KR102155858B1 - Ceramic cooking foil and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to a colored transparent aluminum cooking foil, and in more detail, it relates to an aluminum foil having a far-infrared radiation effect upon heating while having excellent corrosion resistance, acid resistance and alkali resistance, and a method of effectively manufacturing the same.

Description

Ceramic cooking foil and manufacturing method thereof

The present invention relates to a ceramic cooking foil having high far-infrared radiation effect, excellent acid resistance, alkali resistance, and corrosion resistance, and a method of manufacturing the same.

Aluminum cooking foil is widely used for food packaging and cooking because of its high thermal conductivity. In particular, when fish or meat is grilled on an iron plate, the surface of meat or fish in contact with the surface of the iron plate is heated by the heat of the heated iron plate. Because the inside is cooked by convection and conduction by moisture and fat in the meat, the surface of fish or meat burns before it is cooked, causing carbonization. In this way, when the surface of fish or meat burns or is carbonized on the surface of the iron plate of fat from fish or meat, the iron plate must be replaced.The iron plate for grilling is not only heavy, but in a heated state, so it is inconvenient to replace it. Aluminum foil with high thermal conductivity is laid on the surface of the steel plate, and when carbonization occurs, only the aluminum foil is replaced without replacing the steel plate.

If you use aluminum foil when grilling fish or meat on an iron plate, it is convenient to replace it, but the surface in contact with the aluminum foil burns, but the inside is not cooked like when you grill it directly on the iron plate.

To solve this problem, the inventors of the present invention have applied for a patent for a technology in which the irradiated far-infrared rays are absorbed into the food by forming a far-infrared radiation ceramic coating layer on one side of the aluminum foil, and the surface is heated and the inside is also heated to be uniformly cooked. In this technology, a ceramic coating layer is formed on one surface of the aluminum foil by mixing a main material including a ceramic material and a binder including a silica sol, followed by coating and curing the same on one surface of the aluminum foil.

Aluminum itself is somewhat weak to acids, alkalis, and moisture.As a result of recent studies, studies have been published that aluminum components accumulate in the body and accumulate in the brain, causing Alzheimer's, etc.Aluminum foil, silver pot, iron plate when cooking food Etc., or aluminum foil is used for packaging food such as gimbap, and leakage of aluminum components due to acid components generated from food during food cooking and packaging may be problematic. The situation is increasing awareness.

Korean Patent Publication No. 1992-0002709 (announcement date 1992.03.31)

It is an object of the present invention to improve the corrosion resistance and/or acid resistance and alkali resistance of the existing aluminum-based ceramic cooking foil, thereby preventing the leakage of aluminum components from the foil, as well as improving the far-infrared radiation amount, and a method of manufacturing the same. I want to provide.

The ceramic cooking foil of the present invention for solving the above-described problem is an aluminum foil; And a colored far-infrared radiation ceramic coating layer coated on one or both sides of the aluminum foil.

As a preferred embodiment of the present invention, the ceramic coating layer may be a colored transparent coating layer.

In a preferred embodiment of the present invention, the ceramic coating layer may include a thermosetting binder solution containing an alkyltrialkoxysilane and a first solvent; And a ceramic mixture solution including a ceramic mixture powder and a second solvent.

As a preferred embodiment of the present invention, the ceramic coating solution may have a solid content of 50 to 70% by weight.

As a preferred embodiment of the present invention, the ceramic coating solution may include 10 to 25% by weight of a thermosetting binder solution and 75 to 90% by weight of the ceramic mixture.

As a preferred embodiment of the present invention, the thermosetting binder solution may contain 10 to 30 parts by weight of the first solvent based on 100 parts by weight of the alkyltrialkoxysilane.

As a preferred embodiment of the present invention, the ceramic mixture may contain 30 to 50 parts by weight of the second solvent based on 100 parts by weight of the ceramic mixture powder.

In a preferred embodiment of the present invention, the ceramic mixed powder may include silicon alkoxide, transparent milky white inorganic particles, red inorganic particles, and yellow inorganic particles.

As a preferred embodiment of the present invention, the ceramic mixed powder is 45 to 70 parts by weight of transparent milky white inorganic particles, 2 to 8 parts by weight of red inorganic particles, and 12 to 30 parts by weight of yellow inorganic particles based on 100 parts by weight of silicon alkoxide. May contain wealth.

As a preferred embodiment of the present invention, the ceramic mixed powder may further include black inorganic particles.

As a preferred embodiment of the present invention, the ceramic mixed powder may further include 0.1 to 2 parts by weight of black-based inorganic particles based on 100 parts by weight of silicon alkoxide.

As a preferred embodiment of the present invention, the ceramic mixture powder may further include 5 to 15 parts by weight of aluminum alkoxide based on 100 parts by weight of silicon alkoxide.

As a preferred embodiment of the present invention, the transparent milky white inorganic particles may include at least one selected from Al ₂ O ₃ inorganic particles and TiO ₂ .

As a preferred embodiment of the present invention, the red-based inorganic particles may include Fe ₂ O ₃ .

As a preferred embodiment of the present invention, the yellow-based inorganic particles are (Ti _x , Cr _y , Sb _z )O ₂ (Ti _x , Cr _y , Sb _z )O ₂ of x+y+z=1.5 to 2 Can include.

As a preferred embodiment of the present invention, the black-based inorganic particles may include a Cu-Cr-based inorganic pigment.

As a preferred embodiment of the present invention, the aluminum foil may include an A1000 series or A8000 series aluminum alloy.

As a preferred embodiment of the present invention, the aluminum foil may include an A8021 aluminum alloy or an A8079 aluminum alloy .

As a preferred embodiment of the present invention, the aluminum foil may include A8021 O temper material, A8021 H2X material, A8079 O temper material, or A8079 H2X material aluminum alloy.

As a preferred embodiment of the present invention, the aluminum foil is a rolling oil removal treatment, and a surface tension of 50 dyne or more may be used.

As a preferred embodiment of the present invention, the aluminum foil may have an average thickness of 12 ~ 60㎛.

As a preferred embodiment of the present invention, the ceramic coating layer may have an average thickness of 0.3 ~ 1.2㎛.

As a preferred embodiment of the present invention, the ceramic cooking foil of the present invention may have a far-infrared emissivity of 90 to 95% as measured by the KCL-FIR-1005 method and calculated based on Equation 1 below.

[Equation 1]

Far-infrared radiation rate (%) = {(8.63×10 ² (W/㎡)-Measured radiated energy value (W/㎡))/8.63×10 ² (W/㎡) × 100%}

The far-infrared radiation energy of Equation 1 is 8.63×10 ² W/㎡, which is the radiation energy value of the black body measured using the FT-IR spectrometer under the conditions of a measurement temperature of 120° C. and a measurement wavelength of 5 μm to 20 μm. to be.

As a preferred embodiment of the present invention, the ceramic cooking foil of the present invention may be in the range of 8 to 10 RN (Rating Number) in the salt spray test according to the KSD 9502 test standard.

Another object of the present invention relates to a method of manufacturing a ceramic cooking foil of various types described above, comprising: a first step of preparing an aluminum foil and a ceramic coating solution, respectively; A second step of coating one or both sides of the aluminum foil with the ceramic coating solution; And 3 step of forming a colored, far-infrared radiation ceramic transparent coating layer by heat-treating the aluminum foil coated with the ceramic coating solution to cure the ceramic coating solution. It may be manufactured by performing a process including.

Another method of manufacturing a ceramic cooking foil of the present invention includes a first step of preparing an aluminum foil and a ceramic coating solution, respectively; 2-1 step of coating one surface of the aluminum foil with the ceramic coating solution; 2-2 step of heat-treating the ceramic-coated aluminum foil to cure the ceramic coating to form a first ceramic coating layer; 3-1 step of coating the other surface of the aluminum foil on which the first ceramic coating layer is formed with the ceramic coating solution; And 3-2 step of forming a second ceramic coating layer by heat-treating the ceramic coating-treated aluminum foil to cure the ceramic coating.

The ceramic cooking foil of the present invention has excellent thermal conductivity, abrasion resistance, and heat resistance, as well as a far-infrared radiation amount, and thus it is possible to minimize or prevent leakage of harmful substances to the human body during cooking. In addition, it is suitable for use as a food packaging and/or storage material due to its excellent acid resistance, alkali resistance, and corrosion resistance, and its color is excellent in design, so it is easy to identify the coated surface in the outdoor. It is easy and suitable for application as a cooking appliance and/or food storage article.

1 and 2 are photographs before and after the corrosion resistance measurement of the aluminum foils of Comparative Example 6 (A), Comparative Example 7 (B) and Example 1 (C) conducted in Experimental Example 1.
2A to 2C are results of measuring alkali resistance of Example 1 and Comparative Examples 6 to 7 conducted in Experimental Example 2.
3 is a result of the acid resistance measurement experiment of Example 1 and Comparative Examples 6 to 7 conducted in Experimental Example 3.

Hereinafter, it will be described in more detail through the method of manufacturing the ceramic cooking foil of the present invention.

The present invention (preparation method 1) is a first step of preparing an aluminum foil (Al foil) and a ceramic coating solution, respectively; A second step of coating one or both sides of the aluminum foil with the ceramic coating solution; And 3 steps of heat-treating the aluminum foil coated with the ceramic coating solution to cure the ceramic coating solution to form a colored far-infrared radiation ceramic coating layer; by performing a process comprising, a far-infrared radiation ceramic coating layer on one or both sides of the aluminum foil This formed ceramic cooking foil can be manufactured.

In addition, the present invention (Preparation Method 2) is a first step of preparing an aluminum foil and a ceramic coating solution, respectively; 2-1 step of coating one surface of the aluminum foil with the ceramic coating solution; 2-2 step of heat-treating the ceramic-coated aluminum foil to cure the ceramic coating to form a first ceramic coating layer; 3-1 step of coating the other surface of the aluminum foil on which the first ceramic coating layer is formed with the ceramic coating solution; And 3-2 step of forming a second ceramic coating layer by heat-treating the ceramic-coated aluminum foil to cure the ceramic coating to form a second ceramic coating layer; by performing a process including, ceramic cooking in which a far-infrared radiation ceramic coating layer is formed on both sides of the aluminum foil You can also make foil.

The aluminum foil used in the manufacture of the ceramic cooking foil of the present invention may be an aluminum foil of an A1000 series or A8000 series aluminum alloy, preferably an aluminum foil of an A8021 or A8079 aluminum alloy, more preferably A8021 O. Aluminum foil made of soft aluminum alloy material such as temper material, A8021 H2X material, A8079 O temper material, or A8079 H2X material can be used.

In addition, the aluminum foil is an aluminum foil manufactured by rolling the aluminum alloy and removed by heat treatment of the rolling oil used during rolling, and may be an aluminum foil having a surface tension of 50 dyne or more, preferably 55 to 65 dyne. .

In addition, the aluminum foil has an average thickness of 12 to 60 µm, preferably 15 to 40 µm, more preferably 15 to 35 µm, and if the aluminum foil thickness is less than 12 µm, it is too thin to allow usability of the cooking foil. It falls too far, and there may be a problem that the foil is torn when manufacturing the cooking foil.If the thickness of the aluminum foil exceeds 60㎛, it is unnecessarily too thick, and the cost competitiveness of the caulking foil is lowered, and the coating foil is less flexible, making it convenient to use. Since there is a problem of decreasing, it is preferable to use one having a thickness within the above range.

The ceramic coating solution of the manufacturing method (Preparation Method 1 and/or Method 2) of the present invention may contain a solid content of 65 to 85% by weight, preferably 67 to 80% by weight, and more preferably 70 to 75% by weight. . The ceramic coating solution may include a thermosetting binder solution and the ceramic mixture solution.

The thermosetting binder solution forms a layer of the coating film on the aluminum foil and serves to prevent the separation of the ceramic mixed powder in the ceramic coating layer, and contains 10 to 25% by weight, preferably 15 to 25% by weight, in the ceramic coating solution. , More preferably 15 to 20% by weight may be included. At this time, if the content of the thermosetting binder solution is less than 10% by weight, there may be a problem that the ceramic mixed powder is not sufficiently dispersed in the ceramic coating solution, and the bonding force is weakened, so that there may be a problem that the ceramic mixed powder is separated from the cooking foil. In addition, if the content of the thermosetting binder solution exceeds 25% by weight, the ceramic mixed powder may be evenly dispersed on the aluminum foil during coating and may not be coated, and the curing and/or drying time due to the formation of the coating layer may be reduced by excessive use. It is recommended to use within the above range because it becomes longer.

The thermosetting binder solution contains an alkyltrialkoxysilane and a solvent, and the composition ratio is 10 to 30 parts by weight of a solvent, preferably 100 parts by weight of an alkyltrialkoxysilane, based on 100 parts by weight of the alkyltrialkoxysilane. With respect to parts, 12 to 25 parts by weight of the solvent, more preferably 15 to 22 parts by weight of the solvent, based on 100 parts by weight of alkyltrialkoxysilane, is prepared to secure an appropriate viscosity of the thermosetting binder solution and mix with the ceramic mixture. It is preferable in terms of sex. And, as the alkyltrialkoxysilane, (C1 ~ C5 alkyl) tri(C2 ~ C3 alkoxy) silane, preferably (C2 ~ C4 alkyl) tri(C2 ~ C3 alkoxy) silane , More preferably, it is preferable to use propyl triethoxysilane in terms of securing corrosion resistance of the cooking foil.

In addition, among the components of the thermosetting binder solution, the solvent may be used alone or in combination of two or more selected from water, methanol, ethanol, propanol, and butanol, and preferably at least one selected from an aqueous ethanol solution and an aqueous propanol solution is used. It is preferable in terms of miscibility with an alkyl trialkoxysilane.

Next, when the ceramic mixture is described, the ceramic mixture includes a ceramic mixture powder and a solvent, and the composition ratio is 30 to 50 parts by weight of a solvent, preferably 100 parts by weight of the ceramic mixture powder, based on 100 parts by weight of the ceramic mixture powder. It is preferable to include 35 to 50 parts by weight of the solvent based on parts, more preferably 35 to 45 parts by weight of the solvent based on 100 parts by weight of the ceramic powder mixture. At this time, if the amount of solvent used is less than 30 parts by weight, the ceramic mixed powder may not be properly dispersed in the ceramic mixture, and using more than 50 parts by weight reduces the viscosity of the coating solution itself due to excessive use, thereby reducing the amount of thermosetting binder solution used. There may be a problem that satisfies the appropriate coating property only when it is increased.

The solvent in the ceramic mixture may be used alone or in combination of two or more selected from water, methanol, ethanol, propanol, and butanol, and preferably at least one selected from an aqueous ethanol solution and an aqueous propanol solution is used, more preferably It is better to use an aqueous ethanol solution. It is preferable in terms of miscibility with an alkyl trialkoxysilane.

Among the components of the ceramic mixture, the ceramic mixed powder plays a role of giving the cooking foil a far-infrared emission effect and color effect, and the ceramic mixed powder contains silicon alkoxide, transparent milky white inorganic particles, red inorganic particles and yellow inorganic particles. It may, if necessary, may further include black-based inorganic particles, and may further include aluminum alkoxide.

Among the ceramic mixed powder components, the silicon alkoxide is hydrolyzed by reacting with a solvent, and when heat is applied, a polycondensation reaction occurs to form a network structure to form a film, and a coating film is formed with a thermosetting binder component to form a coating film. It serves to prevent separation from the coating layer (or coating film). As the silicon alkoxide, tetra (C1 ~ C10 alkoxy) silicone may be used, preferably tetra (C1 ~ C5 alkoxy) silicone, more preferably tetra (C2 ~ C4 alkoxy) silicone. good.

In addition, in order to increase the compatibility between the silicon alkoxide hydrolyzate hydrolyzed by silicon alkoxide and the ceramic powder, and to increase the corrosion resistance of the cooking foil, the ceramic mixture powder may further include aluminum alkoxide in addition to silicon alkoxide. At this time, as the aluminum alkoxide, tri(C1 to C5 alkoxy) aluminum may be used, and preferably tri(C2 to C3 alkoxy) aluminum may be used. And, it is preferable to use 5 to 15 parts by weight of aluminum alkoxide, preferably 6 to 14 parts by weight of aluminum alkoxide, and more preferably 7 to 12 parts by weight of aluminum alkoxide, based on 100 parts by weight of silicon alkoxide.

Among ceramic mixed powders, inorganic particles containing at least one selected from transparent milky white inorganic particles, red inorganic particles, yellow inorganic particles and black inorganic particles are included, and the inorganic particles are pigments that emit far-infrared rays and impart a colored effect. As the composition serving a role, inorganic particles having a particle diameter of 0.01 µm to 0.8 µm, preferably 0.02 µm to 0.50 µm, and more preferably 0.05 µm to 0.50 µm may be used.

In addition, a ceramic coating layer of a specific color to be obtained may be prepared by adjusting the amount of the inorganic particles, and a preferred embodiment of the composition and composition ratio of the inorganic particles in the ceramic mixed powder is as follows.

The transparent milky white inorganic particles include at least one selected from Al ₂ O ₃ and TiO ₂ , preferably Al ₂ O ₃ and TiO ₂ , more preferably Al ₂ O ₃ and TiO ₂ 1:0.35 ~ It can be included in a weight ratio of 0.80. In addition, the amount of the transparent milky white inorganic particles is not particularly limited, but preferably 45 to 70 parts by weight of transparent milky white inorganic particles, preferably 50 to 65 parts by weight, based on 100 parts by weight of silicon alkoxide, may be used. At this time, if the amount of transparent milky white inorganic particles is less than 45 parts by weight, the coating film hardness of other ceramic coating films (layers) is relatively weak, the alkali resistance decreases, and the coating film density may decrease. If the amount exceeds 70 parts by weight, the coating film Since there may be a problem that the gloss of the film is lowered and the flexibility of the coating film is lowered, it is recommended to use within the above range.

In addition, Fe ₂ O ₃ may be used as the red inorganic particles, and the amount thereof is 2 to 8 parts by weight, preferably 3 to 7 parts by weight, more preferably 3 to 6 parts by weight, based on 100 parts by weight of the silicon alkoxide. We can use wealth.

In addition, as the yellow inorganic particles, x+y+z=1.5-2 (Tix, Cry, Sbz)O ₂ may be used, and the amount used is 12 to 30 parts by weight, preferably based on 100 parts by weight of silicon alkoxide. Preferably, 15 to 30 parts by weight, more preferably 18 to 28 parts by weight may be used.

In addition, the black-based inorganic particles may be used to improve the amount of far-infrared emission and to improve the coloring power, and a Cu-Cr-based inorganic pigment may be used. At this time, the amount of black inorganic particles used is 0.1 to 2 parts by weight, preferably 0.1 to 1 parts by weight, and more preferably 0.1 to 0.8 parts by weight, based on 100 parts by weight of the silicon alkoxide. Good in terms of expression.

The method of coating the ceramic coating solution in the method for manufacturing ceramic cooking foil (Preparation 1 and/or 2) of the present invention can be coated by a general method used in the art (for example, roll coating, gravure coating, bar Coating, etc.). In addition, the ceramic-coated aluminum foil is heat-treated to harden and dry the ceramic coating solution. The heat treatment is performed by applying heat at a temperature of 180 to 250°C, preferably 200°C to 230°C for 10 to 30 seconds. I can. At this time, if the heat treatment temperature is less than 180° C., there may be a problem in that the thermal curing of the thermosetting binder solution does not occur well and the physical properties of the coating layer are poor, and it is uneconomical to exceed 250° C.

In addition, the average thickness of the far-infrared radiation ceramic transparent coating layer formed by curing on one or both sides of the aluminum foil is preferably 0.3 to 1.2 μm, preferably 0.5 to 1.0 μm, more preferably 0.50 to 0.85 μm. At this time, if the thickness of the coating layer is less than 0.3 μm, the coating layer is too thin, so when the cooking foil of the present invention is used, the coating layer may be peeled off from the aluminum foil, or there may be a problem in that physical properties such as acid resistance, alkali resistance and corrosion resistance cannot be sufficiently secured. If the value exceeds 1.2㎛, there is a problem that the convenience of use is inferior due to poor flexibility of the cooking foil.

The ceramic cooking foil of the present invention manufactured by this method and composition includes aluminum foil; And a colored far-infrared radiation ceramic coating layer on one or both sides of the aluminum foil. In addition, the far-infrared radiation ceramic coating layer may be a colored transparent coating layer.

The ceramic cooking foil of the present invention has a far-infrared emissivity of 90 to 97%, preferably 91 to 96.5%, more preferably 92 to 95.5%, as measured by the KCL-FIR-1005 method and calculated according to Equation 1 below. Can be

[Equation 1]

Far-infrared radiation rate (%) = {(8.63×10 ² (W/㎡)-Measured radiated energy value (W/㎡))/8.63×10 ² (W/㎡) × 100%}

The far-infrared radiation energy of Equation 1 is 8.63×10 ² W/㎡, which is the radiation energy value of the black body measured using the FT-IR spectrometer under the conditions of a measurement temperature of 120° C. and a measurement wavelength of 5 μm to 20 μm. to be.

In addition, the ceramic cooking foil of the present invention may be RN (Rating Number) 8 to 10, preferably 9 to 10, and more preferably 9.3 to 10, in the salt spray test according to the KSD 9502 test standard.

In addition, the ceramic cooking foil of the present invention is excellent in acid resistance and alkali resistance.

In the ceramic cooking foil of the present invention having such physical properties, the far-infrared rays irradiated during cooking are absorbed into the food due to the far-infrared radiation effect, so that the surface and the interior are heated at the same time as the surface is heated, so that the surface and the interior can be uniformly cooked. In addition, it has excellent antioxidant function, so long-term storage is possible when storing foods with moisture (meat, fish, etc.) In addition, the existing ceramic coating foil is colorless and transparent, and thus it is difficult to distinguish the coated surface, which is inconvenient to use. However, the present invention is colored, so it is easy to distinguish the coated surface of the foil, so that it is convenient in use.

Hereinafter, the present invention will be described in more detail through examples, but the following examples do not limit the scope of the present invention, which should be interpreted to aid understanding of the present invention.

[ Example ]

Preparation example 1: Preparation of ceramic coating solution

Tetraethoxy silicon (silicone alkoxide), transparent milky white inorganic particles, alumina (Al ₂ O ₃ ) having a particle diameter of 0.1 to 0.2 µm, TiO ₂ having a particle diameter of 0.05 to 0.15 nm, and a red inorganic particle, having a particle diameter of 0.1 µm to 0.2 ㎛ of Fe ₂ O _3, a yellow-based inorganic particles, particle diameter 0.15 ㎛ ~ 0.25 ㎛ of _{(Ti 0 .9, Cr 0 .5} , Sb 0. 5) O 2 And Cu-Cr pigments having a particle diameter of 0.15 µm to 0.35 µm as black inorganic particles were prepared, and then mixed and stirred to prepare a ceramic mixed powder. In addition, 38 parts by weight of an ethanol (second solvent) aqueous solution having a concentration of 85% by volume was mixed with respect to 100 parts by weight of the ceramic mixed powder to prepare a ceramic mixture. At this time, the composition ratio of the ceramic mixed powder is shown in Table 1 below.

Separately, a thermosetting binder solution was prepared by mixing 20 parts by weight of an aqueous propanol solution (first solvent) having a concentration of 90% by volume based on 100 parts by weight of propyltriethoxysilane.

A ceramic coating solution was prepared by mixing and stirring 80% by weight of the ceramic mixture solution and 20% by weight of the thermosetting binder solution.

Preparation example 2

A ceramic coating solution was prepared in the same composition and method as in Preparation Example 1, but when preparing the ceramic mixed powder, triethoxy aluminum, which is an aluminum alkoxide, was further added to prepare a ceramic coating solution having a composition ratio as shown in Table 1 below.

Preparation example 3 to 8 and Comparative preparation example 1 to 7

A ceramic coating solution was prepared in the same composition and method as in Preparation Example 1, but a ceramic coating solution having a composition ratio as shown in Tables 1 to 3 was prepared, respectively.

Classification (part by weight) Preparation example
One Preparation example
2 Preparation example
3 Preparation example
4 Preparation example
5 Ceramic coating liquid
(weight%) Thermosetting binder solution 20% by weight 20% by weight 16% by weight 24% by weight 19% by weight Ceramic mixture 80% by weight 80% by weight 84% by weight 76
weight% 81% by weight Thermosetting binder
solution
(Part by weight) Alkyl trialkoxysilane 100 100 100 100 100 First solvent
(Ethanol aqueous solution) 20 20 20 20 22 Ceramic mixture
(Part by weight) Ceramic mixed powder 100 100 100 100 100 Second solvent
(Isopropanol aqueous solution)) 38 38 38 38 45 mix
powder
(Part by weight) Silicon alkoxide 100 100 100 100 100 Aluminum alkoxide - 10 10 10 10 Alumina 35 35 45 35 35 TiO ₂ 18 18 20 18 18 Fe ₂ O ₃ 5 5 7 5 5 (Ti _0.9 Cr _0.5 Sb _0.5 ) O ₂ 22 22 20 22 22 Cu-Cr 0.4 0.4 0.5 0.4 0.4

Classification (part by weight) Preparation example
6 Preparation example
7 Preparation example
8 compare
Preparation example
One compare
Preparation example
2 Ceramic coating liquid
(weight%) Thermosetting binder solution 20% by weight 22% by weight 20% by weight 13% by weight 28.5% by weight Ceramic mixture 80% by weight 78% by weight 80% by weight 87% by weight 71.5% by weight Thermosetting binder
solution
(Part by weight) Alkyl trialkoxysilane 100 100 100 100 100 First solvent
(Ethanol aqueous solution) 20 22 20 20 20 Ceramic mixture
(Part by weight) Ceramic mixed powder 100 100 100 100 100 Second solvent
(Isopropanol aqueous solution)) 38 36 38 38 38 mix
powder
(Part by weight) Silicon alkoxide 100 100 100 100 100 Aluminum alkoxide 12 8 10 10 10 Alumina 30 35 44 35 35 TiO ₂ 27 25 23 18 18 Fe ₂ O ₃ 4 3 5 5 5 (Ti _0.9 Cr _0.5 Sb _0.5 ) O ₂ 26 27 22 22 22 Cu-Cr 0.7 0.5 0.4 0.4 0.4

Classification (part by weight) compare
Preparation example
3 compare
Preparation example
4 compare
Preparation example
5 compare
Preparation example
6 compare
Preparation example
7 Ceramic coating liquid
(weight%) Thermosetting binder solution 20% by weight 20% by weight 20% by weight 20% by weight 20% by weight Ceramic mixture 80% by weight 80% by weight 80% by weight 80% by weight 80% by weight Thermosetting binder
solution
(Part by weight) Alkyl trialkoxysilane 100 100 100 100 100 First solvent
(Ethanol aqueous solution) 20 8 35 20 20 Ceramic mixture
(Part by weight) Ceramic mixed powder 100 100 100 100 100 Second solvent
(Isopropanol aqueous solution)) 55 38 38 38 38 mix
powder
(Part by weight) Silicon alkoxide 100 100 100 100 100 Aluminum alkoxide 10 10 10 10 - Alumina 35 35 35 50 35 TiO ₂ 18 18 18 25 18 Fe ₂ O ₃ 5 5 5 5 5 (Ti _0.9 Cr _0.5 Sb _0.5 ) O ₂ 22 22 22 22 22 Cu-Cr 0.4 0.4 0.4 0.4 -

Example One

A8021 O TEMPER material aluminum was prepared. Next, the aluminum was rolled to prepare an aluminum foil having a thickness of 50 μm. Next, the aluminum foil was heat-treated to remove the rolling oil from the aluminum foil during rolling to prepare an aluminum foil made of A8021 O TEMPER material having a surface tension of about 50 Dyne.

Next, the ceramic coating solution prepared in Preparation Example 1 was gravure-coated on one side of the aluminum foil. Next, it was heat-treated at 210 to 220°C for 20 seconds to cure the ceramic coating solution, thereby preparing a two-layer aluminum foil having a ceramic coating layer having a thickness of 0.5 μm on one side of the aluminum foil.

And, a photograph of the manufactured aluminum foil is shown in FIG. 1C.

Example 2 ~ Example 8 and Comparative example 1 ~ Comparative example 7

An aluminum foil was prepared in the same manner as in Example 1, but a ceramic coating layer of the same thickness was formed using each of the ceramic coating solutions of Preparation Examples 2 to 8 and Comparative Preparation Examples 1 to 7 instead of the ceramic coating solution of Preparation Example 1. Each of the two-layered aluminum foil was prepared (see Table 4 below).

division Aluminum foil Ceramic coating layer Example 1 A8021 O TEMPER 50㎛ Preparation Example 1 0.5㎛ Example 2 A8021 O TEMPER 50㎛ Preparation Example 2 0.5㎛ Example 3 A8021 O TEMPER 50㎛ Preparation Example 3 0.5㎛ Example 4 A8021 O TEMPER 50㎛ Preparation Example 4 0.5㎛ Example 5 A8021 O TEMPER 50㎛ Preparation Example 5 0.5㎛ Example 6 A8021 O TEMPER 50㎛ Preparation Example 6 0.5㎛ Example 7 A8021 O TEMPER 50㎛ Preparation Example 7 0.5㎛ Example 8 A8021 O TEMPER 50㎛ Preparation Example 8 0.5㎛ Comparative Example 1 A8021 O TEMPER 50㎛ Comparative Preparation Example 1 0.5㎛ Comparative Example 2 A8021 O TEMPER 50㎛ Comparative Preparation Example 2 0.5㎛ Comparative Example 3 A8021 O TEMPER 50㎛ Comparative Preparation Example 3 0.5㎛ Comparative Example 4 A8021 O TEMPER 50㎛ Comparative Preparation Example 4 0.5㎛ Comparative Example 5 A8021 O TEMPER 50㎛ Comparative Preparation Example 5 0.5㎛ Comparative Example 6 A8021 O TEMPER 50㎛ Comparative Preparation Example 6 0.5㎛ Comparative Example 7 A8021 O TEMPER 50㎛ Comparative Preparation Example 7 0.5㎛

Comparative example 8

The A8021 O TEMPER material itself before the ceramic coating layer used in Preparation Example 1 was formed was prepared with aluminum foil.

Comparative example 9

A ceramic cooking foil disclosed in Korean Patent Publication No. 1992-0002709 was prepared.

Specifically, the main body was formed with 65% by weight of tetraethoxy silicon, 30% by weight of ZrO ₂ and 5% by weight of methanol, and 90% by weight of silica sol with 35% by weight of solid content and 10% by weight of Al ₂ O ₃ were used to form a main body. The mixture was mixed so that the weight ratio of the binder to 1: 1 was then treated on one side of the aluminum foil and heat-treated at 200°C to prepare a final aluminum foil. A photograph of the prepared aluminum foil is shown in FIG. 1B.

Experimental example One : Alkali resistance Experiment

Each of the aluminum foils of Example 1, Comparative Example 8, and Comparative Example 9 was immersed in a KOH aqueous solution having a pH of 12 for 1 to 2 hours to perform an alkali resistance experiment, and a photograph of measuring the result is shown in FIG. 2A (right after immersion), 2B (after 1 hour) and 2C (after 2 hours).

Comparing FIGS. 2A to 2C, it can be seen that in Comparative Example 9, corrosion occurs after 1 hour, and in Comparative Example 6, corrosion occurs after 2 hours. However, it was confirmed that Example 1 had excellent alkali resistance since corrosion did not occur at all even after 2 hours.

Experimental example 2 : Acid resistance Experiment

Each of the aluminum foils of Example 1, Comparative Example 8, and Comparative Example 9 was immersed in an aqueous nitric acid solution having a pH of about 3.5 for 2 hours, and then surface corrosion was measured, and the results are shown in FIG. 3. 3, in the case of Example 1 and Comparative Example 9, corrosion did not occur, in the case of Comparative Example 8, it was confirmed that there is a problem that corrosion occurs.

Experimental example 3: corrosion resistance test

Corrosion resistance measurement experiments for each of the aluminum foils of Examples 1 to 8 and Comparative Examples 1 to 9 were performed.

Corrosion resistance measurement experiment was performed for 240 hours in accordance with the KSD 9502 test standard salt spray test, the results are shown in Table 6 below as RN (Rating Number).

In addition, photographs before and after the corrosion resistance measurement for each of the aluminum foils of Example 1, Comparative Example 8, and Comparative Example 9 are shown in FIGS. 1A (before the experiment) and FIG. 1B (after the experiment).

Referring to FIGS. 1A and 1B, it can be seen that in Comparative Examples 8 and 9, there is a problem that the surface is corroded, but corrosion does not occur on the surface of Example 1. Through this, it can be confirmed that the ceramic cooking foil of the present invention has strong corrosion resistance.

The RN (Rating number), which is a measurement value of corrosion resistance in Table 5, is numerically calculated according to the corrosion area rate, and at this time, the corrosion area rate is calculated based on Equation 2 below.

[Equation 2]

Corrosion area rate (%) = (total of corroded area/effective test area) × 100%

RN(rating number) Corrosion area rate (%) 10 0 9.8 Less than 0.02 9.5 0.03 or more to less than 0.05 9.3 0.05 or more to less than 0.07 9 Less than 0.10 8 0.10 or more to less than 0.25 7 0.25 to less than 0.50 6 0.50 or more to less than 1.0 5 1.0 to less than 2.5 4 2.5 or more to less than 5.0 3 5.0 or more to less than 10.0 2 10.0 or more to less than 25.0 One 25 to less than 50

Experimental example 4: far infrared emissivity experiment

Far-infrared emissivity was measured for each of the aluminum foils of Examples 1 to 8 and Comparative Examples 1 to 9 (see Table 6).

The far-infrared emissivity is measured based on a black body using an FT-IR spectrometer according to KCL-FIR-1005:2011 and calculated by Equation 1 below, and the far-infrared radiation energy of the black body is 8.63. It was ×10 ² W/m 2 (measurement temperature 120°C, measurement wavelength 5 μm to 20 μm).

[Equation 1]

Far-infrared radiation rate (%) = {(8.63×10 ² (W/㎡)-Measured radiated energy value (W/㎡))/8.63×10 ² (W/㎡) × 100%}

division Corrosion resistance measurement
(RN) Far-infrared ray emissivity (%) Example 1 RN 9 93.8% Example 2 RN 9.5 93.7% Example 3 RN 9.5 95.2% Example 4 RN 9.5 92.0% Example 5 RN 9.3 92.5% Example 6 RN 9.8 94.1% Example 7 RN 9.3 93.5% Example 8 RN 9.5 95.8% Comparative Example 1 RN 8 93.9% Comparative Example 2 RN 9.8 86.6% Comparative Example 3 RN 9.5 88.4% Comparative Example 4 RN 8 90.8% Comparative Example 5 RN 9 89.7% Comparative Example 6 RN 9.3 96.8% Comparative Example 7 RN 9.5 90.5% Comparative Example 8 RN 6 2.5% Comparative Example 9 RN 8 85.3%

Looking at the corrosion resistance and far-infrared emissivity measurement results in Table 6, it can be seen that in Examples 1 to 8, while having excellent corrosion resistance of RN 9 or more, it has a high far-infrared emissivity of 90% or more.

On the other hand, in the case of Comparative Example 1 in which the thermosetting binder solution was used in an amount of 13% by weight less than 15% by weight, there was a problem in that the corrosion resistance was inferior as compared to Example 2, and there was a problem that the ceramic mixed powder was separated from the cooking foil. In addition, in the case of Comparative Example 2 in which the thermosetting binder solution was used in an amount of 28.5% by weight exceeding 25% by weight, compared with Examples 2 and 4, the corrosion resistance was excellent, but the content of the ceramic mixed powder in the coating layer was relatively small, so far infrared rays There was a problem that the emissivity fell rapidly.

In the case of Comparative Example 3 using 55 parts by weight of the solvent in the ceramic mixture solution exceeding 50 parts by weight, the viscosity of the ceramic mixture solution was too low, so that the dispersibility of the ceramic mixed powder in the coating was lowered, resulting in a problem that the far-infrared emissivity decreased to less than 90%.

In the case of Comparative Example 4 in which 8 parts by weight of the solvent in the thermosetting binder solution is less than 10 parts by weight, the viscosity of the thermosetting binder is too high, so that the dispersion power of the ceramic mixed powder is lowered, and the ceramic coating layer is not formed evenly, thereby reducing corrosion resistance. And, in the case of Comparative Example 5 in which 35 parts by weight of the solvent in the thermosetting binder solution was exceeded by 30 parts by weight, the viscosity was too low, so that the coating property was lowered when the ceramic coating layer was formed, and the adhesive strength was lowered, so that the ceramic inorganic particles were separated.

In the case of Comparative Example 6 in which the transparent milky white inorganic particles of Al ₂ O ₃ and TiO ₂ were used in an amount of 75 parts by weight exceeding 70 parts by weight, the corrosion resistance and far-infrared ray emission rate were excellent, but the flexibility of the coating film was poor, so the feeling of use of the cooking foil was reduced and the cooking foil was There was a problem that the coating film was damaged when it was bent, and the gloss of the coating film was deteriorated.

In addition, in the case of Comparative Example 7 in which the black-based inorganic particles were not used, the far-infrared emissivity was lowered when compared with Examples 1 and 2.

Through the above Examples and Experimental Examples, it was confirmed that the present invention can provide a colored ceramic cooking foil having excellent corrosion resistance and/or acid resistance, and alkali resistance while improving the amount of far-infrared radiation.

Claims (13)

delete delete delete delete delete Aluminum foil; And a colored far-infrared radiation ceramic coating layer on one or both sides of the aluminum foil,
The far-infrared radiation ceramic coating layer includes a cured product of a ceramic coating solution,
The ceramic coating solution includes 15 to 25% by weight of a thermosetting binder solution and a residual amount of a ceramic mixture,
The thermosetting binder solution contains 10 to 30 parts by weight of a solvent containing at least one selected from methanol, ethanol, propanol, and butanol based on 100 parts by weight of alkyltrialkoxysilane,
The ceramic mixture contains 30 to 50 parts by weight of a solvent containing at least one selected from water, methanol, ethanol, propanol and butanol based on 100 parts by weight of the ceramic mixed powder,
The ceramic mixed powder is based on 100 parts by weight of silicon alkoxide, 45 to 70 parts by weight of transparent milky white inorganic particles, 2 to 8 parts by weight of red inorganic particles, 12 to 30 parts by weight of yellow inorganic particles, and 0.1 to 2 black inorganic particles Including parts by weight,
The transparent milky white inorganic particles include Al ₂ O ₃ and TiO ₂ , the red inorganic particles include Fe ₂ O ₃ , and the yellow inorganic particles are x+y+z=1.5 to 2 (Ti _x , Cr _y , Sb _z ) O ₂ , and the black-based inorganic particles include Cu-Cr-based inorganic pigments,
Ceramic cooking foil, characterized in that the far-infrared emissivity is 90 to 95.8% as measured by the KCL-FIR-1005 method and calculated according to Equation 1 below;
[Equation 1]
Far infrared ray emissivity (%) = {(8.63×10 ² (W/㎡)-Measured radiated energy value (W/㎡))/8.63×10 ² (W/㎡) × 100%}
The far-infrared radiation energy 8.63×10 ² W/㎡ of Equation 1 is the radiation energy value of a black body measured using an FT-IR spectrometer under conditions of a measurement temperature of 120°C and a measurement wavelength of 5 μm to 20 μm. to be.
The ceramic cooking foil according to claim 6, wherein the ceramic mixture powder further comprises 5 to 15 parts by weight of aluminum alkoxide based on 100 parts by weight of silicon alkoxide.
The ceramic cooking foil according to claim 6, wherein the aluminum foil comprises a 1000-based aluminum alloy or an 8000-based aluminum alloy, and has a surface tension of 50 Dyne or more.
The ceramic cooking foil according to claim 6, wherein the aluminum foil has an average thickness of 12 to 60 μm, and the ceramic coating layer has an average thickness of 0.3 to 1.2 μm.
delete [10] The ceramic cooking foil according to any one of claims 6 to 9, characterized in that, in the salt spray test according to the KSD 9502 test standard, RN (Rating Number) is 8 to 10.
1 step of preparing an aluminum foil and a ceramic coating solution, respectively;
A second step of coating one or both sides of the aluminum foil with the ceramic coating solution; And
3 step of forming a colored far-infrared radiation ceramic coating layer by heat-treating the aluminum foil coated with the ceramic coating solution to cure the ceramic coating solution, and
The ceramic coating solution includes 15 to 25% by weight of a thermosetting binder solution and a residual amount of a ceramic mixture,
The thermosetting binder solution contains 10 to 30 parts by weight of a solvent containing at least one selected from methanol, ethanol, propanol, and butanol based on 100 parts by weight of alkyltrialkoxysilane,
The ceramic mixture contains 30 to 50 parts by weight of a solvent containing at least one selected from water, methanol, ethanol, propanol and butanol based on 100 parts by weight of the ceramic mixed powder,
The ceramic mixed powder is based on 100 parts by weight of silicon alkoxide, 45 to 70 parts by weight of transparent milky white inorganic particles, 2 to 8 parts by weight of red inorganic particles, 12 to 30 parts by weight of yellow inorganic particles, and 0.1 to 2 black inorganic particles Including parts by weight,
The transparent milky white inorganic particles include Al ₂ O ₃ and TiO ₂ , the red inorganic particles include Fe ₂ O ₃ , and the yellow inorganic particles are x+y+z=1.5 to 2 (Ti _x , Cr _y , Sb _z )O ₂ , wherein the black-based inorganic particles include a Cu-Cr-based inorganic pigment.
1 step of preparing an aluminum foil and a ceramic coating solution, respectively;
2-1 step of coating one surface of the aluminum foil with the ceramic coating solution;
2-2 step of heat-treating the ceramic-coated aluminum foil to cure the ceramic coating to form a first ceramic coating layer;
3-1 step of coating the other surface of the aluminum foil on which the first ceramic coating layer is formed with the ceramic coating solution; And
3-2 step of forming a second ceramic coating layer by heat-treating the ceramic coating-treated aluminum foil to cure the ceramic coating, and performing a process including,
The ceramic coating solution includes 15 to 25% by weight of a thermosetting binder solution and a residual amount of a ceramic mixture,
The thermosetting binder solution contains 10 to 30 parts by weight of a solvent containing at least one selected from methanol, ethanol, propanol, and butanol based on 100 parts by weight of alkyltrialkoxysilane,
The ceramic mixture contains 30 to 50 parts by weight of a solvent containing at least one selected from water, methanol, ethanol, propanol and butanol based on 100 parts by weight of the ceramic mixed powder,
The ceramic mixed powder is based on 100 parts by weight of silicon alkoxide, 45 to 70 parts by weight of transparent milky white inorganic particles, 2 to 8 parts by weight of red inorganic particles, 12 to 30 parts by weight of yellow inorganic particles, and 0.1 to 2 black inorganic particles Including parts by weight,
The transparent milky white inorganic particles include Al ₂ O ₃ and TiO ₂ , the red inorganic particles include Fe ₂ O ₃ , and the yellow inorganic particles are x+y+z=1.5 to 2 (Ti _x , Cr _y , Sb _z )O ₂ , wherein the black-based inorganic particles include a Cu-Cr-based inorganic pigment.

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