JPH09249269A - Microwave absorption heat cooking container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always keep temperatures constant by applying microwave to generate heat by providing a microwave heat-generating metal oxide layer having self-temperature-controlling characteristics on the outer surface of a microwave-transmittable cooking container base material. SOLUTION: A tray-shaped cooking container base material 2 having thereon a glaze layer is formed using a mullite-based earthenware ceramics body earth, and 100 pts.wt. microwave heat-generating metal oxide, 10 pts.wt. frit, and 40 pts.wt. solvent are kneaded together to form a paste, which paste is screen- printed on the underside of the material 2 using a screen of 100 meshes. The printed paste is dried and heated to 500 deg.C-800 deg.C and a microwave heat- generating metal oxide 3 is baked on the underside of the material 2 to form a microwave absorption heat generating cooking container 1. As a result, a desirable cooking can be always achieved without overheating material to be cooked.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a microwave absorbing and exothermic cooking container.

[0002]

2. Description of the Related Art Conventionally, when an object to be cooked is heated and cooked by a microwave oven, the object to be cooked is not charred, which is a characteristic of cooking by a microwave oven. However, on the other hand, the food to be cooked is grilled fish or starch.
In the case of ki, pizza pie, grilled gyoza, etc., it is more preferable to cause some charring, since it has a better texture, a better visual sense, and a better odor, which is desirable for appetizing.

For this reason, metals such as aluminum, tin oxide, antimony oxide, ferrite, barium titanate, calcium titanate, strontium titanate and the like are formed on the central portion of the outer surface of the cooking container base material through which microwaves can pass. There is proposed a microwave heating element layer formed of a metal oxide or silicon carbide. When the microwave heating element layer portion of the cooking container configured as described above is irradiated with microwaves, an eddy current is generated in the microwave heating element layer, and at the same time, jule heat is generated. Further, the microwave irradiation causes orientational polarization in the microwave exothermic metal oxide layer, and intramolecular frictional heat due to dipole rotation due to the polarization motion is generated. And
These heat energies are absorbed by the cooking container, and about 2-3
It is said that the surface temperature of the cooking container becomes 200 to 300 ° C. in a minute and the food to be cooked is properly burned.

[0004]

However, in the conventional example configured as described above, the microwave heating element layer is made of a metal and metal oxide such as aluminum, tin oxide and ferrite, or a material such as silicon carbide. However, such a material inherently does not have physical properties of self-temperature control function. For this reason, the microwave heating element layer heats up in proportion to the microwave irradiation time and gradually rises in temperature, causing not only the self-melting in some cases but also the overheating of the food to be cooked. It's easy. Further, since the cooking container base material is rapidly heated to a high temperature, not only heat resistance but also high thermal shock resistance is required, and the material of the base material is considerably limited.

The present inventor has conducted extensive studies to solve the above conventional problems, and as a result, has found self-temperature controllability, that is, a metal oxide capable of self-controlling at a constant temperature by being heated by microwave irradiation. They have found out the present invention and completed the present invention.

[0006]

According to the present invention, a microwave exothermic metal oxide layer having self-temperature controllability is provided on the outer surface of a cooking container base material through which microwaves can pass. Is the gist.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The shape of a cooking container base material through which microwaves can be transmitted according to the present invention can be formed into a known cooking container shape such as a tray shape or a dish shape. As the material of the cooking container base material, known glass, ceramics, or synthetic resin such as heat-resistant glass, crystallized glass, lithia-based ceramics, mullite, alumina, or polyethylene terephthalate is selected and used.

Further, as a raw material for the microwave exothermic metal oxide layer having self-temperature controllability, VO, V
_{O 2, V 2 O 3,} V 2 O 5 or the like vanadium oxide, NbO, N
Niobium oxide such as bO ₂ , Nb ₂ O ₃ and Nb ₂ O ₅ , WO ₂ and W
Tungsten oxide such as O ₃ and W ₂ O ₅ , CrO, Cr
Chromium oxides such as O ₂ , CrO ₃ and Cr ₂ O _3, tantalum oxides such as Ta ₂ O _{5 and} molybdenum oxides such as MoO ₂ , MoO ₃ and Mo ₂ O ₅ can be preferably used. The metal oxides may be used alone or may be used by appropriately mixing them. For example, V ₂ O ₅ and W
The O _3, V ₂ O ₅ and Al ₂ O _3, V ₂ O ₅ and WO ₃ and Al ₂ O ₃ may be mentioned as an example of a suitable formulation. When forming the microwave exothermic metal oxide layer, the powdered metal oxide is dispersed in an aqueous or oily solvent to prepare a slurry form or a paste form, for example, a spray. -A microwave-exothermic metal oxide layer having a required thickness is formed by applying it on a part or the whole surface of the cooking container base material by a known method such as blowing, dipping, or screen printing, and then heat-treating and baking. Excuse me.

In the cooking container constructed as described above, when the microwave exothermic metal oxide layer is irradiated with microwaves, an overcurrent is generated in the microwave exothermic metal oxide layer as in the conventional case. Occurs, and at the same time, juule heat is generated. Alternatively, orientation polarization occurs in the microwave exothermic metal oxide layer, and intramolecular frictional heat resulting from dipole rotation due to the polarization motion occurs. Such microwave exothermic metal oxide layer,
When irradiated with microwaves, the temperature rises, and when it reaches a certain temperature, it becomes invariable. However, the reason why such a temperature control phenomenon occurs is not clear, but it is considered that it is caused by the generated crystal phase of the baked microwave exothermic metal oxide layer, the degree of growth of the crystal phase, the grain boundary, and the like. Be done. The microwave-exothermic metal oxide layer may be formed on the outer surface of the cooking container base material, preferably on the upper surface or the lower surface. Further, in order to improve the durability and stain resistance of the cooking container, the microwave heating A glass layer, a ceramic layer, a heat-resistant resin film layer or the like may be formed as a protective film on the functional metal oxide layer.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Examples 1 to 8 Comparative Examples 1 to 2 A tray-shaped cooking container base 2 having a glazed layer was formed using a mullite ceramic earth material. Then, 100 parts by weight of the microwave exothermic metal oxide shown in Table 1, 10 parts by weight of the frit and 40 parts by weight of the solvent are kneaded to prepare a paste, and the paste is prepared on the lower surface of the cooking container base material 2. Screen printing was performed using a 100-mesh screen, dried, and then heat-treated at 500 ° C. to 800 ° C., and the microwave-exothermic metal oxide layer 3 was formed on the lower surface of the cooking container base material 2. To form a microwave-absorbing and exothermic cooking container 1 (see FIG. 1). For Comparative Example 2, SnC was formed on the lower surface of the cooking container base material similar to the above.
After allowed deposited SnO ₂ gel solution prepared from l _2,
Heat treated at 500 ° C., to form the microwave absorbing heat generation of the cooking container to form a SnO ₂ layer.

Each of the formed microwave-absorbing and exothermic cooking containers 1 was placed in a commercially available microwave oven (internal dimensions 300 × 300 × 20).
0), the microwave was emitted with an oscillation frequency of 2450 MHz and an output of 600 W, and the surface temperature of the microwave exothermic metal oxide layer 3 was measured with time. The measurement results are also shown in Table 1 and shown as a graph in FIG.

[0012]

[Table 1]

As is clear from Table 1 and FIG. 2, in Comparative Examples 1 and 2, heat is generated by microwave irradiation, and the temperature is raised in proportion to the microwave irradiation time. On the other hand, in Examples 1 to 8, although heat was generated due to microwave irradiation and the temperature was raised, the temperature rise was stopped after about 2 to 4 minutes, and thereafter, continuous irradiation with microwaves was performed. Regardless of this, it can be understood that the heat generation temperature is kept constant and the remarkable self-temperature control function is exerted.

[0014]

As described above, according to the present invention, a microwave-exothermic metal oxide layer having a self-temperature controllability is provided on the outer surface of a cooking container substrate through which microwaves can pass. Therefore, it is possible to generate heat by irradiating microwaves and keep it at a constant temperature at all times.
There is no possibility of overheating and melting itself or overheating of the food to be cooked as in the conventional case, and the required cooking can always be performed properly. Therefore, the cooking container base material is not necessarily required to have high heat resistance and high thermal shock resistance as in the conventional case, and as a result, the material of the cooking container base material can be selected in a wide range and the microwave Various transparent materials can be selected and used.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a graph showing the results of temperature measurement with time when microwaves were applied to the microwave absorbing and exothermic cooking containers formed in the examples of the present invention and the comparative examples.

[Explanation of symbols]

 1 Cooking Container 2 Cooking Container Base Material 3 Microwave Exothermic Metal Oxide Layer

Claims (2)

[Claims] 1. A microwave absorbing metal oxide layer having self-temperature controllability is provided on the outer surface of a cooking container base material through which microwaves can pass. An exothermic cooking container. 2. The material of the microwave exothermic metal oxide layer having self-temperature controllability is a metal oxide selected from the group of vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide and tungsten oxide. The microwave-absorbing and exothermic cooking container according to claim 1, wherein: