WO2005051800A1

WO2005051800A1 - Packaging container for microwave oven

Info

Publication number: WO2005051800A1
Application number: PCT/JP2004/017278
Authority: WO
Inventors: Keizo Kanzaki
Original assignee: Toyo Seikan Kaisha, Ltd.
Priority date: 2003-11-28
Filing date: 2004-11-19
Publication date: 2005-06-09
Also published as: DE602004012898D1; JP4569249B2; EP1693313A4; AU2004293278B2; EP1693313B8; EP1757535A3; KR100986600B1; KR100986599B1; KR20060105804A; DE602004012898T2; EP1757535A2; KR20060135970A; JP2005178903A; EP1693313A1; US20070110856A1; AU2004293278A1; EP1757535B1; EP1693313B1

Abstract

A packaging container for a microwave oven, by which the fact that heating of the container content has been completed and the container has been automatically opened can be easily recognized. This can be achieved without requiring a special member and complex steps, but by processing wrapping materials constructing the packaging container such as a packaging bag, cup, tray, etc. Also provided is a packaging container for a microwave oven, where danger, including spilling of the content of the container and burning by touching an opening section occurring in heating by a microwave oven, can be avoided. Further provided is a packaging container for a microwave oven, sealed by heat-sealing plastic films and having a steam vent seal section having a weakened section. The steam vent seal section has mark emerging means, where, when the steam vent seal section is separated and opened, the means shows different surface- and back face-wrapping materials constituting the steam vent seal section, enabling the recognition of the opening.

Description

Specification

Microwave packaging

Technical field

The present invention relates to a packaging container for a microwave oven, such as a packaging bag, a cup, or a tray, which is filled with a liquid substance, a solid substance, or a mixture thereof, such as retort food. The packaging container of the present invention, when heated in a microwave oven, can automatically release steam and the like generated inside the packaging container, thereby preventing rupture, deformation, and scattering of the contents of the packaging container. It can be easily recognized that the packaging container has opened.

Background art

[0002] When a packaging container such as a packaging bag, a cup, or a tray tightly filled with retort food, frozen food, or the like is heated in a microwave oven, the pressure inside the bag increases due to water vapor generated from the contents accompanying the heating. In addition, the package may rupture and the contents may be scattered, and the inside of the microwave oven may be soiled, or the human body may be burned.

[0003] Therefore, before such a packaging container is heated and cooked in a microwave oven, the packaging container is partially opened in advance, or a hole is formed in the packaging container body, thereby generating the inside of the packaging container. A method of discharging steam or the like to the outside to prevent bursting of the packaging container has been adopted. However, such methods are cumbersome for consumers. In addition, when such a method is adopted, the steam generated by microwave heating is immediately discharged to the outside of the packaging container, so that the steaming effect of the content by the steam is reduced, and the content of the heated and cooked content is reduced. There is a drawback that the taste of the fish falls.

[0004] In order to solve such a drawback, various packaging containers provided with an automatic opening mechanism for automatically releasing an increase in the internal pressure of the packaging container when heating the microwave oven have been proposed! (For example, see Patent Documents 1-4)

In these packaging containers, the fact that the packaging container was opened by heating in the microwave oven can be determined by the sound of steam being released at the time of opening and thereafter, and the inside of the range being clouded with steam. However, such a method of determining the opening sometimes overlooks the opening of the packaging container which is difficult to understand. [0005] In order to solve such a drawback, a type has been proposed in which a separate signal plant is connected to a container dedicated to microwave oven heating, a food bag, or the like (see Patent Document 5). However, these containers use separate costly signal whistles and require the process of connecting the signal whistles, complicating the container manufacturing process and increasing costs. 7

[0006] On the other hand, a hidden printing layer is provided on the heat seal portion of a normal packaging bag that is not heated by a microwave oven to prevent characters or symbols from appearing when the bag is opened, thereby preventing toxic substances or the like from being mixed. Packaging bags that can be used have also been proposed (for example, see Patent Document 6). However, in such a packaging bag, it is difficult to recognize the characters and symbols that appear when the package is opened unless the area where the hidden print layer is provided has a certain area or more. Therefore, such technology could not be diverted to a steam vent seal that automatically opens when heating microwave packaging containers such as packaging bags, cups, and trays.

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. H10-59433

Patent Document 2: JP-A-10-95471

Patent Document 3: JP-A-10-101154

Patent Document 4: JP-A-2002-249176

Patent Document 5: JP-A-6-245861

Patent Document 6: Japanese Utility Model Publication No. 62-90334

Disclosure of the invention

Problems to be solved by the invention

[0008] Accordingly, the present invention provides a packaging container by processing a packaging material itself constituting a packaging container for a microwave oven, such as a packaging bag, a cup, or a tray, without requiring a special member or a complicated process. It is an object of the present invention to provide a packaging container for a microwave oven which can easily recognize that the cooking of the contents has been completed and the packaging container has automatically opened. Another object of the present invention is to provide a packaging container for a microwave oven that can avoid the danger of spilling the contents of the packaging container or touching the opening when burning in a microwave oven. And

Means for solving the problem As a result of the inventor's intensive studies, the present inventors have found that the steam vent seal portions of the front and back packaging materials constituting the packaging container for a microwave oven such as a packaging bag, a cup, or a tray provided with a steam vent seal portion having a weakened portion. In addition, the present inventors have found that the above-mentioned problems can be solved by providing a sign revealing means by which the packaging material on the front and back sides can be recognized as being different at the time of peeling opening of the vapor vent seal portion by a printing cartridge or the like. completed.

That is, the present invention has the following structure.

1. In a packaging container for a microwave oven provided with a vapor release seal portion having a weakened portion in a packaging container which is sealed by heat sealing a plastic film, a peeling opening of the vapor release seal portion is provided in the vapor release seal portion. A packaging container for an electronic range, wherein a sign revealing means is provided, which sometimes makes it possible to recognize that the packaging material on the front and back sides constituting the vapor vent seal portion is different.

2. Provide a printed layer with a white part on the vapor vent seal part of one plastic film that constitutes the packaging container, and correspond to the white part on the vapor vent seal part of the other plastic film that constitutes the packaging container. 2. The packaging container for a microwave oven according to 1, wherein the sign display means is constituted by providing a pattern printing layer.

3.Color the vapor-venting seal of one of the plastic films forming the packaging container to the first color, and apply the vapor-venting seal of the other plastic film that constitutes the packaging container to the second color different from the first color. 2. The packaging container for a microwave oven according to 1, wherein the sign display means is constituted by coloring in a color.

4. The packaging for microwave ovens according to 1, characterized in that there is provided a sign revealing means for making the peeled surface opaque or white with peeling due to cohesive failure of a vapor vent seal part of a plastic film constituting a packaging container. container.

5. The electronic device according to (4), wherein a sign printing means is configured by providing a colored printed layer on an outer layer of at least one of the plastic films constituting the packaging container on the outer surface side of the container on the vapor release seal portion. Microwave packaging container.

6. The packaging container for a microwave oven as described in any one of (1) to (5), wherein the vapor releasing seal portion is provided so as to be connected to a peripheral seal portion of the packaging container.

7. The steam release seal is provided separately from the peripheral seal of the packaging container. 15. The packaging container for a microwave oven according to any one of items 1 to 5.

8. The packaging container for a microwave oven according to any one of items 17 to 17, wherein the weakened portion is formed by providing a through hole, a semi-through hole, or a slit in the steam release seal portion.

9. A notch is provided in the packaging container toward the inside of the container, and a steam vent seal portion having a weakened portion is formed by heat sealing the periphery of the notch. A packaging container for a microwave oven as described in Crab.

10. The packaging container for a microwave oven according to any one of items 1 to 9, wherein a spout forming means is provided in the vicinity of the steam release seal portion.

11. The packaging container for a microwave oven according to any one of items 1 to 10, wherein the packaging container is a packaging bag that is sealed by heat-sealing a plastic film.

12. The packaging container for a microwave oven according to 11, wherein the packaging bag is a standing bouch.

13. The microwave oven packaging container according to 11 or 12, wherein the packaging bag is a packaging bag having a branch portion.

14. The packaging container for a microwave oven as described in any one of 15 to 15, wherein the packaging container is sealed by heat-sealing a lid made of a plastic film on a container body having a flange portion.

15. The packaging container for an electronic range according to 14, wherein a steam release seal portion is formed by projecting a heat seal portion between the flange portion and the lid of the package container toward the inside of the container.

Brief Description of Drawings

FIG. 1 is a view showing one example in which the present invention is applied to a packaging bag for a microwave oven.

FIG. 2 is a view for explaining a sign revealing means provided in a vapor release seal portion of the packaging bag of FIG. 1.

FIG. 3 is a view for explaining a sign that appears when the vapor release seal portion of the packaging bag in FIG. 1 is peeled open.

FIG. 4 is a view showing another example in which the present invention is applied to a packaging bag for a microwave oven.

FIG. 5 is a view showing another example in which the present invention is applied to a packaging bag for a microwave oven.

FIG. 6 is a view showing another example in which the present invention is applied to a packaging bag for a microwave oven. [7] Fig. 7 is a view showing another example in which the present invention is applied to a packaging bag for a microwave oven. [8] Fig. 8 is a view showing another example in which the present invention is applied to a packaging bag for a microwave oven.

FIG. 9 is a view showing an example in which the present invention is applied to a tray-shaped microwave container.

FIG. 10 is a plan view of the container of FIG. 9.

[11] FIG. 10 is a schematic view showing a cross section of a steam release seal portion of the container of FIG.

Explanation of symbols

[0012] 1,21,31,41,51,61 Packaging bag for microwave oven

2,112 Perimeter seal

3,43,53,113 Steam release seal

4,44,54 weakened part

5 notches

6 Perforation

7 Bottom fold

11 White part

12,14 Solid pattern

13

52 Branch

56 Opposite part

57 Opening prevention means

58 Branch base

100 Microwave Oven Packaging Container (Tray)

101 Container body

102 Flange

103

115 Opening section

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] In the present invention, as plastic films constituting a microwave packaging container such as a packaging bag, a cup, a tray, etc., a heat-sealing package usually used in the production of packaging containers is used. A plastic material is used. As such a plastic material, for example, a single-layer film or sheet made of a thermoplastic resin having a heat sealing property, or a thermoplastic resin having a heat sealing property laminated with another thermoplastic resin or the like. Examples include multilayer films and sheets.

Examples of such a plastic material having heat sealing properties include known low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, propylene-ethylene copolymer, ethylene-butyl acetate copolymer, Olefin resins such as olefin resin graft-modified with a tylene unsaturated carboxylic acid or anhydride, polyamide or copolyamide resin, polyester or copolyester resin having a relatively low melting point or low softening point. , Polycarbonate resin and the like are used.

[0014] As other plastic materials to be laminated with the plastic material having heat sealing properties, various types of barrier films having or not having heat sealing properties can be used.

Examples of such a thermoplastic resin include crystalline polypropylene, crystalline propylene-ethylene copolymer, crystalline polybutene 1, crystalline poly4-methylpentene 1, low-, medium-, or high-density polyethylene, ethylene-butyl acetate. Polyolefins such as polymers (EVA), EVA saponified products, ethylene ethyl acrylate copolymer (EEA), ion-crosslinked olefin copolymers (ionomers); aromatic vinyl copolymers such as polystyrene and styrene-butadiene copolymer Halogenated vinyl polymers such as polyvinyl chloride and Shiridani Vilydene resin; Polyacrylic resins; -Tolyl polymers such as acrylonitrile styrene copolymer, acrylonitrile styrene butadiene copolymer; polyethylene terephthalate; Polyesters such as polytetramethylene terephthalate; Ru can be exemplified thermoplastic 榭脂 such polyacetals polyoxymethylene and the like; seed polycarbonate; fluorine-based 榭脂. These thermoplastic resins can be used alone or in combination of two or more. Further, various additives may be blended with these thermoplastic resins and used.

[0015] Examples of various barrier films include silica-deposited polyester films, alumina-deposited polyester films, silica-deposited nylon films, alumina-deposited nylon films, alumina-deposited polypropylene films, carbon-deposited polyester films, and carbon-deposited polyester films. Nylon film, binary vapor-deposited film in which alumina and silica are simultaneously vapor-deposited on a base film such as polyester film or nylon film, Nymouth 6Z meta-xylylenediamine nylon 6 coextruded film, polypropylene / ethylene-bulcohol copolymer Co-extruded film, Polyvinyl alcohol-coated polypropylene film, Polyvinyl alcohol-coated polyester film, Polyvinyl alcohol-coated nylon film, Polyacrylic resin-coated polyester film, Polyacrylic resin-coated nylon film, Polyacrylic Acid-based resin-coated polypropylene film, polyglycolic acid-based resin-coated polyester film, polyglycolic acid-based resin-coated nylon film, polyglycolic acid Organic resin-coated films such as fat-coated polypropylene films, and hybrid coating materials that also have the properties of organic resin and inorganic materials coated on base films such as polyester films, nylon films, and polypropylene films. it can. These barrier films can be used alone or in combination of two or more.

In the present invention, an unstretched or uniaxially or biaxially stretched film or sheet made of the above-mentioned plastic material is formed or molded by a conventional method to form a microwave for packaging bags, cups, trays and the like. Make packaging containers. When a packaging bag is made of a laminated film of a thermoplastic resin with heat sealing property and a thermoplastic resin without heat sealing property, the thermoplastic resin layers with heat sealing property are And heat seal. If necessary, an adhesive resin layer can be interposed between the layers constituting the laminated film.

Next, the packaging container for an electronic range of the present invention will be described in detail with reference to the drawings, focusing on an example in which the present invention is applied to a packaging bag, but the following specific examples limit the present invention. is not.

FIG. 1 to FIG. 3 are diagrams showing an example of a packaging bag for a microwave oven provided with a steam release seal portion having a weakened portion according to the present invention. FIG. 1 is a front view of a packaging bag, and FIG. 2 is an enlarged schematic diagram for explaining a sign revealing means provided on a steam release seal portion of the packaging bag. FIG. 3 is an enlarged schematic diagram illustrating a sign that appears when the vapor release seal portion is peeled open when the packaging bag is heated in a microwave oven. In the packaging bag 1 for a microwave oven, a peripheral portion 2 of a packaging material (plastic film) constituting the front and back of the bag is heat-sealed, and a steam vent seal portion 3 having a weakened portion 4 is provided at a corner of the bag. In this way, it was produced. A notch 5 is formed at the top of the bag to facilitate opening of the bag after cooking in the microwave is completed.

In this packaging bag, the weakened portion 4 is formed by providing one through hole in the steam release seal portion 3, but this weakened portion is formed by providing a semi-through hole or a slit instead of the through hole. You can also. A plurality of through holes, semi-through holes or slits may be provided in the steam release seal portion 3.

[0019] As shown in FIG. 2 (A), a pattern 12 having a white portion 11 is solid-printed on the vapor release seal portion 3 of either the front or back packaging material constituting the packaging bag 1. On the other hand, as shown in FIG. 2 (B), a pattern 13 corresponding to the white portion 11 of FIG. 2 (A) is printed on the steam release sill portion 3 of the other packaging material. The pattern 13 is preferably formed larger than the white portion 11 in order to facilitate alignment when heat-sealing the packaging bag.

[0020] When the steam release seal portion 3 is formed by superimposing and heat sealing the white portion 11 of the front and back packaging materials constituting the packaging bag 1 and the corresponding pattern 13, the steam release seal portion is formed. As shown in FIG. 2 (C), in FIG. 3, a pattern 14 in which the entire surface is uniformly printed is obtained. The weakened portion 4 is formed in the steam release seal portion 3 by providing a through hole at the same time as or after the heat seal.

When the contents of a curry, a stew or the like are filled and sealed in the packaging bag 1, and then heated in a microwave oven, the internal pressure of the packaging bag 1 is increased due to water vapor or the like generated from the contents, and the packaging bag 1 becomes a central point. It expands from P toward the periphery. As a result, stress concentration occurs in the portion B closest to the center point P of the steam release seal portion 3, and the break opening of the steam release seal portion 3 starts.In the steam release seal portion 3, the seal portion retreats due to the stress concentration. However, when the peeling reaches the weakened portion 4, the packaging bag 1 is partially opened and water vapor and the like are discharged to the outside, so that the packaging bag 1 can be prevented from bursting.

As shown in FIGS. 3 (A) and (B), the vapor release seal portion 3 having the peeling opening has white printed on the vapor release seal portion of each packaging material constituting the packaging bag 1. With punched part 11 The solid printed pattern 12 and the pattern 13 corresponding to the white portion 11 appear. As a result, it is possible to easily recognize that the packaging bag 1 has been automatically opened and the cooking of the contents has been completed. Needless to say, the pattern formed on the steam release seal portion can be arbitrarily selected. Also, this pattern can be provided not only on the steam release seal portion but also on a portion adjacent thereto.

In the above example, the sign manifesting means is configured by printing a pattern on the vapor release seal portion of each packaging material constituting the packaging bag. This means for displaying a sign is to color the vapor release seal of one of the packaging materials constituting the packaging bag into a first color, and to color the vapor release seal of the other packaging material in a second color different from the first color. For example, when the front side of the vapor release seal portion of the packaging bag is printed in red and the back side is printed in blue and heat sealed, the vapor release seal portion is colored purple. When the packaging bag is heated in a microwave oven and the vapor release seal is peeled open, the front side turns red and the back side turns blue. Therefore, it is possible to easily recognize that the cooking of the contents has been completed and the bag has been automatically opened.

[0024] In the above example, the circular vent seal portion 3 is provided separately from the peripheral seal portion 2 at the corner of the packaging bag 1, but the position, number, shape, and size of the vapor vent seal portion 3 are provided. Can be arbitrarily selected. Further, the shape, size, and the like of the weakened portion 4 formed in the steam release seal portion 3 can be appropriately selected. The method for forming the weakened portion 4 can be arbitrarily selected, such as mechanical processing such as punching, laser processing, or the like.

FIGS. 4 to 6 are diagrams showing other examples in which the present invention is applied to a packaging bag for a microwave oven.

The packaging bag 21 in FIG. 4 shows an example in which the present invention is applied to a standing voucher. In this example, the shape of the steam release seal portion 3 formed at the corner of the packaging bag 21 is substantially triangular, and the bottom folding portion 7 is provided at the bottom of the packaging bag 21. Other configurations of the packaging bag are the same as those of the packaging bag 1 in FIG.

The shape of the steam release seal part 3 can be appropriately changed to an oval, a square, a trapezoid, etc. in addition to the above! ^. FIG. 5 is a diagram showing another example in which the present invention is applied to a standing voucher.

In the packaging bag 31, the shape of the steam release seal portion 3 was substantially square, and provided so as to be connected to the peripheral seal portion 2 at the corner portion. Also, perforations 6 were formed to facilitate opening of the bag. The other configuration of the packaging bag is the same as that of the packaging bag 21 in FIG.

FIG. 6 is a view showing another example of the packaging bag for a microwave oven of the present invention.

In the packaging bag 41, a notch 44 serving as a weakened portion is provided near the corner of the packaging bag 41 toward the inside of the bag, and the periphery of the notch 44 is heat-sealed to have a weakened portion. A steam release seal portion 43 was formed. An easy-opening means 6 such as a perforation or a laser processing is provided at a portion of the packaging bag 41 where the bag body force is also distinguished by the notch 44, and a notch 5 is provided at the peripheral seal portion 2. In this packaging bag 41, after heating by the microwave oven is completed, the bag 41 is opened from the notch 5 along the easy-opening means 6 to form a spout (not shown).

FIG. 7 is a perspective view showing another example in which the present invention is applied to a packaging bag for a microwave oven.

In the packaging bag 51, a foldable branch portion 52 is formed on one side of the packaging bag body. A notch 54 is provided at the upper edge of the branch portion 52 toward the inside of the bag, and the weakened portion is formed by heat-sealing the peripheral edge to the same width or the same width as the peripheral seal portion 2. A vapor release seal portion 53 is formed. In addition, the vapor release seal 53 of the packaging bag 51 and the adjacent portion 55 are provided with means for displaying a sign by a printed pattern in the same manner as the packaging bag 1 of FIGS.

Further, in the packaging bag 51 provided with the branch portion 52, the branch portion 52 and a portion (opposing portion) 56 facing the branch portion 52 of the packaging bag main body are provided with a heat seal of the packaging bag at the base 58 of the branch portion 52. In order to prevent peeling, breakage of the bag, and leakage of the contents, opening prevention means 57 using a heat seal are provided at four places.

FIG. 8 is a perspective view showing another example in which the present invention is applied to a packaging bag for a microwave oven.

The packaging bag 61 is formed by cutting the outside of the packaging bag 51 of FIG. 7 along the outer periphery of the opening preventing means 57 provided in the branch portion 52. The other configuration of the packaging bag 61 is the same as the packaging bag 51 of FIG.

FIGS. 1 to 8 show an example in which the present invention is applied to a packaging bag for a microwave oven. However, it goes without saying that the present invention can be applied to microwave packaging containers other than packaging bags, such as cups, trays and boxes.

In such containers, the container may be provided with a flange portion, a steam release seal portion having a weakened portion formed on the flange portion, and the sign presenting means of the present invention provided at or near the steam release seal portion. it can.

FIG. 9 to FIG. 11 are diagrams showing an example in which the present invention is applied to a tray-shaped microwave container. FIG. 9 is a perspective view of the container, and FIG. 10 is a plan view of the container. Fig. 11 is a schematic view showing a cross section of the steam release seal portion of the container. (A) is a diagram showing a state before the release of the steam release seal portion, or () is a view showing a state after the release of the steam release seal portion. FIG. In the microwave packaging container 100, the lid 103 is heat-sealed to the flange portion 102 of the polypropylene container body 101, thereby sealing the container. At one corner of the container, a steam vent seal portion 113 is formed by projecting a peripheral heat seal portion 112 in a U-shape toward the inside of the container. The lid 103 is opened after the container has been cooked in a microwave oven by protruding the peripheral seal 112 in a V-shape toward the outside of the container at a part of the corner facing the steam release seal 113. An opening portion 115 is formed.

[0032] As shown in Fig. 11, the lid 103 of the packaging container 100 includes, in order from the outside, a 12 / zm-thick polyethylene terephthalate (PET) 121Z printing layer 122Z adhesive layer 123Z 15-m-thick nylon 124Z. The adhesive layer 123Z comprises an easy peel layer 125 made of unstretched polypropylene resin (CPP) having a thickness of 50 m. The lid 103 is heat-sealed to the flange portion 102 of the container body with the easy peel layer 125.

When this container is heated by a microwave oven, the internal pressure of the container increases due to water vapor or the like generated from the contents filled in the container, and the heat-sealing portion starts from the front end of the steam vent seal portion 113 projecting in a U-shape. The CPP that constitutes the easy peel layer 125 is cohesively broken, and peeling of the steam release seal portion 113 starts. When the internal pressure of the container further rises and reaches the outer edge of the peeling force heat seal portion at the tip of the vapor release seal portion 113, the heat seal portion opens as shown in FIG. 11 (B).

[0033] With the peeling of the heat seal portion in the steam release seal portion 113, cohesive failure occurs. The CPP release surface is roughened by forming irregularities. Also, due to a phenomenon such as stress whitening, the CPP peeling surface changes from transparent to white and opaque, and a white opaque layer 126 is formed on the surface of the easy peel layer 125. As a result, the lower layer of the print layer 122 of the lid 103 is in a state where the lower layer is white-coated, and the print of the peeled portion looks different in color from the peripheral portion, so that it can be easily identified. Even when the printing layer 122 of the lid 103 is omitted, the white opaque layer 126 formed by peeling off the heat seal portion can be identified, but it is preferable to provide the printing layer 122 for clearer identification. ,.

[0034] The layer configuration of the lid 103 is not limited to the above, and can be changed as appropriate. Examples of other layer configurations of the lid 103 include, for example, a 15-meter-thick nip 121Z printed layer 122Z adhesive layer 123Z 12-μm-thick ethylene-butyl alcohol copolymer 124Z adhesive in order from the outside. Layer 123Z An easy peel layer 125 made of a polyolefin resin having a thickness of 50 m, which is also powerful. In addition, it goes without saying that the number of layers constituting the lid 103 may be increased or decreased. The printing layer can be provided not only on the steam release seal portion 113 but also on its adjacent portion or on the entire surface of the lid 103. The adhesive to be interposed between the layers constituting the lid 103 is not particularly limited, and ordinary adhesives such as a polyurethane adhesive and an acid-modified polyolefin adhesive can be used.

Further, the flange portion 102 of the container body can be printed or colored as desired. The shape and dimensions of the container body are arbitrary, and may be, for example, a cylindrical cup, a rectangular parallelepiped tray, a box, or the like.

[0035] The sealing strength of the peripheral seal portion and the steam release seal portion of the packaging container for a microwave oven of the present invention can be set to 2.3 kgZl5 mm width or more.

In conventional packaging containers that automatically open when heated in a microwave oven, the sealing strength of the opened part is significantly reduced during heating, and it is not possible to obtain a sealing strength of 2.3 kgZl5 mm width or more required for packaging containers for retort foods. Helped. In the packaging container for a microwave oven of the present invention, a material whose sealing strength is reduced upon heating is not used for the peripheral seal portion of the container and the seal portion of the steam release seal portion itself. In addition, since the sealing portion is not subjected to the processing for reducing the sealing strength when heated, the sealing strength can be maintained.

[0036] As a result, when refilling the packaging container after filling the content into the packaging container, The packaging container does not rupture from the steam release seal or the peripheral seal. Also, it is possible to prevent the packaging container from being damaged during transportation and storage of the packaging container.

Also, when heating in a microwave oven, the vapor release seal portion of the packaging container maintains the sealing strength for a certain period of time, and the internal pressure in the packaging container is maintained in a state in which the internal pressure is increased by steam. Therefore, since the effect of heating and steaming the contents of the packaging container can be obtained, the taste of the contents is improved and the cooking time of the contents can be shortened.

Claims

The scope of the claims

[1] In a packaging container for a microwave oven provided with a steam release seal portion having a weakened portion in a packaging container hermetically sealed by heat sealing a plastic film, peeling of the steam release seal portion in the steam release seal portion A packaging container for an electronic range, characterized in that a marking revealing means is provided which allows the packaging material on the front and back sides constituting the vapor vent seal portion to be recognized as being different at the time of opening.

[2] A printed layer having a pattern having a white portion is provided on the vapor release seal portion of one plastic film constituting the packaging container, and a white portion is provided on the vapor release seal portion of the other plastic film constituting the packaging container. 2. The packaging container for a microwave oven according to claim 1, wherein the sign revealing means is constituted by providing a printed layer having a corresponding pattern.

[3] One of the plastic films constituting the packaging container is colored with the vapor-venting seal portion in the first color, and the other of the plastic film constituting the packaging container is colored with the second vapor-developing seal portion in the second color different from the first color. 2. The packaging container for a microwave oven according to claim 1, wherein the sign revealing means is constituted by coloring the container with a color.

[4] The signing device according to claim 1, characterized in that there is provided a sign revealing means for making the peeled surface opaque or white with the peeling due to the cohesive failure of the vapor vent seal portion of the plastic film constituting the packaging container. Microwave oven packaging container.

[5] The sign revealing means according to claim 4, characterized in that a sign printed means is constituted by providing a colored printed layer on an outer layer of at least one of the plastic films constituting the packaging container on the outer surface side of the container on the vapor release seal portion. The packaging container for a microwave oven as described in the above.

[6] The packaging container for a microwave oven according to any one of claims 15 to 15, wherein the vapor release sealing portion is provided so as to be connected to a peripheral sealing portion of the packaging container.

[7] The packaging container for a microwave oven according to any one of claims 15 to 15, wherein the steam release seal portion is provided so as to be separated from a peripheral sealing portion force of the packaging container.

[8] The packaging container for a microwave oven according to any one of claims 17 to 17, wherein the weakened portion is formed by providing a through hole, a semi-through hole, or a slit in the steam release seal portion.

[9] The packaging container is provided with a notch toward the inside of the container, and a peripheral portion of the notch is heat-sealed to form a steam vent seal portion having a weakened portion. 16. The packaging container for a microwave oven according to any one of 5.

[10] The packaging container for a microwave oven according to any one of [11] to [19], wherein a spout forming means is provided in the vicinity of the steam release seal portion.

[11] The packaging container for a microwave oven according to any one of claims 110, wherein the packaging container is a packaging bag that is sealed by heat sealing a plastic film.

[12] The packaging container for an electronic range according to claim 11, wherein the packaging container is a standing bag voucher.

13. The packaging container for a microwave oven according to claim 11, wherein the packaging bag is a packaging bag having a branch portion.

[14] The microwave oven package according to any one of claims 15 to 15, wherein the packaging container is sealed by heat-sealing a lid having a plastic film strength to a container body having a flange portion. container.

15. The microwave oven package according to claim 14, wherein the steam vent seal portion is formed by projecting a heat seal portion between the flange portion and the lid of the package container toward the inside of the container. container.