JP2009085518A - Composition of coating for heating cooking apparatus and heating cooking apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition of a coating capable of providing high aesthetic appearance even if used in a high temperature environment. <P>SOLUTION: This composition 2 of the coating formed on a base 3 of the wall surface 1 of a heating cooking apparatus is formed of a multilayer coating with three or more layers. The intermediate layer 5 has metal titanium powder. The layer 6 at the upper side of the intermediate layer has permeability. The layers which are formed at the lower side of the intermediate layer and formed on the surface of the base 3 do not contain metal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coating composition formed on a substrate such as a wall surface of a cooking device, and a cooking device using the coating composition for the cooking device.

Conventionally, cooking stored in the inner wall surface of a heating cooker that heats and cooks food inside, for example, the inner wall surface of an inner pot of a warming pot, an oven range, a microwave oven, or an inner wall surface of an oven toaster It is demanded that an object can be easily peeled off and dirt attached to the wall surface can be easily removed.
Moreover, since these cooking devices cook at high temperatures, the inner wall surface needs to be heat resistant, so the base material of the wall surface is made of metal, and it is necessary to prevent this metal wall from being discolored by oxidation. there were. For this reason, generally, a coating layer having water repellency containing a fluorine resin such as PTFE or PFA, a silicone resin, or the like is often formed on a metal wall (see, for example, Patent Document 1).
In particular, the surface of the wall of a cooking device such as an oven is covered with an oil-repellent fluororesin that has excellent cleanability in order to clean up the burning smoke, oily smoke, and food sprinkles generated during heating. In many cases, a coating layer containing it is provided. In addition, silicone-based heat-resistant coating layers may be provided with an emphasis on heat resistance.

However, as shown in FIG. 4, these coating layers generally have a poor adhesion to the surface of the metal plate that is the base substrate 103 of the wall surface 101. It is considered that a coating layer made of a resin having high adhesion to a metal such as polyethersulfone is formed, and the above-described coating layer 106 having water repellency is provided on the upper layer.
JP 2000-237056 A

However, since the coating layer 106 made of a highly adhesive resin as shown in FIG. 4 is generally opaque, the user cannot visually recognize the surface of the base material 103, especially in the case of the metal base material 103. The metallic luster color tone was not visible from the surface.
In general, in a heating cooker, when the wall surface is visually recognized as metallic, it feels clean and is preferred in design, but the coating layer 102 as shown in FIG. 4 is an opaque high-adhesion coating layer. Since the metallic tone does not appear on the surface, the black color or dark red color of the primary layer 104 which is opaque and colored is visually recognized, and the wall surface of the heating cooker has a problem of poor design. It was.

In order to solve this problem, a method has been considered in which metallic powder is mixed into the primary layer 104 itself and a metallic luster color tone is obtained by providing a fluororesin layer on the upper layer.
However, in this method, since the foreign solid metal powder is mixed in the primary layer 104, the coating layer itself has a fragile structure and has a problem that the adhesion to the metal base material is deteriorated. It was.

  The present invention has been made to solve the above-described problems, and provides a wall surface of a heating cooker that has high designability even in a situation where it is used in a high-temperature environment and that does not deteriorate the adhesion to the base material. It aims at providing the coating composition for heating cookers for this purpose.

  In order to achieve the above object, the coating composition for a heating cooker of the present invention is a coating composition formed on a substrate such as a wall surface of a heating cooker, and is a multilayer coating comprising at least three layers. It is composed of a film, and an intermediate layer of this multilayer coating film contains metallic titanium powder, and the upper layer above this intermediate layer is permeable, and is formed below the intermediate layer and on the surface of the substrate. The main feature is that the layer is constructed so as not to contain metal.

  According to the coating composition for a heating cooker of the present invention, the appearance design of the wall surface of the heating cooker can be improved, and the adhesion with the wall surface substrate of the heating cooker can be maintained. Can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A coating composition for a heating cooker according to the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of a wall surface combining a coating composition for a heating cooker and a substrate according to the present invention.
This wall surface 1 is a sectional view of the wall surface in the heating chamber of the cooking device as shown in FIG. 2 and the inner wall surface of the inner pot in FIG. A layer is formed.
That is, the coating composition 2 formed from three coating layers is provided on the metal substrate 3. The coating composition 2 is composed of a lower primary layer 4 that is in close contact with the substrate 3, an intermediate metallic layer 5, and an upper fluororesin layer 6 that is exposed on the surface.

  Of these layers, the primary layer 4 is made of pure polyethersulfone (hereinafter referred to as “PES”) without entering foreign substances.

  A coating layer (metallic layer 5) having a metallic luster is formed on the surface of the primary layer 4 by mixing titanium powder with a coating layer based on a heat-resistant fluororesin (PTFE) material. Furthermore, the fluororesin layer 6 which consists of a fluororesin which has permeability | transmittance is provided in the upper layer.

  By configuring in this way, the metal wall surface 1 is formed with a layer of pure PES material in which no foreign matter such as metal powder is mixed as the primary layer 4, so that the adhesion with the base material 3 is excellent and fragile. Does not peel off even when used for a long time at high temperatures.

A coating layer containing titanium powder and having a metallic luster was formed on the upper layer of the lower coating layer having excellent adhesion, and a transparent fluororesin layer 6 was formed on the upper layer.
Therefore, since the user can permeate | transmit the fluororesin layer 6 and can visually recognize the metallic layer 5 of the lower layer from the surface of this coating-film composition 2, the surface of the wall surface 1 heated by a heating cooker Can be recognized as having a metallic luster with a metallic luster, and an excellent design can be felt.

  And since the fluororesin layer 6 having heat resistance and water repellency is provided on the uppermost layer, it can be prevented from degrading and peeling even in a high temperature environment, and dirt attached to the surface can be easily cleaned. It is configured.

And since metallic titanium is used as a metallic powder for the metallic layer 5 which is an intermediate layer, it has excellent oxidation resistance, and even when used in a high temperature environment, it has a characteristic that discoloration due to oxidation hardly occurs. Yes.
The cooked food may contain substances such as acids and alkalis. However, since titanium is excellent in corrosion resistance, these substances adhere to the wall 1 and the fluororesin layer 6 is temporarily worn. Titanium will not dissolve or change even if it is missing and peeled off due to etc., or pinholes etc. are generated and adhere to the internal metallic layer 5, and the chemical resistance of the metallic layer 5 itself should be improved. Can do.

Furthermore, the primary layer 4 was formed of polyethersulfone (PES). This PES is a brownish brown thermoplastic non-crystalline resin, which can be melted by heating after being applied to the base material 3 and can maintain strong adhesion to a metal surface or the like. Since this resin is relatively compatible with other resins, the adhesion between the metal surface base material 3 and the upper metallic layer 5 can be maintained more firmly.
Overall, the coating composition 2 can be made tougher.
In addition, a resin such as polyimide amide (PAI) may be mixed with the PES as the primary layer 4.

  Moreover, in the said Example, although the upper layer was demonstrated using the general fluororesin layer 6, in order to improve heat resistance, it is good to use polytetrafluoroethylene (henceforth PTFE) as a fluororesin. However, since PTFE is slightly poor in permeability, it is necessary to coat the metallic layer 5 with a very thin film. By reducing the thickness, the transparency can be increased so that the metallic luster can be visually recognized, and the design can be improved as well as the heat resistance.

  In addition, as the fluororesin layer 6, perfluoroalkoxyalkane (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), etc. It may be used. In the case of a resin having high transparency (transparency), the fluororesin layer 6 can be thickened, so that the coating composition 2 having better wear resistance can be obtained.

  Further, the resin provided in the uppermost layer does not need to be a resin having high transparency as described above, and has a property that the lower metallic layer 5 can be visually recognized by reducing the thickness with a resin having transparency. It only has to be.

Such a coating composition 2 can be provided, for example, on the inner wall surface of an oven of a heating cooker as shown in FIG.
The oven 11 shown in FIG. 2 has a heating chamber 14 for storing cooked food, and the heating chamber 14 is configured by being surrounded by a wall 15 and a door 15 made of a metal plate base material such as an iron plate. Yes.

  The wall surface includes an upper wall 27, a rear wall 28, a left wall 29, a right wall 30 and a bottom wall 31. These wall surfaces 27 to 31 are joined to each other by welding or the like, and have a strong heat insulating property so that the heat in the heating chamber 14 is not diffused. And the wall surfaces 27-31 are comprised when the above-mentioned coating composition 2 is formed in the surface at the metal base material 3. As shown in FIG.

A hot air generator 19 for heating the inside of the heating chamber 14 is installed behind the rear wall 28. The hot air generator 19 includes a fan 22 and an inner heater 23a and an outer heater 23b surrounding the outer periphery thereof. It is comprised by.
The rear wall 28 is formed with a large number of small holes 24 corresponding to the center side of the fan 22, and is also located on both upper and lower sides of the small number of small holes 24. An exhalation opening 25 is formed.

  Based on such a configuration, the oven 11 is configured such that when the fan 22 rotates in the hot air generator 19, the air in the heating chamber 4 is sucked into the hot air generator 19 from the air inlet 24, and the hot air heater is used. It is heated by 23 and discharged into the heating chamber 4 from the upper and lower exhaust ports 25. And the inside of the heating chamber 4 is heated by the circulation of such hot air, and oven cooking is performed favorably.

  When the coating composition 2 is thus provided on the wall surface of the oven 11, the infrared reflection efficiency is improved by the titanium powder of the metallic layer 5, so that the infrared rays emitted in the heating chamber 14 are reflected on the metallic layer 5. Since the food is irradiated and returned, the cooking can be efficiently and uniformly heated in a short time.

Further, a hot air heater 23 as a heating source was installed on the rear wall 28 of the inner wall surface, and the coating composition 2 was also formed on the base material 3 which is the rear wall 28. For this reason, since the metallic layer 5 of the intermediate layer contains titanium having good thermal conductivity, the efficiency of transferring heat transferred from the hot air heater 23 to the rear wall 28 is increased, and the temperature of the wall surface itself is increased in a short time. Therefore, even more efficient cooking is possible.
The coating composition 2 is not only used for the heating chamber wall of the oven 11, but also has the same effect when used for an inner wall surface such as a toaster and a roaster of an IH cooker.

Furthermore, you may use the coating-film composition 2 for the inner wall face of the inner pot of the pot of a rice cooker.
As shown in FIG. 3, the outer shape of the rice cooker 51 is composed of a main body 52 having an accommodating portion 52 c inside and a lid body 60 that covers the upper portion of the main body 52. The storage portion 52c stores an inner pot 54 made of a magnetic material, and the inner pot 54 is closed by covering the upper surface opening of the storage portion 52c with the lid body 60. The heating chamber 53 is formed.

Then, the lid inner shell 63 which is a magnetic material attached to the inside of the lid body 60 by the heating coils 55 and 65 installed on the main body 52 and the lid body 60 and the inner pot 54 are induction-heated. The heating chamber 53 is also heated.
Then, the coating composition 2 is formed on the base material 3 of the pot 54 of the inner pot 54. According to this configuration, since the fluororesin layer 6 having water repellency is provided in the uppermost layer, there is no sticking of rice after cooking.

Furthermore, even if it is used for a long period of time as described above, the coating composition 2 does not peel off, and further, the metallic luster color tone can be visually recognized from the surface of the base material 3 on the inner wall surface of the inner pot 54. In addition, it is possible to provide a pot in the rice cooker 51 that is excellent in design.
Furthermore, since titanium powder that is less problematic against allergies is used as the metal powder, even if the metal component is eluted, it can be used with confidence for the user.

Further, the shape of the titanium powder of the above embodiment may be selected as follows.
For example, a better effect can be obtained by limiting the particle size of the titanium powder contained in the metallic layer 5. That is, it is preferable to contain a large amount of titanium powder having an average particle diameter of 5 to 50 μm.
In general, when the particles of titanium powder are mixed in a coating film, if they are too fine, they do not have a metallic luster color tone, but simply become a black color tone, resulting in poor design. On the other hand, when the titanium particles are too large, it has been recognized that there is a problem that the metallic coating film itself becomes fragile and the adhesion is deteriorated.
Therefore, as described above, the titanium powder has an average particle diameter of 5 to 50 μm and is contained in the coating layer, so that the metallic color tone is not impaired and the adhesion to the primary layer 4 can be maintained.

Further, an effect that may be achieved by changing the shape of the titanium powder itself can be obtained. That is, it is made to contain a titanium powder having a flat shape (for example, a titanium foil prepared by mechanical pulverization).
When such a flat-shaped titanium powder is contained in the metallic layer 5, the size of the flat-shaped titanium powder is equal to or larger than the thickness of the coating film layer. Since it becomes relatively easy to align in the horizontal direction, it becomes possible to exhibit a metallic tone with a smaller amount of titanium powder, and this makes it possible to improve the adhesion without making the coating film brittle.

In addition, the metallic layer 5 may be configured as follows by mixing another powder with respect to the titanium powder of the above embodiment.
In the above embodiment, the metallic layer 5 contains only titanium powder, but aluminum powder may be mixed and contained in this titanium powder. This is because, as described above, the titanium powder has a problem that the coating layer becomes a black tone when it is too fine, and this is avoided. Specifically, by mixing a very small amount of aluminum powder with a particle size of several μm to 10 μm on average into the titanium powder, the aluminum powder aggregates around the titanium powder. The aluminum powder aggregates, and the metal color tone due to the aluminum powder is exhibited.
Therefore, even if titanium powder that is too fine is contained by mixing aluminum powder, it can be prevented from becoming black, and the color tone of the coating composition 2 can be changed to a metal color tone.
Therefore, even if the average particle size of the titanium powder is adjusted to 5 to 50 μm and not contained in the metallic layer 5 as described above, the metallic tone can be exhibited by mixing the aluminum powder with the refined titanium powder. The coating composition 2 can be produced without worrying about the average particle size.

In addition, the metallic layer 5 may not contain only titanium powder, but may be mixed with oxidized titanium powder.
Generally, the color tone of PES used for the primary layer 4 under the metallic layer 5 is often colored and brown, and the color of the primary layer 4 is transmitted to the user through the fluororesin layer 6 and the metallic layer 5. It may be visually recognized.

However, the color of the primary layer 4 can be concealed by mixing the titanium powder and the titanium oxide powder in the metallic layer 5. This is because titanium oxide is used as a white pigment or the like, and when mixed in the metallic layer 5, the color of the primary layer 4 which is the base can be concealed, thereby improving the color development of the metallic layer. This is because there is an effect to do.
Therefore, only the metallic luster color tone of the metallic layer 5 is visually recognized by the user, and the deterioration of the design property caused by adding extra color can be prevented.
In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

Sectional drawing of the cooker wall surface in which the coating-film composition of this invention was formed Front view of oven with wall of coating composition Cross section of rice cooker with wall of coating composition Cross section of cooker wall surface formed by conventional method

Explanation of symbols

1 is a wall surface, 2 is a coating composition, 3 is a substrate, 4 is a primary layer, 5 is a metallic layer, and 6 is a fluororesin layer.

Claims (8)

A coating composition formed on a substrate such as a wall of a heating cooker,
It is composed of at least three or more multilayer coating films,
In the intermediate layer of this multilayer coating film contains metal titanium powder,
The layer above this intermediate layer is permeable,
A coating composition for a heating cooker, characterized in that a layer formed below the intermediate layer and formed on the surface of the substrate does not contain metal.   The coating composition for a heating cooker according to claim 1, wherein a fluororesin-based coating layer having transparency is formed above the intermediate layer containing titanium metal powder.   The coating composition for a heating cooker according to claim 1, wherein the layer formed on the surface of the base material below the intermediate layer containing metal titanium powder is a heat-resistant coating layer containing polyethersulfone. object.   The coating composition for a heating cooker according to claim 1, wherein the metallic titanium powder-containing intermediate layer contains metallic titanium powder having an average particle size of 5 to 50 µm.   The coating composition for a heating cooker according to claim 4, wherein the metal titanium powder-containing intermediate layer contains a flat metal titanium powder.   The coating composition for a heating cooker according to claim 1, wherein the metal titanium powder-containing intermediate layer further contains a mixture of aluminum metal powder.   The coating composition for a heating cooker according to claim 1, wherein the metal titanium powder-containing intermediate layer further contains a titanium oxide powder mixed therein.   A heating cooker using the coating composition for a heating cooker according to any one of claims 1 to 7 on a substrate of an inner wall surface to be heated.

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