JPH0964U - Microwave food packaging - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a packaging container for a microwave oven food, which is easy to assemble and can be incinerated without the inconvenience such as burning of the container due to heating in a microwave oven. [Structure] A peripheral edge 2a of the bottom portion 2 is bent downward, and the surface of the peripheral edge 2a is brought into close contact with the inner surface of the body portion 1 so as to have a substantially U-shaped cross section.
The bottom portion 2 is fixed to the body portion 1 in a letter shape, and the heat generation label 3 which generates heat by receiving microwaves from a microwave oven is attached to a portion of the bottom portion 2 excluding the peripheral edge 2a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a packaging container for microwave oven food such as popcorn produced by heating in a microwave oven, and more particularly to a packaging container for microwave oven food provided with a heating element that generates heat when receiving microwaves from a microwave oven. It is a thing.

[0002]

[Prior art]

 Regarding the packaging container of this kind, the applicant has already disclosed it in the official gazettes of Japanese Utility Model Publication Nos. 1-73112 and 1-128585, and the packaging container disclosed in these publications has a body and a bottom fixed to each other. A cylindrical paper cup container or the like formed by folding the peripheral edge of the bottom portion upward, the back surface of the peripheral edge being in close contact with the inner surface of the body portion, and the bottom portion having a substantially U-shaped cross section fixedly formed on the body portion. It has a structure of.

[0003]

[Problems to be solved by the device]

 By the way, from the viewpoint of heating efficiency, it is desirable that the packaging container for microwave oven food has a so-called raised bottom structure having a space surrounded by the body under the bottom of the container.

However, in order to make the packaging container disclosed in the above publication a raised bottom structure, it is necessary to form the bottom portion whose peripheral edge is folded upward at a position slightly above the lower end of the body portion. However, this has the disadvantage that the assembly is rather troublesome and the mounting structure at the bottom is unstable.

In a conventional general paper cup container or the like, the peripheral edge of the bottom portion is bent downward, and the surface of the peripheral edge is brought into close contact with the inner surface of the body portion to form the bottom portion fixed to the body portion in a substantially U-shaped cross section. The structure with a raised bottom is generally used.

Therefore, the inventor of the present invention configured the bottom portion 2 to be composed of three layers of a paper base material 21, a heating element 22 and a heat resistant film 23 as shown in FIG. Thus, a packaging container having a structure in which the peripheral edge 2a of the bottom portion 2 is bent downward and the bottom portion 2 is fixedly formed on the inner surface of the body portion 1 in a substantially inverted U-shaped cross section was devised. However, as will be described later in detail, when the container was used for microwave popcorn and heated in a microwave oven, when the container was heated to such an extent that the cone was almost completely inflated, the bottom of the container was scorched and pitted. It was found that there was an inconvenience that it could not withstand use due to the presence of this.

The present inventor has completed the present invention as a result of intensive studies in view of the above-mentioned conventional problems.

That is, an object of the present invention is to provide a microwave oven food packaging container provided with a heating element, which does not cause inconvenience such as scorching even when heated in a microwave oven.

[0009]

[Means for Solving the Problems]

 MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the packaging container for microwave oven foodstuffs which concerns on this invention is comprised from a trunk | drum and a bottom at least, the periphery of this bottom is bent downwards, and the surface of this periphery is made into the said body inner surface. The bottom part is closely attached to the body part and the space part surrounded by the body part is formed under the bottom part, and at least a part of the bottom part excluding the peripheral edge receives microwaves. It is characterized in that a heating element that generates heat is provided.

[0010]

[Action]

 By placing the heating element on at least a part of the part excluding the peripheral edge of the bottom part that is fixed to the inner surface of the body part, even if the food of the contents is heated in a necessary and sufficient microwave oven, the container will be burnt. Will not occur.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 is a sectional view of an essential part of a container showing an embodiment of the present invention.

The bottom portion 2 of the container is formed of a paper base material 21 together with the body portion 1, and the peripheral edge 2 a of the bottom portion 2 is bent downward so that the surface of the peripheral edge 2 a is the inner surface of the body portion 1 and has a substantially inverted U-shaped cross section. The bottom part 2 in a fixed manner to the body part 1, and in order to further strengthen the holding structure of the bottom part 2, the lower end part of the body part 1 is folded inward and overlapped on the back surface of the peripheral edge 2a of the bottom part 2. It is firmly attached. Below the bottom 2, there is a space surrounded by the body 1, forming a so-called raised bottom structure. The paper base material 21 forming the body 1 and the bottom 2 of the container depends on the type of food contained therein, but when used for popcorn, for example, it is desirable to use oil-resistant paper and heat-resistant paper. It is also possible to use a sheet in which oil-resistant paper and a plastic film are laminated.

Reference numeral 3 denotes a heat generation label, which generates heat of about 200 ° C. when receiving microwaves from a microwave oven. The heat-generating label 3 is composed of three layers of a paper base 31, a heat-generating body 32, and a heat-resistant film 33, and is attached to the outer surface side of the container bottom portion 2 via an adhesive layer 34. Of course, since the heat-generating label 3 basically has a structure having the heat-generating body 32, it does not matter even if it does not have the three-layer structure as shown. The material of the heating element 32 is not particularly limited as long as it generates heat in a high frequency range, but generally, a thin film layer of a conductive metal such as aluminum formed by a vapor deposition method or the like, or a conductive metal and another material. A thin film layer made of a mixture, a thin film layer made of a magnetic substance such as ferrite, and a thin film layer made of a ferroelectric substance such as barium are generally known.

The heat-generating label 3 is attached to a portion of the bottom portion 2 fixed to the inner surface of the container body 1 excluding the peripheral edge 2a, but its size, shape and the like are arbitrary. That is, the size and shape of the heating label 3 can be arbitrarily set in consideration of the size and shape of the container, the material of the heating element 32, the type of food inside, the required heating amount, and the like. It is a thing. Further, such a heat-generating label 3 may be attached to the inner surface side of the bottom portion 2 instead of the outer surface as shown in the drawing. However, it is considered preferable to attach the heat-generating label 3 to the outer surface of the container bottom 2 in order to avoid the need to consider the safety when the food comes into direct contact with the food.

Further, the shape of the container according to the present embodiment is not limited to the cylindrical shape as shown in the figure, and may be a rectangular tube shape, a tray shape or the like. Further, providing a lid is also optional.

FIG. 2 shows the structure of another embodiment of the present invention. Instead of attaching the heat-generating label of the above embodiment to the bottom, the bottom 2 of the container is preliminarily shown in the paper base 21 as shown. The heating element 22 and the heat-resistant film 23 have a three-layer structure. Specifically, a thin film layer of the heating element 22 is formed on the surface of a heat resistant film (for example, a polyester film) 23 by vapor deposition or the like, and the bottom portion 2 is formed by a sheet which is bonded and integrated with the paper base material 21. Form. It should be noted that the thin-film layer of the heating element 22 is not provided on the entire surface of the heat-resistant film 23 but at a predetermined position so that the heating element 22 does not exist in the portion that becomes the peripheral edge 2a of the bottom portion 2 when the container is assembled. Form in size and shape. According to the structure of the present embodiment, as in the above-described embodiment, it is possible to save the labor of preparing the heat-generating label separately from the container body and then pasting the label together, which is advantageous.

Next, in order to further clarify the effect of the present invention, test results will be shown.

A cup container having the structure shown in FIGS. 1 and 3 was prepared, and corn grains, vegetable oil, salt, and other materials necessary for pop corn production were placed in each container, and a microwave oven with an output of 500 W was used. Microwave heating was performed. The materials used for the cup container having the structure shown in FIG. 1 are as follows. The paper base material 21 of the body portion 1 and the bottom portion 2 is an oil resistant paper, the heat generating element 32 of the heat generating label 3 is a vapor-deposited aluminum thin film, and the heat resistant film 33 is a polyethylene terephthalate (PET) film. Also, in the cup container having the structure shown in FIG. 3, the same material as above is used, the paper base 21 of the body 1 and the bottom 2 is oil resistant paper, the heating element 22 is a vapor-deposited aluminum thin film, and the heat resistant film 23 is P. It is an ET film.

FIGS. 4 and 5 show the results of the unexpanded rate of the cone, the incidence rate of the burntness of the cone, and the degree of burntness of the cup with respect to the heating time of the microwave oven, and the former is the present study shown in FIG. When the container according to the plan is used, the latter is when the container of the comparative example shown in FIG. 3 is used. In the figure, A is the unexpanded rate of the cone, B is the rate of occurrence of charring of the cone, C is the distribution of the degree of charring of the cup, and the degree of charring of the cup was judged according to the following criteria. 5 ... Complete carbonization 4 ... Almost carbonization (a hole is opened when pressed with a finger etc.) 3 ... Partially carbonization occurs 2 ... Discoloration to brownish brown 1 ... Discoloration to light brown 0 ... No change

As is apparent from FIG. 4, when the container according to the present invention is used, 300 seconds is the most suitable heating time, but the degree of charring of the cup at this time is 1 or less, and there is a problem in use. Not all. Even if the heating time exceeds 300 seconds, the degree of charring of the cup is 2 or less. Even if the range setting is wrong and heating is performed more than necessary, the bottom of the cup will be pulled out. There is no.

On the other hand, when the container of the comparative example shown in FIG. 5 is used, the optimum heating time is similarly 300 seconds, but the degree of charring of the cup at this time is 1 to 4 (4 shifts). In most cases, the bottom of the cup is scorched and comes off, which is unusable. As the heating time is further increased, the degree of charring of the cup further increases from 4 to 5.

[0023]

[Effect of the invention]

 As described in detail above, according to the present invention, since no inconvenience such as burning of a container due to heating does not occur, there is an excellent effect that it can be used without anxiety and that it is easily assembled. In addition, since the container of the present invention is made of 90% or more of paper material, it can be incinerated.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a container showing an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a container according to another embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a container of a comparative example.

FIG. 4 is a diagram showing test results when the container of the present invention is used.

FIG. 5 is a diagram showing test results when a container of a comparative example is used.

[Explanation of symbols]

 1 Body part 2 Bottom part 2a Bottom edge 3 Heat label 21 Paper base material 22 Heating element 23 Heat resistant film 31 Paper base material 32 Heating element 33 Heat resistant film 34 Adhesive layer

Claims (2)

[Utility model registration claims] 1. A structure comprising at least a body and a bottom,
A peripheral edge of the bottom portion is bent downward, a surface of the peripheral edge is brought into close contact with the inner surface of the body portion to fix the bottom portion to the body portion, and a space portion surrounded by the body portion is formed under the bottom portion, and A packaging container for a microwave oven food, characterized in that a heating element that receives microwaves to generate heat is provided on at least a part of the bottom portion excluding the peripheral edge. 2. The packaging container for microwave oven food according to claim 1, wherein the heating element is provided on an outer surface of the bottom portion.