Metal shell assembly and preparation method and application thereof

Abstract

The invention discloses a metal shell assembly and a preparation method and application thereof. Wherein the metal shell assembly comprises a metal substrate layer and a passivation layer, the passivation layer is attached to at least part of the surface of the metal substrate layer through a polymeric crystal, the structural formula of the polymeric crystal is as shown in the formula I: # imgabs0 #, n1 is equal to 16, and R1 is saturated or unsaturated C16 alkyl. According to the invention, the adhesive force of the passivation layer to the metal substrate layer and the compactness of the passivation layer are improved, so that the external erosion resistance of the passivation layer can be improved, the condition that the metal shell assembly is oxidized and rusted due to external erosion is avoided, and the rust resistance, oxidation resistance and yellowing resistance of the metal shell assembly are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of household appliances, and particularly relates to a metal shell assembly, a preparation method thereof, and an application thereof. Background Art

[0002] In the field of household appliances, most of the lids of rice cookers and pressure cookers currently adopt stainless steel materials. Under normal circumstances, stainless steel has a relatively high chromium content and has very excellent high-temperature resistance and oxidation resistance, and it is not easy to rust. However, during the process of making the stainless steel into a lid, it is necessary to perform a stretching operation on the stainless steel to make it into a lid with the required shape. During the stretching process, the surface state of the stainless steel is often damaged, such as scratched and abraded, resulting in the exposure of iron elements in the stainless steel on the surface of the stainless steel. If the stainless steel product is placed in a humid environment or an environment with a high iron oxide content for a long time, the iron elements on the surface of the stainless steel product will react with oxygen in the environment, resulting in the easy corrosion of the stainless steel surface and rusting. Therefore, it is necessary to further improve the existing stainless steel lids. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to some extent. For this reason, the object of the present invention is to provide a metal shell assembly, a preparation method thereof, and an application thereof. The present invention improves the adhesion of the passivation layer to the metal base layer and the compactness of the passivation layer, thereby improving the ability of the passivation layer to resist external erosion, avoiding the oxidation and rusting of the metal shell assembly due to external erosion, and thus improving the rust prevention, oxidation resistance, and yellowing resistance of the metal shell assembly.

[0004] In one aspect of the present invention, a metal shell assembly is provided. According to an embodiment of the present invention, the metal shell assembly includes:

[0005] A metal base layer;

[0006] A passivation layer, the passivation layer is attached to at least a part of the surface of the metal base layer through polymer crystals, and the structural formula of the polymer crystals is shown in Formula I:

[0007]

[0008] Wherein, n 1 = 16, R 1 is a saturated or unsaturated C 16 hydrocarbon group.

[0009] The metal shell assembly according to an embodiment of the present invention has a polymeric crystal (whose structural formula is shown in Formula I) between the metal base layer and the passivation layer. This polymeric crystal can help the passivation layer tightly adhere to at least part of the surface of the metal base layer, improving the adhesion between the passivation layer and the metal base layer. Thus, the adhesion of the passivation layer to the metal base layer and the compactness of the passivation layer are enhanced. As a result, the passivation layer is not easily detached from the metal base layer and is not easily penetrated, improving the ability of the passivation layer to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment), avoiding the oxidation and rusting of the metal shell assembly due to external erosion, and thereby improving the rust prevention, anti-oxidation, and anti-yellowing properties of the metal shell assembly.

[0010] In addition, the metal shell assembly according to the above embodiment of the present invention may further have the following additional technical features:

[0011] In some embodiments of the present invention, the polymeric crystal is dispersed in a particulate state between the metal base layer and the passivation layer.

[0012] In some embodiments of the present invention, the particle size of the polymeric crystal is not greater than 1 μm.

[0013] In some embodiments of the present invention, the thickness of the passivation layer is not greater than 1 μm.

[0014] In some embodiments of the present invention, the passivation layer includes a compound shown in Formula II;

[0015]

[0016] where n 2 = 16, and R 2 is a saturated or unsaturated C 16 hydrocarbyl group.

[0017] In some embodiments of the present invention, the metal base layer contains iron element; and / or, the metal base layer includes stainless steel.

[0018] In the second aspect of the present invention, the present invention provides a method for preparing the metal shell assembly of the above embodiments. According to an embodiment of the present invention, the method includes:

[0019] Bringing the metal base layer into contact with a passivation solution so as to form a passivation layer on at least part of the surface of the metal base layer, and a polymeric crystal is formed between the metal base layer and the passivation layer. The passivation layer adheres to at least part of the surface of the metal base layer through the polymeric crystal, and the structural formula of the polymeric crystal is shown in Formula I:

[0020]

[0021] wherein, n 1 = 16, R 1 is a saturated or unsaturated C 16 hydrocarbyl group.

[0022] According to the method for preparing a metal shell assembly of an embodiment of the present invention, a passivation layer including the compound shown in Formula II is formed on at least a part of the surface of the metal base layer, and a polymeric crystal (the structural formula of which is shown in Formula I) is formed between the metal base layer and the passivation layer. This polymeric crystal can help the passivation layer adhere tightly to at least a part of the surface of the metal base layer, improving the adhesion between the passivation layer and the metal base layer, thereby enhancing the adhesion of the passivation layer to the metal base layer and the compactness of the passivation layer. As a result, the passivation layer is not easily detached from the metal base layer, and the passivation layer is not easily penetrated, improving the ability of the passivation layer to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment), avoiding the oxidation and rusting of the metal shell assembly due to external erosion, and thus improving the rust prevention, antioxidant, and anti-yellowing properties of the metal shell assembly.

[0023] In addition, the method according to the above embodiment of the present invention may further have the following additional technical features:

[0024] In some embodiments of the present invention, the passivation solution includes hydrogen peroxide, phytic acid, fatty alcohol polyoxyethylene ether, and water. Based on the total mass of the passivation solution, the mass concentration of hydrogen peroxide is 4% - 7%, the mass concentration of phytic acid is 5% - 10%, and the mass concentration of fatty alcohol polyoxyethylene ether is 5% - 10%.

[0025] In some embodiments of the present invention, the ratio of the mass concentration of phytic acid to the mass concentration of fatty alcohol polyoxyethylene ether is 1:(0.8 - 1.2).

[0026] In some embodiments of the present invention, based on the total mass of the passivation solution, the mass concentration of hydrogen peroxide is 5%, the mass concentration of phytic acid is 10%, and the mass concentration of fatty alcohol polyoxyethylene ether is 10%.

[0027] In some embodiments of the present invention, before bringing the metal base layer into contact with the passivation solution, the method further includes: cleaning the original metal base layer with a cleaning solution to remove contaminants on the surface of the original metal base layer, thereby obtaining the metal base layer.

[0028] In some embodiments of the present invention, the cleaning solution includes a mixed solution of sodium molybdate and sodium dodecylsulfonate. Based on the total mass of the cleaning solution, the mass concentration of sodium molybdate is 3% - 5%, and the mass concentration of sodium dodecylsulfonate is 3% - 5%; and / or, the temperature for cleaning is 50°C - 60°C, and the cleaning time is 5 min - 20 min.

[0029] In the third aspect of the present invention, the present invention provides a cover body. According to an embodiment of the present invention, the cover body includes the metal shell assembly described in the above embodiments or the metal shell assembly prepared by the method described in the above embodiments. Thereby, the ability of the cover body to resist external erosion is improved, and the situation of oxidation and rust of the cover body due to external erosion is avoided, thus improving the rust prevention, antioxidant and anti-yellowing properties of the cover body.

[0030] In the fourth aspect of the present invention, the present invention provides a cooking device. According to an embodiment of the present invention, the cooking device has the cover body of the above embodiments. Thereby, the ability of the cooking device to resist external erosion is improved, and the situation of oxidation and rust of the cooking device due to external erosion is avoided, thus improving the rust prevention, antioxidant and anti-yellowing properties of the cooking device.

[0031] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 SEM electron micrograph of the metal shell assembly prepared in Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0035] In one aspect of the present invention, the present invention provides a metal shell assembly. According to an embodiment of the present invention, the metal shell assembly includes: a metal base layer; a passivation layer, the passivation layer is attached to at least part of the surface of the metal base layer through polymer crystals, and the structural formula of the polymer crystals is shown in Formula I:

[0036]

[0037] Wherein, n 1 = 16, R 1 is a saturated or unsaturated C 16 hydrocarbon group. Its molecular formula is C 54 O 48 P 6 H 106 F.

[0038] Therefore, the present invention improves the adhesion of the passivation layer to the metal base layer and the compactness of the passivation layer, thereby improving the ability of the passivation layer to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment), avoiding the oxidation and rusting of the metal shell component due to external erosion, and thus improving the rust prevention, anti-oxidation and anti-yellowing properties of the metal shell component.

[0039] The principle by which the metal shell component proposed by the present invention can achieve the above beneficial effects will be described in detail below:

[0040] In the related art, during the process of making a stainless steel pot lid, it is necessary to perform a stretching operation on the stainless steel to make it into a pot lid of the required shape. During the stretching process, the surface state of the stainless steel is often damaged, such as scratched and abraded, resulting in the exposure of iron elements in the stainless steel on the surface of the stainless steel. If the stainless steel product is placed in a humid environment or an environment with a high iron oxide content for a long time, the iron elements on the surface of the stainless steel product will react with oxygen in the environment, resulting in the easy corrosion of the stainless steel surface and the occurrence of rust. Therefore, it is necessary to further improve the existing stainless steel pot lid. In addition, in the related art, a passivation solution mainly composed of citric acid is often used. The cleaning effect of this passivation solution is strong, but the passivation layer formed by adhering this passivation solution to the substrate has poor stability under high pressure. The inventor has found through research that the main reasons for the poor stability of the passivation layer under high pressure are the poor adhesion between the passivation layer adhering to the substrate surface and the substrate and the poor compactness of the passivation layer.

[0041] To solve the above problems, the present invention provides a new type of metal shell component, including a metal base layer and a passivation layer, and there is also a polymeric crystal (whose structural formula is shown in Formula I) between the metal base layer and the passivation layer. This polymeric crystal can help the passivation layer tightly adhere to at least part of the surface of the metal base layer, improving the bonding force between the passivation layer and the metal base layer, thereby improving the adhesion of the passivation layer to the metal base layer and the compactness of the passivation layer. Thus, the passivation layer is not easily detached from the metal base layer, and the passivation layer is not easily penetrated, improving the ability of the passivation layer to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment), avoiding the oxidation and rusting of the metal shell component due to external erosion, and thus improving the rust prevention, anti-oxidation and anti-yellowing properties of the metal shell component.

[0042] According to some specific embodiments of the present invention, such as Figure 1As shown, the polymeric crystals can be dispersed in a particulate state between the metal base layer and the passivation layer, and the polymeric crystals in particulate state further improve the adhesion between the passivation layer and the metal base layer and the compactness of the passivation layer. Further, the above-mentioned polymeric crystals are white crystals, and their decomposition temperature is above 380 degrees. Since the passivation layer is generally a transparent film layer, the white polymeric crystal particles can be clearly seen through the transparent passivation layer from the electron micrograph of the metal shell assembly.

[0043] According to some further specific embodiments of the present invention, the particle size of the polymeric crystals can be not more than 1 μm. Thus, the polymeric crystals within this particle size range further improve the adhesion between the passivation layer and the metal base layer and the compactness of the passivation layer.

[0044] In the embodiments of the present invention, the specific material of the above-mentioned metal base layer is not particularly limited as long as it contains a certain amount of iron element. During the process of forming the passivation layer by placing the metal base layer in the passivation solution, the free iron element on the surface of the metal base layer will form polymeric crystals (whose structural formula is as shown in Formula I) with the passivation solution and adhere to the surface of the metal base layer. As a specific example, the above-mentioned metal base layer is stainless steel (such as 430 stainless steel), and the stainless steel contains a certain amount of iron element.

[0045] According to some other specific embodiments of the present invention, the passivation layer comprises a compound shown in Formula II;

[0046]

[0047] wherein, n 2 = 16, and R 2 is a saturated or unsaturated C 16 hydrocarbon group. The passivation layer is formed by the reaction of the passivation solution during the process of placing the metal base layer in the passivation solution. The passivation layer comprising the compound shown in Formula II adheres to at least part of the surface of the metal base layer through polymeric crystals (whose structural formula is as shown in Formula I). Thus, the adhesion between the passivation layer and the metal base layer and the compactness of the passivation layer are further improved, and the ability of the passivation layer to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment) is improved.

[0048] According to some other specific embodiments of the present invention, the thickness of the passivation layer can be not more than 1 μm, for example, it can be 1 μm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, etc. By limiting the thickness of the passivation layer within the above range, the ability of the passivation layer to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment) is further improved.

[0049] In the second aspect of the present invention, the present invention provides a method for preparing the metal shell assembly of the above embodiments. According to the embodiments of the present invention, the method includes:

[0050] Bringing the metal base layer into contact with a passivation solution so as to form a passivation layer on at least part of the surface of the metal base layer, and there is a polymer crystal formed between the metal base layer and the passivation layer, and the passivation layer is attached to at least part of the surface of the metal base layer through the polymer crystal. The structural formula of the polymer crystal is shown in Formula I:

[0051]

[0052] wherein, n 1 = 16, and R 1 is a saturated or unsaturated C 16 hydrocarbon group. Specifically, the polymer crystal is dispersed in a particulate state between the metal base layer and the passivation layer.

[0053] Specifically, the metal base layer can be immersed in the passivation solution for 2 min - 3 min, and the passivation layer and the polymer crystal can be formed at room temperature.

[0054] In the embodiments of the present invention, the passivation solution includes hydrogen peroxide, phytic acid, fatty alcohol polyoxyethylene ether and water. During the process of forming the passivation layer by placing the metal base layer in the passivation solution, the free iron element on the surface of the metal base layer reacts with phytic acid and fatty alcohol polyoxyethylene ether in the passivation solution under the action of the catalyst hydrogen peroxide to form a polymer crystal, which adheres to the surface of the metal base layer. The reaction equation is as follows:

[0055]

[0056] wherein, n = 16, and R is a saturated or unsaturated C 16 hydrocarbon group.

[0057] Meanwhile, phytic acid and fatty alcohol polyoxyethylene ether in the passivation solution also react with each other to form a passivation layer including the compound shown in Formula II. The reaction equation is as follows:

[0058]

[0059] wherein, n = 16, and R is a saturated or unsaturated C 16 hydrocarbon group.

[0060] According to some specific embodiments of the present invention, based on the total mass of the passivation solution, the mass concentration of hydrogen peroxide can be 4% - 7% (for example, it can be 4%, 5%, 6%, 7%, etc.), the mass concentration of phytic acid can be 5% - 10% (for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, etc.), and the mass concentration of fatty alcohol polyoxyethylene ether can be 5% - 10% (for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, etc.). By limiting the mass concentrations of hydrogen peroxide, phytic acid, and fatty alcohol polyoxyethylene ether within the above ranges, the properties of the passivation layer and the polymeric crystals formed by the reaction are relatively excellent, the protective effect on the metal base layer is good, it is not easy to rust, and the appearance of the formed passivation layer is relatively excellent and not easy to turn yellow.

[0061] Preferably, the mass concentration of hydrogen peroxide can be 4% - 6%, the mass concentration of phytic acid is 8% - 10%, and the mass concentration of fatty alcohol polyoxyethylene ether is 8% - 10%. Most preferably, based on the total mass of the passivation solution, the mass concentration of hydrogen peroxide is 5%, the mass concentration of phytic acid is 10%, and the mass concentration of fatty alcohol polyoxyethylene ether is 10%.

[0062] According to some other specific embodiments of the present invention, the ratio of the mass concentration of phytic acid to the mass concentration of fatty alcohol polyoxyethylene ether can be 1:(0.8 - 1.2). By limiting the ratio of the mass concentration of phytic acid to the mass concentration of fatty alcohol polyoxyethylene ether within the above range, the properties of the passivation layer and the polymeric crystals formed by the reaction are relatively excellent, the protective effect on the metal base layer is good, it is not easy to rust, and the appearance of the formed passivation layer is relatively excellent and not easy to turn yellow. Preferably, the ratio of the mass concentration of phytic acid to the mass concentration of fatty alcohol polyoxyethylene ether can be 1:1.

[0063] According to some other specific embodiments of the present invention, before bringing the metal base layer into contact with the passivation solution, the method further includes:

[0064] Cleaning the original metal base layer with a cleaning solution to remove contaminants on the surface of the original metal base layer, obtaining the metal base layer, which is beneficial for the passivation layer and the polymeric crystals to better adhere to the surface of the metal base layer, further improving the adhesion between the passivation layer and the metal base layer and the compactness of the passivation layer.

[0065] According to some other specific embodiments of the present invention, the cleaning solution can include a mixed solution of sodium molybdate and sodium dodecylsulfonate. Based on the total mass of the cleaning solution, the mass concentration of sodium molybdate can be 3% - 5% (for example, it can be 3%, 4%, 5%, etc.), and the mass concentration of sodium dodecylsulfonate can be 3% - 5% (for example, it can be 3%, 4%, 5%, etc.). The above cleaning solution has a better cleaning effect on the original metal base layer and can also avoid damaging the metal base layer, which is further beneficial for the passivation layer and the polymeric crystals to better adhere to the surface of the metal base layer.

[0066] Further, the temperature for cleaning can be 50°C - 60°C (such as 50°C, 52°C, 54°C, 55°C, 56°C, 58°C, 60°C, etc.), and the cleaning time can be 5 min - 20 min (such as 5 min, 8 min, 10 min, 12 min, 15 min, 18 min, 20 min, etc.).

[0067] According to the method for preparing a metal shell assembly of an embodiment of the present invention, a passivation layer including the compound shown in Formula II is formed on at least a part of the surface of the metal base layer, and a polymeric crystal (the structural formula of which is shown in Formula I) is formed between the metal base layer and the passivation layer. This polymeric crystal can help the passivation layer tightly adhere to at least a part of the surface of the metal base layer, improving the adhesion between the passivation layer and the metal base layer, thereby enhancing the adhesion of the passivation layer to the metal base layer and the compactness of the passivation layer. As a result, the passivation layer is not easily detached from the metal base layer, and the passivation layer is not easily penetrated, improving the ability of the passivation layer to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment), avoiding the oxidation and rusting of the metal shell assembly due to external erosion, and thus improving the rust prevention, antioxidant, and anti-yellowing properties of the metal shell assembly.

[0068] In the third aspect of the present invention, the present invention provides a cover body. According to an embodiment of the present invention, the cover body includes the metal shell assembly described in the above embodiments or the metal shell assembly prepared by the method described in the above embodiments. Thereby, the ability of the cover body to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment) is improved, and the oxidation and rusting of the cover body due to external erosion are avoided, thus improving the rust prevention, antioxidant, and anti-yellowing properties of the cover body.

[0069] Specifically, the above cover body can be the cover body of a cooking device, such as the lid of a rice cooker, the lid of a pressure cooker, etc., or the lid of other cooking devices. The above metal shell assembly can be disposed on the inner side of the cover body of the cooking device, that is, the side in contact with the steam.

[0070] In the fourth aspect of the present invention, the present invention provides a cooking device. According to an embodiment of the present invention, the cooking device has the cover body of the above embodiments. Thereby, the ability of the cooking device to resist external erosion (such as high temperature, high pressure, steam, acid environment, salt environment) is improved, and the oxidation and rusting of the cooking device due to external erosion are avoided, thus improving the rust prevention, antioxidant, and anti-yellowing properties of the cooking device.

[0071] According to an embodiment of the present invention, there are no restrictive requirements on the specific type of the cooking device, and those skilled in the art can flexibly select according to actual needs. For example, the cooking device can be a rice cooker, a pressure cooker, a wok, a milk pan, an oven, or other cooking devices.

[0072] Embodiments of the present invention will be described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as a limitation of the present invention. Additionally, if not explicitly stated, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For the reaction conditions not listed, they are also easily obtainable by those skilled in the art.

[0073] Example 1

[0074] This example provides a metal shell assembly, and its preparation method includes:

[0075] 1) First, place the 430 stainless steel substrate in a cleaning solution of sodium molybdate and sodium dodecylsulfonate for deep cleaning. In the above cleaning solution, the mass concentrations of sodium molybdate and sodium dodecylsulfonate are both 3%, the cleaning temperature is 55 °C, and after cleaning for 5 minutes, bake and dry.

[0076] 2) Immerse the cleaned stainless steel substrate in the passivation solution for 3 minutes. Among them, the mass concentration of hydrogen peroxide is 5%, the mass concentration of phytic acid is 10%, and the mass concentration of fatty alcohol polyoxyethylene ether is 10%. The free iron elements on the surface of the metal base layer will react with phytic acid and fatty alcohol polyoxyethylene ether in the passivation solution under the action of the catalyst hydrogen peroxide to form polymer crystals. At the same time, phytic acid and fatty alcohol polyoxyethylene ether in the passivation solution also react with each other to form a passivation layer including the compound shown in Formula II.

[0077] After the reaction is completed, place the formed metal shell assembly for 1 hour, and then conduct electron microscopy observation. The results are as shown in the appendix Figure 1 It can be seen that a transparent passivation layer adheres to the surface of the stainless steel substrate, and white particles (i.e., the particles within the frame) adhere between the stainless steel substrate and the transparent passivation layer.

[0078] Test the components of the white particles and the transparent passivation layer respectively. After testing, it can be determined that the structural formula of the white particles is as shown in Formula I:

[0079]

[0080] Among them, n 1 = 16, R 1 is a saturated or unsaturated C 16 hydrocarbon group. Its molecular formula is C 54 O 48 P 6 H 106 F.

[0081] And the transparent passivation layer includes the compound shown in Formula II;

[0082]

[0083] Among them, n 2 = 16, R 2 is a saturated or unsaturated C 16 hydrocarbyl group.

[0084] Examples 2 - 18

[0085] The difference between Examples 2 - 18 and Example 1 lies only in the composition of the passivation solution. As shown in Table 1, other contents are the same as those in Example 1.

[0086] Table 1

[0087]

[0088] The metal shell components prepared in Examples 1 - 18 were respectively made into the lids of electric pressure cookers. Edible brine with a mass concentration of 1% was added to the inner pot of the electric pressure cooker to the maximum scale water level. The inner pot was placed in the electric pressure cooker and powered on to work in the aging mode (with the lid closed) for 24 hours as a cycle. The pressure of the electric pressure cooker was 70 kPa, and a total of 1 cycle was carried out. After the test, the rusting situation and appearance change of the passivation layer of the lid were observed and recorded. The results are shown in Table 2.

[0089] Judgment criteria for rusting situation:

[0090] No rust: No rust spots; Slight rust: The diameter of the rust spots does not exceed 1 mm; Severe rust: The diameter of the rust spots exceeds 1 mm.

[0091] Table 2

[0092]

[0093]

[0094] As can be seen from Table 2, when the mass concentrations of phytic acid and fatty alcohol polyoxyethylene ether are both in the range of 5% - 10%, and the mass concentration of hydrogen peroxide is in the range of 4% - 7%, the passivation layer of the lid does not rust, and the appearance is normal. When the mass concentrations of phytic acid and fatty alcohol polyoxyethylene ether are less than 5%, the passivation layer of the lid is prone to rust; when the mass concentrations of phytic acid and fatty alcohol polyoxyethylene ether are greater than 10%, the passivation film of the passivation layer of the lid is prone to turn yellow, and the appearance effect is not good.

[0095] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0096] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A metal shell component, characterized in that, it includes: a metal-based bottom layer; a passivation layer, the passivation layer is attached to at least part of the surface of the metal-based bottom layer through polymerized crystals, and the structural formula of the polymerized crystals is shown in Formula I: where n 1 = 16, and R 1 is a saturated or unsaturated C 16 hydrocarbyl group.

2. The metal shell component according to claim 1, characterized in that, the polymerized crystals are dispersed in a particulate state between the metal-based bottom layer and the passivation layer.

3. The metal shell component according to claim 2, characterized in that, the particle size of the polymerized crystals is not greater than 1 μm.

4. The metal shell component according to any one of claims 1-3, characterized in that, the thickness of the passivation layer is not greater than 1 μm.

5. The metal shell component according to any one of claims 1-3, characterized in that, the passivation layer includes a compound shown in Formula II; where n 2 = 16, and R 2 is a saturated or unsaturated C 16 hydrocarbyl group.

6. The metal shell component according to any one of claims 1-3, characterized in that, the metal-based bottom layer contains iron elements; and / or, the metal-based bottom layer includes stainless steel.

7. A method for preparing a metal shell component, characterized in that, it includes: bringing the metal-based bottom layer into contact with a passivation solution so as to form a passivation layer on at least part of the surface of the metal-based bottom layer, and polymerized crystals are formed between the metal-based bottom layer and the passivation layer, and the passivation layer is attached to at least part of the surface of the metal-based bottom layer through the polymerized crystals, and the structural formula of the polymerized crystals is shown in Formula I: where n 1 = 16, and R 1 is a saturated or unsaturated C 16 hydrocarbyl group.

8. The method according to claim 7, characterized in that, the passivation solution includes hydrogen peroxide, phytic acid, fatty alcohol polyoxyethylene ether and water. Based on the total mass of the passivation solution, the mass concentration of hydrogen peroxide is 4%-7%, the mass concentration of phytic acid is 5%-10%, and the mass concentration of fatty alcohol polyoxyethylene ether is 5%-10%.

9. The method according to claim 8, characterized in that, the ratio of the mass concentration of phytic acid to the mass concentration of fatty alcohol polyoxyethylene ether is 1:(0.8-1.2).

10. The method according to claim 8, characterized in that, based on the total mass of the passivation solution, the mass concentration of hydrogen peroxide is 5%, the mass concentration of phytic acid is 10%, and the mass concentration of fatty alcohol polyoxyethylene ether is 10%.

11. The method according to any one of claims 7-10, characterized in that, before bringing the metal-based bottom layer into contact with the passivation solution, the method further includes: cleaning the original metal-based bottom layer with a cleaning solution so as to remove contaminants on the surface of the original metal-based bottom layer to obtain the metal-based bottom layer.

12. The method according to claim 11, characterized in that, the cleaning solution includes a mixed solution of sodium molybdate and sodium dodecylsulfonate. Based on the total mass of the cleaning solution, the mass concentration of sodium molybdate is 3%-5%, and the mass concentration of sodium dodecylsulfonate is 3%-5%; and / or, the temperature for cleaning is 50°C-60°C, and the cleaning time is 5 min-20 min.

13. A cover body, characterized in that, Comprising the metal shell assembly according to any one of claims 1-6 or the metal shell assembly prepared by the method according to any one of claims 7-12.

14. A cooking device, characterized in that it comprises the cover body according to claim 13.

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