ENAMEL COMPOSITION, METHOD FOR PREPARATION THEREOF AND COMPONENT FOR COOKING APPLIANCE

Abstract

There is disclosed a novel enamel composition that may be applied to all diverse components for a cooking appliance, with excellent cleaning performance and adhesion. The enamel composition of the present disclosure may include 10 to 25% by weight of SiO.sub.2, 15 to 30% by weight of P.sub.2O.sub.5, 1 to 15% by weight of B.sub.2O.sub.3, 10 to 25% of at least one of Na.sub.2O, Li.sub.2O and K.sub.2O, 1 to 5% by weight of NaF, 15 to 35% by weight of at least one of Al.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2, and 1 to 10% by weight of at least one of Fe.sub.2O.sub.3, Co.sub.3O.sub.4 and NiO, thereby being applicable to coating of components for a cooking appliance such as a burner cap, a grate and a griddle in which food is vulnerable to contamination and subject to thermal shock.

Claims

1. An enamel composition comprising: 10 to 25% by weight of SiO.sub.2; 15 to 30% by weight of P.sub.2O.sub.5; 1 to 15% by weight of B.sub.2O.sub.3; 10 to 25% of at least one of Na.sub.2O, Li.sub.2O and K.sub.2O; 1 to 5% of by weight NaF; 15 to 35% by weight of at least one of Al.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2; and 1 to 10% by weight of at least one of Fe.sub.2O.sub.3, Co.sub.3O.sub.4 and NiO.

2. The enamel composition of claim 1, wherein the content amount of Na.sub.2O is 5% by weight or more.

3. The enamel composition of claim 1, wherein the content amount of the Al.sub.2O.sub.3 is 5% by weight or more.

4. The enamel composition of claim 1, wherein the content amount of each of the Fe.sub.2O.sub.3 and the Co.sub.3O.sub.4 is 0.1% by weight or more.

5. The enamel composition of claim 4, wherein the total content amount of the Fe.sub.2O.sub.3 and Co.sub.3O.sub.4 is 1% by weight or more.

6. A preparation method of an enamel composition comprises, providing raw materials of an enamel composition comprising 10 to 25% by weight of SiO.sub.2, 15 to 30% by weight of P.sub.2Os, 1 to 15% by weight of B.sub.2O.sub.3, 10 to 25% of at least one of Na.sub.2O, Li.sub.2O and K.sub.2O, 1 to 5% of by weight NaF, 15 to 35% at least one of by weight of Al.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2 and 1 to 10% by weight of at least one of Fe.sub.2O.sub.3, Co.sub.3O.sub.4 and NiO. melting the raw materials of the enamel composition; and cooking the melted enamel composition.

7. The preparation method of an enamel composition of claim 6, wherein the enamel composition comprises 5% by weight or more of the Na.sub.2O.

8. The preparation method of an enamel composition of claim 6, wherein the enamel composition comprises 5% by weight or more of the Al.sub.2O.sub.3.

9. The preparation method of an enamel composition of claim 6, wherein the enamel composition comprises 0.1% by weight or more of each of the Fe.sub.2O.sub.3 and Co.sub.3O.sub.4.

10. The preparation method of an enamel composition of claim 9, wherein the total content of the Fe.sub.2O.sub.3 and Co.sub.3O.sub.4 is 1% by weight or more.

11. A component for a cooking appliance, with a surface on which an enamel coating layer is formed, the enamel coating layer formed from an enamel composition comprising: 10 to 25% by weight of SiO.sub.2; 15 to 30% by weight of P.sub.2O.sub.5; 1 to 15% by weight of B2O3; 10 to 25% of at least one of Na.sub.2O, Li.sub.2O and K.sub.2O; 1 to 5% by weight of NaF; 15 to 35% by weight of at least one of Al.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2 ; and 1 to 10% by weight of at least one of Fe.sub.2O.sub.3, Co.sub.3O.sub.4 and NiO.

12. The component for the cooking appliance of claim 11, wherein the component is selected from a cap for a burner, grate, and a griddle.

13. The component for the cooking appliance of claim 11, wherein the enamel composition comprises 5% by weight or more of the Na.sub.2O.

14. The component for the cooking appliance of claim 11, wherein the enamel composition comprises 5% by weight or more of the Al.sub.2O.sub.3.

15. The component for the cooking appliance of claim 11, wherein the enamel composition comprises 0.1% by weight or more of each of the Fe.sub.2O.sub.3 and Co.sub.3O.sub.4.

16. The component for the cooking appliance of claim 11, wherein the total content of the Fe.sub.2O.sub.3 and Co.sub.3O.sub.4 is 1% by weight or more.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0025] FIG. 1 is a perspective view showing a cooking appliance to which a cooking appliance component according to an embodiment is applied;

[0026] FIG. 2 is a photograph showing a burner cap among the cooking appliance components according to an embodiment;

[0027] FIG. 3 is a photograph showing a grate among the cooking appliance components according to an embodiment;

[0028] FIG. 4 is a photograph showing a griddle among the cooking appliance components according to an embodiment; and

[0029] FIG. 5 is a photograph showing adhesion evaluation criteria of examples and comparative examples.

DESCRIPTION OF SPECIFIC EMBODIMENTS

[0030] The above-described aspects, features and advantages are specifically described hereunder with reference to the accompanying drawings such that one having ordinary skill in the art to which the present disclosure pertains can easily implement the technical spirit of the disclosure. In the disclosure, detailed descriptions of known technologies in relation to the disclosure are omitted if they are deemed to make the gist of the disclosure unnecessarily vague.

[0031] Below, preferred embodiments according to the disclosure are specifically described with reference to the accompanying drawings. In the drawings, identical reference numerals can denote identical or similar components.

[0032] Hereinafter, expressions of ‘a component is provided or disposed in an upper or lower portion’ may mean that the component is provided or disposed in contact with an upper surface or a lower surface. The present disclosure is not intended to limit that other elements are provided between the components and on the component or beneath the component.

[0033] It will be understood that when an element is referred to as being “connected with” another element, the element can be directly connected with the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly connected with” another element, there are no intervening elements present.

[0034] A singular representation may include a plural representation unless it represents a definitely different meaning from the context.

[0035] A singular representation may include a plural representation unless it represents a definitely different meaning from the context. Terms such as “include” or “has” are used herein and should be understood that they are intended to indicate an existence of several components, functions or steps, disclosed in the specification, and it is also understood that greater or fewer components, functions, or steps may likewise be utilized.

[0036] Throughout the disclosure, the terms “A and/or B” as used herein can denote A, B or A and B, and the terms “C to D” can denote C or greater and D or less, unless stated to the contrary.

[0037] Hereinafter, an enamel composition, a method for preparation thereof and components for a cooking appliance according to several embodiments of the present disclosure will be described.

Enamel Composition

[0038] An enamel composition according to the present disclosure may contain 10 to 25% by weight of SiO.sub.2, 15 to 30% by weight of P.sub.2O.sub.5, 1 to 15% by weight of B.sub.2O.sub.3, 10 to 25% by weight of one or more of Na.sub.2O, Li.sub.2O and K.sub.2O, 1 to 5% by weight of NaF, and 15 to 35% by weight of at least one of ZrO.sub.2 Al.sub.2O.sub.3, and TiO.sub.2, and 1 to 10% by weight of one or more of Fe.sub.2O.sub.3, Co.sub.3O.sub.4 and NiO.

[0039] The enamel composition according to the present disclosure is a silico-phosphate-based enamel composition. First, the enamel composition may include SiO.sub.2 that is a component form a glass structure.

[0040] As described above, SiO.sub.2 is a component that forms a glass structure. SiO.sub.2 may enhance a chemical resistance of the enamel composition by strengthening a skeleton of the glass structure and facilitate expression of characteristics of a metal oxide acting as a catalyst. Since it has inferior heat resistance and chemical resistance in comparison to other components, the catalytic metal oxide cannot be contained in the enamel composition in a large amount. However, SiO.sub.2 has a large pore size. When an appropriate amount of SiO.sub.2 is contained in the glass composition, the solubility of the catalytic metal oxide in the glass may be increased. Accordingly, the characteristics of the catalytic metal oxide may be expressed, with excellent heat resistance and chemical resistance, by appropriately controlling the content ratio of SiO.sub.2 and the catalytic metal oxide. The SiO.sub.2 may be contained in the enamel composition in a range of 10 to 25% by weight. If the SiO.sub.2 exceeds 25% by weight, the addition of other components may be hindered, resulting in deterioration of a cleaning function. If the SiO.sub.2 is less than 10% by weight, a problem might occur in that the silico-phosphate glass composition according to the present disclosure collapses.

[0041] Next, the enamel composition according to the present disclosure may contain P.sub.2O.sub.5 that is a glass former forming the glass structure like SiO.sub.2. P.sub.2O.sub.5 is a glass former configured to facilitate addition of a large amount of transition metal oxides. The P.sub.2O.sub.5 may be contained in the enamel composition in a range of 15 to 30% by weight. When the P.sub.2O.sub.5 exceeds 30% by weight, the thermal properties of the enamel composition might be deteriorated and vitrification could be difficult. When P.sub.1O.sub.5 is less than 15% by weight, the addition amount of the transition metal oxide contained in the enamel composition could be reduced.

[0042] Next, B.sub.2O.sub.3 serves as a glass former and has a function of maintaining an appropriate viscosity during firing of the enamel composition and preventing crystallization of the enamel composition. B.sub.2O.sub.3 may be contained in a glass composition in a range of 1 to 15% by weight. When B.sub.2O.sub.3 exceeds 15% by weight, the addition of other components may be hindered which results in deterioration of the cleaning function. When B.sub.2O.sub.3 is less than 1% by weight, the glass composition might collapse or crystallization of the glass composition might occur.

[0043] Li.sub.2O, Na.sub.2O and K.sub.2O may serve to enhance the cleaning function of the enamel composition. At least one of the Li.sub.2O, Na.sub.2O and K.sub.2O may be contained in the enamel composition in a range of 15 to 35% by weight. When the content of the at least one of the Li.sub.2O, Na.sub.2O and K.sub.2O exceeds 35%, the thermal expansion coefficient of the glass might extremely increased, which results in deterioration of coating performance. When the content of the at least one of the Li.sub.2O, Na.sub.2O and K.sub.2O is less than 15%, the cleaning function might be deteriorated

[0044] Preferably, the enamel composition according to the present disclosure may include 5% by weight or more of Na.sub.2O.

[0045] NaF may also serve to improve the cleaning function of the enamel composition. NaF may be contained in the enamel composition in a range of 1 to 5% by weight. When NaF exceeds 5% by weight, addition of other components might be hindered and durability might be deteriorated. When the content of Naf is less than 1% by weight, the cleaning function might be deteriorated.

[0046] Next, the enamel composition according to the present disclosure may include Al.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2. Those components may improve the durability of enamel coating. To this regard, the enamel composition according to the present disclosure may include 15 to 35% by weight of at least one of Al.sub.2O.sub.3, TiO2 and ZrO.sub.2. When the content amount of the at least one of Al.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2 is less than 15% by weight, the durability of the enamel coating might be deteriorated. In contrast, when the content of the at least one of Al.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2 exceeds 35% by weight, the crystallization of the enamel composition might occur.

[0047] Preferably, the enamel composition of the present disclosure may include 10 % by weight or more of Al.sub.2O.sub.3 to improve durability.

[0048] In addition, the enamel composition of the present disclosure may include 1 to 10% by weight of at least one Fe.sub.2O.sub.3, Co.sub.3O.sub.4, and NiO in order to improve adhesion performance with a base material and realize color. When the content of the at least one Fe.sub.2O.sub.3, Co.sub.3O.sub.4, and NiO is less than 1% by weight, the enamel coating and the adhesion performance with the base material might be weakened. When the content of the at least one Fe.sub.2O.sub.3, Co.sub.3O.sub.4, and NiO exceeds 10% by weight, chemical resistance of coating and durability might be deteriorated.

[0049] Preferably, the enamel composition of the present disclosure may include Fe.sub.2O.sub.3 and Co.sub.3O.sub.4 in the respective content of 0.1% by weight or more. The total content of Fe.sub.2O.sub.3 and Co.sub.3O.sub.4 may be 1% by weight or more.

[0050] The enamel composition described above according to the present disclosure may be designed to be applied to other components for a cooking appliance.

[0051] To this regard, in the enamel composition of the present disclosure, the composition ratio of SiO.sub.2, P.sub.2O.sub.5 and B.sub.2O.sub.3 as glass forming components and Na.sub.2O, K.sub.2O and Li.sub.2O as network modifiers may be controlled and adjusted. The composition ratio of the enamel composition according to the present disclosure may be adjusted to match the thermal expansion coefficients of various components.

[0052] Also, in the enamel composition of the present disclosure, the contents of the glass formers, network modifiers described above, and Fe.sub.2O.sub.3, Co.sub.3O.sub.4 and NiO may be adjusted in order to realize adhesion with the base material and provide cleaning functionality.

[0053] As described above, the enamel composition according to the present disclosure may a composition system in which the components implementing glass and the components having the catalytic function are optimized. Accordingly, the enamel composition may be applied to various components of a cooking appliance and also may clean all contaminants at a room temperature without soaking.

Preparation Method of the Enamel Composition

[0054] Hereinafter, a preparation method of an enamel composition according to the present disclosure may include providing an enamel composition raw material containing the ingredients described above; melting the enamel composition material; and cooking the melted composition material.

[0055] After the enamel composition material is sufficiently mixed, the enamel composition material may be melted. Preferably, the composition material may be melted in a temperature range of 1200 to 1400° C. In addition, the composition material may be melted for 1 to 2 hours.

[0056] Hence, the melted composition material may be cooled quickly by a quenching roller. Accordingly, the enamel composition may be prepared.

Components for a Cooking Appliance

[0057] Hence, the enamel composition according to the present disclosure may be coated on one surface of a coating target (e.g., a component for a cooking appliance).

[0058] FIG. 1 is a perspective view showing a cooking appliance to which a cooking appliance component according to an embodiment is applied.

[0059] As shown in FIG. 1, the cooking appliance 100 may include a cabinet 10, a cook top unit 20, and an oven unit 30. The cooking appliance 100 may further include a drawer unit 40 and a control panel 50.

[0060] The cabinet 10 may define an exterior design of the cooking appliance 100 and may have a hexahedral box shape, but the present disclosure is not limited thereto.

[0061] The cook top unit 20 may be mounted on the cabinet 10 and include at least one grate 25 for supporting a cooking target heated by a burner 5. The grate 25 may be one of the components for the cooking appliance according to an embodiment of the present disclosure.

[0062] The cook tope unit 20 may further include a top plate 21 and a manipulation knob 27. In the drawing, it is shown that four burners 5 are provided on the top plate. That is one of the examples and the number of the burners 5 may be variable. Such the burner 5 may be configured to generate a flame for heating the cooking target (i.e., food) by burning a gas mixture mixed with air. The manipulation knob 27 may be provided for allowing a user’s manipulation of operating the burner 5. Although not shown in FIG. 1, a burner cap as the component for the cooking appliance according to an embodiment may be coupled to the burner 5. The burner cap means a component configured to safely protect the burner even if the cooking target or food overflows during the cooking and prevent gas flame from being turned off.

[0063] The oven unit 30 may be disposed inside the cabinet 10 corresponding to a lower portion of the cook top unit 20. The oven unit 30 may include a cavity defining a cooking chamber, and a door 31 configured to selectively open and close the cooking chamber. In other words, the oven unit 30 may be provided with the cooking chamber in which the cooking target is cooked. The cooking chamber may be selectively open and closed by the door 31. Although not shown in the drawings, at least one heating source for heating (e.g., a broil burner, a bake burner and a convection device) may be mounted inside the cooking chamber.

[0064] The drawer unit 40 may be provided inside the cabinet 10 disposed in a lower portion of the cabinet, corresponding to the oven unit 30. Such the drawer unit 40 may be configured to warm a container containing food. The drawer unit 40 may include a drawer 41 configured to slidingly move into and out of the inside of the cabinet 10 and accommodate a container.

[0065] The control panel 50 may be disposed on an upper rear end of the cabinet 10, corresponding to a rear portion of the cook top unit 20. The control panel 50 may be configured to receive an input signal for operations of the oven unit 30 and the drawer unit 40 and display information about the operations.

[0066] Although not shown in FIG. 1, a griddle as the component for the cooking appliance according to an embodiment may be provided in the cooking appliance 100. The griddle is a large, thick iron plate used for cooking. Various foods may be easily cooked by applying heat to the griddle, and the griddle may be used in a state of being placed on the burner.

[0067] Referring to FIGS. 2 to 4, a burner cap, a grate and a griddle according to an embodiment of the present disclosure are shown as components for a cooking appliance.

[0068] The enamel composition may be coated on a surface of the component for a cooking appliance such as the burner cap, the grate and the griddle.

[0069] Specifically, the enamel composition according to the present disclosure may be coated on the surfaces of the components for the cooking appliance through a dry process or a wet process.

[0070] Hereinafter, specific aspects of the present disclosure will be described through embodiments.

EXAMPLES

Preparation of Enamel Composition

[0071] An enamel composition having a composition ratio shown in Table 1 was prepared. Raw materials of the ingredients were sufficiently mixed in a V-mixer for three hours. Na.sub.2Co.sub.3, K.sub.2OO.sub.3, Li.sub.2Co.sub.3 were used as the respective raw materials of Na.sub.2O, K.sub.2O and Li.sub.2O and the rest of the ingredients were the same as those listed in Table 1. The mixed materials were sufficiently melted at 1300° C. for 1 hour and then quick-cooled in a quenching roller to obtain a glass cutllet.

[0072] After the glass cullet obtained in the above process is mixed as shown in Table 2 below and then mixed for about 10 hours, to prepare a slip. The particle size of the prepared slip was controlled to such an extent that 1 g to 3 g of frit remaining when the 60 cc slip passed through a 325 mesh sieve (ASTM C285-88).

TABLE-US-00001 ingredient weight%) Examples Comparative examples 1 1 3 4 1 2 SiO.sub.2 13.49 12.39 13.49 11.49 8.58 13.6 P.sub.2O.sub.5 24.89 24.89 26.52 24.89 25.07 25.05 B.sub.2O.sub.3 7.1 7.1 9.3 10.1 7.15 7.15 Na.sub.2O 12.97 12.97 10.54 12.97 15.05 13.05 K.sub.2O 16.83 16.83 16.83 17.83 18.94 16.94 Li.sub.2O 0.81 0.91 0.81 0.81 2.81 0.81 NaF 1.6 1.6 1.6 1.6 1.61 1.61 Al.sub.2O.sub.3 14.85 15.85 12.65 11.85 13.2 16.1 TiO.sub.2 2.63 2.63 3.35 2.63 2.62 2.45 Fe.sub.2O.sub.3 1.42 1.42 1.5 2.42 1.5 0.7 Co.sub.3O.sub.4 0.53 0.53 0.53 0.53 0.43 0 NiO 0.25 0.25 0.25 0.25 1.06 0.56 ZrO.sub.2 2.63 2.63 2.63 2.63 1.98 1.98

TABLE-US-00002 Ingredients Mixing ratio (by weight) Glass cullet 100 Water 50 Ball clay 5 Aluminum oxide 3 Borax 0.2 Bentonite 0.2 Sodium nitrite 0.3

Preparation of Enamel Composition Specimens

[0073] The enamel frit prepared as described above was coated on surfaces of the burner cap, grate and griddle by using a spray gun, respectively. After the coating, a drying process may be performed at 200° C. to 250° C. for 5 to 10 minutes and then the coated layer was baked for 300 to 420 seconds at a temperature condition of 810° C. to 830° C.

Experimental Example 1-Cleaning Performance Evaluation

[0074] Cleaning performance of the specimens according to the Examples and Comparative examples was evaluated as follows.

[0075] According to a method of measuring the cleaning performance, 1 g of chicken oil as a contaminant was applied on the surface of the specimen according to Examples and Comparative examples evenly and thinly with a brush. Hence, the specimen coated with the contaminant was placed in a thermostat and the contaminant was solidified under conditions of a temperature of 270° C. and a time period of 30 minutes. After the solidification, the specimen was naturally cooled. After that, the hardened chicken oil was wiped with a scrubber for frying fans soaked in room-temperature water with a force of less than 3 khf. A flat-bottomed bar with a diameter of 5 cm was used to level the area to be wiped from the contaminated enamel surface. At this time, the number of reciprocating wiping actions was measured and defined as the number of cleanings. The evaluation index is the same as Table at the bottom left.

TABLE-US-00003 Cleaning reciprocations Level ~ 5 5 ~ 15 4 ~ 25 3 ~ 50 2 50 ~ 1

Experimental Example 2-Adhesion Performance Evaluation

[0076] Adhesion performance of Examples and Comparative examples was measured. According to a method of measuring the adhesion, Dupont Impact Tester (ASTM D1794, JIS K5400) was used. A test specimen was placed in the center of a sample stage and a steel ball with a diameter of about 25.4 mm (i.e., 1 inch) was installed at the center of a flat portion of the specimen. Then, an iron piece weighing 2 kg fell freely from a height of 300 mm, in order to investigate a state of enamel peeling. The criterion for determining the level of adhesion is based on the criterion shown in FIG. 3.

Results of Experimental Examples

[0077] The results of Experimental examples are shown in Table 4.

TABLE-US-00004 Example 1 Example 2 Example 3 Example 4 Comparative example 1 Chicken coil cleanability Lv. 4 Lv. 4 Lv. 4 Lv. 4 Lv. 1 Tomato source Lv. 5 Lv. 5 Lv. 5 Lv. 5 Lv. 2 Adhesion Lv. 5 Lv. 5 Lv. 5 Lv. 5 Lv. 0

[0078] According to the result of evaluation, all contaminants were easily removed at room temperature in test specimens of Examples 1 to 4. In contrast, all contaminants were not removed at room temperature in Comparative example. In addition, Examples have excellent cleaning performance and adhesion at the same time. However, Comparative example has poor adhesion.

[0079] The embodiments are described above with reference to a number of illustrative embodiments thereof. However, the present disclosure is not intended to limit the embodiments and drawings set forth herein, and numerous other modifications and embodiments can be devised by one skilled in the art. Further, the effects and predictable effects based on the configurations in the disclosure are to be included within the range of the disclosure though not explicitly described in the description of the embodiments.

TABLE-US-00005 DESCRIPTION OF REFERENCE NUMERALS 100 Cooking appliance 5 Burner 10 Cabinet 20 Cook top unit 21 Plate 25 Grate 27 Manipulation knob 30 Oven unit 31 Door 40 Drawer unit 41 Drawer 50 Control panel