JPH06124767A - Elf-heating far infrared radiation cooking device material for microwave oven - Google Patents

Abstract

PURPOSE:To promote chemical reaction in a food or action of an enzyme, and improve the taste by forming a sintered tissue body composed of 50-60% of hot charge such as feldspar and a plastic material such as clay containing silicon carbide of 30-45% and alpha-alumina of 5-20%. CONSTITUTION:When blending of silicon carbide is reduced, a calorific value is lowered, so that 30% blending is required to obtain generation of heat necessary for cooking in about a minute. When addition of alumina is taken into consideration, the upper limit becomes 45%, so that it is set in 30-45%. Though a particle diameter of the silicon carbide is preferable to become larger, it is preferable to be a material in which particle size distribution 5-30mum occupies 80% or more in terms of a problem with moldability. Since the silicon carbide of minimum 30% is necessary, when an adding quantity of alpha-alumina is set 5-20%, proper heat generation and high intensification are balanced with each other. In relation to a plastic material and hot charge, it is proper to set the plastic material such as clay in 30-40% and the hot charge such as feldspar in 20-30%. Thereby, flavor or a scorching state desirable in terms of food external appearance can be formed properly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-heating far-infrared radiation cooking utensil for microwave ovens, which uses special additional heating means as a self-heating far-infrared radiation cooking utensil for dishes and other microwave ovens. Instead, the surface of the food is burnt, and far infrared rays are radiated from the equipment itself to promote the chemical reaction in the food and the action of enzymes to improve the taste.

[0002]

2. Description of the Related Art Various self-heating far-infrared radiation cooking appliances for microwave ovens have been put to practical use. That is, a microwave oven normally guides microwaves radiated from a magnetron into an oven to irradiate a food material containing water, and the food material itself, particularly water, absorbs microwaves and heats from inside due to its vibration energy. Although it is a device that cooks by making it heat, it can not make a brown mark on the surface of the food to be cooked because it heats the water, and it does not attract the food, and it was mainly used for heating purposes. .

In order to solve the problems in the conventional general microwave oven, an additional heating means such as a heater is incorporated in the microwave oven to directly heat the object to be cooked in addition to microwaves to make a brown mark. Such a microwave oven has also been proposed and put into practical use.

In addition, it has been studied to heat the container itself for storing the food in the above-mentioned cooking to make the surface of the food brown, that is, silicon carbide or the like is added to the conventional ceramic clay. Various proposals have been made for forming a container by adding it, or forming silicon carbide itself into tableware, and further using it as a porous material or forming it in a specific portion of the tableware (Japanese Patent Laid-Open No. 58-49).
665, JP-A-62-106227, 142928, 2
00766, JP-A-63-14014, 133493,
198288, JP-A-1-95227, JP-A-2-59.
12).

[0005]

The above-mentioned one using the additional heating means in the microwave oven requires two kinds of magnetrons and heaters as a heat source even if it is possible to make a brown spot, and the apparatus becomes complicated and large in size. There is a disadvantage inevitably that the cost will increase with the realization.

In addition, as described above, in the proposal of using silicon carbide, the study of the composition for properly obtaining the above-mentioned charred porcelain as a ceramics is insufficient, and the specific amount of silicon carbide is specified. In the case of JP-A-58-49665 mentioned above, it is 70% or more, and it is difficult to obtain a practically preferable heat generation condition, and the body strength cannot withstand local heating by silicon carbide. However, there is a defect that proper durability cannot be obtained, such as damage due to slight use.

[0007]

The present invention has been studied to solve the technical problems in the above-mentioned conventional ones, and specified silicon carbide, α-alumina and plastic materials such as clay and a melting material. The compounding composition has succeeded in forming an appropriate browning at the time of heating as a microwave oven and effectively obtaining durability and the like, as follows.

(1) A container body molded and fired using kneaded clay, wherein silicon carbide is 30 to 45% and α-alumina is 5 to 5.
20%, 50% plastic material such as clay and 50% molten material such as feldspar
A self-heating far-infrared radiation cooking appliance for a microwave oven, which is a sintered structure consisting of ˜65%.

(2) 30-40% of plastic material such as clay
The melting material such as feldspar is 20 to 30%, and the self-heating far-infrared radiation cooking utensil for microwave oven according to the item (1) is characterized.

(3) Particle size distribution of silicon carbide 0.5 to 30
μm is 80% or more, The self-heating far-infrared radiation cooking utensil for microwave ovens according to the item (1) or (2).

(4) Primary particle size of α-alumina 0.5
~ 8 μm is 70% or more.
Self-heating far-infrared radiation cooking equipment for microwave ovens.

[0012]

[Function] In a microwave oven, heat generated by an insulator such as ceramics is considered to be an assembly of dipoles having a positive and negative electric charge in a ceramic dielectric. At this time, electric power converted into heat in the dielectric. The loss P is given by the following formula 1.

[0013]

## EQU1 ## P = 0.556εrtan δfE ² × 10 ⁻¹⁰ [W
/ M ³ ] εr: relative permittivity of substance tan δ: dielectric loss of substance f: frequency [Hz] E: electric field strength [V / m]

That is, according to the above formula 1, it is sufficient to use a microwave oscillator having high frequency and high output (electric field strength) for heat generation. However, the frequency of household microwave oven is 2.45 GHz and ISM (Industrial S).
Since the band is defined by "Cientific and Medical" and the output is also determined by the machine, it cannot be changed unnecessarily. So insulator (tableware)
The amount of heat generation can be increased by increasing the dielectric loss factor (εrtan δ) of (1) by some method, and the compounding composition according to the present invention is as follows.

Silicon Carbide: 30 to 45% The amount of silicon carbide blended into the body of a tableware or the like is better if only the calorific value is taken into consideration.
%, The runaway state (run
Away phenomenon) occurs, and a red heat state occurs, and it is difficult to obtain appropriate cooking conditions. Furthermore, in terms of formability, 50
If the composition is more than%, the ceramic molding method (casting, extrusion,
It becomes difficult to use a roller machine (automatic lathe molding machine), and it becomes impossible to obtain a perfect molded body. Further, when the amount of the mixture is reduced, the calorific value is reduced and the heat required for cooking cannot be obtained. To obtain the heat (200 ° C) required for cooking in about 1 minute, 30% of the composition is required. Considering the addition of alumina, the upper limit is 45%, and by setting it to 30 to 45%, these relationships can be satisfied.

Regarding the compounding relationship of silicon carbide as described above, a temperature rising curve when the compounding amount is changed to 20 to 60% is shown in FIG. 1. Silicon carbide to be compounded has a particle size and a grain boundary. Since the permittivity increases in proportion to the ratio (the relative permittivity can be further increased by relatively increasing the grain size of silicon carbide and reducing the thickness of grain boundaries), the larger the better. However, due to the problem of moldability, it is desirable that the particle size distribution of 0.5 to 30 μm accounts for 80% or more.

Α-alumina: 5 to 20% It was announced by Austin et al. In 1946 that the strength was increased by substituting alumina particles with quartz particles in general kneaded clay (CR Austin, HZ. Scho
filed, N.M. L. Haldy, J. et al. Am. Cera
m. Soc. , 29,), when considering a reinforced porcelain in which alumina is added as an aggregate for strengthening particle dispersion, the maximum addition amount of alumina can be the entire aggregate, but in that case, it is The composition becomes 0% and heat generation does not occur. That is, as described above, since at least 30% of silicon carbide is required for heat generation, the addition amount of α-alumina is 5%.
By setting the content to -20%, it is possible to achieve a proper balance between heat generation and high strength.

Regarding this α-alumina, the primary particle diameter is 0.5 to 8 μm under the above-mentioned compounding conditions.
When m is 70% or more, moldability and particle dispersion strengthening are properly achieved.

Although silicon carbide itself is a material having very excellent thermal shock resistance (even as dispersion strengthening particles), when it is dispersed in a porcelain material as a heat source, considering the porcelain as a whole, the shock characteristics due to self-heating. Will be lowered.
That is, since the silicon carbide particles absorb microwaves and generate heat in the microwave oven, thermal shock is given to the surrounding vitreous matrix to generate minute cracks. The cracks generated in each particle propagate at once and lead to destruction. On the other hand, the alumina particles do not generate heat by microwaves and can stop cracks generated around the silicon carbide. Therefore, the amount and size of the alumina particles must be such that the generated cracks cannot be avoided. α-alumina is 5, 1
The bending strength when 0, 20% is added is as shown in FIG. 2, and the strength can be improved to about 15 kg / cm ² or more.

Plasticizer and Melt Material: 50 to 65% Under the compounding conditions of silicon carbide and α-alumina as described above, the plasticizer and melt material such as clay and feldspar are 50 to 65%.
It becomes 65%. That is, such silicon carbide (SiC), α
-Alumina (α-Al ₂ O ₃ ) and clay and feldspar are shown in a ternary state as shown in FIG. 3. Stable strength and thermal shock resistance can be satisfied.

With respect to the plastic material and the molten material, the preferable composition is 30 to 40% of the plastic material such as clay,
It is suitable that the amount of the molten material such as feldspar is 20 to 30%.

To obtain containers such as tableware, the raw materials having the above-mentioned composition are pulverized and mixed in a ball mill, filter-pressed, and then used as a roller machine and a raw material for extrusion molding. This is the same as ordinary clay and manufacturing method, and firing is not limited to atmosphere. Can be fired in an oxidizing or reducing atmosphere (can be fired in a normal shuttle or roller house kiln)
Is.

The equipment to be obtained in the present invention includes various dishes such as dishes such as plates and bowls, cooking utensils such as pots and kettles, lids of these appliances or plate-like bodies set on the inner bottom surface of the appliances or the inner surface of the lids. It is apparent that the equipment can be appropriately formed and implemented.

[0024]

EXAMPLES Specific examples of the present invention will be described below. (Example 1) 30% of silicon carbide (80% of CB-F particle size distribution 1-10 μm manufactured by Taiheiyo Random Co., Ltd.), which is a heat source,
10% of α-alumina for particle dispersion strengthening (80% of A32 particle size distribution 0.5 to 4 μm made by Nippon Light Metal Co., Ltd.), frog clay 30
%, And feldspar 30% were crushed and mixed by a ball mill to form a slurry, which was molded into a plate shape by casting and baked at 1250 ° C. for 30 minutes in an oxidizing atmosphere. The same sintered body was heated in a microwave oven and evaluated. The results are shown in Table 1 below together with the examples described later.

The evaluation item is the water absorption rate (JIS C214
1), moldability [casting, extrusion, roller machine (automatic potter's wheel molding machine)] possible 3 methods, ○, 2 methods △, 1 method ×. Bending strength (JIS R160
1), temperature rising characteristics in microwave oven (by LUXTRON optical fiber thermometer using optical attenuation method that is not affected by electromagnetic wave. Microwave oven is Toshiba Microwave oven ER-
470JF, high frequency output 500W, heating time 3 minutes),
Thermal shock resistance (box shape created by casting (155m
(m × 120 mm × 25 mm) After heating at once in 10 microwave ovens (3 minutes), put in water (about 20 ° C.), do this 20 times, and express by the survival rate of 10).

(Embodiment 2) Silicon carbide (80% of UF-15 particle size distribution 0.5-1 μm manufactured by Lonza, 80%) which is a heat source is used.
0%, α-alumina for strengthening particle dispersion (A3 made by Nippon Light Metal Co., Ltd.
4 particle size distribution 1 to 8 μm 70%) 20%, frog eye clay 3
0% and 20% of feldspar were crushed and mixed with a ball mill to form a slurry, which was molded into a plate by casting and fired at 1200 ° C. for 30 minutes in an oxidizing atmosphere. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Example 3) Silicon carbide (RCP-200F manufactured by Taiheiyo Random Co., Ltd., particle size distribution 10 to 30 μm) as a heat source
m is 80%) and α-alumina for particle dispersion strengthening (A32 made by Nippon Light Metal Co., Ltd. particle size distribution 0.5 to 4 μm is 80%).
%), 30% of frog clay and 30% of feldspar are crushed and mixed in a ball mill to form a slurry, which is molded into a plate by casting and baked at 1100 ° C. for 30 minutes in an oxidizing atmosphere. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Example 4) Silicon carbide as a heat source (CB-F manufactured by Taiheiyo Random Co., Ltd. has a particle size distribution of 1 to 10 μm of 80).
%), 5% of α-alumina for strengthening particle dispersion (80% of A32 particle size distribution 0.5-4 μm made by Nippon Light Metal Co., Ltd.),
30% of frog clay and 25% of feldspar are crushed and mixed with a ball mill to form a slurry, which is then cast into a plate shape for 1100
The product was baked at 30 ° C. for 30 minutes in an oxidizing atmosphere to obtain a product. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Embodiment 5) Silicon carbide which is a heat source (CB-F particle size distribution 1-10 μm manufactured by Taiheiyo Random Co., Ltd. is 80).
%) 45%, α-alumina for particle dispersion strengthening (80% of A32 particle size distribution 0.5-4 μm made by Nippon Light Metal Co., Ltd.) 5%,
30% of frog clay and 20% of feldspar are crushed and mixed in a ball mill to form a slurry, which is then molded into a plate by casting 1250.
Firing was performed in an oxidizing atmosphere at 30 ° C. for 30 minutes. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Example 6) Silicon carbide as a heat source (manufactured by Taiheiyo Random Co., Ltd. has a CB-F particle size distribution of 1 to 10 μm of 80).
%), 5% α-alumina for particle dispersion strengthening (70% of A34 particle size distribution 1-8 μm made by Nippon Light Metal Co., Ltd., 40% frog eye clay, 25% feldspar in a ball mill to form a slurry, Plate-shaped by cast molding, 1250 ° C 3
It was fired in an oxidizing atmosphere for 0 minutes. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

Comparative examples for the examples of the present invention as described above are as follows. (Comparative Example 1) 0% silicon carbide, which is a heat source, and α-alumina (Nihon Light Metal A32 particle size distribution 0.5-4 μm is 80%).
%), 40% of frog clay and 30% of feldspar are crushed and mixed in a ball mill to form a slurry, which is molded into a plate by casting and baked at 1350 ° C. for 30 minutes in an oxidizing atmosphere. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Comparative Example 2) Silicon carbide which is a heat source (CB-F particle size distribution 1-10 μm manufactured by Taiheiyo Random Co., Ltd. is 80).
%) And 10% of α-alumina for particle dispersion strengthening (80% of A32 particle size distribution 0.5-4 μm made by Nippon Light Metal Co., Ltd.).
%, Frogme clay 40%, feldspar 30% crushed with a ball mill
Mix to make a slurry, and cast into a plate shape by casting 12
Firing was carried out at 50 ° C. for 30 minutes in an oxidizing atmosphere. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Comparative Example 3) Silicon carbide as a heat source (RPC-200 particle size distribution manufactured by Taiheiyo Random Co., Ltd. 10 to 30 μm)
80%), 30%, 40% of frog clay and 30% of feldspar are crushed and mixed in a ball mill to form a slurry, which is cast into a plate and fired at 1250 ° C. for 30 minutes in an oxidizing atmosphere.
The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Comparative Example 4) Silicon carbide as a heat source (CB-F manufactured by Taiheiyo Random Co., Ltd. has a particle size distribution of 1 to 10 μm of 80).
%) 50%, α-alumina for strengthening particle dispersion (80% of A32 particle size distribution 0.5-4 μm made by Nippon Light Metal Co., Ltd.) 5%,
25% frog clay and 20% feldspar are crushed and mixed with a ball mill to form a slurry, which is then cast into a plate shape for 1100
Firing was performed in an oxidizing atmosphere at 30 ° C. for 30 minutes. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

(Comparative Example 5) Silicon carbide which is a heat source (CB-F particle size distribution 1-10 μm manufactured by Taiheiyo Random Co., Ltd. is 80).
%), 20% of frog clay and 20% of feldspar are pulverized and mixed in a ball mill to form a slurry, which is molded into a plate by cast molding and fired at 1200 ° C. for 30 minutes in an oxidizing atmosphere. The evaluation items and evaluation method for the obtained product are the same as in Example 1.

The results of the above Examples and Comparative Examples are summarized and shown in Tables 1 and 2 below.

[0037]

[Table 1]

[0038]

[Table 2]

The contents of each evaluation item in Table 2 above are as follows. Water absorption rate is JIS C214
It was evaluated by 1. Regarding the moldability, among the three molding methods of casting, extrusion and roller machine, ○ indicates that 3 methods are possible, Δ indicates that 2 methods are possible, and × indicates that 1 method is possible.
The bending strength was evaluated according to JIS R1601. The temperature rising characteristic in the microwave oven is the actual temperature of the product after heating for 3 minutes. Here, the temperature measuring device is an optical fiber thermometer manufactured by LUXTRON, the microwave oven is manufactured by Toshiba Corporation, and the high frequency output is 500W. The thermal shock resistance is a box type (155 mm × 120 mm × 25 m) created by casting.
m) After heating 10 pieces in a microwave at once (3 minutes),
The process of putting in water (about 20 degreeC) was performed 20 times, and it is represented by the survival rate in 10 pieces. Far-infrared characteristics, device: JEOL Ltd. Fourier transform infrared spectrophotometer JIR-3
505, sample temperature 180 ± 2 ° C, range: 2200-50
The integrated spectral emissivity at 0 cm ^-1 is measured. In the comprehensive evaluation, ◯ means good, Δ means normal, and × means bad.

That is, according to the results of Tables 1 and 2, the one according to the present invention has good moldability, bending strength is appropriately obtained as tableware, and the temperature rise in the microwave oven is 385 to 400.
It was confirmed that it is a preferable cooking device for a microwave oven because it shows a preferable temperature condition for obtaining a brown color on the food when it is placed at ℃, and also has good thermal shock resistance and far-infrared characteristics.

[0038]

According to the present invention as described above, it is possible to properly form a brown mark which is preferable in flavor and food appearance without using special additional heating means, and is excellent in strength and thermal shock resistance. It is possible to provide a self-heating far-infrared radiation cooking equipment for microwave ovens having high durability, and is an invention having a great industrial effect.

[Brief description of drawings]

FIG. 1 is a chart showing the relationship between the content of silicon carbide and the temperature rise in a microwave oven.

FIG. 2 is a chart showing the relationship between the amount of alumina added and the strength.

FIG. 3 is a table showing the scope of the present invention in a ternary phase diagram regarding silicon carbide, aluminum oxide, a plastic material, and a molten material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Kawai 1-34-1 Kambara, Kambara-cho, Anbara-gun, Shizuoka Prefecture Nipparu Giken Co., Ltd. No. 1 within Nikkei Giken Co., Ltd. (72) Inventor Reiko Takazawa 1-34-1 Kambara, Kambara-cho, Anbara-gun, Shizuoka Prefecture

Claims (4)

[Claims] 1. A container body formed and fired using kneaded clay, wherein silicon carbide is 30 to 45% and α-alumina is 5 to 20.
%, Plastic materials such as clay and molten materials such as feldspar are 50 to 6
A self-heating far-infrared radiation cooking appliance for a microwave oven, which is a sintered structure composed of 5%. 2. The self-heating far infrared radiation cooking for a microwave oven according to claim 1, wherein the plastic material such as clay is 30 to 40% and the molten material such as feldspar is 20 to 30%. Equipment. 3. The self-heating far-infrared radiation cooking utensil for a microwave oven according to claim 1, wherein the particle size distribution of silicon carbide is 0.5 to 30 μm of 80% or more. 4. The primary particle diameter of α-alumina is 0.5 to 8 μm.
The self-heating far-infrared radiation cooking utensil for a microwave oven according to claim 1, wherein m is 70% or more.