Low-surface-energy non-stick pan with boron nitride layer

Abstract

A low-surface-energy boron nitride layer non-stick pan is characterized in that the surface of a pan body is covered with a silicon, chromium, aluminum or alloy layer to serve as a transition layer, the transition layer is covered with a low-surface-energy boron nitride layer, the thickness of the silicon, chromium, aluminum or silicon-based, chromium-based and aluminum-based alloy layer ranges from 30 nanometers to 2 micrometers, and the thickness of the low-surface-energy boron nitride layer ranges from 30 nanometers to 500 nanometers; and the silicon, chromium, aluminum or silicon-based and aluminum-based alloy layers and the low-surface-energy boron nitride layer material are covered by PVD (Physical Vapor Deposition). Due to the PVD boron nitride, the surface hardness is higher, and the safety to a human body is higher during use.

Description

Technical Field

[0001] This invention relates to a non-stick pan with a low surface energy boron nitride layer, which is an uncoated metal non-stick pan. In particular, it relates to the application and preparation of a non-stick pan with an alloy layer and nano-microstructure concave hole distribution (especially polygonal concave holes) in rice cookers and electric griddles. Background Technology

[0002] Existing processes for preparing low surface energy materials typically involve fluorinated resins, epoxy resins, and compounded curing agents. These materials possess excellent weather resistance, lubrication properties, and environmental friendliness, indicating a promising market outlook. With the development of marine engineering and shipbuilding industries, the demand for low surface energy materials is increasing year by year, demonstrating significant market application potential.

[0003] However, low surface energy boron nitride nonstick pans have not yet been publicly disclosed.

[0004] Low surface energy materials refer to materials with low surface energy, typically possessing properties such as non-stickiness, easy cleaning, and self-lubrication. These materials exhibit a contact angle with water greater than 90°, demonstrating hydrophobic and oleophobic characteristics. The low surface energy of low surface energy materials is primarily due to the weak adsorption force of their surface molecules or structures on liquids, making it difficult for liquids to spread on their surfaces. Existing low surface energy materials mainly include the following categories: Fluorine-containing low surface energy materials: These materials reduce surface energy by introducing fluorine atoms into the polymer chain. For example, the surface energy of polytetrafluoroethylene (PTFE) is approximately 20 mN / m. Low surface energy drag-reducing coatings: Primarily used for hydrophobic drag reduction and coating drag reduction, achieving drag reduction by reducing the shear stress of fluids on the wall surface. Antifouling coatings: Utilizing the properties of low surface energy materials, these prevent the adhesion of contaminants to their surfaces, suitable for applications such as shipbuilding and marine engineering.

[0005] Low surface energy materials have wide applications in many fields: Marine engineering: used in docks, bridges, offshore platforms, etc., to prevent marine organisms from adhering and reduce frictional resistance. Shipbuilding: reduce navigation resistance, prevent fouling, and improve navigation efficiency. Winter sports: used in skis, ice skates, etc., to reduce friction and improve athletic performance.

[0006] CN201710462896.9 describes an alumina ceramic pot body and its preparation method, a ceramic-inlaid metal inner pot, and a cooking utensil. The alumina ceramic pot body has a microporous structure formed on its inner surface, the depth of which is less than the thickness of the alumina ceramic pot body. The applicant also applies for a sticky pot, including an uncoated pot body (thickness 1 mm or more), a metal pot body (thickness 1 mm or more), and uniformly distributed recessed holes on the food-contact surface of the pot body. The hole diameter is 0.1–0.8 mm, particularly 0.3–0.5 mm, the hole edge spacing is 0.3–2 mm, the hole depth is 0.1–0.3 mm, particularly 0.1–0.15 mm, and the hole area accounts for 15–40% of the total pot body area. The recessed holes are circular or polygonal; the recessed holes are gradually recessed from a flat surface. The metal used is iron, stainless steel, etc.

[0007] Magnetron sputtering coating involves filling a vacuum chamber with argon gas and applying a negative bias voltage to the magnetron sputtering target. Argon ions bombard the target surface under the influence of an electric field. As the sputtered film atoms migrate towards the workpiece, some are ionized and accelerated under the negative bias voltage of the substrate, ultimately depositing a film on the workpiece. Cathodic arc ion plating and multi-arc ion plating are also common surface treatment technologies. They utilize a high-temperature, high-energy ion beam generated by an arc discharge to deposit metal ions onto the workpiece surface, thereby altering the workpiece's physical and chemical properties. Multi-arc ion plating, also known as the multi-arc method, is based on the cold cathode discharge theory. Under vacuum conditions, gas discharge evaporates and ionizes the target material to form plasma, which is then deposited onto the substrate surface. While forming a dense metal coating is not the focus of this invention, multi-arc ion plating can also produce particulate film coatings. The coating surface consists of tiny particles called "microdroplets," which currently require further processing. This invention utilizes these particulate films to form a direct coating layer. Summary of the Invention

[0008] To address the aforementioned problems, the present invention aims to provide an uncoated metal non-stick pan, particularly a low surface energy boron nitride layer non-stick pan, which can have a nano-microstructure concave hole distribution and is a low-cost prepared spray-coated alloy non-stick pan and various cookware.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a low surface energy boron nitride layer non-stick pan, wherein the surface of the pan body is covered with a silicon, chromium, aluminum or alloy layer as a transition layer, and a low surface energy boron nitride layer is covered on the transition layer. The thickness of the silicon, chromium, aluminum or silicon-based, chromium-based, aluminum-based alloy layer is 30 nanometers to 2 micrometers, and the thickness of the low surface energy boron nitride layer is 30 nm to 500 nm. The silicon, chromium, aluminum or silicon-based, aluminum-based alloy layer and the low surface energy boron nitride layer are all covered by PVD.

[0010] Furthermore, the boron nitride layer thickness is 50-300 nm.

[0011] Furthermore, the pot body is made of stainless steel, iron, or titanium; the thickness of the transition metal layer is 50 nanometers to 400 nanometers; when the pot body is made of aluminum, the thickness of the transition metal layer is optional.

[0012] Furthermore, the transition layer is a silicon-based or aluminum-based alloy. The silicon-based alloy is a single, binary, or multi-element alloy of iron, chromium, nickel, manganese, aluminum, titanium, and zirconium with a silicon weight ratio of more than 60%. The aluminum-based alloy is a single, binary, or ternary alloy of copper, magnesium, manganese, zinc, titanium, and zirconium with an aluminum weight ratio of more than 60%.

[0013] Furthermore, the surface of the metal pot body is uniformly distributed with concave and convex structures, wherein the diameter of the micro-nano depressions includes densely distributed depressions ranging from 0.05 to 2 μm; the micro-nano protrusions in the concave and convex structures adopt a structure of particle film coating.

[0014] Furthermore, the diameters of the micro-nano depressions with multiple diameter sizes include 40±20μm and 5±2μm; the micro-nano depressions are fabricated using pressing or etching methods; the depth of the micro-nano depressions is 20-1500nm.

[0015] Furthermore, the pore size distribution of the micro-nano recessed structure is as follows: 40±20μm, 5±2μm, and 0.2±0.1μm.

[0016] Furthermore, the pot body is made of stainless steel, titanium, iron, or aluminum, and the surface of the pot body that contacts the food is provided with uniformly distributed composite multi-sized concave holes; the diameter of the concave holes is 0.1-0.8mm, preferably 0.3-0.5mm, the distance between the edge of the holes is 0.1-2mm, the depth of the holes is 0.01-0.3mm, and the area of ​​the holes accounts for 15-40% of the total area of ​​the pot body. The concave holes are circular or polygonal; the concave holes are gradually recessed from the plane.

[0017] Furthermore, the metal pot body is provided with uniformly distributed elliptical or polygonal recesses, the maximum size of the elliptical or polygonal holes is 0.3 to 1.2 mm, the size of the protrusions between the elliptical or polygonal holes is 0.1 to 0.6 mm, and the uniformly distributed elliptical or polygonal recesses are covered with a PVD coating layer; the recesses are arranged in a parallel array or an interlaced array; the hole depth is 0.2 to 0.5 mm.

[0018] The pot body is made of aluminum and does not require a transition layer, but due to its softness, an aluminum alloy pot body would be better. Alternatively, a silicon or silicon-based alloy layer with a thickness of 50 nanometers to 400 nanometers can be added as a transition layer.

[0019] Furthermore, the silicon-based alloy is a silicon-iron alloy, silicon-manganese alloy, or silicon-iron-manganese alloy with a silicon weight ratio of 60% or more.

[0020] Furthermore, the surface of the metal pot body is uniformly distributed with micro-nano uneven structures; the micro-nano uneven structures include micro-nano depressions, the diameter of which includes densely distributed depressions of 0.1-0.98μm.

[0021] Furthermore, it features micro-nano convex and concave structures with multiple diameter dimensions; the diameter of the micro-nano depressions also includes 40±20μm and 5±2μm; the micro-nano depressions are fabricated using pressing and etching methods; the depth of the micro-nano depressions ranges from 20nm to 0.8mm.

[0022] Furthermore, the pore size distribution of the micro-nano recessed structure is as follows: 40±20μm, 5±2μm, 5±2μm, and 0.2±0.1μm.

[0023] Furthermore, the pot body is made of stainless steel, titanium, or iron, and the surface of the pot body that contacts the food is provided with uniformly distributed composite multi-sized concave holes; the diameter of the concave holes is 0.1-0.8 mm, especially 0.3-0.5 mm, the distance between the edge of the holes is 0.1-2 mm, the depth of the holes is 0.01-0.3 mm, and the area of ​​the holes accounts for 15-40% of the total area of ​​the pot body. The concave holes are circular or polygonal; the concave holes are gradually recessed from the plane.

[0024] The micro-nano protrusions in the micro-nano concave-convex structure adopt the structure of particle film coating; the particle diameter of the particle film is best formed by multi-arc ion plating.

[0025] The fabrication of a non-stick pan with a uniformly distributed micro-nano structure on its surface, featuring multi-level micro-nano structural depressions, achieves true non-stick performance without any chemical or organic coatings or modifications. The preparation of this coating-free non-stick pan primarily involves creating a pan body through the formation of concave holes or granular film protrusions on a uniformly micro-nano structured metal surface. The concave holes in the non-stick pan are prepared by pressing a titanium plate-shaped pan body onto the inner surface of the pan body using a uniformly rounded protrusion from an alloy mold (matching the size of the pan body and the concave shape of the inner pan). The non-stick pan can also be made using austenitic titanium, martensitic stainless steel, or titanium plates to create the concave pan body, or even iron pans, etc.

[0026] Even when stir-fried at high temperatures or when the pan is heated dry, the uncoated non-stick pan does not release any toxic substances or gases, and will not contaminate the food being cooked or the kitchen environment, making cooking safer.

[0027] Beneficial Effects: The low surface energy material of this invention provides excellent non-stick properties. By covering the surface of stainless steel or other metals with an alloy layer, and using a large number of diffusely distributed nano-micro-pore arrays and nanopores, the contact area between the food and the pot body is altered. The pores contain oil and water, reducing the heat directly transferred to the food from the pot body, preventing the food from sticking due to excessive heat. The oil content is constrained by the micro-pores and surface tension, achieving an unexpectedly good non-stick effect, comparable to existing fluorinated non-stick materials. The inner surface of the stainless steel pot body does not require an additional anti-stick coating; it is a natural stainless steel + PVD coating. Even with high-temperature stir-frying or dry heating, the non-stick pot releases no toxic substances or gases, preventing contamination of the food and the kitchen environment, making cooking safer. Because the coating of this invention is an alloy and ceramic PVD, excessive element release is less likely, ensuring the hygiene and safety of the cookware. The nano-pores in the cookware absorb air and oil during actual use, generating hot air and oil mist during heating, while simultaneously supporting the food. The velvety effect achieved through the nipple-like structure reduces friction between food and the inner surface of the pan, achieving a non-stick effect through physical means without any chemical coating, making food cooking healthier for consumers. This invention is resistant to metal spatulas and can be cleaned with a metal brush; its non-stick performance reaches Grade 1 (e.g., it can fry more than 50 eggs continuously without sticking even in the absence of oil or with only trace amounts of oil). Due to the PVD boron nitride, its surface hardness is higher, making it safer for human use. These features and advantages of this invention will be disclosed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the densely arranged rectangular concave holes in the pot body according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the densely arranged hexagonal concave holes in the pot body according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the distribution of concave holes in the pot body according to an embodiment of the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings: embodiments of the present invention are described in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same objects throughout.

[0032] Coated metal non-stick pans: A transition layer is prepared on the surface of stainless steel or iron using PVD. Figures 1-2The metal pot body can be made of a heat-equalizing layer (with a composite aluminum layer), or a metal pot body, especially stainless steel or iron; this embodiment relates to the application of a pressed non-stick pot body, the pot body has polygonal holes 1, the distribution of the polygonal holes can also be that the bottom of the pot is more densely distributed than the edge of the pot; there are protrusions 2 between adjacent polygonal holes.

[0033] The metal pot body can be treated by cleaning the surface, sanding (coarse sanding to increase the roughness of the metal surface), or first shot blasting and then cleaning before applying a PVD transition layer and boron nitride layer.

[0034] The material weight ratios are as follows for each alloy composition example.

[0035] The thickness of the transition layer is 50 nm, 100 nm, 330 nm, 500 nm, 1 and 1.5 μm, and the thickness of the low surface energy boron nitride layer is 30 nm, 80 nm, 100 nm, 200 nm and 500 nm. The alloy layer materials of the transition layer and the low surface energy boron nitride layer are covered by magnetron or multi-arc ion PVD.

[0036] The transition layer is a silicon-based alloy or an aluminum-based alloy, consisting of iron, chromium, nickel, manganese, and aluminum (with a silicon weight ratio of 60% or more) in a single, binary, or ternary alloy. The aluminum-based alloy is a single, binary, or ternary alloy containing copper, magnesium, manganese, and zinc (with an aluminum weight ratio of 60% or more). (A single alloy refers to an alloy with one added element; a binary alloy refers to an alloy with two added elements; and a multi-element alloy refers to an alloy with three or more added elements. Highly pure metals are not required as the target material for the coating; only the requirements of PVD need to be met.) For example, if FeSi75-A is selected, its silicon content is 74.0%-80.0%, calcium content is no more than 1.0%, phosphorus content is no more than 0.035%, sulfur content is no more than 0.020%, carbon content is no more than 0.10%, and the balance is iron.

[0037] Taking FeSi75-A as an example, its silicon content is 74.0%-80.0%, aluminum content is no more than 0.5%, calcium content is no more than 1.0%, phosphorus content is no more than 0.035%, sulfur content is no more than 0.020%, and carbon content is no more than 0.10%.

[0038] Silicon by weight can be 60%, 80%, 95%, or pure silicon.

[0039] Direct PVD coating of aluminum-magnesium alloy pot bodies is also an embodiment of this invention.

[0040] Low surface energy boron nitride (BN) layers offer excellent anti-stick properties for cookware. The BN layer is applied via PVD, particularly magnetron sputtering. A thickness of 50nm-300nm is preferable for the low surface energy BN layer, with the thickness controlled by the PVD time. This invention provides cookware surfaces with excellent anti-stick properties; by applying PVD to metal surfaces such as stainless steel, it can be directly applied to aluminum pots.

[0041] The application of low surface energy boron nitride nonstick cookware is the focus of this invention. Considering the preparation process and adhesion to the cookware body, a transition layer is employed. This transition layer can have nano- or micro-structures, and an inert atmosphere such as Ar is used for protection during PVD. The transition layer is effectively achieved using PVD methods such as magnetron sputtering or multi-arc sputtering.

[0042] When fabricating transition layers and boron nitride films on metal surfaces using PVD (Polyvinyl Dioxide) technology, the roughness of the transition layer is controlled through the process. Then, a boron nitride film containing pores ranging from tens to hundreds of nanometers is superimposed, creating a nanostructured surface. Specifically, when preparing the transition layer and boron nitride layer using a multi-arc method, a granular film coating structure is employed when micro / nano protrusions are included; this structure has nanoscale pores ranging from tens to hundreds of nanometers; even in recessed areas, a granular film coating can still be applied, and pores remain.

[0043] The metal pot body is provided with evenly distributed elliptical or polygonal recesses. The maximum size inside the elliptical or polygonal holes is 0.3 to 1.2 mm, and the size of the protrusions between the elliptical or polygonal holes is 0.1 to 0.6 mm. The evenly distributed elliptical or polygonal recesses are covered with an alloy layer.

[0044] The metal pot body (the surface in contact with food) has evenly distributed elliptical or polygonal recesses; the elliptical or polygonal holes are arranged in a parallel or staggered array; the surface material of the metal pot body can be stainless steel, iron, or even titanium; composite materials are also acceptable.

[0045] The concave holes are arranged in a parallel or staggered array; the hole depth is between 0.2 and 0.5 mm.

[0046] The pot is divided into several small areas, and each small area has an elliptical or polygonal hole.

[0047] The total area of ​​the elliptical or polygonal holes accounts for more than 50% of the total area.

[0048] The direction of the small-area elliptical or polygonal hole is perpendicular to the direction of the adjacent elliptical or polygonal hole.

[0049] The stainless steel pot body can be combined with an aluminum heat-conducting layer.

[0050] The longitudinal section of the elliptical or polygonal concave hole is wavy.

[0051] The larger spacing between polygonal holes makes the area of ​​the protruding part of the rib smaller than that of the concave part, thus making them easier to manufacture. The maximum dimension between the highest point of the protrusion and the lowest point of the concave arc of the polygonal hole does not exceed 500 micrometers.

[0052] PVD employs vacuum evaporation or vacuum sputtering deposition. High-purity targets are prepared according to the following examples. The target is heated to evaporate, and the vapor condenses on the substrate surface to form a film. Common methods include electron beam evaporation, resistance evaporation, arc evaporation, and laser evaporation. Alternatively, high-energy particles can bombard the target, causing target atoms to sputter and deposit onto the workpiece surface. DC sputtering, radio frequency sputtering, and magnetron sputtering are used. Magnetron sputtering is particularly effective: Argon gas is introduced into a vacuum chamber, and a negative bias is applied to the magnetron sputtering target. Argon ions bombard the target surface under an electric field. During the migration of sputtered film atoms towards the workpiece, some are ionized and accelerated under the negative bias of the substrate, ultimately depositing a film on the workpiece.

[0053] The film thickness of PVD coating technology typically has the following characteristics: Standard thickness range: Most PVD coatings are controlled between 0.1 and 10 micrometers in thickness, generally 0.1 to 2 micrometers; submicrometer thickness is sufficient for this invention, as it affects the original dimensions of the workpiece; PVD transition layer and nano-layer pots can be non-stick pots with distributed polygonal holes, including metal pot bodies with uniformly distributed polygonal holes on the food contact surface; including outer stainless steel layers with polygonal holes arranged in parallel or radial arrays on the surface, especially when the pot is divided into several small areas, each with polygonal holes arranged in a parallel array. The area of ​​each small area can be 20-100 square centimeters; if not divided into small areas, concentric polygonal holes or radial polygonal holes are also possible.

[0054] The pot body is made of 304 stainless steel, which is the surface that comes into contact with food. It is made of steel-aluminum composite or steel-aluminum-steel composite (referred to as three-layer steel, the purpose of which is to reduce weight and make the heat conduction more even). 316 stainless steel is even better, and iron pots can also be used.

[0055] The pot body is concave, formed by pressing a flat plate using a hydraulic press. A handle is attached to the pot body. The back of the pot is made of stainless steel with an aluminum composite layer. When using a composite material pot body, the stainless steel thickness is approximately 0.5-1mm, while the aluminum layer is approximately 1.5mm. This can be achieved through pressing or explosive bonding of stainless steel or titanium with aluminum.

[0056] Preparation of polygonal holes: A mold with uniform polygonal hole protrusions on an alloy mold is used to press the stainless steel pot surface to form polygonal holes. The polygonal hole mold can also be prepared by electrochemical methods.

[0057] Polygonal hole arrays, including triangular, rectangular, square, pentagonal, hexagonal, and octagonal holes, as well as nanopores, can be prepared using etching or mold engraving methods. Nanopores, especially those produced by pressing abrasives (dry or slurry) with nanometer-scale dimensions of 30-300 nm (500 nm is also possible), are even better when nitrided on the surface of the pot.

[0058] Magnetron ion plating is used to deposit micro / nano particle films, particularly on metals such as silicon, chromium, nickel, titanium, zirconium, or their alloys, or BN. The choice of target material or working atmosphere is key. Magnetron sputtering involves filling a vacuum chamber with argon gas and applying a negative bias to the magnetron sputtering target. Argon ions bombard the target surface under the influence of an electric field. As the sputtered film atoms migrate towards the workpiece, some are ionized and accelerated under the negative bias of the substrate, ultimately depositing a film on the workpiece. This process requires relatively extreme conditions to achieve multi-arc ion plating for particle film deposition.

[0059] The processing method for the micro-nano uneven structure of the indentation distribution on the surface of the uncoated non-stick pan is based on the applicant's prior patent application (already published): A mechanical rolling or pressing method is used, particularly by applying a hard granular paste to a mechanical rolling roller or metal plate. The particle size distribution consists of at least two or three particle sizes (D50): 50±20μm, 5±2μm, and 0.2±0.1μm (containing at least 0.2±0.1μm particles). These particles are mixed in a certain proportion to form a slurry. The mass of the two or three particle sizes is essentially the same, or the mass of the smaller particles can be 100-200% of the mass of the larger particles. The appropriate rolling roller pressure is adjusted to roll the surface of the metal plate. After the metal sheet is rolled, it is used to form the pot body. Each mechanical rolling roller uses a narrow roller (e.g., 10-30cm) to apply pressure to the metal surface to be pressed, and each mechanical rolling roller presses a 10-30cm wide indentation. The rollers are arranged sequentially: whether the rollers are staggered or arranged in sequence, each roller can apply greater pressure, which is supplied to each roller shaft and applied to the roller through hydraulic or other means. The width of several mechanical rolling rollers can cover and press the entire width of the metal sheet, which is between 1 meter and 2.4 meters. If each roller is 30cm wide, 8 rollers can continuously press a 2.4-meter wide plate. After pressing, the mixed slurry is collected (by shoveling) and the metal sheet is cleaned. The metal sheet is then pressed into the pot body. The layer of the pot body that comes into contact with food is made of iron, stainless steel, etc., and the back of the stainless steel can be laminated with an aluminum layer.

[0060] Mechanical rolling or pressing, combined with multi-sized hard fine particles (such as corundum, boron carbide, silicon carbide, silicon nitride, boron nitride, various corundum, cerium salts containing tetravalent cerium ions, and oxidants): The particle size distribution should include at least two particle sizes (D50): 50±20μm (marked by 33 in the figure), 5±2μm (marked by 22 in the figure), and 0.2±0.1μm (at least containing particles with a diameter of 0.2±0.1μm). These are mixed into a slurry in a certain proportion. In addition to the hard particles, the mixed slurry should ideally contain various aminocarboxylic acids, PEG (or polyvinyl alcohol), and at least 40wt% water, stirred to form a paste before use.

[0061] Rolling can be done in more than one pass, i.e., multiple passes of rolling or pressing. Micro- and nano-depressions can also be formed by etching, where uniform micro- and nano-depressions are formed by screen printing photoresist, followed by cleaning and etching with an etchant.

[0062] The recessed holes in the pot body can be created by pressing on the pot body itself. Static pressure pressing is also possible, using a slurry of at least two particle sizes, requiring a high-tonnage press (e.g., 6000 tons or more) to press a metal surface with an area of ​​approximately one square meter. This hard granular paste is used for direct static pressure pressing on metal plates to create a recessed distribution of micro-nano uneven structures, while roller pressing yields even better results. It is highly efficient and has low equipment costs. It can cause the formation of multi-size composite distributed micro-nano uneven (recessed) structures on metal surfaces, i.e., nano-uneven structures superimposed on micron-sized uneven surfaces, with micron-sized unevenness ranging from 0.2μm to 0.1mm and nano-sized unevenness ranging from 10nm to 200nm.

[0063] This application can be used not only for various cooking pots, but also for electric griddles and rice cookers.

[0064] Application of the electric griddle: An electric griddle with an alloy layer nanostructured polygonal hole non-stick coating includes upper and lower heating plates, a pot body, and heating elements. The heating elements are located inside the upper and / or lower heating plate pot bodies. The upper and lower heating plates are respectively mounted on a top cover and a base. The pot body has a structure where the lower surface of the upper heating plate and the upper surface of the lower heating plate have evenly distributed protrusions. The pot bodies are made of stainless steel or an aluminum-aluminum composite material. The part of the pot body that contacts the food is the alloy layer nanostructured polygonal hole non-stick coating.

[0065] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A low surface energy boron nitride layer non-stick pan characterized by, The surface of the pot body is covered with a transition layer of silicon, chromium, aluminum or alloy, and a low surface energy boron nitride layer is further covered on the transition layer, the thickness of the silicon, chromium, aluminum or silicon-based, chromium-based and aluminum-based alloy layer is 30 nm-2 μm, and the thickness of the low surface energy boron nitride layer is 30 nm-500 nm; the silicon, chromium, aluminum or silicon-based, chromium-based and aluminum-based alloy layer and the low surface energy boron nitride layer are all covered by PVD.

2. The low surface energy boron nitride layer non-stick pan of claim 1, wherein, The thickness of the boron nitride layer is 50-300 nm.

3. The low surface energy boron nitride layer non-stick pan according to any one of claims 1-2, characterized in that, The pot body is made of stainless steel, iron or titanium; the thickness of the transition layer is 50 nm-400 nm; when the pot body is made of aluminum, the thickness of the transition layer is selected.

4. The low surface energy boron nitride layer non-stick pan of claim 3, wherein, The transition layer is a silicon-based or aluminum-based alloy, the silicon-based alloy is a single or binary or multi-alloy of iron, chromium, nickel, manganese, aluminum, titanium and zirconium with a silicon content of more than 60% by weight, and the aluminum-based alloy is a single or binary or ternary alloy containing copper, magnesium, manganese, zinc, titanium and zirconium with an aluminum content of more than 60% by weight.

5. The low surface energy boron nitride layer non-stick pan of claim 3, wherein, The surface of the metal pot body is uniformly distributed with concave-convex structures, wherein the size of the micro-nano concave includes densely distributed 0.05-2 μm concaves; the micro-nano convex in the concave-convex structure adopts a structure of a particle film plating layer.

6. The uncoated non-stick pan of claim 1 wherein, The size of the micro-nano concave further includes 40±20 μm and 5±2 μm; the micro-nano concave is prepared by pressing or etching; the depth of the micro-nano concave is 20 nm-0.8 mm.

7. The uncoated non-stick pan according to claim 1, wherein The pore size distribution of the micro-nano concave structure is as follows: 40±20 μm, 5±2 μm and 0.2±0.1 μm.

8. The uncoated non-stick pan according to any of claims 5-7, characterized in that the pan The pot body is made of stainless steel, titanium, iron or aluminum, and a plurality of uniformly distributed composite multi-size concaves are further arranged on the surface of the pot body in contact with food; the concave has a pore size of 0.1-0.8 mm, preferably 0.3-0.5 mm, a spacing between the edges of the concave is 0.1-2 mm, the depth of the concave is 0.01-0.3 mm, the area ratio of the concave to the entire pot body is 15-40%, the concave is circular or polygonal, and the concave is gradually concave from a plane.

9. The uncoated non-stick pan according to claims 5-7, characterized in that, The metal pot body is provided with uniformly distributed elliptical or polygonal concaves, the maximum size of the elliptical or polygonal concave is 0.3-1.2 mm, the size of the convex between the elliptical or polygonal concaves is 0.1-0.6 mm, and the uniformly distributed elliptical or polygonal concaves are covered with a PVD coating layer. The concaves are arranged in parallel or staggered arrays, and the depth of the concave is 0.2-0.5 mm.

10. The uncoated non-stick pan according to claim 9, characterized in that, The total area of the elliptical or polygonal concave is greater than 50% of the entire area.

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