JP2012117754A - Cooking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wall material of a cooking device, which has a superior heat resistance and durability, and which facilitates removal of contaminants deposited on a wall surface in a heating chamber.SOLUTION: The cooking device 11 includes the heating chamber 12 for storing food, and a heating unit for heating the food in the heating chamber 12. The wall material 14 composing the inside of the heating chamber 12 contains a metal base 29, a surface treated steel sheet plated with a metal 30 having discoloration difference by thermal oxidation smaller than the metal base 29, and a coating layer 31 formed on the surface of the surface treated steel sheet and having heat resistance, corrosion resistance, and hydrophilicity. Accordingly, even if the wall material 14 composing the inside of the heating chamber 12 is contaminated by scattering of a soup, oil, seasoning or the like during cooking, water penetrates between the contaminants and the coating layer 31 owing to hydrophilicity of water with the coating layer 31 to thereby reduce adhesion of contaminants and facilitate removal thereof, resulting in achieving a clean condition all the time.

Description

  The present invention relates to a heating cooker such as a microwave oven, and more specifically to a configuration of a heating chamber that improves the removal performance of contaminants soiled by cooking food and is excellent in heating efficiency.

  In heating cookers such as microwave ovens, the walls inside the heating chamber are contaminated by food that is scattered by cooking, juice from seasonings, etc., so remove these contaminants and keep them always clean and clean. There is a strong demand for it.

  Conventionally, in order to easily clean contaminants, this type of cooking device such as a microwave oven has a non-adhesive fluororesin formed on the surface of a wall material made of a metal member that constitutes the inside surface of the heating chamber. Yes (see, for example, Patent Document 1).

  FIG. 5 shows the structure of the wall material on the inner surface of the heating chamber constituting the conventional cooking device described in Patent Document 1. As shown in FIG. As shown in FIG. 5, the wall material 1 constituting the inside surface of the heating chamber has a non-adhesive film 3 made of a fluororesin having a thickness of about several tens of μm formed on the surface of a metal member 2 such as an aluminized steel plate. .

  On the other hand, there is also a technique in which contaminants attached to the wall surface of the heating chamber are oxidatively decomposed by a catalyst to keep the heating chamber clean without maintenance (for example, see Patent Document 2).

  FIG. 6 shows the configuration of the wall material on the inner surface of the heating chamber constituting another conventional cooking device described in Patent Document 2. As shown in FIG. As shown in FIG. 6, the wall material 4 constituting the inside surface of the heating chamber has a self-cleaning layer 6 including a catalyst that oxidizes and decomposes contaminants at a lower temperature than thermal decomposition on the surface of a metal member 5 of a stainless steel plate. Yes.

  This self-cleaning layer 6 can be obtained by applying a mixture of enamel glaze and a catalyst material such as iron oxide, manganese oxide, copper oxide on the surface of the metal member 5 and baking it, and has a film thickness of 100 μm. It is the above porous layer.

JP 2001-59617 A JP 2004-53212 A

  However, the conventional non-adhesive film made of fluororesin described in Patent Document 1 is an organic resin, so the film is soft and easily scratched when rubbed against the hard surface of a sponge used for cleaning. If it is high, there is a problem that the non-adhesive film peels off.

  In addition, in order to prevent scratches and peeling of the non-adhesive film, it is necessary to wipe it lightly with the soft surface of the sponge, and there is a problem that it cannot be completely removed if the contaminants are firmly attached. It was.

In addition, the fluororesin used as the non-adhesive film has a heat resistance of about 280 ° C. or less, and the non-adhesiveness due to the thermal deterioration of the non-adhesive film is reduced by long-term use or for oven cooking at 300 ° C. or higher. There was a problem that it could not be used.

  On the other hand, the self-cleaning layer containing the catalyst according to the other conventional example described in Patent Document 2 sufficiently exhibits the catalytic effect of oxidatively decomposing contaminants unless the entire surface of the heating chamber is heated to a high temperature of 300 ° C. or higher. However, there is a problem that tarred contaminants remain.

  In addition, since the self-cleaning layer is porous, contaminants erode inside the self-cleaning layer, and it is impossible to completely remove contaminants that could not be oxidatively decomposed by the catalyst with a sponge. The problem is that the remaining contaminants become a source of off-flavors.

  Moreover, the enamel glaze and the composition of the catalyst material constituting the self-cleaning layer absorb energy in the microwave frequency band. In a cooking device that uses microwaves as the heating means, the microwave energy used to heat the food is reduced, so the heating efficiency of the food is degraded, the cooking time is increased, and more power is required. Had problems.

  Further, since the self-cleaning layer is formed by enamel processing, a high temperature of 800 ° C. or higher is required, and there is a problem that an aluminum-plated steel sheet having a low melting point cannot be used.

  The present invention solves the above-mentioned conventional problems, is excellent in heat resistance and durability, can easily remove contaminants attached to the wall surface of the heating chamber, and suppresses absorption loss of microwaves. An object of the present invention is to provide a wall material on the inner surface of a heating chamber that improves the heating efficiency of food.

  In order to solve the above-described problems, the heating cooker according to the present invention includes a heating chamber for storing food and a heating unit for heating the food placed in the heating chamber. The wall material constituting the inner surface of the surface-treated steel plate plated with a metal base material and a metal having a smaller discoloration difference due to thermal oxidation than the metal base material, and heat resistance and corrosion resistance formed on the surface of the surface-treated steel sheet, It is comprised with the coating layer which has hydrophilic property.

  As a result, even if the juice, oil, seasonings, etc. from the food during cooking are scattered and contaminated on the wall surface material constituting the inner surface of the heating chamber, the coating layer having excellent hydrophilicity is applied to the surface of the wall surface material of the present invention. If it is cleaned with a sponge soaked in water or detergent, the water and the coating layer will be familiar, so water will easily penetrate between the contaminant and the coating layer. The contaminants can be easily removed by lowering.

  Furthermore, even if a surface-treated steel plate plated with a metal having a smaller color change difference due to thermal oxidation than a metal base material that is inferior in heat resistance and corrosion resistance to a stainless steel plate as a wall material, the coating layer has excellent heat resistance in addition to hydrophilicity. And corrosion resistance, it is possible to prevent deterioration due to heat and corrosion even when exposed to severe high temperature and corrosion environments such as oven cooking.

  The cooking device of the present invention comprises the inner surface of the heating chamber with a wall material in which a hydrophilic coating layer is formed even if the inner surface of the heating chamber is contaminated by juice, oil, seasonings, etc. that are produced from food during cooking. Therefore, the adhered contaminants can be easily removed, and the surface of the heating chamber can always be kept clean.

Furthermore, it has excellent heat resistance and corrosion resistance in addition to hydrophilicity, so it can prevent deterioration even under severe high temperature and corrosive environment such as oven cooking, and has excellent durability and reliability as a cooking device. Can be realized.

Side surface sectional drawing of the heating equipment cooker in Embodiment 1 of this invention The partial cross section figure of the wall surface material which comprises the heating chamber in Embodiment 1 of this invention Partial sectional drawing of the wall surface material which comprises the heating chamber in Embodiment 2 of this invention Partial sectional view of the wall surface material constituting the heating chamber in Embodiment 3 of the present invention Partial cross-sectional view of a wall material constituting a conventional heating chamber Partial sectional view of wall material constituting another conventional heating chamber

  1st invention is a heating cooker provided with the heating chamber which accommodates a foodstuff, and the heating means which heats the foodstuff mounted in the said heating chamber, The wall surface material which comprises the inner surface of the said heating chamber is metal A surface-treated steel plate that is plated with a base material and a metal having a smaller discoloration difference due to thermal oxidation than the metal equipment, and a heat-resistant, corrosion-resistant, hydrophilic coating layer formed on the surface of the surface-treated steel plate. Is.

  As a result, even if juice, oil, seasonings, etc. from food during cooking are scattered and contaminated on the wall surface material that constitutes the inner surface of the heating chamber, the water and the coating layer are familiar, so the water is covered with the contaminants. It can easily penetrate between the layers and can be easily removed by reducing the adhesion of contaminants, so that a cooker that is always clean can be realized.

  In addition to using a surface-treated steel plate plated with a metal having a smaller color change difference due to thermal oxidation than a metal base material that is inferior in heat resistance and corrosion resistance to a stainless steel plate as a wall material, the coating layer is excellent in addition to hydrophilicity. Because it has heat resistance and corrosion resistance, it can prevent deterioration due to heat and corrosion even when exposed to severe high temperature and corrosion environments such as oven cooking, and realizes excellent durability and reliability as a heating cooker can do.

  In particular, the second invention is the surface-treated steel sheet according to the first invention, wherein the metal substrate contains iron, and the metal having a smaller discoloration difference due to thermal oxidation than the metal substrate contains aluminum or zinc. is there.

  As a result, even if it is affected by thermal oxidation during the formation of the coating layer, since it is close to the original color, there is no discoloration that impairs the appearance, and the heat-cured coating layer has excellent heat resistance, so the color change proceeds Is prevented, and the color at the time of forming the coating layer can be maintained.

In the third invention, in particular, the coating layer of any one of the first and second inventions is made of a material containing SiO ₂ . As a result, high heat resistance and wear resistance can be realized, so that excellent durability can be realized, and in the cooking device using microwaves as a heating means, the complex permittivity of the wall surface material can be reduced. Therefore, the absorption of the microwave by the wall material can be suppressed, and the heating efficiency of the food by the microwave can be increased.

  In the fourth invention, in particular, the coating layer of any one of the first to third inventions has a thickness of 1 μm or less. As a result, the microwave absorption loss due to the wall material can be greatly suppressed, and the high heat reflection heat characteristics of the metal member can be prevented from being lowered, so that the heating efficiency of the food can be further improved, and the cooking time Shortening and excellent energy saving performance can be realized.

In the fifth invention, in particular, a conductive coating layer is formed on the surface of the coating layer of any one of the first to fourth inventions so that a part of the coating layer is exposed. Thereby, since the electric field generated by the microwave can be reduced by the conductive coating layer, loss due to microwave absorption of the coating layer can be further suppressed, and the heating efficiency of the food can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a cross-sectional view as viewed from the side of the heating cooker according to Embodiment 1 of the present invention.

  In FIG. 1, the heating chamber 12 is provided in the main body 11 of the heating cooker, and is composed of an opening / closing door 13 for taking in and out food and a wall surface material 14 including a bottom plate, a side plate, an upper plate, and a rear plate.

  An upper heater 15 and a lower heater 16 are provided in the heating chamber 12, and the food 18 placed on the net 17 is heated so as to be sandwiched between the upper heater 15 and the lower heater 16. A magnetron 19 that generates microwaves as heating means is provided behind the heating chamber 12, and the food can be heated by supplying at least one of microwaves and radiant heat and convection heat of the upper and lower heaters. It is like that.

  The upper heater 15 is provided with an upper heater thermocouple 20 so as to be in contact with the surface thereof, and is covered with a metal tube so as not to be affected by the microwave from the magnetron 19, and a heater radiation amount detecting means of the upper heater 15 is provided. It is composed. Further, a lower heater thermocouple 21 is similarly provided on the surface of the lower heater 16 and serves as a heater radiation amount detecting means.

  The heating chamber 12 is provided with a thermistor 22 which is an internal temperature detecting means, and the upper heater thermocouple 20, the lower heater thermocouple 21 and the thermistor 22 are electrically connected to the control means 23, respectively. Based on the output, the amount of heating can be controlled by controlling the energization of the upper heater 15 and the lower heater 16.

  A rotating antenna 24 is provided as radio wave agitating means for irradiating the microwave generated from the magnetron 19 into the heating chamber 12. Then, the microwave generated from the magnetron 19 is transmitted to the rotating antenna 24, and the microwave is supplied from the rotating antenna 24 into the heating chamber 12 with stirring.

  The magnetron 19 and the rotating antenna 24 are provided on the rear and top surfaces of the heating chamber 12, but are not limited thereto, and may be provided on the bottom or side of the heating chamber 12.

  In order to ventilate the air in the heating chamber 12, an exhaust port 25 provided at the upper part of the side wall in the heating chamber 12 and an exhaust outlet 26 provided to communicate with the outside of the main body 11 and a blower 27 as a ventilation means. The air in the heating chamber 12 is exhausted to the outside of the main body 11.

  FIG. 2 is a partial cross-sectional view of wall surface material 14 constituting the inner surface of the heating chamber according to Embodiment 1 of the present invention.

In the figure, the wall surface material 14 constituting the inner surface of the heating chamber 12 includes a surface-treated steel plate in which a metal 30 having a smaller color change difference due to thermal oxidation than the metal substrate 29 is plated on the surface of the metal substrate 29, and the surface treatment. A coating layer 31 having heat resistance, corrosion resistance, and hydrophilicity is formed on the surface of the steel plate.

  In addition, heat resistance here means that discoloration due to heat of the surface-treated steel sheet does not occur even in a temperature environment of 500 ° C. or higher, and corrosion resistance means corrosion caused by ingredients used in cooking and seasonings. No, hydrophilic means that the contact angle with water is 20 ° or less.

  As the metal base material 29 used for the surface-treated steel sheet, since it becomes a skeleton of the heating chamber 12 of the heating cooker, it is excellent in workability and mechanical strength, and low cost is required. It is desirable to use a steel plate as a component.

However, the coating layer 31 is obtained by applying a coating containing the components of the coating layer 31 to a base material and heat-curing. When using a steel plate mainly composed of iron, the coating layer 31 is subjected to heat-curing. The surface is easily affected by oxidation due to diffusion of oxygen, and iron is oxidized in a steel sheet containing iron as a main component to generate Fe ₂ O ₃ . Due to this reaction, the steel sheet containing iron as a main component changes its color from grayish white to brown, and a remarkable appearance color change occurs.

  Therefore, it is necessary to use a surface-treated steel plate in which a metal 30 having a small difference in discoloration due to thermal oxidation is plated on a steel plate mainly composed of iron. Examples of the metal 30 with less discoloration due to thermal oxidation include those containing aluminum or zinc.

  Even when aluminum and zinc are affected by thermal oxidation during the formation of the coating layer 31, they are close to the original color, so there is no discoloration that impairs the appearance, and the heat-cured coating layer 31 is excellent in heat resistance. The progress of the color change is prevented, and the color at the time of forming the coating layer 31 can be maintained.

  As these surface-treated steel plates, aluminum-plated steel plates, galvanized steel plates, and galvalume steel plates containing aluminum and zinc are optimal.

  When the food is cooked, the wall material 14 is contaminated by the scattering of juice, oil, seasonings, and the like from the heated food. Conventionally, as a wall material of this type of cooking device, a material having a non-adhesive film containing a fluororesin is often used. This is because the fluororesin has an excellent water repellency and therefore has a weak adhesive force with contaminants and can be easily removed.

  However, when the cooking temperature is increased, contaminants such as oil are tarred by the polymerization reaction, and the contaminants adhere firmly even to the fluororesin. In order to remove this stubborn dirt, if a cleaning member such as a sponge used for cleaning is strongly pressed and rubbed, there is a problem that a non-adhesive film containing a fluororesin is scratched or peeled off. It was.

  In addition, when the wall surface material is used at a temperature of 280 ° C. or higher, the fluororesin is thermally deteriorated and the water repellency is lowered. Therefore, the non-adhesive film containing the fluororesin is limited to use at 280 ° C. or lower Met.

  Since the coating layer 31 applied to the present invention has hydrophilicity unlike a non-adhesive film containing a fluororesin, the coating layer 31 is well-familiar with water, and water used for cleaning penetrates between the coating layer 31 and contaminants. Since the adhesion of contaminants can be significantly reduced, the contaminants can be easily removed.

Examples of the material of the coating layer 31 include a siliceous (SiO ₂ ) coating layer formed by a sol-gel method, and an oxide-based coating layer containing silicon and zirconium. Zirconium complex oxides are suitable.

Further, since the coating layer 31 is composed of an inorganic compound containing siliceous (SiO ₂ ), the coating layer 31 has high heat resistance and can maintain hydrophilic properties even in a temperature environment of 500 ° C. or higher. Since the hardness of 31 is high and it has high wear resistance, excellent durability can be realized.

  The covering layer 31 can be formed as a thin film. By forming a thin film, the dielectric constant and dielectric loss (complex dielectric constant) in the microwave frequency band can be reduced, so that loss of microwave power can be suppressed and food heating efficiency can be increased. Can do. As a result, cooking time can be shortened and energy can be saved.

  Moreover, the coating layer 31 needs to suppress absorption loss due to microwaves and maintain long-term adhesion with the surface-treated steel sheet used as the base material of the wall surface material 14, and the coating layer 31 is formed. Since it is necessary to prevent peeling and cracking when performing press working or bending later, the film thickness of the coating layer 31 is preferably in the range of several hundred nm to 1 μm.

Moreover, since the coating layer 31 is a thin film and the main component of the material of the coating layer 31 is siliceous (SiO ₂ ), the coating layer 31 can be formed as a transparent film. It is possible to effectively reflect the radiant heat from the upper heater 15 and the lower heater 16 without lowering the heater power, and it is possible to suppress the loss of heater power.

  Furthermore, since the coating layer 31 has a dense film structure and can suppress the permeation of oxygen even when the temperature of the wall surface material 14 rises to 500 ° C. or higher, the coating layer 31 is plated on the metal base material 29. Oxidation of the metal 30 having a smaller discoloration difference due to thermal oxidation than the metal base material 29 is prevented, and discoloration due to heat can be prevented. As a result, the appearance color and heat reflection characteristics of the initial wall surface material 14 can be maintained even when used at a high temperature for a long time, and excellent durability can be realized.

  In order to form the coating layer 31 into a thin film, the particle size of the starting material for film formation is at the nm level, or the particle size generated by the hydration reaction or hydrolysis reaction of a silicon compound or a zirconium compound is nm. It needs to be a level.

  The coating layer 31 having a film thickness of 1 μm or less does not cause peeling or cracking even if it is pressed or bent. Therefore, the coating layer 31 can be pre-coated, and the coating layer 31 is formed after the surface-treated steel plate plated with the metal 30 having a smaller color difference due to thermal oxidation than the metal substrate 29 is processed into the shape of the heating chamber 12. The processing cost is lower than that of the post coat to be processed, and the cost can be reduced.

  As the coating layer 31, an oxide-based coating layer containing silicon and zirconium has been described. However, the coating layer 31 is not limited to this material, and the metal base material 29 in which the surface energy of the coating layer 31 is the base material of the wall surface material 14. A material whose surface energy is smaller than the surface energy of the metal 30 having a smaller discoloration difference due to thermal oxidation than the metal substrate 29 plated on the surface, or a ratio of the surface energy of contaminant particles to the surface energy of the coating layer 31 is increased. Material is applied.

  In addition, even if welding may be accompanied when processing into the shape of the heating chamber 12, since the coating layer 31 is a thin film, weldability is not impaired, but the coating layer 31 of the welded portion is damaged, so that welding is performed. Caulking is desirable instead of.

  Further, by providing the coating layer 31 on the glass surface inside the opening / closing door 13, the contamination resistance of the opening / closing door 13 can be improved.

(Embodiment 2)
FIG. 3 is a partial cross-sectional view of the wall surface material constituting the inner surface of the heating chamber according to Embodiment 2 of the present invention. The difference from the first embodiment is that a thick coating layer is provided instead of the thin coating layer 31.

  In the figure, a wall surface material 32 constituting the inner surface of the heating chamber 12 includes a surface-treated steel plate in which a metal 30 having a smaller color change difference due to thermal oxidation than the metal substrate 29 is plated on the surface of the metal substrate 29, and this surface treatment. A coating layer 33 having heat resistance, corrosion resistance, and hydrophilicity is formed on the surface of the steel plate.

This coating layer 33 is a metal in which an inorganic ceramic oxide mainly composed of siliceous (SiO ₂ ) is mixed with an inorganic metal oxide that does not impair hydrophilicity and has a smaller discoloration difference due to thermal oxidation than the metal substrate 29. 30 is applied to the surface of the surface-treated steel plate plated and fired, and the layer has a smooth surface with a film thickness of several tens of μm.

  Unlike the non-adhesive film containing a fluororesin, the coating layer 33 applied to the present invention has hydrophilicity, unlike the non-adhesive film containing the fluororesin, so it is familiar with water and used during cleaning. Since water permeates between the coating layer 31 and the contaminants, and the adhesive force of the contaminants can be significantly reduced, the contaminants can be easily removed.

  Since the coating layer 33 in the present embodiment has a thickness of several tens of μm, the effect of suppressing discoloration and corrosion resistance of the surface-treated steel sheet due to thermal oxidation can be improved as compared with the first embodiment.

  Further, since the coating layer 33 is thick, even when it is rubbed with a hard nylon bundler when cleaning the inside of the heating chamber 12, it is possible to lengthen the time until the surface-treated steel sheet is exposed. Therefore, durability superior to the coating layer 31 of the first embodiment can be realized.

  Further, by increasing the film thickness of the covering layer 33, it is possible to increase the effect of preventing thermal oxidation and corrosion of the surface-treated steel sheet as a base, so that the color change difference due to thermal oxidation is smaller than that of the metal substrate 29. There is no need to use a surface-treated steel plate on which the metal 30 is plated, and a steel plate containing iron as a main component can be applied, and cost reduction can be achieved.

On the other hand, since the coating layer 33 is thick, the complex dielectric constant in the microwave frequency band is larger than that of the coating layer 31 of the first embodiment, and the loss of the microwave power is increased, so that the coating layer becomes a skeleton. It is better to reduce the amount of materials other than siliceous (SiO ₂ ) and make the film thickness as thin as possible.

  In addition, since the coating layer 33 is thick, if the pressing or bending process is performed after the coating layer 33 is formed on the surface-treated steel sheet, cracks or peeling occurs in the coating layer 33. Such a precoat cannot be applied, and it is necessary to form the coating layer 33 after processing the surface-treated steel sheet into the shape of the heating chamber 12 in advance.

  In addition, the material similar to the coating layer 31 can be applied as the material of the coating layer 33.

(Embodiment 3)
FIG. 4 is a partial cross-sectional view of a wall surface material constituting the inner surface of the heating chamber according to Embodiment 3 of the present invention.

The difference from the second embodiment is that a conductive coating layer is provided on the surface of the thick coating layer 33 so that a part of the coating layer 33 is exposed. Other materials are the same as those of the second embodiment. The same applies.

  In the figure, a wall surface material 34 constituting the inner surface of the heating chamber 12 is a surface-treated steel plate in which a metal 30 having a smaller color change difference due to thermal oxidation than the metal substrate 29 is plated on the surface of the metal substrate 29, and this surface treatment. A coating layer 33 having heat resistance, corrosion resistance, and hydrophilicity is formed on the surface of the steel plate, and a conductive coating layer 35 is formed so that a part of the coating layer 33 is exposed on the surface of the coating layer 33. This conductive coating layer 35 is formed of a thin film of several μm or less.

  By forming the conductive coating layer 35 so that a part of the coating layer 33 is exposed, the electric field generated by the microwave can be eliminated by the conductive coating layer 35, so that the coating layer 33 absorbs the microwave. The amount of loss can be reduced, and the heating efficiency of food can be improved.

  The conductive coating layer 35 needs to cover the entire coating layer 33 in order to reduce the loss due to the absorption of microwaves. However, since the intended hydrophilic function is lost, a part of the coating layer 33 is formed. It is desirable to form so as to be exposed.

  The conductive coating layer 35 is preferably a film that is electrically connected on the surface of the coating layer 33 because the higher the conductivity, the greater the effect of eliminating the electric field generated by the microwave.

  The material of the conductive coating layer 35 preferably has high conductivity, but metal oxides such as tin oxide and indium oxide are preferable in terms of conductivity and durability.

  Moreover, the concealment area with respect to the coating layer 33 of the electroconductive coating layer 35 is suitably set by the required specification of the heating efficiency as a heating cooker, and is not limited.

  Moreover, the conductive coating layer 35 can suppress loss due to microwave absorption of the door 13 by providing it on the glass surface inside the door 13.

  In addition, in Embodiment 1-3 of this invention, although the microwave heating cooker was described as a heating cooker, the coating layer of this invention is contaminated with foods and seasonings, such as an IH cooker, an electric oven, and a gas range. Applicable to all cookers.

  As described above in detail, the cooking device according to the present invention can easily remove contaminants by providing a hydrophilic coating layer on the wall surface of a cooking device that is contaminated with food and seasonings, and is hygienic. Therefore, it can be applied to household appliances and industrial equipment such as an inner pot of a rice cooker and a drum of a washing machine that require cleanliness in addition to cooking equipment.

12 Heating chamber 1, 4, 14, 32, 34 Wall material 29 Metal base material 30 Metal 31, 33 Coating layer 35 Conductive coating layer

Claims (5)

In a heating cooker comprising a heating chamber for storing food and a heating means for heating the food placed in the heating chamber, the wall material constituting the inner surface of the heating chamber includes a metal substrate and the metal substrate. A cooking device comprising a surface-treated steel plate plated with a metal having a smaller color difference due to thermal oxidation than a material, and a coating layer having heat resistance, corrosion resistance, and hydrophilicity formed on the surface of the surface-treated steel plate. 2. The cooking device according to claim 1, wherein the surface-treated steel sheet has a configuration in which a metal base contains iron, and a metal having a smaller discoloration difference due to thermal oxidation than the metal base contains aluminum or zinc. The cooking device according to claim 1, wherein the coating layer includes SiO ₂ . The cooking device according to any one of claims 1 to 3, wherein the coating layer has a thickness of 1 µm or less. The cooking device according to any one of claims 1 to 4, wherein a conductive coating layer is formed on the surface of the coating layer so that a part of the surface of the coating layer is exposed.

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