KR100451155B1 - Composition for coating the interior parts of cooking appliances using light - Google Patents

Abstract

By providing a composition containing a photocatalyst for the internal coating of the cooking utensil using light, the interior of the cooking utensil using the light can maintain a clean state by itself through its own oil decomposition function and the like.

Description

COMPOSITION FOR COATING THE INTERIOR PARTS OF COOKING APPLIANCES USING LIGHT}

The present invention relates to a coating composition that can be used inside a cooking utensil using light. More specifically, the present invention relates to a composition for internal coating of a cooking utensil using light containing a photocatalyst and a transition metal catalyst, in particular, in cooking of all kinds of cooking utensils including light as a heat source, when cooking in the utensil. If the oil is on the wall of the cooking utensils or the inside of the door is a technology for a functional coating film that maintains a clean state by disassembling such oil itself.

Most of the conventional cooking utensils are cooked by heating or cooking food by directly heating food in an oven. However, since the development of microwave ovens, food can be cooked quickly without applying fire directly to food. The microwave oven is a method of installing a microwave generator in the food cooking chamber and cooking food using the microwaves generated by the generator. The principle of cooking food is that microwaves induce the vibration energy of water molecules in the food to cook or warm the food to cook the food.

While these microwave ovens have the advantage of being able to cook food easily, they cause some problems when cooking. First, since the heat is generated only by the vibration energy of the water molecules present in the food, the shape of the cooked food does not look as delicious as using the conventional oven. Second, according to many reports that the electromagnetic wave generated from the microwave generating device adversely affects the human body, housewives are reluctant to use it. Third, because the energy applied to food is limited in principle in the microwave oven, the cooking time can be shortened to some extent, but there is a limit to the extent. Finally, when a microwave is applied to the surface of the metal, it easily oxidizes and turns black. Accordingly, there is a limitation of the container that can be used in the microwave oven.

Therefore, in recent years, various attempts have been made to develop cooking utensils for overcoming the above disadvantages while utilizing the convenience of the microwave oven. Typical examples thereof include a cooking apparatus using light as a heat source. Using light as a heat source can control energy more easily than using an oven, preventing food from carbonizing. In addition, the shape of the food after cooking, which is a disadvantage of the microwave oven, looks delicious because it uses fire, does not generate electromagnetic waves, and gives sufficient energy to food, so the cooking time is very short. The development of a cooking utensil using this new light has made it possible to achieve a lot of convenience when cooking food.

However, in the case of cooking utensils using light so far, when the inside thereof is made of stainless steel or ceramics without any coating, oils generated in food during cooking remain on the inner wall or inside of the cooking utensil. However, the problem is that such contaminants are not easily removed and their removal becomes more difficult by light irradiation during cooking.

Therefore, in the present invention, by introducing a functional coating film containing a photocatalyst and a transition metal catalyst into the cooking utensil using light, it is possible to effectively remove contaminants such as oil generated during cooking in the cooking utensil. There is his purpose.

1 shows the principle of the photocatalyst.

Figure 2 shows a schematic diagram of the efficiency increase of the photocatalyst redox reaction including metal particles.

3A and 3B show a result of oil decomposition when a large amount of cooking oil is applied to the reflecting plate. FIG. 3A is a reflecting plate before the decomposition experiment, and FIG. 3B shows a reflecting plate after the decomposition experiment.

4A and 4B show the results of oil decomposition when a small amount of cooking oil is applied to the reflecting plate. FIG. 4A shows the reflecting plate before the decomposition experiment, and FIG. 4B shows the reflecting plate after the decomposition experiment.

The present invention provides a composition for internal coating of a cookware using light containing a photocatalyst and a transition metal catalyst, and particularly preferably contains at least 5% by weight of the photocatalyst and 0.001 to 10% by weight of the transition metal catalyst.

As described above, the present invention introduces a coating film containing a photocatalyst into the interior of a cooking utensil using light made of stainless steel, ceramics, or the like, thereby maintaining self-cleaning properties and providing a transition metal as a promoter. It is intended to enhance this effect by adding.

Such a coating composition of the present invention can be used for all kinds of cooking utensils including light as a heat source. The light source that can be used here is conventionally cooked using light, such as a lamp that irradiates a long wavelength including the far infrared band, a lamp that emits light of all wavelengths such as a halogen lamp, and a lamp that emits light of a relatively short wavelength such as a xenon lamp. All kinds of light sources known to be usable for the instrument are included.

The photocatalytic material used in the coating composition of the present invention may be used by selecting a suitable material according to the light source used in the cooking utensil, and in particular, may be changed depending on the wavelength of the light source. Photocatalyst materials accessible in the present invention include homogeneous photocatalysts and heterogeneous photocatalysts, and may be added with a layered perovskite type photocatalyst, coated with zeolite and photocatalysts, or synthesized in a form including these photocatalysts. It can also be used to enhance the performance. For example, a homogeneous photocatalyst may be a dye or a metal complex such as Ru (bipy) ₃ ²⁺ , a metal porphyrin, and the like, and a heterogeneous photocatalyst may be a binding semiconductor such as Si or Ge or a metal such as Cds or TiO ₂ . Ionic bond semiconductor materials of oxides. Preferably, a titanium dioxide photocatalyst can be used.

The content of the photocatalyst of the present invention varies depending on the material of the cookware internal material, which is a coating target material, and the performance of the cookware, and in some cases, may form a coating film containing only the photocatalyst, preferably 5 wt% or more, more Preferably it can be used in the content of 25 to 60% by weight. The content of such photocatalyst component should be more than the minimum range in terms of performance, it is preferable not to include in an excessive amount in terms of economic efficiency.

Self-cleaning properties of the coating composition of the present invention take advantage of the properties of the oxidation-reduction reaction of the photocatalyst, such oxidation-reduction reaction of the photocatalyst is generally carried out by photons irradiated with light to transfer energy to the photocatalyst particles. It is known that the particles are separated into electrons (e ⁻ ) and holes (H ⁺ ), and the formed electrons and holes move to the surface of the photocatalyst particles to undergo a reduction reaction and an oxidation reaction (FIG. 1). The generated electrons and holes do not participate in the oxidation-reduction reaction, and most of them move to the surface of the photocatalyst particles and recombine and disappear. Therefore, suppressing the disappearance of holes and electrons by recombination and increasing the effect of the oxidation-reduction reaction of the photocatalyst becomes an important factor for the activity of the catalyst. In the present invention, as one of methods for suppressing recombination of electrons and holes, photocatalytic performance can be enhanced by doping or injecting transition metal particles onto a surface. When using this method, it is possible to effectively trap electrons generated in the photocatalyst particles, thereby inhibiting recombination of electrons and holes, thereby effectively increasing the redox reaction of the photocatalyst (FIG. 2). In addition, even when the zeolite form is used as the photocatalyst, the efficiency can be further increased by the function of helping to lengthen the contact time between the gas and the photocatalyst.

As described above, in the present invention, a photocatalyst in which a transition metal is added as a cocatalyst in order to more effectively remove oil and the like generated during cooking in all kinds of cooking utensils using light as a heat source to maintain a clean and sanitary cooking utensil at all times. A functional coating film can be used.

As the metal catalyst to be used in the present invention, any catalyst compound containing any of transition metals (groups 3A to 2B) on the periodic table can be used. Preferred transition metal catalysts include compounds containing palladium (Pd), silver (Ag), platinum (Pt), gold (Au), ruthenium (Ru) and the like, and platinum and palladium are particularly preferred.

In addition, the transition metal particles used in the present invention are not only used to increase the efficiency of the redox reaction of the photocatalyst. Since the added transition metal particles easily undergo an oxidation reaction at a high temperature themselves, the transition metal particles may have an excellent function of removing the generated oil more effectively when the internal temperature of the cooking apparatus is high.

In the present invention, the amount of the transition metal compound varies depending on the type of photocatalyst, the coating material and the light source, and the type of the metal compound particles, etc., but may be generally used in an amount of about 0.001 to 10% by weight in the total composition. . If it is used at less than 0.001% by weight, the transition metal compound cannot obtain the effect of activating the oxidation-reduction reaction of the photocatalyst, and when it is used at more than 10% by weight, the performance compared to using an expensive reagent in excess The difference in the degree of improvement in effectiveness is low, and such transition metal compounds may cause cracks or deformations on the photocatalyst coating to damage the entire coating.

In addition, the coating composition of the present invention may further contain other additive materials such as binders to reinforce the coating strength and the like depending on the material. As the binder material usable in the present invention, inorganic binders such as inorganic oxide particles such as silica, alumina, zirconia, ceria, yttria, boronia, magnesia, calcia, barium titanate and calcium silicate may be dispersed in water or ethyl alcohol. It may also be used in combination with the organic compound which can be converted into an inorganic binder with a silicon precursor such as siloxane, hydrolyzable silane derivative or organic silica sol. Preferably, silica (SiO ₂ ) -based or alumina (Al ₂ O ₃ ) -based compounds may be used, and particularly silica-based compounds are more preferable.

On the other hand, when coating the inside of the cooking utensil using light using the coating composition of the present invention, in consideration of the area to be coated, etc., a well-known coating method may be generally used. For example, the coating method may include dip coating, spray coating, gravure coating, comma coating, roll coating, bar coating, electrolytic coating, deposition method and the like.

In addition, the thickness of the film during such coating may be appropriately adjusted in consideration of the use temperature range of the cooking utensil, etc., but is preferably in the range of 0.7 to 0.9 μm. After coating, it may be treated to achieve more effective deposition or bonding between the coating material and the inner surface of the cookware, such as by heat treatment at high temperatures.

EXAMPLE

Example 1

Preparation of the Invention Compositions.

The functional coating solution of the present invention used a titanium dioxide photocatalyst (P-25, Degussa) as a photocatalyst material, and metal compound particles containing platinum as a transition metal catalyst, and hydrogen hexachloroplatinate (IV) hydrate in the coating solution. (Aldrich) was used after reduction. Inorganic silica sol (SNOTEX-O ^™ , Ilsan Chemical) was used as the binder material, and tetraethyl orthosilicate (Aldrich) and fluoride oxypropyltrimethoxysilane (Aldrich), which are organic silanes, were used. In particular, photocatalyst P-25, 59.5 wt%; SNOTEX-O, 25 weight percent; Tetraethylorthosilicate, 7.5 wt%; 3-glyoxideoxypropyltrimethoxysilane, 7.5 wt%; And 0.5% by weight of hexachloroplatinate hydrate resulted in the desired coating composition.

Example 2

Evaluation of Oil Degradation Rate when Cookware Using Halogen Lamp as Heat Source

The functional coating solution of the present invention prepared in the preferred mixing range in Example 1 was coated on a reflecting plate (material: galvalume) of a halogen lamp used as a heat source of the cooking utensil to prepare a functional coating film. The thickness of the coating film was 0.8 μm.

In order to measure the oil decomposition efficiency of the functional coating film, the amount of cooking oil was artificially changed to evaluate the decomposition efficiency after application.

First, the excess cooking oil (0.5 mg / cm ² ) was applied to the reflector at a time, and then cookware was operated 10 times in 45 seconds, and then the reflector state was observed. In Figure 3 (a) is a photograph of the reflector before the decomposition experiment, (b) is a photograph of the reflector after the decomposition experiment. As shown in the picture, it can be observed that the surface of the reflecting plate turns yellow as the applied oil is decomposed. The surface where the functional coating film is present (left) is very good compared to the part that is not (right). Can be.

Second, after applying a small amount of cooking oil (0.05 mg / cm ² ) to the reflecting plate, the cooking utensil was operated for 45 seconds, and after applying the same amount of cooking oil again the operation of the cooking utensil was repeated 10 times. Therefore, the amount of cooking oil applied is 0.5 mg / cm ² in total, which is the same as the first case, and the time for which the light source is irradiated is also the same as 450 seconds in total. In Figure 4 (a) is a photograph of the reflector before the decomposition experiment, (b) is a photograph of the reflector after the decomposition experiment. As shown in the photographic results, when a small amount of cooking oil is gradually applied, it can be seen that the portion (left) where the functional coating film is present remains completely clean.

From the above experimental results, it can be seen that the functional coating film of the present invention effectively removes oil generated during cooking, and particularly, when the amount of oil generated is small, the effect is very excellent.

As described above, in the cooking utensil prepared using the functional coating film according to the present invention, when oil or the like generated during cooking of food in the utensil is smeared on the inner wall or door, contaminants such as these oils themselves. It can be seen that it is very excellent in terms of the performance of decomposition. Therefore, by introducing the functional coating film of the present invention into the cooking utensils, cookware manufacturers always provide clean and sanitary cooking utensils to the user, and the user is less hygienic to clean the inside of the cooking utensil that is difficult to structurally clean. There is an effect of using a conventional cooking utensil, and can increase the functionality and universalization of the cooking utensils, such as using light it can be said that the industrial applicability is very large.

Claims (8)

25 to 60% by weight photocatalyst selected from the group consisting of homogeneous catalysts, heterogeneous catalysts, homogeneous catalysts or mixtures of heterogeneous catalysts with zeolites, and their layered perovskite forms, and palladium, silver, platinum, A composition for internal coating of a cookware using light, containing 0.001 to 10 wt% of a transition metal catalyst selected from the group consisting of gold and ruthenium. delete delete The coating of claim 1, wherein the photocatalyst is selected from the group consisting of Ru (bipy) ₃ ²⁺ , metal porphyrin, Si, Ge, CdS, titanium dioxide and a semiconductor material containing the same. Composition. delete The composition for internal coating of a cookware using light according to claim 1, further comprising a binder material. The method of claim 5, wherein the binder is selected from the group consisting of silica, alumina, zirconia, ceria, yttria, boronia, magnesia, calcia, barium titanate, calcium silicate, siloxane, hydrolyzable silane derivative and organic silica sol. Composition for internal coating of cookware using. The composition for internal coating of a cooker using light according to claim 1, wherein the cooker is operated at a high temperature.