Non-stick pans with silicon nitride or chromium nitride layers

Abstract

To provide a non-stick pan with a silicon nitride or chromium nitride layer. [Solution] A metal pot body has a layer of silicon nitride, chromium nitride, aluminum nitride, or titanium nitride evenly distributed on the surface that comes into contact with food, with the layer having a thickness of 0.02 μm to 100 μm. This reduces the amount of heat directly transferred from the pot body to food, preventing overheating and burning of the food. Non-stick pots with the addition of such nitrides maintain the original color of stainless steel 2 for long periods of use, exhibit good non-stick properties, and are easy to clean.

Description

[Technical Field]

[0001] The present invention relates to the application of a nitride layer and nano-structured pores distributed in the body of a metal pot, especially a stainless steel pot, to non-stick pots, including rice cookers and electric grills. [Background technology]

[0002] CN2017104628969 discloses an alumina ceramic pot body and its manufacturing method, a ceramic-inlaid metal pot, and a cookware, in which a pore structure is formed on the inner surface of the alumina ceramic pot body, the depth of the pore structure being smaller than the thickness of the alumina ceramic pot body. The ceramic-inlaid metal pot includes an inner ceramic layer (1), an outer metal layer (3), and a heat-conducting layer (2) located between the ceramic layer (1) and the metal layer (3), in which a pore structure is formed on the inner surface of the ceramic layer (1), the depth of the pore structure being smaller than the thickness of the alumina ceramic pot body. It is generally considered necessary to avoid using a metal shovel when using a pot, and to avoid using a metal brush when cleaning.

[0003] The applicant has already filed a patent application for an electric grill, with application number CN2023232150967, and application number CN2024117012902, which is the applicant's method for manufacturing a non-stick pan, but does not involve nitride coating. Polygonal hole non-stick pans with silicon nitride or chromium nitride layers or nano-structures have better application effects.

[0004] Silicon nitride, chromium nitride, and titanium nitride layers have good physical and chemical properties, excellent heat resistance, and good strength and wear resistance, but they are not currently used in non-stick pans.

[0005] Currently, the stainless steel pot body cannot maintain its original color when used, and the poor anti-stick properties are important requirements for the application of the pot. Summary of the Invention [Problem to be solved by the invention]

[0006] To solve the above problems, the purpose of this invention is to provide a non-stick pan that is coated with a nitride such as silicon nitride, titanium nitride, or chromium nitride, titanium nitride, etc., mainly to achieve a non-stick effect and prevent the pan body from yellowing. [Means for solving the problem]

[0007] The technical solution of this invention is a silicon nitride or chromium nitride layer non-stick pan, in which a silicon nitride, chromium nitride, aluminum nitride or titanium nitride layer is evenly distributed on the food contact surface of the metal pan body, and the thickness of the silicon nitride, chromium nitride, aluminum nitride or titanium nitride layer is 0.02 μm to 100 μm.

[0008] Furthermore, the metal pot body is provided with a nano-structured pore distribution.

[0009] Furthermore, the thickness of the silicon nitride, chromium nitride, aluminum nitride or titanium nitride layer coated by PVD is 0.05 μm to 15 μm.

[0010] The pot body may first adopt a titanium carbonitride film as a base layer, that is, coated with 0.02 to 0.1 microns by PVD.

[0011] Furthermore, the metal pot body is provided with uniformly distributed elliptical or polygonal recesses, the maximum dimension within the elliptical or polygonal recesses is 0.3 to 1.2 mm, and the dimension of the protrusions between the elliptical or polygonal holes is 0.1 to 0.6 mm. The uniformly distributed elliptical or polygonal recesses are coated with a silicon nitride or chromium nitride layer, and the aluminum nitride or titanium nitride has good thermal conductivity, resulting in an even more effective pot product.

[0012] Furthermore, the pits are in a parallel array or a staggered array, and the pit depth dimension is 0.2 to 0.5 mm.

[0013] The silicon nitride or chromium nitride layer is coated on the stainless steel pot body using techniques such as PVD.

[0014] The pot is divided into a number of small areas, each of which has oval or polygonal holes distributed therein.

[0015] The total area of ​​the elliptical or polygonal holes accounts for more than 50% of the total area.

[0016] The direction of the small area elliptical or polygonal holes is perpendicular to the direction of the adjacent elliptical or polygonal holes.

[0017] An aluminum heat-conducting layer may be combined with the lower part of the stainless steel pot body.

[0018] The longitudinal cross section of the elliptical or polygonal recess is wavy.

[0019] The pitch of the polygonal holes is large, and the area of ​​the protruding portions of the ribs is smaller than the recessed areas thereof, making them easy to process. The maximum dimension of the highest point of the protrusion between adjacent polygonal holes and the lowest point of the recessed arc of the polygonal holes is 500 microns or less. [Effects of the Invention]

[0020] The beneficial effects of this invention are as follows: The pot body is coated with a silicon nitride, chromium nitride, aluminum nitride, or titanium nitride layer primarily via PVD. The polygonal and circular pore arrays allow for the deposition of a large number of dispersed nanoparticle pore arrays. The nanopores allow for the change of contact area between the food and the pot body, allowing oil and moisture to be retained within the pores, reducing the amount of heat directly transferred from the pot body to the food and preventing overheating and burning. Non-stick pots incorporating this nitride maintain the original stainless steel color for extended periods of use, exhibiting excellent non-stick properties and easy cleaning. The retained oil and moisture are trapped in the pores and also by surface tension, resulting in unexpectedly excellent non-stick properties. These features and advantages of the invention are described in detail in the following specific embodiments and drawings. [Brief explanation of the drawings]

[0021] [Figure 1] 3 is a schematic diagram showing the high-density arrangement distribution of rectangular recesses in a pot body according to an embodiment of the present invention; [Figure 2] 3 is a schematic diagram showing the distribution of hexagonal recesses in a pot body according to an embodiment of the present invention; [Figure 3] 1 is a structural diagram showing a cross section of a pot body according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will now be further described with reference to the drawings, which set forth in detail embodiments of the present invention, examples of which are illustrated in the drawings, wherein like or similar reference numerals refer to like elements throughout.

[0023] Manufacturing a non-stick pan using a coated metal: PVD (magnetic sputtering) is used on the surface of the pan, and the pan body in Figures 1 and 2 is stainless steel 2. This embodiment relates to the application of a coating of silicon nitride, titanium nitride, or chromium nitride or titanium nitride rolled onto the non-stick pan body, preferably with uniformly distributed polygonal holes 1 of uniform depth, and the polygonal holes may be distributed more densely at the bottom of the pan than at the rim of the pan. All protrusions 2 are formed between adjacent polygonal holes. The pan body is treated by surface cleaning, magnetron sputtering, or multi-arc sputtering to coat the pan body with a silicon nitride, titanium nitride, chromium nitride, or titanium nitride coating, and then a metal target material is used in a nitrogen atmosphere to coat the surface of the pan body with silicon nitride, chromium nitride, aluminum nitride, or titanium nitride.

[0024] According to the following examples, high-purity silicon nitride or chromium nitride, aluminum nitride or titanium nitride target material is manufactured, and the target material is heated and evaporated, and the vapor is condensed on the substrate surface to form a film. Methods include electron beam evaporation, resistance evaporation, arc evaporation, laser evaporation, etc., or high-energy particles are used to bombard the target material, sputtering the target material and depositing it on the surface of the workpiece.

[0025] PVD uses vacuum deposition plating, magnetron sputtering, in which ions bombard the target material and sputter particles, resulting in a coating with high density and adhesion strength, superior chemical stability, corrosion resistance, and no heavy metal contamination compared to traditional electroplating. The thickness of the film can be adjusted by the time of vacuum deposition. The thickness of aluminum nitride, titanium nitride, silicon nitride, or chromium nitride can be 0.02μm, 0.05μm, 0.2μm, 1μm, 2μm, 3μm, 4μm, etc., with similar results. Generally, a thickness of 15μm or less is sufficient to achieve a certain effect.

[0026] The metal pot body is provided with a nano-structured pore distribution. Refer to the applicant's method for manufacturing nano-structured pores for a non-stick pot in CN2024117012902. The pot body is coated with a titanium carbonitride film as a base layer, i.e., 0.02-0.1 microns thick, by PVD.

[0027] After forming a nano-structured pore distribution in the metal pot body, further PVD plating is performed. The nano-structured pore distribution may be achieved using a non-stick pot including a metal pot body coated with a silicon nitride or chromium nitride layer, or a silicon nitride or chromium nitride layer with nano-structured polygonal pores, as previously described in the present application. The polygonal pores are uniformly distributed on the food contact surface of the metal pot body, and the polygonal pores on the surface including the stainless steel layer are in a parallel or radial array. In particular, the pot is divided into multiple small areas, and the polygonal pores in each small area are in a parallel line array. The area of ​​each small area may be 20 to 100 square centimeters. If not divided into small areas, the polygonal pores may be in a concentric circle structure.

[0028] The longitudinal cross section of the polygonal holes is wavy, the maximum dimension within the elliptical or polygonal holes may be 0.3 to 1.2 mm, the polygonal hole pitch (rib width between polygonal holes) dimension is 0.1 to 0.6 mm, preferably 0.3 to 0.5 mm, and the polygonal hole depth dimension is 0.2 to 0.5 mm, particularly 0.3 to 0.4 mm.

[0029] In another solution, the rib width of the polygonal hole can be 300, 400, or 500 microns. A mold made of cemented carbide is pressed into the polygonal hole by a pressure device, and the resulting polygonal hole and pot body both have a hardened layer structure. A mold with uniformly distributed convex ribs is made of cemented carbide and pressed into the pot body plate material to achieve a uniform polygonal hole distribution in the pot body.

[0030] The total area of ​​the polygonal holes is relatively large, generally more than 50% of the total area, which not only ensures the physical non-stick properties of the entire non-stick pan, but also ensures the service life of the pan.

[0031] A silicon nitride, chromium nitride, aluminum nitride or titanium nitride layer is used to provide the surface of the pan body, i.e. the surface that comes into contact with the food.

[0032] One of the key points of this application is that the area for lifting food (protrusions) should account for 30-50% of the total area of ​​the pot body (pot bottom), especially 30-45%, providing excellent anti-stick performance. After spraying ions onto the pot, the surface can be further polished (grinded), polished, etc. to reduce the roughness of the inner surface of the pot body, reducing the friction between the food and the inner surface of the pot body, making it easier to shovel when frying, and the anti-stick effect basically reaches the same level as the application of new PTFE Teflon coating. The manufacturing cost is particularly low, half the manufacturing cost of other functional anti-stick pots.

[0033] The pot body plate material has a concave pot shape, which is formed by pressing a flat plate using a hydraulic press. A pot handle is attached to the pot body. When a composite material pot body is used, a composite of stainless steel and an aluminum layer is used, with the stainless steel being approximately 0.5 to 1 mm thick and the aluminum layer being approximately 1.5 mm thick. The composite stainless steel and aluminum plate may be pressed or exploded. The pot body plate material has a concave pot shape, which is formed by pressing a flat plate using a hydraulic press. A pot handle is attached to the pot body.

[0034] Manufacturing polygonal holes: A mold with uniform polygonal hole protrusions is used in the alloy mold, and polygonal holes are formed by pressing the surface of the titanium aluminum pot using the mold and pressing equipment. Polygonal hole molds can also be manufactured by electrochemical methods.

[0035] Polygonal hole arrays such as triangular, rectangular, square, pentagonal, hexagonal, and octagonal holes, and nanopores can be manufactured by etching or stamping. Nanopores are particularly manufactured by abrasive grain compression, with the abrasive grain size being on the nanometer scale of 30 to 300 nm (500 nm is also possible). This application is applicable not only to various cooking pots, but also to electric grills and rice cookers.

[0036] In the application to an electric grill, the electric grill comprises an upper heating plate, a lower heating plate, a pan body, a pan surface, and a heat-generating assembly, the heat-generating assembly is disposed inside the pan body of the upper heating plate and / or the lower heating plate, the upper and lower heating plates are respectively attached to an upper lid and a base, and the pan surfaces of the upper and lower heating plates that come into contact with food are the silicon nitride, chromium nitride, aluminum nitride, or titanium nitride layer nano-microstructured polygonal hole non-stick pans.

[0037] Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are illustrative and should not be construed as limiting the present invention, and that those skilled in the art may 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 silicon nitride or chromium nitride layer non-stick pan, characterized in that the silicon nitride, chromium nitride, aluminum nitride or titanium nitride layer is uniformly distributed on the food contact surface of the metal pan body, and the silicon nitride, chromium nitride, aluminum nitride or titanium nitride layer has a thickness of 0.02 μm to 100 μm.

2. The non-stick pan with silicon nitride or chromium nitride layer according to claim 1, characterized in that the metal pan body is provided with a nano-fine structured pore distribution.

3. The non-stick pan with silicon nitride or chromium nitride layer according to claim 1, characterized in that the thickness of the silicon nitride, chromium nitride, aluminum nitride or titanium nitride layer coated by PVD is 0.05 μm to 15 μm.

4. The non-stick pan with silicon nitride or chromium nitride layer according to any one of claims 1 to 3, characterized in that the pan body adopts a titanium carbonitride film as a base layer, and is coated with a thickness of 0.02 to 0.1 microns by PVD.

5. The non-stick pan with silicon nitride or chromium nitride layer according to claim 1, characterized in that the metal pan body is provided with uniformly distributed elliptical or polygonal recesses, the maximum dimension within the elliptical or polygonal recesses is 0.3-1.2 mm, the dimension of the protrusions between the elliptical or polygonal recesses is 0.1-0.6 mm, and the uniformly distributed elliptical or polygonal recesses are coated with a silicon nitride or chromium nitride layer.

6. The non-stick pan with silicon nitride or chromium nitride layer according to claim 5, characterized in that the recesses are in a parallel array or a staggered array, and the dimension of the hole depth is 0.2-0.5 mm.

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