JP3001749B2 - Coating for high-temperature cooking appliance and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a structure of a film formed on a base material such as a wall surface of a heating chamber such as a microwave oven and an oven toaster, and a cooking surface such as a hot plate and a cooking pot. In particular, the present invention relates to a coating for a high-temperature cooking appliance which is improved so that oil stains are not noticeable even when food oil quality adheres. Further, the present invention relates to a method for producing such a film for a high-temperature cooking appliance.

[0002]

2. Description of the Related Art A microwave oven and a hot plate as conventional high-temperature cooking appliances are respectively shown in the drawings. FIG.
FIG. 4 is a perspective view of a microwave oven, and FIG. 4 is a perspective view of an inner box used in the microwave oven. The microwave oven 2 includes a main body 4 and a door 6. An inner box 8 is fitted into the main body 4, and the inner box 8 includes left and right side walls 10a,
10b, a top plate 12, a bottom plate 14, a back plate 16, and a front plate 18. The top plate 12 is provided with a high-temperature heat irradiation hole portion 20 having a plurality of holes for introducing heat of a heater (not shown) provided on the top plate 12 into the inner box 8. ing. In addition, 22 is a back surface of the door.

FIG. 5 is a sectional view of an electric hot plate. The electric hot plate 24 includes a plate 26 and a lid 28.
Consists of The plate 26 is made of an aluminum alloy casting die-cast material, and has a sheath heater 30 embedded therein.

[0004] Then, the wall surface of the inner box 8 of the microwave oven and the cooking surface 25 of the plate plate 26 of the electric hot plate.
Include stainless steel sheet having heat resistance, enameled steel sheet or tetrafluoroethylene resin, PES resin,
A heat-resistant polymer composition comprising a binder such as a silicone resin or a polysiloxane resin, an inorganic pigment and a filler, or a heat-resistant metal coated with ceramic is used.

[0005] In the development of high-temperature, high-speed cooking appliances, there is a demand for shortening the cooking time in order to improve the taste of cooked foods and to make effective use of time. Therefore, it is necessary to process foodstuffs at high temperature, and it is necessary to make the cooking surface 25, the inner wall of the inner box of the oven, and the inner surface of the door heat-resistant. However, the above-mentioned conventional microwave oven and electric hot plate were insufficient in high-temperature heat resistance.

Therefore, an organic solvent varnish using polytitanocarbosilane as a binder, a heat-resistant pigment made of a heat-resistant metal oxide or composite oxide, and a paint containing a paint additive are added to a cooking surface of a hot plate or There has been disclosed a technique for baking on the wall surface of an inner box of a microwave oven or the like to improve heat-resistant oxidation resistance, corrosion resistance, and cleanability, and to prevent burning of food (hereinafter referred to as Prior Art 1).

Further, in order to further improve these, a coating material in which a fluorine resin powder which is familiar with the above-mentioned coating material using polytitanocarbosilane as a binder is added in an amount of 20% or less is coated on the uppermost layer. There is a technology for forming
282626 publication: Prior art 2).

[0008] Further, after a coating film is formed by using a coating material containing polytitanocarbosilane containing the above-mentioned fluororesin powder as a binder, a thin non-adhesive film of fluororesin is further formed on the uppermost layer. (Japanese Unexamined Patent Publication No. 3-326)
No. 18: Prior Art 3).

As a next improvement, there is a technique in which an uneven layer having a color tone different from that of a ceramic layer formed in a lumpy spot pattern is provided under a thin non-adhesive film made of a fluororesin of prior art 3 (particularly). Published Unexamined Japanese Patent Application No. Hei 4-93517: Prior Art 4).

[0010]

In the above prior art 1, the coating film formed from the coating material containing polytitanocarbosilane as a main component is hardened and sintered at 300 to 320 ° C. for 20 minutes. When the temperature is further increased, about 400
From the temperature of ℃, the polymer of polytitanocarbosilane becomes ceramic. By heating for a long time or further heating at a high temperature of 600 to 800 ° C., the polytitanocarbosilane polymer is completely ceramicized. The ceramic coating thus obtained is unique in that it has high temperature heat resistance.

However, cooking appliances using the ceramic coating film also have the following problems. That is, in an oven using an infrared heater that emits a high temperature of 800 ° C., meat and oily drip scattered from cooked foods such as fish, beef, pork, and chicken adhere to the coating film and become charred, I do. The wall temperature at this time is 2
If the temperature is 50 ° C. or lower, or if the cooking time is 30 minutes or less even when heated to 300 ° C., the solidified matter adhered to the wall surface is immediately peeled off, and there is no problem in cleaning properties.

However, when the internal temperature is raised to a high temperature of 300 ° C., the general wall surfaces (side walls 10 a and 10 b and the back plate 16) are heated to a high temperature of 280 to 300 ° C. The bottom surface 14 to which the heat rays of ℃ are irradiated becomes as high as 300 ℃. Further, in a microwave oven having a convection function of circulating hot air and keeping the inside of the refrigerator at 300 ° C., the temperature near the hot air blowing hole becomes a high temperature of about 400 to 450 ° C. Under such high temperatures, the oil droplets attached to the coating film have very strong adhesion,
It cannot be easily obtained by ordinary cleaning. Therefore, if used for 7 hours to 100 hours, the attached oil droplets solidify, carbonize, and finally ash, causing a situation in which the coating is eroded to expose the bare ground. . Therefore, the coating film containing polytitanocarbosilane as a main component has a problem in practical use.

Next, problems of the prior art 2 will be described. FIG. 6 is a cross-sectional view of the film structure disclosed in Prior Art 2. Reference numeral 32 denotes a base material such as a cooking surface of a high-temperature cooking appliance or a wall surface of a heating chamber. On a base material 32, a ceramic layer 34 formed by converting polytitanocarbosilane as a main component into a ceramic is formed. Pigment particles 36 are embedded in the ceramic layer 34. Ceramic layer 3
A non-adhesive resin layer 38 containing a non-adhesive resin is formed on 4. At the interface between the ceramic layer 34 and the non-adhesive resin layer 38, the ratio between the non-adhesive resin 40 and the polytitanocarbosilane continuously changes up and down. That is, the concentration of the non-adhesive resin 40 increases toward the upper layer of the ceramic layer 34, and the concentration of the non-adhesive resin 40 reaches 100% in the uppermost layer of the ceramic layer 34.

However, actually, when a microwave oven or a hot plate is manufactured in a mass production line, the prior art 2 is a method in which non-adhesive resin powder is baked on the ceramic layer 34. It is very difficult to finish the structure shown in FIG. 6, and the non-adhesive resin 40 may not float and deposit on the uppermost layer of the ceramic layer due to the secondary adhesion of paint mist during spraying. Further, in order to finish as shown in FIG. 6, it is necessary to spray a sufficient amount of paint to increase the film thickness excessively and to obtain a glossy painted surface. However, when such a thick film is finished, a wavy or "sagging" may occur, and the appearance may be unsightly. Further, even if the concentration of the non-adhesive resin 40 is 100% in the uppermost layer, even if the tetrafluororesin powder, which is a high-temperature heat-resistant material for adding paint, reaches the melting point, its fluidity is poor, It is difficult to say that the non-adhesiveness due to high-temperature food scorch is sufficient because it has a fine space in which the particles are in close contact with the particles.

Next, problems of the prior art 3 will be described. FIG. 7 is a cross-sectional view of the film structure disclosed in Prior Art 3. E represents a base material such as a cooking surface of a high-temperature cooking appliance or a wall surface of a heating chamber. On a base material E, a ceramic layer A is formed by ceramicizing a paint containing polytitanocarbosilane, which is a main component, pigment particles, and fluororesin powder. The fluororesin layer C is formed on the ceramic layer A. The fluororesin layer C is formed by applying a liquid coating of a dispersion-type fluororesin on the ceramic layer A in a marbling state or in a thin and continuous manner, followed by baking.

The prior art 3 also discloses a film structure shown in FIG. That is, on the base material E, the ceramic layer D formed by converting the main component polytitanocarbosilane and pigment particles into a ceramic is formed. On the ceramic layer D, there is formed a ceramic layer A made of a main component of polytitanocarbosilane, pigment particles, and fluororesin powder. The fluororesin layer C is formed on the ceramic layer A.

In the prior art 3, the coating for a high-temperature cooking appliance constituted as described above has the non-adhesive property while maintaining the excellent characteristics of polytitanocarbosilane such as high-temperature heat resistance. Therefore, this film has complete long-term durability and is non-adhesive, and has a film structure that prevents staining due to penetration of contaminants into the ceramic film. In a microwave oven that has been mass-produced and made into a product, when pork, beef, chicken and the like are actually cooked, good results can be obtained in terms of oily or charred adhesion. However, if you look closely, there is a problem that the trace of adhesion of the grease remaining after cleaning is soaked into the ceramic layer A, and there is a problem that the trace of oil stain is conspicuous depending on the viewing angle.

Next, problems of the prior art 4 will be described. FIG. 9 is a cross-sectional view of the film structure disclosed in Prior Art 4. E represents a base material such as a cooking surface of a high-temperature cooking appliance or a wall surface of a heating chamber. On a base material E, a ceramic layer D formed by ceramicizing polytitanocarbosilane as a main component and pigment particles is formed. On the ceramic layer D, there is formed a ceramic layer A made of a main component of polytitanocarbosilane, pigment particles, and fluororesin powder. An uneven layer B having a lumpy spot pattern is formed on the ceramic layer A by using a paint obtained by adding a few percent of mica powder pigment to the paint for the ceramic layer A,
The fluororesin layer C is formed on the uneven layer B.
The fluororesin layer C is formed by applying a dispersion-type fluororesin liquid paint continuously or thinly on the uneven layer B, followed by baking.

In the prior art 4, the coating for high-temperature cooking equipment constituted as described above has the high-temperature heat resistance and non-adhesiveness of polytitanocarbosilane, and is dyed by the penetration of contaminants into the ceramic coating. By adding the uneven layer B having a lumpy spot pattern, even if the fats and oils of the adhering foods permeate the ceramic layer A, the stain marks are caused by the light interference phenomenon caused by the black color of the ceramic layer A and the lumpy spots of the uneven layer B. , The stain marks disappear, and as a result,
Oil stains are less noticeable. However, although the oil stain became inconspicuous, the non-adhesiveness which had been a problem in the prior art 3 caused the surface of the fluororesin layer C to be oxidized by heat and food contaminants during long-term use, and that the fluororesin layer C Was marbled or formed into a thin film having a thickness of 5 μm, and it was left unresolved that the food adhered to the food and became sticky and fixed.

In view of the above, the present invention has been developed for long-term use while maintaining the high-temperature heat resistance of polytitanocarbosilane and the non-adhesiveness of a fluororesin film, with no noticeable oil stain marks. An object of the present invention is to provide a coating for a high-temperature cooking appliance and a method for producing the coating, which are improved so as to maintain non-adhesion forever against scorching caused by burning.

[0021]

The object of the present invention is to provide a film formed on a substrate E such as a cooking surface of a high-temperature cooking appliance or a wall surface of a heating chamber. A fluororesin is added to the undercoat D on which a certain polytitanocarbosilane varnish and heat-resistant pigment are ceramicized, and an acrylic resin, a silicone resin or a silicone acrylic resin is added as an additive X. A mixed layer, which is an intermediate coating film A that has been ceramicized by coating with a mixture of the above, and a black dispersion-type fluororesin coating to which an inorganic pigment including a metal oxide pigment is added is applied on the mixed layer, And a non-viscous film which is a baked continuous film-like upper coating film C.

The method for producing this film is such that a coating material in which a polytitanocarbosilane varnish as a main component and a heat-resistant pigment are made liquid with an organic solvent is applied and formed on a substrate E, and then the coating material is coated with a fluororesin. After coating and forming the intermediate coating A on the lower coating D with an acrylic resin, a silicone resin or a coating mixed with a silicone acrylic resin, the organic coating is applied to the intermediate coating A by drying at room temperature or by forced drying. In a state where only the surface is volatilized, a liquid coating of a black dispersion type fluororesin to which an inorganic pigment containing a metal oxide is added is applied on the intermediate coating film in a continuous film form and sintered. is there.

[0023]

In the above means for solving the above problems, the intermediate coating A contains a fluororesin powder and an acrylic resin, a silicone resin or a silicone acrylic resin to form a mixed layer of a ceramic and a fluororesin, and the intermediate coating A is dried at room temperature. In the state,
Because only the surface is dried and the liquid paint of the dispersion type fluororesin is applied, the bond between the ceramic layer and the fluororesin film becomes stronger with acrylic resin, silicone resin or silicone acrylic resin interposed.
No peeling occurs. In addition, in the upper coating film C, the whitening phenomenon at high temperature is prevented by the fluororesin containing the metal oxide pigment, and the trace due to oil contamination in actual cooking is not seen.

[0024]

FIG. 1 is a sectional view of a film for a high-temperature cooking appliance according to one embodiment of the present invention. On the base material E, a paint to be the lower coating film D is spray applied so as to have a finish of 10 to 20 μm. As the base material E, an aluminum-plated steel sheet, an Al-Zn-plated steel sheet (galvalume steel sheet), or a 13 or 18Cr stainless steel sheet which has been subjected to pretreatment such as degreasing, rust removal, chemical conversion treatment, and sandblasting in advance is used.

As the undercoat paint, polytitanocarbosilane (for example, Tyrannocoat manufactured by Ube Industries, Ltd.)
And C that withstand high temperatures in organic solvent varnishes containing
A mixture of an inorganic pigment of a metal oxide such as o, Mn, and Cr or a composite oxide, a dispersant, a silicone oil, and an organic solvent was used. The general proportions of this paint are summarized below.

Organic solvent varnish containing tyrano coat: 20 to 30 parts Heat resistant pigment: 30 to 40 parts Dispersant and oil: 1 to 2 parts Solvent: 30 to 40 parts In the above mixing ratio, the specific gravity of the coating material is 1.1. ~
1.8, it is preferred that the paint be blended so that the nonvolatile content of the paint is 55 to 60%. The color of the paint is preferably black, which is close to black, by carefully selecting heat-resistant pigments and additives.

Next, on the lower coating film D, 1
Sprayed to a finish of 0-20 μm. To this paint, 15 ± 5 parts of a fluororesin powder (Hostaflon # 9205 manufactured by Hoechst Japan KK) was added and mixed in addition to the blending ratio of the above-mentioned paint, and further, to improve the adhesion of the fluororesin. As the additive X, an acrylic resin, a silicone resin, or a black paint having a white tint obtained by adding and mixing 15 to 25 parts of a silicone acrylic resin is preferable. The coating film A is dried at room temperature or forcedly dried,
The organic solvent is volatilized, and only the outermost surface is dried.

Next, as the upper coating film C, a liquid coating of a fluororesin of a dispersion type tetrafluoroethylene resin (for example, black silk type product number EK-4609BK of Daikin Industries Co., Ltd.) having a thickness of 5 to 15 μm. It is applied to a continuous film so as to have a thickness, dried at room temperature or pre-dried at 150 ° C. for 20 minutes, and then dried at 380 to 420 ° C.
At a temperature of 10-20 minutes. Then, a film having a cross-sectional structure shown in FIG. 1 is formed. At this time, the upper coating film C can be conventionally finished only as a thin film having a thickness of 5 μm or less or a marbling, but a continuous film of 5 to 15 μm has a sufficient amount of a fluororesin film (tetrafluoroethylene resin).
Becomes In addition, Fe-M is contained in the black paint of the fluororesin.
When a paint containing a black inorganic pigment containing an n-Co-Cr-based composite oxide and carbon black is used, heat-resistant discoloration and whitening can be prevented. In the above embodiment, the case where the undercoat D is formed has been described, but a structure in which the undercoat D is omitted may be employed.

Next, a film having the above-described structure is
Points to be considered for making the upper coating film C of the uppermost layer thicker than the conventional coating film will be described.

An organic solvent varnish containing polytitanocarbosilane and a middle-coat paint mainly composed of a heat-resistant paint improve the interlayer adhesion between the thick paint and the upper paint as compared with the conventional paint. Therefore, the composition must be such that it does not delaminate even at high temperatures or for a long time. That is, the coating composition of the portion corresponding to the conventional middle coat A is
When the paint for the top coat is applied thickly, the middle coat A
From the interface between the film and the upper coating film C. Therefore, conventionally, the paint for the upper coating film has been finished into a thin marbled film or a film having a thickness of 5 μm or less to prevent delamination. On the surface of the coating film formed by the conventional method, since the coating film of the upper coating film C is thin,
The food oil quality at the time of cooking is scattered and adheres, and the temperature rises to 150 to 400 ° C., so that it passes through the upper coat C and reaches the middle coat A, and combines with the ceramic to firmly stick and adhere. As a result, the cooking surface was not easily peeled off, quickly contaminating the cooking surface and giving an unsightly appearance.

Therefore, a test was conducted to select the resin to be added to the coating for the intermediate coating in order to enhance the adhesion of the fluororesin to the coating for the intermediate coating and to enable the formation of a thick film of the fluororesin. It is shown in FIG.

[0032]

[Table 1]

Here, the coating material A is a coating material in which a fluororesin powder is added in a blending amount of 20% or less to a coating material using polytitanocarbosilane as a binder. The adhesion of the fluororesin is determined by a 2 mm-wide gobang test. The acrylic resin is, for example, Acridic A4 manufactured by Dainippon Ink and Chemicals, Inc.
05, alkyd resin is, for example, Beccolite M-6005-60 manufactured by Dainippon Ink and Chemicals, and epoxy resin is, for example, Epicron 84 manufactured by Dainippon Ink and Chemicals, Inc.
0, melamine resin is, for example, Super Beckamine J-820-60 manufactured by Dainippon Ink and Chemicals, silicone resin is, for example, KR211 manufactured by Shin-Etsu Chemical Co., Ltd., silicone acrylic resin is, for example, KR9706 manufactured by Shin-Etsu Chemical Co., Ltd., The silicone polyester resin is, for example, KR5203 manufactured by Shin-Etsu Chemical Co., Ltd.

This indicates that the adhesion of the fluororesin can be obtained by adding any of the acrylic resin, the silicone resin, and the silicone acrylic resin to the coating for the intermediate coating.

In addition, a resin variation test of the middle coat paint was conducted to select an optimum mixing ratio of the resin to be added to the middle coat paint, and the results are shown in Table 2.

[0036]

[Table 2]

Here, the coating material A is a coating material in which a fluororesin powder is added in a blending amount of 20% or less to a coating material using polytitanocarbosilane as a binder. Silicone acrylic resin is, for example, KR9706 manufactured by Shin-Etsu Chemical Co., Ltd.
It is. The adhesion of the fluororesin is determined by a 2 mm-wide gobang test. The coating performance is a performance required as a coating for high-temperature cooking equipment having heat resistance, acid resistance, alkali resistance, detergent resistance, boiling water resistance, stain resistance, and corrosion resistance.

Thus, when the mixing ratio is 15 to 25%, it is possible to obtain a coating for a middle coating film having excellent adhesion of the fluororesin and excellent film performance.

Further, a film thickness change test of the fluororesin applied on the intermediate coating film A was carried out, and the results are shown in Table 3. From this, it can be seen that when the thickness of the fluororesin is 5 to 15 μm, the adhesion and non-adhesion of the fluororesin to the intermediate coating film A are improved.

[0040]

[Table 3]

Here, the coating material A is a coating material in which a fluororesin powder is added in a blending amount of 20% or less to a coating material using polytitanocarbosilane as a binder. Silicone acrylic resin is, for example, KR9706 manufactured by Shin-Etsu Chemical Co., Ltd.
It is. The adhesion of the fluororesin is determined by a 2 mm-wide gobang test. The term "non-adhesiveness" refers to the ease with which meat and oily drip scattered from cooked food such as fish, beef, pork, and chicken adhere to the coating film after 30 minutes at 300 ° C.

Next, Table 4 shows the results of the heat discoloration resistance test when a metal oxide was added to the fluororesin of the paint for the top coat.

[0043]

[Table 4]

Here, the paint C is a dispersion type 4
A fluorinated ethylene resin paint, for example, Silkware EK4609BK manufactured by Daikin Industries, Ltd. The metal oxide is, for example, Black 44 manufactured by Asahi Kasei Kogyo Co., Ltd. The heat discoloration resistance is the degree of discoloration after heating at 400 ° C. for 16 hours. Non-adhesive means 300 ° C x
Thirty minutes later, meat and oil drips scattered from cooked foods such as fish, beef, pork and chicken adhere to the coating film and are easily removed.

This indicates that the addition of the metal oxide at a mixing ratio of 10% can prevent the whitening phenomenon at a high temperature without impairing the non-adhesiveness of the fluororesin.

Therefore, in the film forming method of the present invention,
Since the acrylic resin, silicone resin or silicone acrylic resin is added to the composition of the coating for the intermediate coating, a strong film that does not peel off even when the upper coating C is formed into a thick film on the intermediate coating A A fluororesin layer can be formed in close contact with the surface, and even if food oils adhere after cooking, they do not pass or permeate through the upper coating film C, and oil stains and scorching become extremely inconspicuous. Moreover, since the metal oxide is added to the upper coating film C, the heat discoloration resistance is also improved, and the stain mark due to oil contamination during cooking can be made invisible.

Next, the film for a high-temperature cooking appliance of the present invention is shown in FIG.
The method was applied to a microwave oven shown in FIG. 4, and an appropriate coating method, a lamination procedure of a dispersion type fluororesin paint, and firing conditions were determined. Left and right side walls 10a, 1 of inner box 8
0b, the bottom plate 14, the back plate 16, the front plate 18, and the back surface 22 of the door 6 in contact with the front plate 18 are provided with an aluminum-plated steel sheet so as to withstand a temperature in the range of 250 to 450 ° C.
Galvalume steel plate or SUS430, SUS41
0, SUS304 stainless steel plate was used. The top plate 12 is provided with a heater (not shown), and its maximum temperature is as high as 800 ° C. Therefore, a stainless steel plate such as SUS444 having excellent heat resistance is used for the top plate 12.

(Example 1) First, the top plate 12, bottom plate 14, back plate 16, right and left side walls 10
a, 10b on the inner surface of 10b and the surface of front plate 18
m is sprayed to give a finished thickness of m. Next, using the paint for the middle coat, spraying is applied to the portions other than the top plate 12, namely, the bottom plate 14, the back plate 16, the left and right side walls 10a and 10b, and the front plate 18 so as to have a thickness of 10 to 20 μm. Perform painting. Since the top plate 12 is provided with a heater at 800 ° C., a one-coat finish as shown in FIG. Thereby, a durable coating film having heat resistance up to 800 ° C. can be adhered.

Next, the surface excluding the top plate 12 is spray-finished using a paint for an upper coating film so as to form a continuous film of 5 to 15 μm. Thereafter, after preliminary drying at 150 ° C. for 10 to 15 minutes, baking is performed at 380 to 420 ° C. for 10 to 20 minutes, and a ceramic is formed and a fluororesin is formed into a film, thereby completing the process. In addition, when a heater for circulating hot air is provided outside the back plate 16, the temperature of the back plate 16 exceeds 400 ° C. Do not do. In the above steps,
The point to pay special attention to is that when spraying the paint for the top coat, if the solvent in the paint for the middle coat sprayed earlier evaporates quickly and it dries out, When the paint is sprayed, interlayer break-in does not occur, so after spraying the middle coat paint, the surface of this paint is skipped with the organic solvent and only the surface is dried, it is to apply repeatedly. . When the thickness of the paint for the top coat applied on the paint for the middle coat exceeds 15 μm and becomes 20 μm or more, the interlayer adhesion decreases, so it is necessary to finish the coating so as not to increase the thickness of the coat.

(Embodiment 2) In the case of the hot plate shown in FIG. 5, unlike the process of Embodiment 1, a top plate requiring a heat resistance of 800 ° C. or more and a heat plate of 400 ° C. or more are required. Since there is no back plate, coating is performed only on the base material in the order of the lower coating, the middle coating, and the upper coating, followed by the same drying and firing as in Example 1 to finish.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

[0052]

As is apparent from the above description, according to the present invention, the coating for high-temperature cooking appliances has a middle coating containing a fluorine resin and an acrylic resin, a silicone resin or a silicone acrylic resin. Even if the upper coating film is formed as a thick film on the film, it can form a firmly adhered fluororesin film that does not peel off even if it is cooked, even if food oil quality adheres, Without passing through or permeating the oil, so that oil stains and scorching become less noticeable.

Further, by adding a metal oxide to the fluororesin of the upper coating film, it is possible to prevent the whitening phenomenon at a high temperature, prevent discoloration of the coating film even after a long-term use, and remove traces of oil contamination during actual cooking. This has the effect of making it invisible.

Therefore, it is possible to provide a film which maintains high-temperature heat resistance and non-adhesiveness of the surface forever, and which does not lose its resistance to scorching even during long-term use.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a coating for a high-temperature cooking appliance according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a film formed on a top plate of a microwave oven to which the present invention is applied.

FIG. 3 is a perspective view of a microwave oven.

FIG. 4 is a perspective view of an inner box fitted into a microwave oven.

FIG. 5 is a sectional view of an electric hot plate.

FIG. 6 is a sectional view of a film structure disclosed in Prior Art 2 related to the present invention.

FIG. 7 is a sectional view of a film structure disclosed in another prior art 3 related to the present invention.

FIG. 8 is a cross-sectional view of a coating structure disclosed in another prior art 3 related to the present invention.

FIG. 9 is a sectional view of a film structure disclosed in another prior art 4 related to the present invention.

[Explanation of symbols]

 A Middle coat C Upper coat D Lower coat E Base material X Additive

────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI C09D 183/04 C09D 183/04 C09J 133/00 C09J 133/00 (56) References JP-A-4-148116 (JP, A) JP-A-3-254718 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24C 7/02 511 F24C 7/04 F24C 15/00

Claims (6)

(57) [Claims] 1. A coating formed on a base material such as a cooking surface of a high-temperature cooking appliance or a wall surface of a heating chamber, wherein the base material is a black paint containing a polytitanocarbosilane varnish as a main component and a heat-resistant pigment. An undercoat consisting of a ceramic layer applied on a material and ceramized,
And intercoat film comprising a mixed layer was ceramic of the addition of fluororesin, in a high temperature cooking apparatus for coating comprising three layers of the topcoat film made of a fluorine resin, in the mixed layer, the thickness to the ceramic layer Painted
A film for a high-temperature cooking appliance, wherein an acrylic resin, a silicone resin, or a silicone acrylic resin is added to enhance the adhesion of the upper coating film. 2. The mixing ratio of acrylic resin, silicone resin or silicone acrylic resin to the mixed layer is 15 to 2
The coating for a high-temperature cooking appliance according to claim 1, wherein the coating amount is 5%. 3. The coating for a high-temperature cooking appliance according to claim 1, wherein a metal oxide is added to the fluororesin of the upper coating. 4. The film for a high-temperature cooking appliance according to claim 3, wherein the upper film has a continuous film thickness of 5 to 15 μm. 5. An undercoating film of 10 to 20 μm and a middle coating film of 10
The coating for a high-temperature cooking appliance according to claim 1, wherein the entire three layers are formed to a thickness of 30 to 40 µm, with the thickness of the upper coating being 5 to 15 µm and the upper coating being 5 to 15 µm. 6. An undercoat film is formed on a base material with a paint containing a polytitanocarbosilane varnish as a main component and a heat-resistant pigment, and then a fluororesin powder is added to the paint to form an acrylic resin or a silicone resin. Alternatively, form a middle coat with a paint mixed with silicone acrylic resin and dry the middle coat at room temperature or by forced drying to evaporate only the coated surface with an organic solvent. And a method for producing a coating for a high-temperature cooking appliance, in which a liquid coating material of a dispersion type fluororesin is applied in a continuous film form and sintered.