Cooking utensil and preparation method thereof

Abstract

The invention relates to a cooking utensil and a preparation method thereof. The cooking utensil comprises a cooking container provided with a cooking cavity, the cooking container is composed of a porous ceramic base body, a carbon film is attached to the surface of the porous ceramic base body, the inner surface of the porous ceramic base body and the hole structure close to the carbon film are filled with a carbon material, at least part of the macro-hole structure is further filled with a hole sealing material, and the hole sealing material is used for sealing the inner surface of the porous ceramic base body. Wherein the hole sealing material comprises a curing material of which the hydrophobic angle is greater than or equal to 100 degrees. The cooking utensil not only has excellent heat conduction efficiency and far infrared heating effect, but also is low in water absorption rate, easy to clean and resistant to pollution, so that the performance of the cooking utensil is more comprehensive and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of daily necessities, in particular to a cooking vessel and a preparation method thereof. Background Art

[0002] Ceramic utensils are increasingly used in the field of small household appliances due to their healthy and stable materials. However, their poor thermal conductivity and high heat storage lead to higher temperatures in household appliances, and low power is also a major problem that limits their large-scale application. Innovative technologies such as carburizing or vapor deposition infiltration are used to deposit carbon on the surface and in the pores of porous ceramics to improve thermal conductivity and far-infrared heating effects. This technology not only enables ceramic utensils to be widely used in multiple products such as rice cooker liner, electric stew pot, electric stew pot liner, decoction pot, health pot heating plate, etc., but also plays a key role in the performance improvement and innovation of small household appliances.

[0003] However, despite the use of advanced technologies such as carburizing and vapor deposition infiltration, current ceramic utensils still face a series of technical difficulties: since processes such as carburizing and vapor deposition infiltration cannot completely close the pores, the water absorption rate of ceramic utensils still remains at a certain level, usually between 3-6%, causing ceramic ware products to be prone to water seepage, absorption of odors and causing odor cross-talk, while also increasing the difficulty of cleaning ceramic ware products. In addition, the easy-to-clean effect of ceramics themselves is not ideal, making it difficult to effectively clean ceramic ware products for adhesion problems such as water stains and oil stains.

[0004] To address the above problems, two methods are usually used: surface coating and surface glazing. However, surface coatings such as fluororesin coatings and silicon oxide ceramics are difficult to maintain their performance in long-term use due to defects such as poor bonding, easy hydrolysis and low hardness; and surface glazing needs to be prepared under high temperature conditions, resulting in the failure of the carbon film on the surface and inside after carburization due to oxidation at high temperatures, thereby making the high thermal conductivity of ceramic ware products ineffective. Summary of the invention

[0005] Based on this, it is necessary to provide a cooking utensil and a preparation method thereof to address the above problems; the cooking utensil not only has excellent thermal conductivity and far-infrared heating effect, but also has low water absorption, is easy to clean, and is resistant to pollution, making the performance of the cooking utensil more comprehensive and reliable.

[0006] A cooking vessel for cooking utensils comprises a cooking container provided with a cooking cavity, the cooking container is composed of a porous ceramic substrate, a carbon film is attached to the surface of the porous ceramic substrate, and a carbon material is filled in the pore structure close to the carbon film on the inner surface of the porous ceramic substrate, wherein at least part of the macroporous structure is also filled with a sealing material, and the sealing material includes a solidified material with a hydrophobic angle ≥100°.

[0007] The cooking vessel described in the present invention, on the one hand, part of the pores and defects in the porous ceramic matrix constituting the cooking vessel are filled with carbon, which is beneficial to reducing the thermal resistance in the ceramic heat transfer process. At the same time, the filled carbon atoms can not only form part of the carbide phase, which is beneficial to improving the thermal conductivity, but also can replace other atoms in the ceramic crystal structure, change the crystal structure, thereby further improving the thermal conductivity and achieving an excellent far-infrared heating effect; on the other hand, a part of the macroporous structure close to the hydrophilic carbon film is further filled with a solidified material with a hydrophobic angle ≥100°, which not only makes the porosity of the cooking vessel ≤1%, thereby reducing the water absorption rate, but also constitutes a unique hydrophilic-hydrophobic surface area, achieving the dual effects of oleophobic and hydrophobic, making the cooking vessel easy to clean and anti-pollution.

[0008] Therefore, using the cooking vessel of the present invention for cooking utensils can not only achieve excellent thermal conductivity and far-infrared heating effect, but also have low water absorption, easy cleaning and anti-pollution, making the performance of the cooking utensils more comprehensive and reliable, and more convenient in daily use.

[0009] In one embodiment, the macroporous structure filled with the sealing material has a distribution depth greater than the thickness of the carbon film;

[0010] and / or, in the pore structure filled with carbon material, part of the micropore structure is also filled with a sealing material;

[0011] And / or, in the pore structure filled with carbon material, part of the mesoporous structure is also filled with sealing material.

[0012] By regulating the distribution depth of the macroporous structure filled with sealing materials to be greater than the thickness of the carbon film, and regulating the sealing materials to be filled in part of the microporous structure and mesoporous structure, it is beneficial to further reduce the porosity and improve the dual effects of oleophobicity and hydrophobicity, making cooking utensils easier to clean and more resistant to pollution.

[0013] In one embodiment, the macroporous structure filled with sealing material has a distribution depth of 50 μm-1000 μm;

[0014] And / or, the carbon film has a thickness of 1 μm-10 μm.

[0015] By precisely controlling the depth of the macroporous structure filled with sealing materials and the thickness of the carbon film, it is helpful to further reduce the porosity and enhance the dual effects of oleophobicity and hydrophobicity, making cooking utensils easier to clean and more resistant to pollution.

[0016] In one embodiment, the sealing material also includes alkaline mineral material.

[0017] In one embodiment, the mass ratio of the alkaline mineral material to the solidifying material is 20:1-2:1;

[0018] And / or, the particle size of the alkaline mineral material is 1 μm-10 μm;

[0019] And / or, the alkaline mineral material includes at least one of sodium bicarbonate, calcium bicarbonate, sodium silicate, potassium silicate and calcium silicate;

[0020] And / or, the curing material includes curing silicone oil containing silicon dioxide.

[0021] By adding alkaline mineral materials as sealing materials, the water quality of the cooking vessel can be adjusted to weak alkaline water during the cooking process, which is beneficial to further improve the cooking effect and nutritional effect.

[0022] A method for preparing the cooking vessel as described above comprises the following steps:

[0023] providing a porous ceramic substrate;

[0024] Carburizing the porous ceramic substrate in a reaction atmosphere containing a carbon source to obtain a carbon-containing substrate;

[0025] The sol sealing agent is placed at least on the inner surface of the carbon-containing matrix, and the cooking vessel is obtained by heat curing, wherein the surface energy of the sol sealing agent is 40 J / m 2 -100J / m 2 .

[0026] The preparation method of the cooking vessel described in the present invention uses the synergistic effect of carburizing treatment and a sol sealer with specific surface energy to decompose the carbon source and deposit it on the surface of the porous ceramic substrate to form a carbon film, which then penetrates into the interior and fills part of the pores of the macropores, micropores and mesopores of the porous ceramic substrate. The sol sealer with specific surface energy is then used to further fill the macropores partially filled with carbon material, so that the macropores close to the carbon film are blocked and the porosity is reduced. Moreover, after thermal curing, the sol sealer cooperates with the hydrophilic carbon film to form a unique hydrophilic-hydrophobic surface area, thereby achieving the dual effects of oleophobic and hydrophobic, and overcoming a series of problems brought about by traditional surface coatings and glazing solutions.

[0027] In one embodiment, the carburizing treatment satisfies at least one of the following conditions:

[0028] (1) The carbon source is selected from at least one of alkanes, alkenes, alkyl acids or alkyl alcohols;

[0029] (2) The concentration of the carbon source in the reaction atmosphere is 5wt%-10wt%;

[0030] (3) The reaction atmosphere further includes at least one of an inert gas and a reducing gas;

[0031] (4) The carburizing treatment is carried out at a temperature of 700°C to 1100°C and for a time of 12h to 24h.

[0032] By regulating the carbon source and its concentration, reaction atmosphere, temperature and time of carburizing treatment, the penetration of carbon atoms is facilitated and a good carbon content distribution effect is achieved.

[0033] In one of the embodiments, the carbon content of the carbon-containing matrix is ​​5wt%-20wt%.

[0034] By precisely controlling the carbon content in the carbon-containing matrix, it is not only beneficial to improve the thermal conductivity of the cooking utensils, but also to improve the adverse effects of the presence of carbides on the thermal shock properties of the porous ceramic matrix at high temperatures, reduce energy consumption and lower costs.

[0035] In one embodiment, the method of placing the sol sealer on the surface of the carbon-containing substrate is selected from an impregnation treatment, and the impregnation treatment satisfies at least one of the following conditions:

[0036] (1) The impregnation treatment method includes vacuum impregnation or pressure impregnation;

[0037] (2) The content of sol particles in the sol sealing agent is 5wt%-20wt%;

[0038] (3) The sol sealing agent is selected from silicone oil-based silica sol, and the particle size of silicon dioxide in the silicone oil-based silica sol is 5nm-20nm;

[0039] (4) The sol sealing agent also includes alkaline mineral materials, and the content of the alkaline mineral materials in the sol sealing agent is 1wt%-10wt%.

[0040] By adjusting the preparation conditions for the penetration of the sol sealer into the carbon-containing matrix, it is not only beneficial to control the penetration of the sol sealer and achieve a good hydrophobic effect, but also the pH value of water during the cooking process can be adjusted by adding alkaline mineral materials, thereby improving the cooking effect and nutritional effect.

[0041] In one embodiment, after the thermal curing process, a polishing process is also included.

[0042] Polishing treatment can remove the residual sealer attached to the surface, so that the solidified material is distributed in the macropores on the surface of the porous ceramic matrix. This not only reduces the surface roughness to below Rz3μm, forming a smooth surface and further improving the easy-to-clean effect, but also prevents the residual sealer on the surface from entering the cooked food during the cooking process, thereby improving cooking safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 This is the element distribution map of the cooking vessel surface obtained in Example 1. DETAILED DESCRIPTION

[0045] For ease of understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific implementation methods or embodiments and are not intended to limit the present invention.

[0047] The present invention provides a cooking vessel for cooking utensils, comprising a cooking container provided with a cooking cavity, wherein the cooking container is composed of a porous ceramic substrate, wherein a carbon film is attached to the surface of the porous ceramic substrate, and it can be understood that the carbon film is attached to both the inner surface and the outer surface of the porous ceramic substrate.

[0048] On the inner surface of the porous ceramic substrate, the pore structure near the carbon film is filled with carbon material. It can be understood that the pore structure includes macropores, micropores and mesopores, and the macropores, micropores and mesopores near the carbon film are all filled with carbon material.

[0049] Among them, at least part of the macroporous structure is also filled with a sealing material, and the sealing material includes a solidified material with a hydrophobic angle ≥ 100°. It can be understood that among the pore structures filled with carbon materials, there are macroporous structures that are partially filled with both carbon materials and sealing materials, and the remaining macroporous structures are only filled with carbon materials, or the macroporous structures filled with carbon materials are also filled with sealing materials. The present invention does not limit the microporous structure filled with carbon materials and the mesoporous structure filled with carbon materials, and they may be filled with sealing materials or not.

[0050] The cooking vessel described in the present invention, on the one hand, part of the pores and defects in the porous ceramic matrix constituting the cooking vessel are filled with carbon, which is beneficial to reducing the thermal resistance in the ceramic heat transfer process. At the same time, the filled carbon atoms can not only form part of the carbide phase, which is beneficial to improving the thermal conductivity, but also can replace other atoms in the ceramic crystal structure, change the crystal structure, thereby further improving the thermal conductivity and achieving an excellent far-infrared heating effect; on the other hand, a part of the macroporous structure close to the hydrophilic carbon film is further filled with a solidified material with a hydrophobic angle ≥100°, which not only makes the porosity of the cooking vessel ≤1%, thereby reducing the water absorption rate, but also constitutes a unique hydrophilic-hydrophobic surface area, achieving the dual effects of oleophobic and hydrophobic, making the cooking vessel easy to clean and anti-pollution.

[0051] It should be noted that the macropores, micropores and mesopores mentioned in the present invention are conventional pore sizes in the art, and the present invention does not limit this. For example, the macropore size is above 50nm, the micropore size is 2nm-50nm, and the mesopore size is less than 2nm.

[0052] In one embodiment, on the inner surface of the porous ceramic substrate, the distribution depth of the macropore structure filled with sealing material is greater than the thickness of the carbon film, wherein the distribution depth of the macropore structure filled with sealing material is preferably 50μm-1000μm, and the thickness of the carbon film is preferably 1μm-10μm.

[0053] Preferably, in the pore structure filled with carbon material, part of the microporous structure is also filled with sealing material, and / or part of the mesoporous structure is also filled with sealing material, more preferably, part of the microporous structure and part of the mesoporous structure are filled with sealing material.

[0054] By regulating the distribution depth of the macroporous structure filled with sealing materials and the thickness of the carbon film, and regulating the filling of sealing materials in some microporous structures and mesoporous structures, it is beneficial to further reduce the porosity and improve the dual effects of oleophobicity and hydrophobicity, making cooking utensils easier to clean and more resistant to pollution.

[0055] In one embodiment, the sealing material also includes an alkaline mineral material, which can release soluble alkaline ions during the cooking process. After the alkaline ions are dissolved in water, they can combine with hydrogen ions in the water, thereby adjusting the acidity and alkalinity of the water to make the pH value weakly alkaline. Or when the alkaline mineral material contains bicarbonate, it can release hydroxide ions in the water, thereby adjusting the pH value of the water to be weakly alkaline, which is beneficial to improving the cooking effect and nutritional effect.

[0056] In one embodiment, the particle size of the alkaline mineral material is preferably 1 μm-10 μm. Preferably, the mass ratio of the alkaline mineral material to the solidifying material is 20:1-2:1, which is more conducive to achieving a good sealing effect together with the solidifying material.

[0057] Specifically, the curing material includes curing silicone oil containing silicon dioxide.

[0058] The alkaline mineral material includes but is not limited to at least one of sodium bicarbonate, calcium bicarbonate, sodium silicate, potassium silicate and calcium silicate.

[0059] In one embodiment, the surface roughness of the cooking vessel is lower than Rz3 μm, which is beneficial to further improve the easy-to-clean effect.

[0060] Therefore, the cooking vessel of the present invention is used in cooking utensils, such as the inner pot of an electric rice cooker, an electric stew pot, an electric stew pot, the heating bottom plate of a health pot, etc., which can not only achieve excellent thermal conductivity and far-infrared heating effect, but also has low water absorption, is easy to clean, and is resistant to pollution, making the performance of the cooking utensils more comprehensive and reliable, and more convenient in daily use.

[0061] The present invention also provides a method for preparing the cooking vessel as described above, comprising the following steps:

[0062] S1, providing a porous ceramic substrate;

[0063] S2, carburizing the porous ceramic substrate in a reaction atmosphere containing a carbon source to obtain a carbon-containing substrate;

[0064] S3, placing a sol sealing agent at least on the inner surface of the carbon-containing matrix, and subjecting the sol sealing agent to thermal curing to obtain the cooking vessel, wherein the surface energy of the sol sealing agent is 40 J / m 2 -100J / m 2 .

[0065] In step S1, an existing conventional porous ceramic substrate may be used, or it may be prepared by itself according to conventional processes, specifically including mud embryo molding, surface drying, biscuit firing, high-temperature sintering and other processes, which are not limited in the present invention.

[0066] Preferably, the porosity of the porous ceramic matrix is ​​less than 25%.

[0067] In step S2, the carbon source is decomposed by carburizing treatment and deposited on the surface of the porous ceramic matrix to form a carbon film, which penetrates into the interior and fills part of the pores of the macropores, micropores and mesopores of the porous ceramic matrix. On the one hand, part of the pores and defects in the porous ceramic matrix are filled with carbon, which is beneficial to reduce the thermal resistance in the heat transfer process of the ceramic; on the other hand, the filled carbon atoms can not only form a partial carbide phase, which is beneficial to improve the thermal conductivity, but also can replace other atoms in the ceramic crystal structure, change the crystal structure, thereby further improving the thermal conductivity and achieving excellent far-infrared heating effect.

[0068] In one embodiment, the carburizing treatment satisfies at least one of the following conditions:

[0069] (1) The carbon source is selected from at least one of alkanes, alkenes, alkyl acids or alkyl alcohols;

[0070] (2) The concentration of the carbon source in the reaction atmosphere is 5wt%-10wt%;

[0071] (3) The reaction atmosphere further includes at least one of an inert gas and a reducing gas;

[0072] (4) The carburizing treatment is carried out at a temperature of 700°C to 1100°C and for a time of 12h to 24h.

[0073] By regulating the carbon source and its concentration, reaction atmosphere, temperature and time of carburizing treatment, the penetration of carbon atoms is facilitated and a good carbon content distribution effect is achieved.

[0074] Specifically, the alkane includes but is not limited to methane, ethane or propane; the olefin includes but is not limited to ethylene or propylene; the alkyl acid includes but is not limited to acetic acid or propionic acid; the alkyl alcohol includes but is not limited to methanol or ethanol; the inert gas includes but is not limited to argon, nitrogen or helium; the reducing gas includes but is not limited to hydrogen or carbon monoxide.

[0075] It should be noted that the carburizing treatment can adopt existing technical means, and the present invention is not limited to this.

[0076] In one embodiment, the carbon content of the carbon-containing matrix is ​​5wt%-20wt%.

[0077] By precisely controlling the carbon content in the carbon-containing matrix, it is not only beneficial to improve the thermal conductivity of the cooking utensils, but also to improve the adverse effects of the presence of carbides on the thermal shock properties of the porous ceramic matrix at high temperatures, reduce energy consumption and lower costs.

[0078] In step S3, a sol sealer with a specific surface energy is used to further fill the macropores partially filled with carbon material, so that the macropores close to the carbon film are blocked, reducing the porosity. Moreover, after thermal curing, the sol sealer cooperates with the hydrophilic carbon film to form a unique hydrophilic-hydrophobic surface area, thereby achieving the dual effects of oleophobic and hydrophobic, overcoming a series of problems brought about by traditional surface coatings and glazing solutions.

[0079] It should be noted that the present invention does not limit the method of placing the sol sealing agent on the surface of the carbon-containing substrate, and can adopt dipping, coating, spraying and other methods.

[0080] Preferably, the method of placing the sol sealer on the surface of the carbon-containing matrix is ​​selected from impregnation treatment, and the impregnation treatment method specifically includes vacuum impregnation or pressure impregnation. By adjusting the preparation conditions for the sol sealer to penetrate into the carbon-containing matrix, it is beneficial to control the penetration of the sol sealer and achieve a good hydrophobic effect.

[0081] Preferably, the sol sealing agent is selected from silicone oil-based silica sol, which forms a hydrophobic network structure with silicon dioxide as the main body after thermal curing and film formation. It not only has a certain bonding effect with the porous ceramic matrix, which is beneficial to improve the bonding strength and thus improve the durability, but also helps to improve the water permeability.

[0082] Specifically, the silicone oil-based silica sol includes but is not limited to at least one of polymethylsiloxane silica sol and polydimethylsiloxane silica sol; the content of sol particles in the sol sealing agent is preferably 5wt%-20wt%; the particle size of silicon dioxide in the silicone oil-based silica sol is 5nm-20nm.

[0083] In one embodiment, the sol sealer further includes alkaline mineral material, and the content of the alkaline mineral material in the sol sealer is 1wt%-10wt%, which can adjust the pH value of water during cooking, thereby improving the cooking effect and nutritional effect.

[0084] In one embodiment, the sol sealing agent further comprises a surfactant and / or an organic solvent, wherein the content of the surfactant in the sol sealing agent is preferably 0.1wt%-1wt%, and the organic solvent includes but is not limited to ethanol.

[0085] In one embodiment, after the heat curing treatment, a polishing treatment is also included. The polishing treatment can remove the residual sealant attached to the surface and distribute the cured material in the macropores on the surface of the porous ceramic matrix, which not only reduces the surface roughness to below Rz3μm to form a smooth surface and further improve the easy-to-clean effect, but also prevents the residual sealant on the surface from entering the cooked food during the cooking process, thereby improving cooking safety.

[0086] The cooking vessel and the preparation method thereof will be further described below by the following specific examples. However, those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are followed. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0087] It should be noted that the concentration of silica sol is generally between 1% and 10%; the particle size of silica sol is generally between 5nm and 20nm; the proportion of silicone oil modified silica sol is generally between 5% and 30%; alkaline substances such as sodium bicarbonate, potassium carbonate, calcium carbonate, etc. can be added to the solution as needed, and the proportion range is generally between 0.1% and 5%; the ratio of surfactant and ethanol ranges from 0.1% to 5%; the particle size range of alkaline minerals: 1μm-500μm; surfactants include silane coupling agents and silicone surfactants.

[0088] Example 1

[0089] A porous oxide ceramic substrate with a thickness of 5 mm, a water absorption rate of 3%, and a volume of 4 L was selected, and was cleaned with deionized water and dried to remove grease, dust, and other impurities on the surface.

[0090] The porous oxide ceramic substrate was placed in a heat treatment atmosphere furnace, nitrogen was introduced and the temperature was gradually preheated to 200°C for 1 hour, then the temperature was raised to 700°C, and methane was introduced into the nitrogen at the same time, so that the concentration of methane in the mixed gas was about 5wt%, and the temperature was kept for 8 hours. After completion, it was slowly cooled to room temperature, and after cleaning, a carbon-containing ceramic substrate with a carbon content of 5% was obtained.

[0091] The silicone oil-based silica sol was prepared by the sol-gel method, wherein the surface energy of the silicone oil-based silica sol was 40 J / m 2 , and the concentration of silicon dioxide in the silicone oil-based silica sol is 5wt% and the particle size is 20nm. 20% silicone oil-based silica sol, 20% sodium bicarbonate (particle size is 1μm), 1% silane coupling agent, 1% ethanol and the remaining water are mixed evenly as a sealing agent, and the sealing agent is infiltrated into the surface of the carbon-containing ceramic matrix by spraying. After completion, surface drying and dehydration treatment and thermal curing treatment are carried out, and the above steps are repeated 2-5 times. After completion, polishing treatment is carried out to reduce the surface roughness to below Rz3μm to obtain a cooking vessel.

[0092] The surface of the cooking vessel obtained in Example 1 was subjected to EDS element analysis, and the results were as follows: Figure 1 As shown, it can be seen that the carbon element and the elements K, Na, Mg and the like contained in the alkaline minerals on the surface of the cooking vessel are evenly distributed.

[0093] Example 2

[0094] A porous oxide ceramic substrate with a thickness of 5 mm, a water absorption rate of 4%, and a volume of 4 L was selected, and was cleaned with deionized water and dried to remove grease, dust, and other impurities on the surface.

[0095] The porous oxide ceramic substrate was placed in a heat treatment atmosphere furnace, nitrogen was introduced and the temperature was gradually preheated to 200°C for 1 hour, then the temperature was raised to 900°C, and methane was introduced into the nitrogen at the same time, so that the concentration of methane in the mixed gas was about 6wt%, and the temperature was kept for 8 hours. After completion, it was slowly cooled to room temperature, and after washing, a carbon-containing ceramic substrate with a carbon content of 10% was obtained.

[0096] The silicone oil-based silica sol was prepared by the sol-gel method, wherein the surface energy of the silicone oil-based silica sol was 60 J / m 2 , and the concentration of silicon dioxide in the silicone oil-based silica sol is 10wt% and the particle size is 17nm. 20% silicone oil-based silica sol, 10% calcium bicarbonate (particle size is 4μm), 1% silane coupling agent, 1% ethanol and the remaining water are mixed evenly as a sealing agent, and the sealing agent is infiltrated into the surface of the carbon-containing ceramic matrix by coating. After completion, surface drying and dehydration treatment and thermal curing treatment are carried out, and the above steps are repeated 2-5 times. After completion, polishing treatment is carried out to reduce the surface roughness to below Rz3μm to obtain a cooking vessel.

[0097] Example 3

[0098] A porous oxide ceramic substrate with a thickness of 5 mm, a water absorption rate of 5%, and a volume of 4 L was selected, and was cleaned with deionized water and dried to remove grease, dust, and other impurities on the surface.

[0099] The porous oxide ceramic substrate was placed in a heat treatment atmosphere furnace, nitrogen was introduced and the temperature was gradually preheated to 200°C for 1 hour, then the temperature was raised to 1000°C, and methane was introduced into the nitrogen at the same time, so that the concentration of methane in the mixed gas was about 8wt%, and the temperature was kept for 8 hours. After completion, it was slowly cooled to room temperature, and after cleaning, a carbon-containing ceramic substrate with a carbon content of 15% was obtained.

[0100] The silicone oil-based silica sol was prepared by the sol-gel method, wherein the surface energy of the silicone oil-based silica sol was 80 J / m 2 , and the concentration of silicon dioxide in the silicone oil-based silica sol is 15wt% and the particle size is 11nm. 20% silicone oil-based silica sol, 4% sodium silicate (particle size is 7μm), 1% silane coupling agent, 1% ethanol and the remaining water are mixed evenly as a sealing agent, and the sealing agent is infiltrated into the surface of the carbon-containing ceramic matrix by dipping under vacuum conditions. After the dipping is completed, the surface is dried and dehydrated and heat-cured, and the above steps are repeated 2-5 times. After completion, polishing is performed to reduce the surface roughness to below Rz3μm to obtain a cooking vessel.

[0101] Example 4

[0102] A porous oxide ceramic substrate with a thickness of 5 mm, a water absorption rate of 6%, and a volume of 4 L was selected, and was cleaned with deionized water and dried to remove grease, dust, and other impurities on the surface.

[0103] The porous oxide ceramic substrate was placed in a heat treatment atmosphere furnace, nitrogen was introduced and the temperature was gradually preheated to 200°C for 1 hour, then the temperature was raised to 1100°C, and methane was introduced into the nitrogen at the same time, so that the concentration of methane in the mixed gas was about 10wt%, and the temperature was kept for 8 hours. After completion, it was slowly cooled to room temperature, and after washing, a carbon-containing ceramic substrate with a carbon content of 20% was obtained.

[0104] The silicone oil-based silica sol was prepared by the sol-gel method, wherein the surface energy of the silicone oil-based silica sol was 100 J / m 2 , and the concentration of silicon dioxide in the silicone oil-based silica sol is 20wt% and the particle size is 5nm. 20% silicone oil-based silica sol, 1% sodium silicate (particle size is 10μm), 1% silane coupling agent, 1% ethanol and the remaining water are mixed evenly as a sealing agent, and the sealing agent is infiltrated into the surface of the carbon-containing ceramic matrix by dipping under vacuum conditions. After the dipping is completed, the surface is dried and dehydrated and heat-cured, and the above steps are repeated 2-5 times. After completion, polishing is performed to reduce the surface roughness to below Rz3μm to obtain a cooking vessel.

[0105] Example 5

[0106] The difference between Example 5 and Example 4 is that 21% of silicone oil-based silica sol, 1% of sodium silicate (with a particle size of 10 μm), 1% of a silane coupling agent, 1% of ethanol and the remainder of water are uniformly mixed to form a sealing agent.

[0107] Comparative Example 1

[0108] The difference between Comparative Example 1 and Example 1 is that no impregnation treatment is performed, and the carbon-containing ceramic substrate is directly used as a cooking vessel.

[0109] Comparative Example 2

[0110] The difference between Comparative Example 2 and Example 1 is that the porous oxide ceramic substrate is directly impregnated without carburizing.

[0111] Comparative Example 3

[0112] The difference between Comparative Example 3 and Example 1 is that the silicone oil-modified silica sol in the sealing agent is replaced with an equal amount of silicon dioxide powder (with a hydrophobic angle of 80°).

[0113] The cooking vessels prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to characterization tests, and the results are shown in Table 1.

[0114] Table 1

[0115]

[0116] The cooking vessels prepared in Examples 1-5 and Comparative Examples 1-3 were used as inner pots of electric stew pots to perform performance tests. The results are shown in Table 2.

[0117] The test method is as follows: (1) Surface hydrophobic angle: use a hydrophobic angle tester; (2) pH value: add 1-2L of pure water into the inner container, boil it and then cool it to 25-40°C, then use a pH meter to test the pH value of the water; (3) Water seepage test: add water to 80% of the volume of the container, then lay clean white paper on the bottom, leave it for 24 hours, and observe whether there is water seepage on the bottom white paper; (4) Thermal conductivity test: place the container on a constant temperature table at 200°C, fill the container with 2kg of water, test the time it takes for the water temperature to reach 99°C, and evaluate the thermal efficiency. The shorter the time, the higher the thermal efficiency.

[0118] Table 2

[0119]

[0120] According to Table 2, after the impregnation treatment, the porosity of the carbon ceramic matrix is ​​below 1%, which can pass the water permeability test. In addition, the sealing material contains a hydrophobic curing material, which can greatly increase the surface hydrophobic angle, thereby improving the easy-to-clean effect. After testing, the hydrophobic angle reaches more than 90°, and the easy-to-clean effect can reach level one; in addition, the alkaline minerals in the sealing material can release calcium and magnesium ions, thereby adjusting the pH value of the water in the cooking food, making the cooking water weakly alkaline, thereby improving the cooking effect. Since the ceramic matrix in Comparative Example 2 has not been carburized, its thermal conductivity is poor and its energy efficiency is low.

[0121] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A cooking vessel for cooking utensils, the cooking vessel comprising a cooking container provided with a cooking cavity, characterized in that: The cooking container is composed of a porous ceramic substrate, a carbon film is attached to the surface of the porous ceramic substrate, and the pore structure on the inner surface of the porous ceramic substrate close to the carbon film is filled with carbon material, wherein at least part of the macroporous structure is also filled with sealing material, and the sealing material includes a solidified material with a hydrophobic angle ≥100°.

2. The cooking vessel according to claim 1, characterized in that: On the inner surface of the porous ceramic substrate, the macroporous structure filled with sealing material has a distribution depth greater than the thickness of the carbon film; and / or, in the pore structure filled with carbon material, part of the micropore structure is also filled with a sealing material; And / or, in the pore structure filled with carbon material, part of the mesoporous structure is also filled with sealing material.

3. The cooking vessel according to claim 1 or 2, characterized in that: The macroporous structure filled with sealing material has a distribution depth of 50μm-1000μm; And / or, the carbon film has a thickness of 1 μm-10 μm.

4. The cooking vessel according to claim 1, characterized in that: The sealing material also includes alkaline mineral material.

5. The cooking vessel according to claim 4, characterized in that: The mass ratio of the alkaline mineral material to the solidifying material is 20:1-2:1; And / or, the particle size of the alkaline mineral material is 1 μm-10 μm; And / or, the alkaline mineral material includes at least one of sodium bicarbonate, calcium bicarbonate, sodium silicate, potassium silicate and calcium silicate; And / or, the curing material includes curing silicone oil containing silicon dioxide.

6. A method for preparing a cooking vessel according to any one of claims 1 to 5, characterized in that: The steps include: providing a porous ceramic substrate; Carburizing the porous ceramic substrate in a reaction atmosphere containing a carbon source; The sol sealing agent is placed at least on the inner surface of the carbon-containing matrix, and the cooking vessel is obtained by heat curing, wherein the surface energy of the sol sealing agent is 40 J / m 2 -100J / m 2 .

7. The method for preparing a cooking vessel according to claim 6, characterized in that: The carburizing treatment satisfies at least one of the following conditions: (1) The carbon source is selected from at least one of alkanes, alkenes, alkyl acids or alkyl alcohols; (2) The concentration of the carbon source in the reaction atmosphere is 5wt%-10wt%; (3) The reaction atmosphere further includes at least one of an inert gas and a reducing gas; (4) The carburizing treatment is carried out at a temperature of 700°C to 1100°C and for a time of 12h to 24h.

8. The method for preparing a cooking vessel according to claim 6, characterized in that: The carbon content of the carbon-containing matrix is ​​5wt%-20wt%.

9. The method for preparing a cooking vessel according to claim 6, characterized in that: The method of placing the sol sealer on the surface of the carbon-containing substrate is selected from the impregnation treatment, and the impregnation treatment satisfies at least one of the following conditions: (1) The impregnation treatment method includes vacuum impregnation or pressure impregnation; (2) The content of sol particles in the sol sealing agent is 5wt%-20wt%; (3) The sol sealing agent is selected from silicone oil-based silica sol, and the particle size of silicon dioxide in the silicone oil-based silica sol is 5nm-20nm; (4) The sol sealing agent also includes alkaline mineral materials, and the content of the alkaline mineral materials in the sol sealing agent is 1wt%-10wt%.

10. The method for preparing a cooking vessel according to claim 6, characterized in that: After the heat curing process, polishing is also included.

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