Method for manufacturing cookware comprising thermochromic composite coating and cookware manufactured by the method

Abstract

The present invention relates to a method for manufacturing a cookware comprising a thermochromic composite coating and the cookware manufactured by the method. In a specific example, the method for manufacturing a cooker including a thermochromic composite coating includes: a primer layer forming step, forming a primer layer including a fluororesin on the surface of a metal substrate; a tinting layer forming step, applying a tinting coating agent including a matrix resin and a tinting pigment to at least a portion of the surface of the primer layer to form a tinting layer; a thermochromic layer forming step, applying a thermochromic coating agent including a thermochromic compound and a color-changing pigment to at least a portion of the surface of the primer layer to form a thermochromic layer; and a top coating layer forming step, applying a top coating agent on the surface of the primer layer forming the thermochromic layer and performing a heat treatment to form a top coating layer, wherein the top coating agent includes 100 parts by weight of a fluororesin, 10 to 50 parts by weight of an alkoxysilane compound, 5 to 50 parts by weight of a first pigment, 0.5 to 15 parts by weight of molybdenum disulfide, and 1 to 15 parts by weight of a phosphate compound.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a cookware comprising a thermochromic composite coating and the cookware manufactured by the method. Background Art

[0002] Frypans, frying pans, soup pots, and the like, which are heating cookers, are made of metal materials, and a coating having heat resistance and corrosion resistance is formed on the surface of the heating cookers that contacts the food to be cooked.

[0003] On the other hand, when using the above-mentioned heating cooker for cooking, it is difficult to clearly judge to what extent the cooker is heated by the fire. In order to solve the above-mentioned problem, a coating agent containing a temperature-indicating pigment is applied to the surface of the cooker and hardened to form a thermochromic coating, thereby producing a cooker that can grasp the heating state by the thermochromic change of the coating.

[0004] The background technology related to the present invention is Korean Patent Gazette No. 10-1686414 (published on December 14, 2016, invention name: Ceramic coating capable of indicating heating state, preparation method of ceramic coating and coating method thereof, and heating device using the method). Summary of the invention

[0005] Technical issues

[0006] An object of the present invention is to provide a method for manufacturing a cooker comprising a thermochromic composite coating, which can easily identify the heating state of the cooker.

[0007] Another object of the present invention is to provide a method for manufacturing a cookware including a thermochromic composite coating having excellent wear resistance, durability and interlayer adhesion of the composite coating.

[0008] Another object of the present invention is to provide a method for manufacturing a cooker including a thermochromic composite coating having excellent thermal conductivity and antifouling properties and excellent non-stick properties so that food does not stick to the surface of the composite coating during cooking.

[0009] Another object of the present invention is to provide a cooker manufactured by the method for manufacturing the cooker.

[0010] Solutions to the problem

[0011] One aspect of the present invention relates to a method for making cookware comprising a thermochromic composite coating. In a specific example, the method for manufacturing a cooker including a thermochromic composite coating includes: a primer layer forming step, forming a primer layer including a fluororesin on the surface of a metal substrate; a tinting layer forming step, applying a tinting coating agent including a matrix resin and a tinting pigment to at least a portion of the surface of the primer layer to form a tinting layer; a thermochromic layer forming step, applying a thermochromic coating agent including a thermochromic compound and a color-changing pigment to at least a portion of the surface of the primer layer to form a thermochromic layer; and a top coating forming step, applying a top coating agent on the surface of the primer layer forming the thermochromic layer and performing a heat treatment to form a top coating, the top coating agent comprising 100 parts by weight of a fluororesin, 10 to 50 parts by weight of an alkoxysilane compound, 5 to 50 parts by weight of a first pigment, 0.5 to 15 parts by weight of molybdenum disulfide and 1 to 15 parts by weight of a phosphate compound, the tinting pigment comprising titanium oxide, and the color-changing pigment comprising red iron oxide.

[0012] In one embodiment, the heat treatment may be performed at a temperature of 380°C to 450°C.

[0013] In a specific example, the top coating agent may further include 0.5 to 5 parts by weight of germanium oxide relative to 100 parts by weight of the fluorine-based resin. The top coating agent may include the germanium oxide and the phosphate compound in a weight ratio of 1:1 to 1:5.

[0014] In a specific example, the toning layer and the thermochromic layer can be formed by pad printing.

[0015] In a specific example, the primer layer can be formed by a primer agent, which can include 100 parts by weight of a fluorine-based resin, 1 part by weight to 40 parts by weight of a second pigment, 1 part by weight to 15 parts by weight of a phosphate compound, and 0.5 parts by weight to 5 parts by weight of germanium oxide.

[0016] In a specific example, the fluororesin may include one or more of polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and polyvinylidene fluoride (PVDF).

[0017] In a specific example, the tinting coating agent may include 100 parts by weight of a matrix resin and 0.5 to 50 parts by weight of a tinting pigment, the thermochromic coating agent may include 100 parts by weight of a thermochromic compound and 0.5 to 30 parts by weight of a color-changing pigment, and the thermochromic compound may include one or more of a mercuric iodide complex and a vanadium oxide.

[0018] In a specific example, the first pigment may include one or more of carbon black, perylene red, manganese iron black, copper chrome black, bismuth vanadate, yellow iron hydroxide, chrome oxide green, and cobalt aluminum blue.

[0019] Another aspect of the present invention relates to a cooker manufactured by the method for manufacturing the cooker. In a specific example, the cooker includes: a metal substrate; a primer layer formed on one or more surfaces of the metal substrate and including a fluororesin; a tinting layer formed on at least a portion of the surface of the primer layer; a thermochromic layer formed on at least a portion of the surface of the primer layer; and a top coating layer formed on the surfaces of the primer layer and the thermochromic layer, the top coating layer being formed by a top coating agent, the top coating agent including 100 parts by weight of a fluororesin, 10 parts by weight to 50 parts by weight of an alkoxysilane compound, 5 parts by weight to 50 parts by weight of a first pigment, 0.5 parts by weight to 15 parts by weight of molybdenum disulfide, and 1 part by weight to 15 parts by weight of a phosphate compound, the tinting layer being formed by a tinting coating agent, the tinting coating agent including a matrix resin and a tinting pigment, the thermochromic layer being formed by a thermochromic coating agent, the thermochromic coating agent including a thermochromic compound and a color-changing pigment, and the tinting pigment including titanium oxide. The color changing pigment comprises red iron oxide.

[0020] Effects of the Invention

[0021] When the cookware including the thermochromic composite coating of the present invention is used, the thermochromic layer does not appear on the surface at room temperature. When heated to a temperature above a specified temperature, the thermochromic layer appears and can be identified on the surface of the cookware, thereby making it easy to identify the heating state of the cookware. In addition, the thermochromic composite coating has excellent wear resistance and durability, and the interlayer adhesion, thermal conductivity, and antifouling properties of the composite coating, thereby facilitating cleaning and management. The composite coating has excellent non-stick properties that prevent food from sticking to the surface during cooking. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flowchart showing a method for manufacturing a cooker according to a specific example of the present invention;

[0023] Figure 2 The method for manufacturing a cooker of the present invention is illustrated in a schematic manner;

[0024] Figure 3 is a photograph of a cooker manufactured according to Example 1;

[0025] Figure 4 This is a photograph of the cooker manufactured according to Example 1 after heating. DETAILED DESCRIPTION

[0026] When describing the present invention, if it is determined that a detailed description of a related known technology or structure may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

[0027] Furthermore, the terms described below are defined in consideration of their functions in the present invention, and since these terms may differ depending on the intentions or practices of users or operators, they must be defined based on the entire text of this specification that describes the present invention.

[0028] A method for manufacturing cookware comprising a thermochromic composite coating.

[0029] One aspect of the present invention relates to a method for making cookware comprising a thermochromic composite coating. Figure 1 The flowchart of a method for manufacturing a cooker according to a specific example of the present invention is shown below. Figure 2 The method for manufacturing a cooker of the present invention is illustrated in a schematic manner. Figure 1 and Figure 2 , the method for manufacturing a cooker includes: step S10, forming a primer layer; step S20, forming a toning layer; step S30, forming a thermochromic layer; and step S40, forming a top coating layer and heat treatment. More specifically, the method for manufacturing a cooker including a thermochromic composite coating includes: step S10, forming a primer layer including a fluororesin on the surface of a metal substrate; step S20, applying a toning coating agent including a matrix resin and a toning pigment to at least a portion of the surface of the primer layer to form a toning layer; step S30, applying a thermochromic coating agent including a thermochromic compound and a color-changing pigment to at least a portion of the surface of the primer layer to form a thermochromic layer; and step S40, applying a top coating agent to the surface of the primer layer forming the thermochromic layer and performing a heat treatment to form a top coating layer.

[0030] In this specification, the term "thermochromic composite coating" is defined as including a primer layer, a tinting layer, a thermochromic layer and a top coating layer.

[0031] Hereinafter, the method for manufacturing the cookware including the thermochromic composite coating of the present invention will be described in steps.

[0032] Primer layer forming step (step S10)

[0033] The step is a step of applying a primer agent containing a fluororesin to at least a portion of a metal substrate and drying the primer agent to form a primer layer.

[0034] Refer to the Figure 2 In the portion (a), the primer layer 20 may be formed on the surface of the metal substrate 10 that contacts the cooking material. In a specific example, the metal substrate 10 may include one or more of aluminum, aluminum alloy, copper, manganese, aluminum-plated steel, iron, and stainless steel.

[0035] In a specific example, before applying the primer, the surface of the metal substrate to which the primer is applied may be subjected to sand blasting. When the sand blasting is performed, the surface area of ​​the metal substrate may be increased, thereby improving the adhesion of the primer layer.

[0036] In a specific example, the primer layer can be formed by a primer agent, which can include 100 parts by weight of a fluorine-based resin, 5 parts by weight to 50 parts by weight of a second pigment, 1 part by weight to 15 parts by weight of a phosphate compound, and 0.5 parts by weight to 5 parts by weight of germanium oxide.

[0037] In a specific example, the fluororesin may include one or more of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer and polyvinylidene fluoride. When the fluororesin is used, the primer layer can have excellent chemical resistance, wear resistance, durability and heat resistance. For example, it may include one or more of polytetrafluoroethylene and tetrafluoroethylene-hexafluoropropylene copolymer.

[0038] In a specific example, the second pigment may include one or more of carbon black, perylene red, ferromanganese black, copper chrome black, bismuth vanadate, yellow iron hydroxide, chromium oxide green and cobalt aluminum blue. For example, ferromanganese black and perylene red may be included. In a specific example, 1 to 40 parts by weight of the second pigment may be included relative to 100 parts by weight of the fluororesin. When the second pigment in the range is included, the mixing and dispersibility of the primer agent is not reduced, and the durability and mechanical properties of the primer layer can be prevented from being reduced. For example, 5 to 20 parts by weight of the second pigment may be included.

[0039] In a specific example, the average particle size of the second pigment may be 5 μm to 30 μm. Within the above range, excellent dispersibility and mixing properties can be achieved.

[0040] The phosphate compound can be used to improve the durability of the primer layer of the present invention and the adhesion to the substrate. The phosphate compound can be a phosphate compound containing one or more of a hydroxyl group and a carboxyl group.

[0041] In a specific example, the phosphoric acid ester compound is contained in an amount of 1 to 15 parts by weight relative to 100 parts by weight of the fluororesin. When the phosphoric acid ester compound is contained in the above range, the durability and adhesion of the primer layer can be improved, and the excessive increase in the viscosity of the primer can be prevented. For example, the phosphoric acid ester compound can be contained in an amount of 1 to 8 parts by weight.

[0042] The germanium oxide can be used to improve the adhesion between the metal substrate, the primer layer and the top coating of the present invention. In a specific example, 0.5 to 5 parts by weight of the germanium oxide can be included relative to 100 parts by weight of the fluororesin. Under the conditions, the primer of the present invention can have excellent mixing and dispersibility, and the interlayer adhesion of the primer layer can be excellent. For example, 1 to 3 parts by weight of the germanium oxide can be included.

[0043] In a specific example, the germanium oxide and the phosphate compound can be included in a weight ratio of 1:1 to 1:5. When the germanium oxide and the phosphate compound are included in the weight ratio range, the primer agent can have excellent mixing and operability, and the interlayer adhesion and durability of the primer layer can be excellent. For example, the germanium oxide and the phosphate compound can be included in a weight ratio of 1:2 to 1:4.

[0044] In a specific example, the primer may further include a solvent. The solvent may include one or more of water, alcohols having 1 to 10 carbon atoms, toluene, xylene, diisobutyl ketone, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 1-methoxy-2-propanol, ethanol, ethylene glycol butyl ether, cyclohexane, n-butyl acetate, N-methylpyrrolidone, dimethylformamide, ethyl acetate, acetone, methyl acetate, isobutyl acetate, isopropyl acetate and dimethyl carbonate. In a specific example, the alcohols having 1 to 10 carbon atoms may include one or more of methanol, ethanol, propanol, isopropanol, n-butanol and isobutanol.

[0045] The solvent may be contained in an amount of 10 to 500 parts by weight relative to 100 parts by weight of the fluororesin. When the solvent is contained in the above range, the composition of the primer can be easily adjusted, and the dispersibility and workability can be improved.

[0046] In a specific example, the primer may further include additives such as surfactants, leveling agents, defoamers, etc. The primer may include 0.1 to 20 parts by weight of the additives relative to 100 parts by weight of the fluororesin.

[0047] The primer can be prepared by a common method.

[0048] In a specific example, the primer can be applied and dried at a temperature of 80° C. to 160° C. to form a primer layer. When dried under the above conditions, the primer layer can have excellent smoothness and durability. The primer can be applied by a common method. For example, it can be applied by an air sprayer.

[0049] In a specific example, the primer can be applied more than once by respectively changing the color of the second pigment. For example, a first primer can be applied on one side of a metal substrate to form a first primer layer, wherein the first primer comprises 100 parts by weight of a fluorine-based resin, 5 to 50 parts by weight of a second pigment comprising perylene red, 1 to 15 parts by weight of a phosphate compound, and 0.5 to 5 parts by weight of germanium oxide. Then, a second primer is applied to at least a portion of the surface of the first primer layer and dried at a temperature of 80°C to 160°C to form a second primer layer, wherein the second primer comprises 100 parts by weight of a fluorine-based resin, 5 to 50 parts by weight of a second pigment comprising manganese iron black or carbon black, 1 to 15 parts by weight of a phosphate compound, and 0.5 to 5 parts by weight of germanium oxide. When dried under the conditions, the smoothness and durability of the primer layer can be excellent. The primer can be applied by conventional methods. For example, it can be applied using an air sprayer.

[0050] In a specific example, the thickness of the primer layer may be 5 μm to 30 μm. Under the above thickness condition, the primer layer can have excellent durability.

[0051] Coloring layer forming step (step S20)

[0052] The step is a step of forming a toning layer comprising a matrix resin and a toning pigment on at least a portion of the surface of the primer layer. Figure 2 As shown in part (b) of FIG. 1 , the step may form the toning layer 30 by pad printing the toning coating agent on at least a portion of the surface of the primer layer 20 .

[0053] In a specific example, the toning coating agent may include a base resin and a toning pigment. When the base resin and the toning pigment are included in the above ranges, the workability and durability of the toning layer can be improved.

[0054] For example, the matrix resin may include one or more of polyetheretherketone, polyurethane, polyethylene sulfide, polyphenylene sulfide, ethyl cellulose, polyvinyl alcohol, and polyvinyl pyrrolidone, but is not limited thereto.

[0055] In a specific example, the coloring pigment includes titanium oxide. The titanium oxide (TiO2) is used to display white, so that the color (pattern) of the thermochromic layer displayed when the cookware described later is heated can be more clearly distinguished.

[0056] In a specific example, the average particle size of the coloring pigment may be 5 μm to 30 μm. Within the above range, excellent dispersibility and thermochromic effect can be achieved.

[0057] In a specific example, the toning coating agent may include 100 parts by weight of the matrix resin and 0.5 to 50 parts by weight of the toning pigment. When the matrix resin and the toning pigment are included in the above range, the dispersibility and mixing properties of the components of the toning coating agent can be improved, and the adhesion of the coating layer can be improved.

[0058] In a specific example, the toning coating agent may further include a solvent. The solvent may include one or more of water, alcohols having 1 to 10 carbon atoms, toluene, xylene, diisobutyl ketone, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 1-methoxy-2-propanol, ethanol, ethylene glycol butyl ether, cyclohexane, N-methylpyrrolidone, dimethylformamide, n-butyl acetate, ethyl acetate, acetone, methyl acetate, isobutyl acetate, isopropyl acetate, and dimethyl carbonate. In a specific example, the alcohols having 1 to 10 carbon atoms may include one or more of methanol, ethanol, propanol, isopropanol, n-butanol, and isobutanol.

[0059] In a specific example, the solvent may be contained in an amount of 10 to 300 parts by weight relative to 100 parts by weight of the matrix resin. When the solvent is contained in the above range, the viscosity of the toner coating composition can be easily adjusted, and the mixing property, dispersibility and operability can be improved.

[0060] In a specific example, the toning coating agent may be applied by pad printing or coating and then dried. The drying may be performed at 80° C. to 150° C. Under the above conditions, the durability of the toning layer can be improved.

[0061] In a specific example, the thickness of the color-adjusting layer may be 1 μm to 30 μm. Under the above thickness condition, the color-adjusting layer may have excellent durability.

[0062] Thermochromic layer forming step (step S30)

[0063] As stated Figure 2 As shown in part (c), the step is a step of pad printing a thermochromic coating agent containing a thermochromic compound and a color-changing pigment on at least a portion of the surface of the primer layer 20 to form the thermochromic layer 40 .

[0064] In a specific example, the thermochromic coating agent may include 100 parts by weight of the thermochromic compound and 0.5 to 30 parts by weight of the color-changing pigment. When the thermochromic compound and the color-changing pigment are included in the above range, the operability and the effectiveness and reliability of the thermochromic effect can be improved.

[0065] In the case of existing heating appliances, although the phenomenon of thermochromic change caused by heating to a temperature above a specified temperature is utilized, it is difficult to confirm the thermochromic change, and therefore there is a problem of difficulty in distinguishing the heating state. In contrast, the present invention does not cause discoloration of the thermochromic layer at room temperature, and the thermochromic layer (pattern) does not appear, but when heated to a temperature above a specified temperature, the thermochromic layer changes color (pattern), thereby making it easy to distinguish the heating state of the cooker. In particular, in a specific example, a red pigment such as perylene red is used in the first pigment or the second pigment of the primer layer or the top coating layer, and the color can be combined with the thermochromic layer to form a color that is not distinguishable by the naked eye at room temperature.

[0066] In a specific example, the color-changing pigment includes red iron oxide. When the color-changing pigment under the above conditions is used to form a thermochromic layer, it can provide excellent distinguishability and can also provide excellent aesthetics for users. In particular, at room temperature, the color (or pattern) of the thermochromic layer does not appear on the surface of the cookware, and when heated to a predetermined temperature or above, it changes color and shows the color (or pattern), which can provide excellent distinguishability.

[0067] In a specific example, the average particle size of the color-changing pigment may be 5 μm to 30 μm. Within the above range, the dispersibility and the thermochromic effect can be excellent.

[0068] In a specific example, the color-changing pigment may be included in an amount of 0.5 to 30 parts by weight relative to 100 parts by weight of the thermochromic compound. When the color-changing pigment is included in the above range, the dispersibility and operability of the components of the thermochromic coating agent may be excellent. When the color-changing pigment is included in the above range, the operability and the effectiveness and reliability of the thermochromic effect may be excellent.

[0069] The thermochromic compound may include one or more of mercuric iodide complex salt and vanadium oxide.

[0070] In a specific example, the mercuric iodide complex salt may include one or more of silver mercuric iodide (Disilver Tetraiodomercurate, Ag2HgI4) and copper mercuric iodide (Dicopper Tetraiodomercurate, Cu2HgI4).

[0071] In a specific example, the thermochromic coating agent may further include a solvent. The solvent may include water, an alcohol having 1 to 10 carbon atoms, toluene, xylene, diisobutyl ketone, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 1-methoxy-2-propanol, ethanol, ethylene glycol butyl ether, cyclohexane, n-butyl acetate, N-methylpyrrolidone, dimethylformamide, ethyl acetate, acetone, methyl acetate, isobutyl acetate, isopropyl acetate and dimethyl carbonate. In a specific example, the alcohol having 1 to 10 carbon atoms may include one or more of methanol, ethanol, propanol, isopropanol, n-butanol and isobutanol.

[0072] In a specific example, the solvent may be contained in an amount of 10 to 300 parts by weight relative to 100 parts by weight of the thermochromic compound. When the solvent is contained in the above range, the dispersibility and handleability of the components of the thermochromic coating agent may be improved.

[0073] In one specific example, the thermochromic layer can be formed by pad printing.

[0074] In a specific example, the toner coating agent may be dried after pad printing or coating. In a specific example, the drying may be performed at 80° C. to 150° C. Under the above conditions, the thermochromic layer may have excellent durability.

[0075] In a specific example, the thickness of the thermochromic layer may be 1 μm to 30 μm. Under the above thickness condition, the thermochromic layer may have excellent durability.

[0076] Top coating formation and heat treatment step (step S40)

[0077] As stated Figure 2 As shown in part (d) of the embodiment, the step is to apply a top coating agent containing a fluororesin on the surface of the primer layer forming the thermochromic layer 40 and heat-treat it to form the top coating layer 50. In a specific example, as described Figure 2 As shown in part (d) of FIG. 1 , the top coating layer may be formed on the surface of the toning layer 30, the surface of the thermochromic layer 40, and the surface of the primer layer 20. If the heat treatment is not applied, defects such as reduced adhesion of the coating layer and reduced smoothness of the coating surface may occur.

[0078] The top coating layer can prevent the toning layer and the thermochromic layer from being damaged, and at the same time, make the cooked food have excellent non-stick properties, and have excellent wear resistance, thermal conductivity, chemical resistance, smoothness and durability.

[0079] Furthermore, when the top coating layer of the present invention is formed, the thermochromic layer may not be visible on the surface at room temperature, but may be visible when heated to a predetermined temperature or higher.

[0080] In a specific example, the top coating agent includes 100 parts by weight of a fluorine-based resin, 10 to 50 parts by weight of an alkoxysilane compound, 5 to 50 parts by weight of a first pigment, 0.5 to 15 parts by weight of molybdenum disulfide, and 1 to 15 parts by weight of a phosphate compound.

[0081] In a specific example, the fluororesin may include one or more of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer and polyvinylidene fluoride. When the fluororesin is used, the top coating layer can have excellent smoothness, chemical resistance, durability and heat resistance.

[0082] The alkoxysilane compound can be used to improve the adhesion and durability between the top coating layer, the toning layer, the thermochromic layer and the primer layer.

[0083] In a specific example, the alkoxysilane may include one or more of glycidoxypropyltrimethoxysilane, mercaptopropyltriethoxysilane, methacrylpropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, methacrylpropyltriethoxysilane and glycidoxypropyltriethoxysilane.

[0084] The alkoxysilane compound may be included in an amount of 10 to 50 parts by weight relative to 100 parts by weight of the fluorine-based resin. If the alkoxysilane compound is included in an amount of less than 10 parts by weight, the durability and adhesion of the top coating layer are reduced, and if the alkoxysilane compound is included in an amount of more than 50 parts by weight, the mixing and operability of the top coating agent, the smoothness and appearance of the top coating layer may be poor. For example, the alkoxysilane compound may be included in an amount of 15 to 35 parts by weight.

[0085] In a specific example, the first pigment may include one or more of carbon black, perylene red, ferroxene black, copper chrome black, bismuth vanadate, yellow ferric hydroxide, chrome oxide green, and cobalt aluminum blue. For example, ferroxene black and perylene red may be included.

[0086] In a specific example, 5 to 50 parts by weight of the first pigment are included relative to 100 parts by weight of the fluororesin. When the first pigment in the range is included, the dispersibility can be excellent, and the durability and mechanical properties of the top coating can be prevented from being reduced. If less than 5 parts by weight of the first pigment is included, the effect of its addition is minimal, and if more than 50 parts by weight of the first pigment is included, it is difficult to disperse in the top coating agent, thereby reducing the appearance and durability of the top coating. For example, 10 to 40 parts by weight of the first pigment can be included.

[0087] In a specific example, the average particle size of the first pigment may be 5 μm to 30 μm. Within the above range, excellent dispersibility and mixing properties can be achieved.

[0088] The molybdenum disulfide (MoS2) can be used to improve the lubricity of the top coating. In a specific example, 0.5 to 15 parts by weight of the molybdenum disulfide can be included relative to 100 parts by weight of the fluorine-based resin. When the fluorine-based resin in the above range is included, the dispersibility can be excellent, and the lubricity of the top coating and the non-stick properties that prevent food from sticking to the surface of the top coating can be excellent. For example, 3 to 15 parts by weight of the fluorine-based resin can be included.

[0089] The phosphate compound can be used to improve the durability of the top coating layer of the present invention and the adhesion to the substrate. The phosphate compound can be a phosphate compound containing one or more of a hydroxyl group and a carboxyl group.

[0090] In a specific example, the phosphate compound is included in an amount of 1 to 15 parts by weight relative to 100 parts by weight of the fluororesin. When the phosphate compound is included in the range, the durability and adhesion of the top coating can be excellent, and the viscosity of the top coating agent can be prevented from excessively increasing. If less than 1 part by weight of the phosphate compound is included, the adhesion of the top coating may be reduced, and if more than 15 parts by weight of the phosphate compound is included, the durability of the top coating may be reduced. For example, 1 to 8 parts by weight of the phosphate compound may be included.

[0091] In a specific example, the top coating agent may further include 0.5 to 5 parts by weight of germanium oxide relative to 100 parts by weight of the fluorine-based resin. The germanium oxide can be used for the purpose of improving the interlayer adhesion of the top coating of the present invention. If less than 0.5 parts by weight of the germanium oxide is included, the adhesion of the top coating of the present invention may be reduced. If more than 5 parts by weight of the germanium oxide is included, the miscibility of the top coating agent may be reduced, resulting in poor smoothness and appearance. For example, 1 to 3 parts by weight of germanium oxide may be included.

[0092] In a specific example, the average particle size of the germanium oxide may be 0.1 μm to 20 μm. Within the above range, the dispersibility and mixing properties can be excellent, and the interlayer adhesion of the top coating layer can be excellent.

[0093] In a specific example, the germanium oxide and the phosphate compound can be included in a weight ratio of 1:1 to 1:5. When the germanium oxide and the phosphate compound are included in the weight ratio range, the mixing property and workability of the top coating agent, the interlayer adhesion and durability of the top coating, and the smoothness and appearance of the top coating can be excellent. For example, the germanium oxide and the phosphate compound can be included in a weight ratio of 1:2 to 1:4.

[0094] In a specific example, the average particle size of the molybdenum disulfide may be 1 μm to 80 μm. Within the above range, excellent dispersibility and mixing properties can be achieved.

[0095] In a specific example, the top coating agent may further include a solvent, and the solvent may include one or more of water, alcohol having 1 to 10 carbon atoms, toluene, xylene, diisobutyl ketone, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 1-methoxy-2-propanol, ethanol, ethylene glycol butyl ether, cyclohexane, n-butyl acetate, N-methylpyrrolidone, dimethylformamide, ethyl acetate, acetone, methyl acetate, isobutyl acetate, isopropyl acetate and dimethyl carbonate. In a specific example, the alcohol having 1 to 10 carbon atoms may include one or more of methanol, ethanol, propanol, isopropanol, n-butanol and isobutanol.

[0096] The solvent may be included in an amount of 10 to 500 parts by weight relative to 100 parts by weight of the fluorine-based resin. When the solvent is included in the above range, the dispersibility and workability of the components of the top coating agent may be excellent.

[0097] In a specific example, the top coating agent may further include additives such as a surfactant, a leveling agent, and a defoaming agent, etc. The top coating agent may include 0.1 to 20 parts by weight of the additives relative to 100 parts by weight of the fluorine-based resin.

[0098] In a specific example, the heat treatment may be performed at a temperature of 380° C. to 450° C. Under the above conditions, the primer layer, the toning layer, the thermochromic layer and the top coating layer may be hardened, and the interlayer adhesion and durability may be excellent.

[0099] In a specific example, the thickness of the top coating layer may be 5 μm to 30 μm. In a specific example, the thickness of the top coating layer may be measured from the surface of the thermochromic layer. Under the above thickness conditions, the top coating layer may have excellent durability.

[0100] A cookware manufactured by a method for manufacturing a cookware comprising a thermochromic composite coating.

[0101] Another aspect of the present invention relates to a cooker manufactured by the method for manufacturing the cooker. In a specific example, the cookware includes: a metal substrate; a primer layer, formed on one or more surfaces of the metal substrate, comprising a fluororesin; a tinting layer, formed on at least a portion of the surface of the primer layer; a thermochromic layer, formed on at least a portion of the surface of the primer layer; and a top coating layer, formed on the surface of the thermochromic layer, the top coating layer being formed by a top coating agent, the top coating agent comprising 100 parts by weight of a fluororesin, 10 to 50 parts by weight of an alkoxysilane compound, 5 to 50 parts by weight of a first pigment, 0.5 to 15 parts by weight of molybdenum disulfide, and 1 to 15 parts by weight of a phosphate compound, the tinting layer being formed by a tinting coating agent, the tinting coating agent comprising a matrix resin and a tinting pigment, the thermochromic layer being formed by a thermochromic coating agent, the thermochromic coating agent comprising a thermochromic compound and a color-changing pigment, the tinting pigment comprising titanium oxide, and the color-changing pigment comprising red iron oxide.

[0102] The top coating agent may further include 0.5 to 5 parts by weight of germanium oxide relative to 100 parts by weight of the fluorine-based resin, and the germanium oxide and the phosphate compound may be included in a weight ratio of 1:1 to 1:5.

[0103] The primer agent and top coating agent constituting the primer layer, and the toning coating agent and thermochromic coating agent forming the toning layer can be applied with the components and contents as described above, and the description thereof will be omitted here.

[0104] Embodiments of the present invention

[0105] The structure and function of the present invention are described in more detail below through the preferred embodiments of the present invention. However, the following embodiments are only used to help understand the present invention, and the scope of the present invention is not limited to the following embodiments.

[0106] The structure and function of the present invention are described in more detail below through the preferred embodiments of the present invention. However, these embodiments are only provided as preferred examples of the present invention, and the present invention cannot be interpreted as being limited thereto in any sense. A person of ordinary skill in the art to which the present invention belongs can fully derive the contents not described here, so the description thereof will be omitted.

[0107] Examples and Comparative Examples.

[0108] The ingredients used in the examples and comparative examples are as follows:

[0109] A first primer and a second primer.

[0110] (A) Fluorine-based resins: polytetrafluoroethylene and tetrafluoroethylene-hexafluoropropylene copolymers are used;

[0111] (B) Second pigment: Perylene red (first primer) and manganese iron black (second primer);

[0112] (C) using carboxyl-containing phosphate compounds;

[0113] (D) using germanium oxide having an average particle size of 10 μm;

[0114] (E) Additives: use surfactants and defoaming agents;

[0115] (F) Distilled water was used as the solvent.

[0116] Top coating agent.

[0117] (A) Fluorine-based resins: polytetrafluoroethylene and tetrafluoroethylene-hexafluoropropylene copolymers are used;

[0118] (B) Alkoxysilane compound: glycidyloxypropyltriethoxysilane;

[0119] (C) First pigment: manganese iron black is used;

[0120] (D) using molybdenum disulfide;

[0121] (E) using carboxyl-containing phosphate compounds;

[0122] (F) using germanium oxide having an average particle size of 10 μm;

[0123] (G) Additives: use surfactants and defoamers;

[0124] (H) Distilled water was used as the solvent.

[0125] Examples 1 and 2 and Comparative Examples 1 and 6.

[0126] (1) Forming a primer layer: After degreasing one surface of a metal substrate (stainless steel), sandblasting is performed using 60 mesh alumina for pretreatment. Then, the first primer and the second primer are prepared using the components and contents described in Table 1 below, with only the type of the second pigment being changed. After the first primer is applied to the pretreated surface of the metal substrate using a sprayer to form a first primer layer, the second primer is applied to the edge of the surface of the first primer layer using a sprayer, and the second primer layer is formed after drying at a temperature of 90°C to 100°C. The sum of the thicknesses of the first primer layer and the second primer layer is 12μm to 15μm.

[0127] (2) Forming a coloring layer and a thermochromic layer: A coloring coating agent containing 100 parts by weight of a matrix resin (polyphenylene sulfide) and 30 parts by weight of a coloring pigment (titanium dioxide) is applied to a portion of the surface of the second primer layer to form a coloring layer (specific pattern morphology) with a thickness of 5 μm to 10 μm. Then, a thermochromic coating agent containing 100 parts by weight of a thermochromic compound (Ag2HgI4) and 15 parts by weight of a color-changing pigment (red iron oxide) is applied to the center of the surface of the second primer layer to form a thermochromic layer with a thickness of 5 μm to 10 μm.

[0128] (3) Formation of top coating layer and heat treatment: A top coating agent containing the components and contents shown in Table 2 below is prepared by a conventional method and applied to the surfaces of the tinting layer, the thermochromic layer and the second primer layer, and then heat treated at a temperature of 430° C. to 440° C. to form a top coating layer with a thickness of 12 μm to 15 μm, thereby manufacturing a cooker (wok).

[0129] [Table 1]

[0130]

[0131]

[0132] [Table 2]

[0133]

[0134] Physical property evaluation method

[0135] For Examples 1 to 2 and Comparative Examples 1 to 6, the physical properties of the composite coatings were evaluated based on the following items. The results are shown in Table 3.

[0136] (1) Appearance: The appearance of the composite coatings of Examples and Comparative Examples was visually observed to determine whether cracks occurred, and the results were evaluated using the following three criteria (◎: no cracks occurred, △: partial cracks occurred, X: severe cracks occurred).

[0137] (2) Corrosion resistance evaluation: According to the standard of JIS K 5400 9.1, the cookware of the embodiment and the comparative example was immersed in a 5% NaCl solution at 35°C for 100 hours and then taken out to observe the corrosion state of the thermochromic composite coating film of the embodiment and the comparative example, and evaluated according to the following three standards (◎: no coating corrosion, △: partial corrosion occurred, X: severe corrosion occurred).

[0138] (3) Pencil hardness: tested in accordance with JIS K5600-5-4.

[0139] (4) Adhesion evaluation: The adhesion of the composite coatings of the examples and comparative examples was evaluated by a cross-cut test in accordance with JIS K 5400. The number of cross-cuts that were not peeled off was shown compared to the total number of cross-cuts (100).

[0140] (5) Evaluation of antifouling property: 20 ml of soy sauce was dripped onto the surface of the composite coating formed on the cookware of the above-mentioned Example and Comparative Example, and heated at a temperature of 200°C to make the soy sauce adhere thereto. Then, the antifouling property was evaluated by the convenience of removing the contaminants on the surface of the composite coating using a cloth soaked in water (◎: easy to remove the contaminants, △: although the contaminants were removed, it took a long time, X: although the contaminants were removed for a long time, the contaminants were hardly removed).

[0141] (6) Evaluation of wear resistance: The surfaces of the composite coatings formed on the cookware of the embodiments and comparative examples were rotated 15,000 times using a Taber abrasion tester at a speed of 60 rpm, with a load of 3 kg and a GS-17, and the damage of the coating was confirmed for evaluation (◎: no damage, △: partial damage to the coating, X: most of the coating was damaged).

[0142] [Table 3]

[0143]

[0144] Figure 3 is a photograph of a cooker manufactured according to Example 1, Figure 4 This is a photo of the cooker after heating according to Example 1. Figure 3 and Figure 4 In the case of the embodiment of the present invention, although the thermochromic layer is not visible at room temperature because no color change occurs, when heated to a temperature above a specified temperature, the color change (pattern) of the thermochromic layer is revealed, and it can be seen that the heating state of the cooker can be easily distinguished.

[0145] In addition, referring to the results in Table 3, it can be seen that the thermochromic composite coatings of Examples 1 to 2 using the composite coating of the present invention have excellent wear resistance and adhesion between the coatings, and excellent antifouling properties, so they are easy to wash and manage, and have excellent non-stick properties that the food does not stick to the surface of the composite coating during cooking. On the contrary, in the case of Comparative Examples 1 to Comparative Examples 6 not using the present invention, it can be seen that the appearance, wear resistance, adhesion or antifouling properties are reduced compared to Examples 1 to 2.

[0146] A person skilled in the art to which the present invention belongs may easily implement simple modifications or changes of the present invention, and these modifications or changes may be considered to be included in the scope of the present invention.

Claims

1. A method for manufacturing a cooker comprising a thermochromic composite coating, wherein: include: a primer layer forming step of applying a primer agent containing a fluororesin to at least a portion of the metal substrate and drying the primer layer; a coloring layer forming step of applying a coloring coating agent containing a matrix resin and a coloring pigment on at least a portion of the surface of the primer layer to form the coloring layer; a thermochromic layer forming step, coating at least a portion of the surface of the primer layer with a thermochromic coating agent containing a thermochromic compound and a color-changing pigment to form the thermochromic layer; as well as a top coating layer forming step of applying a top coating agent to the surface of the toning layer, the surface of the thermochromic layer, and the surface of the primer layer and performing heat treatment to form a top coating layer, The top coating agent comprises 100 parts by weight of a fluorine-based resin, 10 to 50 parts by weight of an alkoxysilane compound, 5 to 50 parts by weight of a first pigment, 0.5 to 15 parts by weight of molybdenum disulfide, and 1 to 15 parts by weight of a phosphate compound. The tinting pigment comprises titanium oxide, The color changing pigment comprises red iron oxide.

2. The method for manufacturing a cooker comprising a thermochromic composite coating according to claim 1, wherein: The heat treatment is performed at a temperature of 380°C to 450°C.

3. The method for manufacturing a cooker comprising a thermochromic composite coating according to claim 1, wherein: The top coating agent further comprises 0.5 to 5 parts by weight of germanium oxide relative to 100 parts by weight of the fluorine-based resin, The top coating agent includes the germanium oxide and the phosphate compound in a weight ratio of 1:1 to 1:

5.

4. The method for manufacturing a cooker comprising a thermochromic composite coating according to claim 1, wherein: The toning layer and the thermochromic layer are formed by pad printing.

5. The method for manufacturing a cooker comprising a thermochromic composite coating according to claim 1, wherein: The primer layer is formed by a primer agent, The primer comprises 100 parts by weight of a fluorine-based resin, 1 to 40 parts by weight of a second pigment, 1 to 15 parts by weight of a phosphate compound, and 0.5 to 5 parts by weight of germanium oxide.

6. The method for manufacturing a cooker comprising a thermochromic composite coating according to claim 1, wherein: The fluororesin includes one or more of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer and polyvinylidene fluoride.

7. The method for manufacturing a cooker comprising a thermochromic composite coating according to claim 1, wherein: The toning coating agent comprises 100 parts by weight of a matrix resin and 0.5 to 50 parts by weight of a toning pigment. The thermochromic coating agent comprises 100 parts by weight of a thermochromic compound and 0.5 to 30 parts by weight of a color-changing pigment. The thermochromic compound includes at least one of mercuric iodide complex salt and vanadium oxide.

8. The method for manufacturing a cooker comprising a thermochromic composite coating according to claim 1, wherein: The first pigment includes one or more of carbon black, perylene red, manganese iron black, copper chrome black, bismuth vanadate, yellow iron hydroxide, chrome oxide green and cobalt aluminum blue.

9. A cooking utensil, wherein: Include: Metal substrate; a primer layer, formed on at least a portion of the metal substrate, comprising a fluororesin; A toning layer is formed on at least a portion of the surface of the primer layer; a thermochromic layer formed on at least a portion of the surface of the primer layer; as well as A top coating layer is formed on the surface of the toning layer, the surface of the thermochromic layer and the surface of the primer layer, The top coating layer is formed of a top coating agent, which includes 100 parts by weight of a fluorine-based resin, 10 to 50 parts by weight of an alkoxysilane compound, 5 to 50 parts by weight of a first pigment, 0.5 to 15 parts by weight of molybdenum disulfide, and 1 to 15 parts by weight of a phosphate compound. The toning layer is formed by a toning coating agent, and the toning coating agent contains a matrix resin and a toning pigment. The thermochromic layer is formed by a thermochromic coating agent, and the thermochromic coating agent contains a thermochromic compound and a color-changing pigment. The tinting pigment comprises titanium oxide, The color changing pigment comprises red iron oxide.

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