Non-stick cooker

Abstract

The utility model provides a non-stick cooker, the non-stick cooker comprises a cooker body and a non-stick layer formed on the cooker body, the non-stick layer is a lipophilic metal oxide layer, the metal oxide layer has a porous structure, the porosity of the porous structure is 50%-70%, and the pore size is 10 nm-10 [mu] m. According to the non-stick layer, the metal oxide layer has the porous structure with high porosity, pores of the porous structure can be filled with silicone oil or grease, the filled silicone oil or grease can be continuously released in the use process of the cooker, the metal oxide layer can effectively resist abrasion and high temperature in the cooking process, and the service life of the cooker is prolonged. The silicone oil or grease is protected, so that the lasting non-stick property of the non-stick layer can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of non-stick layers, and particularly relates to non-stick layers and cooking utensils. Background Art

[0002] In the field of cooking utensils, non-stick materials have always been a research hotspot. With the development of non-stick industry technologies, solid spraying materials mainly based on ceramics, since they do not require the use of organic liquid coatings such as fluorine coatings or ceramic coatings, can reduce the psychological burden of customers using cooking utensil products, and can avoid various problems caused by atomized spraying, and have broad development prospects and potential.

[0003] Specifically, solid spraying materials mainly based on ceramics (such as titanium oxide, titanium nitride, titanium carbide, iron tetroxide, iron oxide, ferrous oxide, aluminum oxide, chromium oxide, nickel oxide, etc.) can form a non-stick layer, namely the so-called "non-coating non-stick technology". The non-coating here is only to indicate that it does not use organic coatings such as fluorine coatings or ceramic coatings.

[0004] However, the coating formed by the particles of the above-mentioned ceramic materials through thermal spraying, although wear-resistant, has poor initial non-stickiness and cannot meet the national standard requirements for initial stickiness. Usually, it is necessary to add grease or modify it with materials having good non-stickiness (such as modifying it with polysiloxanes, fluorinated materials), and since the oil film or the modifying material is easy to be damaged, the long-term non-stickiness of the cooking utensil with such a coating is average. Summary of the Utility Model

[0005] Based on the above deficiencies of the prior art, the inventive concept of the present invention provides a non-stick layer and a cooking utensil to solve the problem that conventional ceramic materials cannot have both initial stickiness and long-term non-stickiness at the same time.

[0006] According to one aspect of the exemplary embodiment, a non-stick layer is provided, wherein the non-stick layer is a lipophilic metal oxide layer, wherein the metal oxide layer has a porous structure, the porosity of the porous structure is 50%-70%, and the pore size is 10nm-10μm.

[0007] According to the present application, the metal oxide layer is a porous structure with a relatively high porosity and is lipophilic. Based on the principle of similar dissolution, the pores of the porous structure can be filled with silicone oil or grease, and the filled silicone oil or grease can be continuously released during the use of the cooking utensil, so that the cooking utensil coating can easily exhibit non-stickiness due to the continuous and stable oil film. And the metal oxide layer itself has a certain hardness and can effectively resist wear and high temperature during cooking, protecting the silicone oil or grease, so it can improve the long-term non-stickiness of the non-stick layer. In summary, the non-stick layer for cooking utensils of the present application can have excellent properties such as initial non-stickiness and long-term non-stickiness at the same time.

[0008] In some embodiments, the metal oxide layer is formed by a plurality of microspheres having a porous structure, the porosity of the porous structure is 35%-50%, and the pore size is 10nm-1μm. Using a plurality of microspheres as non-stick materials, the surface of each microsphere is slightly melted by spraying to form a metal oxide layer as the non-stick layer of the present application. The metal oxide layer can retain the pore structure of the microspheres as much as possible, thereby forming a metal oxide layer with a porous structure that is more complex than the pore structure. The metal oxide layer with a porous structure is easier to absorb and lock silicone oil or grease than in conventional situations, and under the protection of the wear-resistant metal oxide, the silicone oil can be continuously and stably released to form an oil film, thereby ensuring the long-lasting non-stickiness of the non-stick layer.

[0009] In some embodiments, the microspheres having a porous structure are formed by stacking a plurality of metal oxide particles.

[0010] In some embodiments, the microspheres are spherical or quasi-spherical; they can easily form a relatively dense non-stick layer through close spherical stacking. In addition, spherical or quasi-spherical microspheres have good fluidity and can be easily spread and distributed during the coating process, so that they can help form a uniform and smooth non-stick layer due to good fluidity, thereby improving the quality and performance of the coating. The particle size of the microspheres is 15μm45μm. The particle size within this range can take into account the convenience of the bonding force and the spraying process. Specifically, if the particle size of the microspheres is small, although it has a larger specific surface area to combine with the cooker body to enhance the bonding force, it may be easy to completely melt due to the small particle size. The molten microspheres will lose their original shape and structure, so that the original pore structure of the microspheres cannot be retained by thermal spraying to achieve the purpose of forming a non-stick layer with an expected porous structure. If the particle size of the microspheres is large, although it can provide better fluidity, it is easy to increase the risk of clogging, which is not conducive to the smooth progress of spraying.

[0011] In some embodiments, in the metal oxide layer, the porous structure includes a plurality of large pores between the microspheres and a plurality of small pores inside the microspheres, the size of the large pores is 500nm-10μm, and the size of the small pores is 10nm-1μm. The large pores enable silicone oil or grease to easily enter the non-stick layer, and the small pores enable silicone oil or grease to be easily retained, thereby ensuring the non-stick performance of the cookware with the non-stick layer due to the stable release of the oil film.

[0012] In some embodiments, the particle size of the metal oxide particles is nanometer-level or micrometer-level, and the metal oxide particles forming the microspheres are relatively small. When the microspheres are combined with the cooker body, they have a larger specific surface area, thereby ensuring the bonding force between the microspheres and the cooker body.

[0013] In some embodiments, the particle size of the metal oxide particles ranges from 100 nm to 10 μm. A suitable particle size of the metal oxide particles can provide a larger specific surface area. The formed microspheres can contribute to enhancing the adhesion between the coating formed therefrom and the cookware body due to the large specific surface area, and can form microspheres with a pore structure required by the present application. If the particle size of the metal oxide particles is too small, the preparation difficulty and cost of the metal oxide particles will increase. If the particle size of the metal oxide particles is too large, microspheres with the expected pore structure cannot be formed, affecting the non-stick performance.

[0014] In some embodiments, the metal oxide layer is a magnetite layer, a titanium oxide layer or a titanium suboxide layer. The above coatings themselves have good lipophilicity, so that they can exhibit non-stick properties due to the formation of a stable oil film. The metal oxide layer is formed by thermal spraying, and the formation method is simple, which can reduce environmental pollution.

[0015] In some embodiments, the thickness of the metal oxide layer is 60 μm - 200 μm. Such a thickness range can ensure that the non-stick layer can obtain a relatively deep oil storage depth, avoid insufficient oil storage affecting the formation of the oil film, and prevent the non-stick performance of the non-stick layer from disappearing due to wear because it is not too thin, and can also prevent the non-stick layer from peeling off due to excessive stress. The cookware with this non-stick layer has durable non-stick performance. And / or the surface of the metal oxide layer has a concavo-convex structure, making the non-stick layer not easily damaged by a spatula, so as to improve the non-stick life.

[0016] In some embodiments, the metal oxide layer has a carbonized product of a binder, and the carbonized product of the binder adheres to a part of the surface of the metal oxide particles forming the metal oxide layer.

[0017] In these embodiments, the binder forms a carbonized product. Since the carbonized product of the binder is mainly composed of non-polar carbon elements and has a certain lipophilicity, the non-stick layer of the cookware formed by such microspheres is more easily filled with silicone oil.

[0018] In some embodiments, at least part of the porous structure in the metal oxide layer is filled with silicone oil or grease.

[0019] In these embodiments, filling the porous structure of the metal oxide layer with silicone oil or grease can optimize the initial non-stick property and can improve the durable non-stick property to a certain extent. In addition, when the filler is silicone oil, the porous structure can effectively reduce the conduction and diffusion of heat, reduce the possibility of decomposition of silicone oil due to high temperature, and improve the durable non-stick performance.

[0020] According to another aspect of the exemplary embodiments, a cookware is provided, wherein the cookware includes a cookware body and a non-stick layer formed on the cookware body according to the above description.

[0021] In some embodiments, the non-stick layer is formed on the inner surface of the cooking utensil body, wherein the inner surface of the cooking utensil body has a rough surface or a rough transition layer is provided between the cooking utensil body and the non-stick layer to enhance the bonding force between the cooking utensil body and the non-stick layer.

[0022] In some embodiments, a plurality of spaced apart ribs are formed on the inner surface of the cooking utensil body, and there is a gap between adjacent ribs. The non-stick layer is formed in the gap and has a thickness not less than the upper ends of the ribs.

[0023] In these embodiments, by providing the non-stick layer in the gaps between adjacent ribs, the ribs can protect the non-stick layer from wear, and the silicone oil or grease filled in the non-stick layer can form a stable and durable oil film during use, which can further enhance the long-term non-stick property of the cooking utensil coating. Description of the Drawings

[0024] Figure 1 Shows a SEM image of the surface morphology of the microspheres provided according to an exemplary embodiment of the present application before sintering;

[0025] Figure 2 Shows a SEM image of the surface morphology of the microspheres provided according to an exemplary embodiment of the present application after sintering;

[0026] Figure 3 Shows a schematic structural diagram of the microspheres provided according to an exemplary embodiment of the present application;

[0027] Figure 4 Shows a schematic structural diagram of a cooking utensil provided according to an exemplary embodiment of the present application;

[0028] Figure 5 Shows Figure 4 An enlarged schematic structural diagram of part I;

[0029] Figure 6 Shows a schematic structural diagram of the non-stick layer of another cooking utensil provided according to an exemplary embodiment of the present application.

[0030] Symbol Description

[0031] 10. Microspheres; 11. Metal oxide particles; 12. Carbonized product;

[0032] 100. Cooking utensil body; 200. Non-stick layer. Detailed Description of the Embodiments

[0033] The following specific embodiments are provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, or systems described herein. However, after understanding the disclosure of this application, various changes, modifications, and equivalents of the methods, devices, or systems described herein will be apparent. For example, the order of operations described herein is merely exemplary and is not limited to those set forth herein, but may be changed as will be apparent after understanding the disclosure of this application, except for operations that must occur in a specific order. Additionally, descriptions of features known in the art may be omitted for greater clarity and conciseness.

[0034] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Instead, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, or systems described herein, which will be apparent after understanding the disclosure of this application.

[0035] As used herein, the term "or" includes any one of the associated listed items and any combination of any two or more thereof.

[0036] Although terms such as "first," "second," and "third" may be used herein to describe various components, elements, regions, layers, or parts, these components, elements, regions, layers, or parts should not be limited by these terms. Instead, these terms are only used to distinguish one component, element, region, layer, or part from another. Thus, a first component, first element, first region, first layer, or first part referred to in the examples described herein may also be referred to as a second component, second element, second region, second layer, or second part without departing from the teachings of the examples.

[0037] In the specification, when an element such as a layer, region, or substrate is described as "on" another element, "connected to" or "mounted to" another element, the element may be directly "on" the other element, directly "connected to" or "mounted to" the other element, or there may be one or more other elements therebetween. In contrast, when an element is described as "directly on" another element, "directly connected to" or "directly mounted to" another element, there may be no other elements therebetween.

[0038] The terms used herein are only for describing various examples and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. The terms "comprising," "including," and "having" specify the presence of the recited features, quantities, operations, components, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, or combinations thereof. The term "plurality" represents any quantity of two and more than two.

[0039] The definitions of orientation terms such as "front", "rear", "upper", "lower", "inner" and "outer" in this application are all based on the orientation of the cooking utensil in a practical state as a reference.

[0040] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which this utility model pertains after understanding this utility model. Unless explicitly defined as such herein, terms such as those defined in a general dictionary shall be construed to have a meaning consistent with their meaning in the context of the relevant field and this utility model, and shall not be idealized or construed too formally.

[0041] In addition, in the description of the examples, when it is considered that a detailed description of known related components or functions will cause a blurred interpretation of this utility model, such detailed description will be omitted.

[0042] The following will be combined with Figures 1 to 6 to introduce the non-stick layer provided by the embodiments of this application.

[0043] This utility model provides a non-stick layer for a cooking utensil. Here, the cooking utensil can be a pot, such as a wok, a frying pan, etc., or it can also be the inner liner of a pressure cooker or an electric rice cooker. Among them, the non-stick layer is a lipophilic metal oxide layer. The metal oxide layer has a porous structure, the porosity of the porous structure is 50%-70%, and the pore size is 10nm-10μm.

[0044] According to this application, the metal oxide layer has a porous structure with a relatively high porosity and is lipophilic. Based on the principle of like dissolves like, the pores of the porous structure can be filled with silicone oil or grease, and the filled silicone oil or grease can be continuously released during the use of the cooking utensil, so that the cooking utensil coating can easily exhibit non-stickiness due to the continuous and stable oil film. And the metal oxide layer itself has a certain hardness, which can effectively resist wear and high temperature during cooking and protect the silicone oil or grease, so it can improve the long-term non-stickiness of the non-stick layer. In summary, the non-stick layer for a cooking utensil of this application can simultaneously possess excellent properties such as initial non-stickiness and long-term non-stickiness.

[0045] In some embodiments, the metal oxide layer is formed by a plurality of microspheres having a porous structure, wherein the porosity of the porous structure is 35%-50%, and the pore size is 10nm-1μm. Using a plurality of microspheres as non-stick materials, the surface of each microsphere is slightly melted by spraying to form a metal oxide layer as the non-stick layer of the present application. The metal oxide layer can retain the pore structure of the microspheres as much as possible, thereby forming a metal oxide layer with a porous structure that is more complex than the pore structure. The metal oxide layer with a porous structure is easier to absorb and lock silicone oil or grease than in conventional situations, and under the protection of the wear-resistant metal oxide, the silicone oil can be continuously and stably released to form an oil film, thereby ensuring the long-lasting non-stickiness of the non-stick layer.

[0046] According to the present application, the microspheres are spherical or quasi-spherical, and can easily form a relatively dense non-stick layer by closely stacking the spheres. In addition, the spherical or quasi-spherical microspheres have good fluidity, and can be easily spread and distributed during the coating process, so that they can help to form a uniform and smooth non-stick layer due to good fluidity, thereby improving the quality and performance of the coating. The particle size of the microspheres is 15μm45μm. The particle size within this range can take into account the convenience of the binding force and the spraying process. Specifically, if the particle size of the microspheres is small, although it has a larger specific surface area to combine with the cooker body to enhance the binding force, it may be easy to completely melt due to the small particle size. The molten microspheres will lose their original shape and structure, so that the original pore structure of the microspheres cannot be retained by thermal spraying to achieve the purpose of forming a non-stick layer with an expected porous structure. If the particle size of the microspheres is large, although it can provide better fluidity, it is easy to increase the risk of clogging, which is not conducive to the smooth progress of spraying.

[0047] According to the present application, in the microspheres, the contact portions between adjacent metal oxide particles are interlocked, so that the particles of the microspheres have sufficiently strong bonding forces to ensure the stability of the microspheres in the subsequent process of forming a non-stick layer.

[0048] According to the present application, the microspheres are formed by stacking metal oxide particles. As an example, the microspheres are obtained by spray drying and sintering a mixed slurry of conventional metal oxide particles and a binder. Among them, the metal oxide particles are nanometer-level or micrometer-level. The microspheres formed by metal oxide particles in this range can have a large specific surface area with the cooker body, so as to ensure the bonding force between it and the cooker body. At the same time, the metal oxide particles forming the microspheres are relatively small, nanometer-level or micrometer-level, and even if the spraying parameters with power lower than that of conventional ceramic materials are used, it can be ensured that the surface of the microspheres is easy to melt and deposit on the cooker body during the spraying process, so as to ensure the deposition efficiency of the material. It can be understood that the spraying power of the microspheres according to the present application can be set relatively low, and the pore structure in the microspheres can be better retained. In addition, the microspheres are solid materials, and there is no need for atomization spraying to form a non-stick layer, which can avoid the environmental pollution problem caused by atomization spraying liquid coatings.

[0049] A method for manufacturing microspheres is provided herein, wherein the method for manufacturing microspheres comprises:

[0050] Step S1, providing a mixed slurry including nano-scale metal oxide particles and a binder.

[0051] Step S2, spray drying the mixed slurry, and then sintering it at a preset temperature to form microspheres with a porous structure.

[0052] According to the method for manufacturing microspheres provided by the embodiment of the present application, by spray drying the mixed slurry of nano-scale metal oxide particles and a binder, and then sintering at a preset temperature, microspheres with a porous structure can be formed, and the non-stick layer formed by such microspheres can retain the pore structure of the microspheres as much as possible, thereby forming a non-stick layer with a corresponding porous structure, and the non-stick layer with a porous structure is easy to absorb grease, so that it can exert excellent non-stick properties due to the oil film non-stick principle. In addition, the wear resistance of the metal oxide is good, so that the long-lasting non-stick performance of the cooker with the non-stick layer can be guaranteed. In addition, the particles of the metal oxide forming the microspheres are small, at the nanometer level or micrometer level. When the microspheres are combined with the cooker body, they have a large specific surface area, so that the bonding force between them and the cooker body can be guaranteed. In summary, the cooker coating formed by the microspheres of the present application can simultaneously have excellent performance in terms of initial non-stickiness, long-lasting non-stickiness and bonding force.

[0053] In some embodiments, the particle size of the metal oxide particles is 100 nm - 10 μm. A suitable particle size of the metal oxide particles can provide a larger specific surface area. The formed microspheres can help improve the adhesion between the coating formed therefrom and the cookware body due to the large specific surface area, and can form microspheres with a pore structure required by the present application. If the particle size of the metal oxide particles is too small (such as less than 100 nm), the preparation difficulty and cost of the metal oxide particles will increase. If the particle size of the metal oxide particles is too large (such as greater than 10 μm), microspheres with the expected pore structure cannot be formed, affecting the non-stick performance. It should be noted that the particle size of the above materials can be the maximum length of each particle, rather than specifically limiting that the material has a spherical or quasi-spherical shape. For example, but not limited to, when the material has an elliptical shape, the particle size of the material can refer to the length of its major axis.

[0054] Next, in order to more specifically illustrate the method for preparing microspheres according to the present application, taking metal oxide particles at the nanometer level as an example, the method for preparing microspheres according to the present application will be introduced in detail.

[0055] Providing metal oxide particles

[0056] According to the present application, the nanoscale metal oxide particles include magnetite particles, titanium oxide particles or titanium suboxide particles. Among them, it should be noted that the titanium oxide particles refer to TiO2 particles, and the titanium suboxide includes Ti2O3, Ti3O4 or Ti4O7 particles. Correspondingly, the metal oxide layer is a magnetite layer, a titanium oxide layer or a titanium suboxide layer.

[0057] The above-provided nanoscale metal oxide particles can form microspheres with an expected pore structure after spray drying (powder granulation) and sintering. By using multiple microspheres to form a non-stick layer by spraying, the entry of silicone oil or grease can be ensured. And in products such as cookware, the metal oxide particles in the microspheres can effectively protect the relatively inner silicone oil, avoiding the direct contact of the silicone oil with the heat source and volatilization. In addition, the microspheres can effectively reduce the conduction and diffusion of heat, reducing the possibility of direct contact between the silicone oil and high temperature decomposition, thereby improving the stability of the metal oxide layer.

[0058] In some embodiments, the nanoscale magnetite particles can be commercially available or obtained by reacting ferric chloride and ferrous chloride. As some examples, the method for preparing magnetite nanoparticles by coprecipitation is specifically as follows:

[0059] Step 1, weigh ferric chloride and ferrous chloride according to a molar ratio of 2:1, add water to dissolve them fully to form a mixed solution. To prevent hydrolysis, a small amount of dilute hydrochloric acid can be added to make the pH value of the solution acidic, such as pH less than 5.

[0060] Step 2: Heat, maintain the temperature at 50°C - 80°C, slowly add sodium hydroxide solution or ammonia water to make the pH of the system greater than 10, and continuously stir until black iron tetroxide precipitates.

[0061] Step 3: Filter, wash with ethanol, and dry to obtain iron tetroxide particles at the nanoscale.

[0062] In some embodiments, nanoscale titanium oxide particles can be obtained commercially or through chemical reactions. As another example, nanoscale titanium oxide particles are prepared by the homogeneous precipitation method. Specifically, it includes the following steps:

[0063] Step 1: Prepare a mixed solution of titanium oxysulfate and urea according to a molar ratio of 1:1 - 1:2, form a mixed solution with water at a concentration of 1 mol / L - 3 mol / L, and place it in a high-pressure reactor for reaction. The reaction time is 1 h - 3 h, and the temperature is 100°C - 120°C.

[0064] Step 2: Filter and wash the reaction product to remove impurities, and then vacuum dry to obtain metatitanic acid precipitate.

[0065] Step 3: Finally, sinter the metatitanic acid precipitate in a high-temperature furnace. The sintering temperature is 700°C - 900°C, and the time is 1 h - 3 h to obtain nanoscale titanium oxide particles.

[0066] In addition, nanoscale titanium suboxide particles can be obtained commercially or by high-temperature sintering of nanoscale titanium oxide particles.

[0067] In some embodiments, the metal oxide particles are spherical or quasi-spherical. The spherical or quasi-spherical metal oxide particles can easily form microspheres with a pore structure. The pores in the pore structure are relatively uniformly distributed and have a relatively high through-hole porosity, which not only facilitates the adsorption and storage of silicone oil or grease but also ensures the mechanical strength and wear resistance of the formed microspheres.

[0068] Form a mixed slurry

[0069] According to the present application, the step of forming a mixed slurry includes providing metal oxide particles and a binder, and ball-milling and mixing the metal oxide particles and the binder to form a mixed slurry. Specifically, add the metal oxide particles and the binder into a ball-milling tank, then add deionized water as a grinding medium, and grind for 4 h - 8 h to obtain a uniformly dispersed mixed slurry including metal oxide particles and a binder. The binder in the mixed slurry can enhance the bonding force between the particles forming the microspheres to form a stable particle stack, enabling the microspheres to have a certain mechanical strength to ensure the stability of the non-stick layer formed subsequently and avoid breakage, which may affect the formation of the porous structure.

[0070] In some embodiments, the mixed slurry includes metal oxide particles and a binder, and the weight ratio of the metal oxide particles to the binder is 98: (1-3). As an example, the binder includes an alcohol binder and a cellulose binder. As an example, the binder may include at least one of a cellulose binder and an alcohol binder. The cellulose binder may include at least one of a hydroxymethyl cellulose binder, a hydroxyethyl cellulose binder, and a hydroxypropyl cellulose binder. The alcohol binder may include at least one of polyethylene glycol, a polyvinyl alcohol binder, a polypropylene alcohol binder, and other higher alcohol binders containing more than six carbon atoms. However, the present application is not limited thereto, but a suitable binder may be selected according to actual needs.

[0071] It should be noted that according to the present application, the binder will volatilize or carbonize during the subsequent sintering process. Whether it is volatilization or carbonization depends largely on the heating rate, sintering temperature and time of the subsequent sintering stage. Here, carbonization is the process in which organic matter is decomposed by heat at high temperature to remove hydrogen, oxygen, etc. other than carbon as low molecular compounds, leaving only residual carbon. Volatilization is the process in which organic matter changes from liquid to gas after reaching the boiling point.

[0072] According to the present application, under an inert atmosphere such as nitrogen and argon, at a faster heating rate, a higher sintering temperature and a longer sintering time, a small portion of the binder will volatilize, leaving pores, and most of the binder will be carbonized to form a high-carbon material-binder carbonization product, and adjacent particles interact with each other to form microspheres having a metal oxide particle stack and a carbonization product and a porous structure.

[0073] As an example, the carbonization temperature of the binder of the present application is roughly between 250°C and 500°C. Under the influence of the subsequent sintering temperature and time, most of the binder will form a carbonized product. Since the carbonized product of the binder is mainly composed of non-polar carbon elements and has a certain lipophilicity, the non-stick layer of the cookware formed by such microspheres is easier to be filled with silicone oil. In some embodiments, 10% of the binder will volatilize, and 90% of the binder will be carbonized.

[0074] Spray drying to form wet microspheres

[0075] After the pulping is completed, the mixed slurry is spray dried. According to some embodiments of the present application, a spray drying device (such as a pressure spray dryer, a centrifugal spray dryer, etc.) is used to atomize the mixed slurry into fine droplets. The atomized droplets are in contact with hot air, the solvent evaporates rapidly, and the metal oxide particles and the binder form a microsphere structure. As an example, the mixed slurry can be transported to a high-speed atomization disk to form droplets, and then the droplets are blown into a drying tower using hot air. The droplets stay for a short time during the descent process and finally form wet microspheres.

[0076] According to the present application, by adjusting the process parameters of spray drying (e.g., the rotation speed of the atomization disk and the hot air temperature), characteristics such as the particle size, pore size, and distribution of the microspheres can be controlled. As an example, during the high-speed movement of the atomization disk, by controlling the rotation speed of the atomization disk, the mixed slurry can be dispersed into extremely small droplets. In some embodiments, the rotation speed of the atomization disk can be controlled within the range of 4000 revolutions per minute to 15000 revolutions per minute, and preferably, it can be controlled within the range of 6000 revolutions per minute to 12000 revolutions per minute. According to some embodiments of the present application, the temperature of the hot air can be controlled within the range of 60°C to 100°C, the temperature of the drying tower can be controlled within the range of 100°C to 400°C, and the short residence time of the droplets in the drying tower can be controlled to be 5 seconds to 15 seconds. The hot air with a relatively low temperature can reduce the loss of the binder, so that sufficient binder is retained in the obtained preformed wet microspheres, thereby ensuring that pores can be formed by the volatilization or carbonization of the binder during the subsequent sintering process.

[0077] Sinter the microspheres after spray drying

[0078] According to the method for manufacturing microspheres of the present application, the wet microspheres obtained after spray drying are sintered. During the sintering process, the mutually contacting metal oxide particles are mutually interlocked at the contacting parts after sintering to form microspheres, so that there is a sufficiently strong bonding force between the particles of the microspheres to ensure the stability of the microspheres in the subsequent processes.

[0079] According to some embodiments of the present application, the microspheres after spray drying can be heated to a temperature above the carbonization temperature at a relatively high heating rate in an inert atmosphere such as nitrogen or argon and maintained for a long time, so that as much binder as possible undergoes carbonization during this process. As an example, the microspheres are placed in a sintering furnace in an inert atmosphere such as nitrogen or argon. The initial temperature of sintering is 20°C to 30°C, the heating rate is 15°C per minute to 20°C per minute, and it is heated to 500°C to 650°C. Then, it is kept warm for 6 hours to 8 hours to carbonize the binder in the microspheres after spray drying as much as possible. Finally, it is heated to 1200°C to 1250°C at a heating rate of 55°C per minute to 100°C per minute, and then kept warm for 12 hours to 24 hours, so that the adjacent metal oxide particles interact with each other to be mutually interlocked at the contacting parts, and the volume shrinks, leaving pores between the particles, and finally forming microspheres of a carbonized product with a certain pore structure and having metal oxide particles and a binder. Therefore, the formed metal oxide layer has a carbonized product of metal oxide particles and a binder, and the carbonized product of the binder adheres to a part of the surface of the metal oxide particles. As an example, in the metal oxide layer, the weight ratio of the carbonized product of the binder to the metal oxide particles is (0.5 - 1):98.

[0080] In these embodiments, there is also a small amount of carbonized product of the binder in the microspheres. Since the carbonized product of the binder is mainly composed of non-polar carbon elements and has a certain lipophilicity, it can further enhance the overall lipophilicity of the microspheres, making the non-stick layer formed therefrom easier to fill with silicone oil.

[0081] In addition, during the sintering process, when the metal oxide particles are titanium oxide, titanium oxide will lose oxygen under the influence of the reducing atmosphere and high temperature of solid-phase sintering and at least partially form titanium suboxide. The special chemical properties and surface structure of titanium suboxide help to reduce the contact between food and the surface of the cooking utensil and reduce the possibility of food adhesion.

[0082] Figure 1 The SEM image of the surface morphology of the microspheres provided according to the exemplary embodiments of the present application before sintering is shown. Figure 2 The SEM image of the surface morphology of the microspheres provided according to the exemplary embodiments of the present application after sintering is shown. Referring to Figure 1 and Figure 2 , it can be seen that before sintering, the wet microspheres do not have obvious pores, while after sintering, the microspheres have obvious pore structures, and the pores of the pore structures are generally evenly distributed.

[0083] Figure 3 The schematic structural diagram of the microspheres provided according to the exemplary embodiments of the present application is shown. As Figure 3 shown, the microsphere 10 includes metal oxide particles 11 and the carbonized product 12 of the binder connected to a part of the surface of the metal oxide particles 11.

[0084] According to the method for manufacturing microspheres of the present application, the sintered microsphere particles can also be screened after the sintering step, so as to obtain microspheres in different particle size ranges. The microsphere powder can be screened into different particle size ranges according to needs for application to different products. For example, the sintered powder is vibrated and screened to obtain spherical or quasi-spherical microspheres with a particle size of 10 μm - 45 μm.

[0085] According to the method for manufacturing microspheres of the present application, the finally formed microsphere particles do not only refer to a single particle in the sense of quantity, but can be multiple particles aggregated together. The particle size of the finally formed microsphere particles is not less than the particle sizes of the original various powders.

[0086] According to the present application, channels exist inside or between the microsphere particles after spray drying, which can allow gases or liquids to pass through. That is, the pores of the pore structure in the microspheres formed by spray drying in the present application are mostly open pores or connected pores, that is, through holes, while a small number are closed pores. As an example, the volume ratio of the through holes is about 80% - 90%, and the balance is closed pores.

[0087] According to the present application, the non-stick layer can be formed by microspheres using a thermal spraying process. Among them, the non-stick material is microspheres with a pore structure. During the thermal spraying process, the surface of the microspheres is heated, the interior remains almost unchanged, and the non-stick layer is formed on the cookware body as a whole. Therefore, the pore structure of the microspheres can be basically maintained in the formed non-stick layer. It can be understood that the porous structure in the non-stick layer is largely determined by the pore structure of the microspheres.

[0088] As an example, in the formed metal oxide layer, the porous structure includes a plurality of large pores located between the microspheres and a plurality of small pores located inside the microspheres. The size of the large pores is 500 nm - 10 μm, and the size of the small pores is 10 nm - 1 μm. The large pores can make it easy for silicone oil or grease to enter the non-stick layer, and the small pores can make it easy for silicone oil or grease to be retained, so that the non-stick performance of the cookware with the non-stick layer can be ensured due to the stable release of the oil film.

[0089] In some embodiments, the thermal spraying includes flame spraying, arc spraying, and plasma spraying. Taking plasma spraying as an example, the specific parameters are: powder feeding speed 10 g / min - 25 g / min, spraying distance 100 mm - 130 mm, arc current 450 A - 550 A, hydrogen pressure 0.6 MPa - 0.8 MPa, hydrogen flow rate 100 L / h - 200 L / h, argon pressure 1.0 MPa - 1.5 MPa, and argon flow rate 1500 L / h - 2500 L / h.

[0090] According to the present application, the thickness of the non-stick layer is in the range of 60 μm - 200 μm, so that the long-lasting non-stick performance of the cookware with this non-stick layer can be ensured.

[0091] According to the second aspect of the present application, a cookware is provided, wherein, as Figure 4 shown, the cookware includes a cookware body 100 and a non-stick layer 200 formed on the inner surface of the cookware body 100. Among them, the non-stick layer is a metal oxide layer formed by spraying the above-mentioned microspheres.

[0092] In some embodiments, the non-stick layer has a porous structure. As an example, the porosity of the porous structure is 50% - 70%, and the pore size is 10 nm - 10 μm. Such a porous structure with a pore proportion can be filled with silicone oil.

[0093] In these embodiments, the porous structure of the non-stick layer is a structure suitable for filling and locking silicone oil. When the porous structure of the non-stick layer is filled with silicone oil, the silicone oil can be continuously released from the porous structure to optimize the non-stick property of the non-stick layer.

[0094] According to the present application, the cookware coating can have various structural forms.

[0095] In some embodiments, a non-stick layer is formed on the inner surface of the cooking utensil body, wherein the inner surface of the cooking utensil body is a rough surface, and the rough surface can be obtained by sanding the inner surface of the cooking utensil body. As Figure 5 shown, the inner surface of the cooking utensil body is a rough surface. Spraying a non-stick layer on the cooking utensil body with a rough surface can make the surface of the non-stick layer have a concave-convex structure. As an example, the concave-convex structure is at the micron level and is composed of a plurality of convex hulls. The height of the convex hull is 100 μm - 500 μm, the width is 200 μm - 400 μm, and the spacing between adjacent convex hulls is 200 μm - 400 μm. The non-stick layer at the trough position between adjacent convex hulls is not easily damaged by a spatula, so as to improve the non-stick life.

[0096] In some other embodiments, a rough transition layer is provided between the cooking utensil body and the non-stick layer, and the rough transition layer can further improve the bonding force between the coating and the cooking utensil body. As an example, the rough transition layer can be formed by thermally spraying a metal material on the surface of the cooking utensil body.

[0097] In still some other embodiments, a plurality of convex ribs are formed on the inner surface of the cooking utensil body at intervals, and there is a gap between adjacent convex ribs. The non-stick layer is formed in the gap and has a thickness not less than the upper end of the convex ribs. Among them, the convex ribs can be prepared on the surface of the cooking utensil body by existing methods. As an example, the convex ribs can be prepared on the surface of the cooking utensil body by mechanical, laser, chemical, electrochemical and other methods.

[0098] As Figure 6 shown, the cross-section of the convex rib is circular or annular. The non-stick layer is formed in the gap between adjacent convex ribs and has a thickness flush with the upper end of the convex rib.

[0099] In these embodiments, by arranging the non-stick layer in the gap between adjacent convex ribs, the convex ribs can protect the non-stick layer from wear. The silicone oil or grease filled in the non-stick layer can form a stable and lasting oil film during use, which can further improve the lasting non-stick property of the cooking utensil coating.

[0100] Hereinafter, taking the filling of silicone oil as an example, specific embodiments will be described for the manufacturing method of the cooking utensil according to the present application. For the example of filling grease, no specific description will be made.

[0101] Provide a cooker body

[0102] According to the present application, the cooking utensil body can be made of common materials. Exemplarily, the materials can be stainless steel, titanium, aluminum, titanium alloy, aluminum alloy, and composite materials formed by the above materials. The cooking utensil body can have a shape corresponding to its function. Exemplarily, when the non-stick cooking utensil is a non-stick pan, the cooking utensil body can have a conventional pan shape.

[0103] In some embodiments, the inner surface of the cooking utensil body is a rough surface, which can be obtained by sanding the inner surface of the cooking utensil body. As an example, the roughness of the rough surface is in the range of 3 μm - 6 μm in terms of Ra value. In some other embodiments, a rough transition layer is provided between the cooking utensil body and the non-stick layer, and the rough transition layer can further improve the bonding force between the coating and the cooking utensil body. As an example, the rough transition layer can be formed by thermally spraying a metal material on the surface of the cooking utensil body.

[0104] Form the non-stick layer

[0105] According to the present application, the non-stick layer can be formed by using microspheres through the above-mentioned thermal spraying method.

[0106] In some embodiments, the thermal spraying includes flame spraying, arc spraying, and plasma spraying. Taking plasma spraying as an example, the specific parameters are: powder feeding speed 10 g / min - 25 g / min, spraying distance 100 mm - 130 mm, arc current 450 A - 550 A, hydrogen pressure 0.6 MPa - 0.8 MPa, hydrogen flow rate 100 L / h - 200 L / h, argon pressure 1.0 MPa - 1.5 MPa, and argon flow rate 1500 L / h - 2500 L / h.

[0107] According to the present application, the thickness of the non-stick layer is in the range of 60 μm - 200 μm. Such a thickness range can ensure that the non-stick layer can obtain a relatively deep oil storage depth, avoid insufficient oil storage affecting the formation of the oil film, and prevent the non-stick performance of the non-stick layer from disappearing due to wear due to being too thin, and also prevent the non-stick layer from peeling off due to excessive stress. The cooking utensil with such a non-stick layer has durable non-stick performance.

[0108] Provide silicone oil

[0109] According to the present application, the silicone oil can be selected from at least one of methyl silicone oil, dimethyl silicone oil, hydroxyl silicone oil, hydrogen-containing silicone oil, and polyether-modified silicone oil. The above silicone oils have specific viscosities and surface tensions and are more likely to enter the pore structure of the microspheres. In this case, the silicone oil is adsorbed or bonded to the pore structure of the microspheres. In addition, by weight percentage, the silicone oil includes 20% - 30% of low molecular weight silicone oil, 40% - 60% of medium molecular weight silicone oil, and 20% - 30% of high molecular weight silicone oil, wherein the molecular weight of the low molecular weight silicone oil is between 500 and 1000, the molecular weight of the medium molecular weight silicone oil is between 3000 and 6000, and the molecular weight of the high molecular weight silicone oil is between 12000 and 30000.

[0110] In these embodiments, the combination of silicone oil with large molecular weight and the structure formed by the accumulation of metal oxide particles is more firm, and the release rate is slower. The small molecular weight silicone oil has better free mobility, thus having better non-stick property. The medium molecular weight silicone oil takes into account both free mobility and firm combination. Therefore, by combining low molecular weight silicone oil, medium molecular weight silicone oil and high molecular weight silicone oil, on the one hand, the possibility of silicone oil entering the microspheres is further increased, and on the other hand, silicone oils with different binding forces can be continuously released at each stage of use to achieve a better non-stick effect. As an example, the binding force between the silicone oil and the microspheres is approximately between 10 KPa and 25 KPa. Such a binding force can ensure the continuous release of the silicone oil and avoid premature release or non-release of the silicone oil.

[0111] According to the present application, after selecting the silicone oil and the microspheres, the non-stick layer formed by the microspheres is impregnated with the silicone oil, so as to obtain a cooking utensil with the silicone oil combined in the pore structure of the non-stick layer. As an example, in the cooking utensil coating, based on the total weight of the cooking utensil coating being 100%, the weight of the silicone oil accounts for 5% - 10% of the total weight of the cooking utensil coating, and the balance is the non-stick layer formed by the microspheres. As an example, the impregnation time of the silicone oil into the non-stick layer can be 2h - 3h, and the temperature can be 80°C - 100°C.

[0112] In some embodiments, at least part of the porous structure in the metal oxide layer is filled with silicone oil or grease. In the embodiments of the present application, when a mixture of silicone oil and grease is used for filling the metal oxide layer, the silicone oil and the grease can be first stirred and mixed, and then the filling step can be carried out. As an example, the silicone oil can be methyl silicone oil or hydroxy silicone oil, and the grease can be food oil or olive oil. In addition, it should be noted that the present application does not limit the mixing ratio of the silicone oil and the grease.

[0113] In these embodiments, the porous structure of the metal oxide layer is filled with silicone oil or grease, which can optimize the initial non-stick property and can, to a certain extent, improve the lasting non-stick property. In addition, when the filler is silicone oil, the porous structure can effectively reduce the conduction and diffusion of heat, reduce the possibility of the silicone oil decomposing due to high temperature, and improve the lasting non-stick performance.

[0114] Although one or more embodiments of the present utility model have been described with reference to the accompanying drawings, those of ordinary skill in the art will understand that various changes in form and detail can be made without departing from the spirit and scope defined by the claims.

Claims

1. A non-stick cooker, characterized in that: The non-stick cookware comprises a cookware body and a non-stick layer formed on the cookware body, wherein the non-stick layer is an oleophilic metal oxide layer, wherein the metal oxide layer has a porous structure, the porosity of the porous structure is 50%-70%, and the pore size is 10nm-10μm.

2. The non-stick cooker according to claim 1, characterized in that: The metal oxide layer is formed of a plurality of microspheres having a pore structure, the porosity of the pore structure is 35%-50%, and the pore size is 10nm-1μm.

3. The non-stick cooker according to claim 2, characterized in that: The microspheres with a porous structure are formed by stacking a plurality of metal oxide particles.

4. The non-stick cooker according to claim 2, characterized in that: The microspheres are spherical or quasi-spherical; and / or the particle size of the microspheres is between 15 μm and 45 μm; and / or in the microspheres, the contact portions between adjacent metal oxide particles are interlocked with each other; and / or in the metal oxide layer, the porous structure includes a plurality of large pores between the microspheres and a plurality of small pores inside the microspheres, the size of the large pores is between 500 nm and 10 μm, and the size of the small pores is between 10 nm and 1 μm.

5. The non-stick cooker according to claim 3, characterized in that: The particle size of the metal oxide particles is nanometer level or micrometer level.

6. The non-stick cookware according to claim 5, characterized in that: The particle size of the metal oxide particles is in the range of 100 nm to 10 μm.

7. The non-stick cooker according to claim 1, characterized in that: The thickness of the metal oxide layer is 60 μm-200 μm; and / or the surface of the metal oxide layer has a concavo-convex structure; and / or the metal oxide layer is formed by thermal spraying.

8. The non-stick cookware according to any one of claims 1 to 7, characterized in that: The metal oxide layer has a carbonized product of a binder therein, and the carbonized product of the binder adheres to a part of the surface of metal oxide particles forming the metal oxide layer.

9. The non-stick cookware according to claim 1, characterized in that: The metal oxide layer is a ferroferric oxide layer, a titanium oxide layer or a titanium suboxide layer.

10. The non-stick cookware according to claim 1, characterized in that: At least a portion of the porous structure in the metal oxide layer is filled with silicone oil or grease.

11. The non-stick cooker according to claim 1, characterized in that: The non-stick layer is formed on the inner surface of the cooker body, the inner surface of the cooker body has a rough surface or a rough transition layer is provided between the cooker body and the non-stick layer; or, The inner surface of the cooker body is formed with a plurality of convex ribs arranged at intervals, and there are gaps between adjacent convex ribs. The non-stick layer is formed in the gaps, and its thickness is not lower than the upper ends of the convex ribs.

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