food, and by cooking with a microwave oven, a predetermined position is gently opened by an increased internal pressure to release the internal pressure and the contents It is to provide a sealed container for heating a microwave oven without blowout, rupture of the container, or deformation.

In order to achieve the above-mentioned object, the inventor of the present invention described in claim 1 includes a bottomed container body having a flange portion at an opening, and a knob for the opening of the bottomed container body. a microwave heating a sealed container sealed with strip heat seal portion provided along the flange portion by the cover having only one place, the opposite side to the arrangement to be the position of the knob portion of the strip heat-bonding portion forming a protruding heat-bonding portion which is protruded inwardly of the container only one place, and characterized in that projecting heat output bonding portion at least covers the size of the electric heating layer is formed on the lid To do.

Moreover, the present invention according to claim 2 is the sealed container for heating a microwave oven according to claim 1, wherein the lid body is formed of a laminate including at least a base material layer and a thermoadhesive resin layer, The conductive heat generating layer is provided on the surface of the heat-adhesive resin layer side of the layer by a printing method using printing ink, and the surface resistivity of the conductive heat generating layer is 10Ω / □ or more and 10 ⁷ Ω / □ or less. it is characterized in that.

  The sealed container for heating a microwave oven according to the present invention has a band-like heat formed on the flange portion of the bottomed container body by heating the conductive heating layer provided on the lid when microwave cooking is performed. The heat-bonded part where the lid is heat-bonded at the protruding heat-bonded part of the bonded part is heated and melted, and the heat-bonded part heated and melted by the internal pressure increased by heating the contents can be opened and the internal pressure can be released gently An excellent effect is exhibited, and thereby an excellent effect is achieved that the contents can be blown out and the container can be prevented from being ruptured or deformed.

The present invention will be described in detail below with reference to the drawings.
FIG. 1 shows an embodiment of a sealed container for heating a microwave oven according to the present invention, (a) is a front view, (b) is a longitudinal sectional view of (a), and FIG. 2 is a sealed microwave oven according to the present invention. It is a figure explaining the relationship between the strip | belt-shaped heat bonding part provided in the flange part of the bottomed container main body of a container, and the electroconductive heat generating layer provided in the cover body, 1 in the figure is a sealed container for microwave oven heating, 3 Is a belt-like heat bonding portion, 30 is a protruding heat bonding portion, 10 is a bottomed container body, 11 is a flange portion, 20 is a lid, 21 is a knob portion, and A is a conductive heating layer.

  1A and 1B show an embodiment of a sealed container for heating a microwave oven according to the present invention. FIG. 1A is a front view, FIG. 1B is a longitudinal sectional view of FIG. A lid provided with a bottomed container main body 10 having a flange portion 11 in a circular opening for storing contents such as, and a knob portion 21 for covering the circular opening of the bottomed container main body 10 The lid body 20 is composed of a body 20 and is heat-sealed and sealed by a belt-like thermal bonding portion 3 (see FIG. 2) provided on the flange portion 11 of the bottomed container body 10.

  The bottomed container body 10 and the lid body 20 are not particularly limited as long as they transmit microwaves and can withstand heating using a microwave oven. Examples of the bottomed container body 10 include polyethylene, Polypropylene, polyolefin such as ethylene-propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, polyester such as polycarbonate, single-layer or multi-layer molded products made of synthetic resin such as polyamide, or coated paper or the above synthetic resin Examples include paper. If necessary, a polyvinylidene chloride, an ethylene-vinyl alcohol copolymer, or a vapor deposition layer of an inorganic substance such as silicon oxide or aluminum oxide may be used in the layer structure.

  The lid 20 is composed of a laminate including at least a base material layer and a heat-adhesive resin layer, and the base material layer includes polypropylene, polyethylene terephthalate, polyamide, and the like. A biaxially oriented film is preferred. Further, the heat-adhesive resin layer is not particularly limited as long as it is a resin that adheres to the resin constituting the inner surface of the bottomed container body 10 by heat pressure, and constitutes the inner surface of the bottomed container body 10. Depending on the resin to be used, it may be appropriately selected and used. In particular, when the bottomed container body 10 is made of polypropylene or an ethylene-propylene copolymer, as the heat-adhesive resin layer constituting the lid body 20, for example, manufactured by Tosero Co., Ltd .: TAF-650C, Use of a sealant film having easy peel properties such as CMPS022C, or Toray Film Processing Co., Ltd .: 7601A, or J Film Co., Ltd .: VMX XB15FT is preferable because easy peelability can be obtained. .

  Moreover, you may provide an intermediate | middle layer between a base material layer and a thermoadhesive resin layer as needed. The intermediate layer is usually provided when the base layer and the heat-adhesive resin layer alone cannot sufficiently function as a lid. The functions include gas barrier properties, mechanical toughness, flex resistance, puncture resistance, impact resistance, wear resistance, cold resistance, heat resistance, chemical resistance, etc., which are required as a lid. These final functions are achieved by providing an intermediate layer. Examples of the substrate used as the intermediate layer include polyolefins such as polyethylene terephthalate, polyamide, polyethylene, and polypropylene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, ethylene-propylene copolymer, saponified ethylene-vinyl acetate copolymer, and the like. Films, films coated with polyvinylidene chloride on these films, films provided with an inorganic vapor deposition layer such as silicon oxide and aluminum oxide, films such as polyvinylidene chloride, paper, cellophane, synthetic paper, non-woven fabric, etc. are used. be able to. One or more of these substrates can be used in combination. In addition, the lamination | stacking method used as the said laminated body should just employ | adopt well-known lamination | stacking methods, such as the dry lamination method performed using an adhesive agent, and the sandwich lamination method performed using a T-die extruder suitably.

  FIG. 2 is a diagram for explaining the relationship between the band-shaped heat bonding portion provided on the flange portion of the bottomed container body of the sealed container for microwave heating according to the present invention and the conductive heating layer provided on the lid, The microwave heating sealed container 1 has the flange portion 11 of the bottomed container body 10 (see FIG. 1) having a flange portion 11 (a portion surrounded by a concentric circle made of a broken line in FIG. 2) in a circular opening. The lid 20 is heat-sealed and sealed, and the lid 20 is formed so as to protrude inward of the circular opening at the flange portion 11 of the bottomed container body 10 (see FIG. 1). It is sealed by a band-shaped heat bonding portion 3 having a protruding heat bonding portion 30. The protruding thermal bonding portion 30 provided on the belt-shaped thermal bonding portion 3 is provided at a position substantially opposite to the knob portion 21 provided on the lid body 20 and covers the protruding thermal bonding portion 30. The conductive heat generating layer A is provided in a rectangular shape. The conductive heat generating layer A is provided between the base material layer and the thermoadhesive resin layer constituting the lid body 20 or on the surface of the base material layer. Is generally printed with a product name, etc., and must be provided in register with the print of the product name, etc. The surface on which the conductive heat generating layer A is formed is a layer structure of the lid 20 Etc. are to be determined.

  Further, in FIG. 2, the protruding thermal bonding portion 30 provided in the band-shaped thermal bonding portion 3 has a hook shape protruding inward of the circular opening, but is not limited thereto, and the circular opening is not limited thereto. Any shape that protrudes inward of the appropriate circular opening, such as V-shape, U-shape, trapezoidal shape, arc shape, etc., is acceptable. is there. In FIG. 2, the conductive heat generating layer A is formed so as to completely cover the protruding heat bonding portion 30 provided on the belt-shaped heat bonding portion 3. The size of the conductive heating layer A is not limited to a rectangular shape as long as it covers the tip of the bonding portion 30. For example, a trapezoidal shape, a triangular shape, a fan shape, a circular shape, and the like are available. The appropriate shape can be adopted. In the embodiment, the bottomed container body 10 having a circular opening is shown. However, the bottomed container body is not limited to this, and the bottomed container body having an approximately rectangular opening. In this case, the lid body also has a substantially rectangular shape. Further, the belt-like heat bonding portion 3 may be formed by processing a hot plate so as to have the protruding heat bonding portion 30, and the flange portion of the bottomed container body 10. The band-shaped heat bonding part 3 having the protruding heat bonding part 30 may be formed as a flange part in which a rib having a shape of the band-shaped heat bonding part 3 having the protruding heat bonding part 30 is formed. Moreover, what is necessary is just to determine suitably according to the width | variety of a flange part about the width | variety of the said strip | belt-shaped heat bonding part 3, and the protrusion length of the said protrusion heat bonding part 30. FIG.

Further, the conductive heat generating layer A generates heat by receiving microwaves, and the protruding heat bonding portion 30 in the region where the conductive heat generating layer A is provided is heated and melted, and is heated and melted by the internal pressure increased by heating the contents. The protruding thermal bonding part 30 is opened to release the internal pressure. The conductive heat generating layer A may be any material that generates heat by absorbing microwaves, and is not particularly limited. However, considering that it is converted into an ink, carbon black, silver, aluminum, ITO ( Indium tin oxide) is suitable, and carbon black is suitable because it can be easily used as a printing ink, for example, a gravure printing ink. The surface resistivity is preferably 10 Ω / □ or more and 10 ⁷ Ω / □ or less. The reason for this is less than 10 [Omega / □ heating value is reduced to the microwave is reflected, it is because the 10 ⁷ Ω / □ ultra heating value resistor is too large is reduced. In the embodiment, the conductive heat generating layer A is provided at a position facing the knob 21, but this is cooked in a microwave oven in the region where the conductive heat generating layer A is provided. The protruding thermal bonding part 30 is heated and melted, and the protruding thermal bonding part 30 heated and melted by the internal pressure increased by heating the contents is opened to release the internal pressure. Therefore, the knob 21 is preferably provided at a position away from this portion, and is not limited to a position facing the conductive heat generating layer A. Further, the position where the protruding heat bonding part 30 is provided is not limited to one place, and may be a plurality of places.

  Next, the present invention will be described in more detail.

[Production of bottomed container body]
Injection of a polypropylene container having a substantially inverted trapezoidal cross section with a flange section inner diameter (opening diameter) of 90 mm, flange section outer diameter of 104 mm, height of 75 mm, and bottom section outer diameter of 55 mm It was produced by a molding method.

(Production of lid)
A conductive heating layer A shown in FIG. 2 by a gravure printing method using a gravure printing ink having a composition shown in Table 1 on a corona discharge-treated surface of a biaxially stretched polyethylene terephthalate film (hereinafter referred to as PET) having a thickness of 12 μm. After printing, a 15 μm-thick biaxially stretched nylon film and a 50 μm-thick easy peel sealant (manufactured by Tosero Co., Ltd .: CMPS022C) were sequentially laminated by the dry lamination method, and the diameter was about 72 mm. 2 was punched into a shape such that the conductive heat generating layer A and the knob portion 21 face each other as shown in FIG.

  The polypropylene container prepared above is filled with 150 ml of water, and using the lid body of Example 1 prepared above, a protruding heat bonding portion is located in the region of the conductive heat generating layer A as shown in FIG. A sealed container for heating a microwave oven of the present invention sealed with a band-shaped heat bonding part was produced.

[Comparative Example 1]
A lid body without a conductive heat generating layer was produced in the same manner as in Example 1, and this lid body was used as a comparative example sealed with a belt-like thermothermal adhesive part having a protruding thermal adhesive part as in Example 1. A sealed container for range heating was produced.

  Steam produced in the microwave oven sealed containers of Example 1 and Comparative Example 1 produced above was 10W (40 units in total) in two types of microwave ovens of 600W (for home use) and 1600W (for business use). Heat until it escapes, 1) Time from heating until steam escapes (steaming time), 2) Temperature of the lid at the part where steam escapes (steam port temperature), 3) Lids other than the part where steam escapes Four items were evaluated: body temperature (peripheral temperature), and 4) state when steam escapes (sensory evaluation). The results are summarized in Table 2.

  As is apparent from Table 2, the sealed container for heating a microwave oven according to the present invention opens an increased internal pressure at a predetermined position in both a household microwave oven (600 W) and a commercial microwave oven (1600 W). The internal pressure can be released gently from a predetermined position, and there is an excellent effect that the contents are not blown out or the container is not ruptured or deformed.

(A) which shows one Example of the sealed container for microwave oven heating concerning this invention is a front view, (b) is a longitudinal cross-sectional view of (a). It is a figure explaining the relationship between the strip | belt-shaped thermobonding part provided in the flange part of the bottomed container main body of the sealed container for microwave ovens concerning this invention, and the electroconductive heat generating layer provided in the cover body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealing container for microwave ovens 3 Strip | belt-shaped heat-bonding part 30 Protruding heat-bonding part 10 Bottomed container main body 11 Flange part 20 Cover body 21 Knob part A Conductive heat generating layer

Claims (2)

A bottomed container body having a flange portion on the opening and sealed with strip heat seal portion provided along the flange portion by the lid having the opening of the bottomed-shaped container body of the knob only one place a sealed container for microwave heating, to form the projecting heat-bonding portion which is protruded inwardly of the container only in one place on the opposite side of the distribution is the position of the knob portion of the strip heat-bonding portion, A sealed container for heating a microwave oven, wherein a conductive heat generating layer having a size covering at least the protruding heat bonding part is formed on the lid. The lid body is composed of a laminate including at least a base material layer and a heat-adhesive resin layer, and the conductive heat generating layer is formed by a printing method using a printing ink on a surface of the base material layer on the heat-adhesive resin layer side. The sealed container for heating a microwave oven according to claim 1 , wherein a surface resistivity of the conductive heat generating layer is 10 Ω / □ or more and 10 ⁷ Ω / □ or less .

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