A method for making a non-stick pan with a wear-resistant antibacterial coating

Abstract

The application discloses a manufacturing method of a non-stick pot with wear-resistant and antibacterial coating, which comprises the following steps: S1, extruding an aluminum or aluminum alloy base material to form a non-stick pot blank; S2, placing the non-stick pot blank into a centrifugal steel shot machine, and performing a shot blasting roughening treatment by using silicon carbide ceramic as a shot, so that a concave-convex protruding structure is formed on the inner surface of the pot; S3, cleaning the non-stick pot blank, and then performing a hard anodic oxidation treatment and cleaning; and S4, performing a spraying operation of the wear-resistant and antibacterial coating on the inner surface of the non-stick pot blank, and then baking at a temperature of 320-410 DEG C for 10-20 min to obtain the non-stick pot with the wear-resistant and antibacterial coating. The non-stick pot prepared by the method has excellent bonding force between the coating material and the non-stick pot blank, and has good wear resistance, antibacterial property, thermal stability and chemical stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-stick pots, in particular to a non-stick pot with wear-resistant and antibacterial coating and a manufacturing method thereof. BACKGROUND

[0002] With the improvement of people's living standards, the requirements for kitchen utensils are getting higher and higher. Anti-sticking coating is widely used in daily kitchen utensils such as electric rice cookers, non-stick pots, range hoods and gas stoves due to its good anti-sticking performance and easy cleaning characteristics, and is favored by consumers.

[0003] The applicant previously disclosed a composite coating for a non-stick pot and a preparation method thereof, with a publication number of CN112961546B. An enamel coating is arranged between the non-stick layer and the substrate of the aluminum-based non-stick pot, and then a modified polytetrafluoroethylene layer is coated on the enamel coating, thereby improving the high-temperature resistance, thermal stability, chemical stability and wear resistance of the aluminum-based non-stick pot coating. The non-stick pot of the above patent document does not have antibacterial properties, and there is a lot of room for improvement in the overall performance of existing antibacterial non-stick pots. With the development of antibacterial and environmentally friendly cookware, the cookware industry is paying more and more attention to it. In view of this, it is urgent to provide a non-stick pot with wear-resistant and antibacterial coating to meet the use requirements and food safety requirements under high-temperature use conditions, and at the same time have the performance advantage of antibacterial properties. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a manufacturing method of a non-stick pot with wear-resistant and antibacterial coating to solve the problem that the surface coating of the existing aluminum-based non-stick pot has low adhesion with the non-stick pot blank, and the coating surface cannot simultaneously have the comprehensive properties of wear resistance, antibacterial properties, thermal stability and chemical stability.

[0005] To achieve the above purpose, the technical solution adopted by the present application is as follows:

[0006] A manufacturing method of a non-stick pot with wear-resistant and antibacterial coating, the manufacturing method comprising the following steps:

[0007] S1: extruding an aluminum or aluminum alloy substrate, and then performing pretreatment to obtain an aluminum-based non-stick pot blank;

[0008] S2: placing the aluminum-based non-stick pot blank treated in step S1 into a centrifugal steel shot machine, using silicon carbide ceramic as shot blasting, and performing shot blasting roughening treatment to form a rough structure on the inner surface of the pot body; the shot blasting roughening treatment is beneficial to the combination of the non-stick pot coating material and the blank.

[0009] S3: the aluminum-based non-stick pot blank body after step S2 is cleaned and then is subjected to hard anodizing treatment, and is cleaned for standby; the present application obtains an oxide film layer on the surface of the non-stick pot blank body by the hard anodizing treatment, the oxide film layer has a dense structure, has strong bonding force with the blank body, and is beneficial to the wet adhesion of the organic coating on the surface of the oxide film layer, so that the overall surface coating of the non-stick pot has good heat resistance, corrosion resistance and wear resistance.

[0010] S4: the inner surface of the aluminum-based non-stick pot blank body after step S3 is subjected to a spraying operation of a wear-resistant and antibacterial coating, is baked at a temperature of 320-410 ℃ for 10-20 min, and a non-stick pot with a wear-resistant and antibacterial coating is obtained.

[0011] Preferably, the pretreatment operation comprises at least one operation step of trimming, inverting the bottom angle, removing oil, hot re-punching, cold re-bottoming, pot bottom shaping or tungsten steel knife bottom shaping. The non-stick pot blank body after the extrusion molding is subjected to trimming, inverting the bottom angle, removing oil, hot re-punching, pot bottom shaping or tungsten steel knife bottom shaping, which are all conventional technical means in the field and will not be described here.

[0012] Preferably, the hard anodizing treatment is performed by using a sulfuric acid solution added with an organic acid to form an oxide film layer on the surface of the non-stick pot blank body. The hard anodizing treatment of the present application uses a sulfuric acid solution added with an organic acid, and the synergistic effect of the inorganic strong acid and the organic acid further improves the density and wettability of the oxide film layer.

[0013] Preferably, the organic acid is at least one of oxalic acid, sulfamic acid, tartaric acid, malic acid and ascorbic acid.

[0014] Preferably, the operation conditions of the hard anodizing treatment are as follows: the temperature is -5-7 ℃, the voltage is 60-100 V, the pulse power current density is 2.0-4.0 A / dm 2 , and the oxidation time is 30-80 min.

[0015] Preferably, the wear-resistant and antibacterial coating is a modified polytetrafluoroethylene coating with an interpenetrating network structure, which is prepared from raw materials including pyridinium salt modified polyimide and polytetrafluoroethylene. The modified polytetrafluoroethylene coating with an interpenetrating network structure of the present application is prepared from pyridinium salt modified polyimide and polytetrafluoroethylene, and the interpenetrating network structure has excellent heat resistance, chemical resistance and wear resistance; meanwhile, the introduction of the pyridinium functional group modifies the polyimide, so that the non-stick coating has long-lasting antibacterial performance.

[0016] Preferably, the pyridinium salt-modified polyimide is obtained by polycondensation and imidization reaction of hexafluorodianhydride and a diamine comprising fluorinated pyridinium salt diamine and ethylenediamine. The pyridinium salt-modified polyimide raw material of this application contains polyfluorinated hexafluorodianhydride and fluorinated pyridinium salt diamine. The introduction of a large number of fluorine atoms further ensures that the non-stick coating on the non-stick surface of the polytetrafluoroethylene film will not be reduced due to the introduction of the modifier, while also helping to ensure the wear resistance, thermal stability, and chemical stability of the non-stick coating.

[0017] Preferably, the fluorinated pyridinium salt diamine is obtained by a substitution reaction between a fluorinated pyridinium diamine and a long-chain bromoalkane. The fluorinated pyridinium salt diamine obtained in this application contains long-chain alkanes, which further improves the impact resistance and toughness of the non-stick cookware surface coating.

[0018] Preferably, the fluorinated pyridine diamine is at least one selected from 4-trifluoromethyl-2,6-pyridine diamine, 5-(trifluoromethyl)-2,3-pyridine diamine, 3-fluoro-5-methyl-2,6-pyridine diamine, 5-fluoro-2,3-pyridine diamine, 2-fluoro-3,4-pyridine diamine, 6-fluoro-3,4-pyridine diamine, 6-fluoro-2,3-pyridine diamine, 2,5,6-trifluoro-3,4-pyridine diamine, 3-fluoro-2,4-pyridine diamine, 3,5-difluoro-4-methyl-2,6-pyridine diamine, 2-fluoro-6-methoxy-3,5-pyridine diamine, and 3-fluoro-2,6-pyridine diamine.

[0019] Preferably, the long-chain bromoalkane is at least one of 1-bromooctane, bromoheptane, and bromohexane.

[0020] Preferably, the modified polytetrafluoroethylene coating with an interpenetrating network structure is prepared by first swelling polytetrafluoroethylene in ethylenediamine under the action of supercritical carbon dioxide, followed by the addition of hexafluorodianhydride for polycondensation. Simultaneously, during the reaction, fluorinated pyridinium salt diamine is added stepwise to participate in the polycondensation reaction. After the reaction is complete, an imidization reaction is carried out to finally obtain the modified polytetrafluoroethylene coating material with an interpenetrating network structure. This application utilizes the synergistic effect of ethylenediamine and supercritical carbon dioxide to more fully intertwine the pyridinium salt-modified polyimide and polytetrafluoroethylene into a cohesive whole, forming a coating with an interpenetrating network structure, thereby further improving the overall performance of the non-stick cookware coating of this application.

[0021] The beneficial effects of this invention are:

[0022] This invention relates to a method for manufacturing a wear-resistant and antibacterial non-stick pan. After the non-stick pan blank is extruded and formed, shot blasting and hard anodizing treatments are combined to improve the bonding force between the blank and the non-stick coating, so that the coating material is firmly bonded to the surface of the non-stick pan blank. In addition, the modified polytetrafluoroethylene coating with an interpenetrating network structure prepared from raw materials including pyridinium salt-modified polyimide and polytetrafluoroethylene gives the non-stick pan surface coating excellent comprehensive properties such as wear resistance, antibacterial properties, thermal stability, and chemical stability. Detailed Implementation

[0023] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0024] Example 1

[0025] This embodiment describes a method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating, the method comprising the following steps:

[0026] S1: Extruding aluminum or aluminum alloy substrates, followed by pre-treatment operations such as turning the opening, chamfering the bottom corners, degreasing, hot re-beating, shaping the bottom of the pot or turning the bottom shape with a tungsten carbide tool, to obtain an aluminum-based non-stick pot blank;

[0027] S2: Place the aluminum-based non-stick pan blank after step S1 into a centrifugal steel shot machine and use silicon carbide ceramic as shot blasting material to roughen it by shot blasting, so that an uneven raised structure is formed on the inner surface of the pan.

[0028] S3: After cleaning the aluminum-based non-stick pan blank processed in step S2, perform hard anodizing treatment to form an oxide film layer on the surface of the non-stick pan blank, and then clean it for later use. The hard anodizing treatment is carried out using a sulfuric acid solution with added aminosulfonic acid. The mass concentration of the sulfuric acid solution is 30%, and the mass ratio of aminosulfonic acid to sulfuric acid solution is 1:10. The operating conditions are as follows: temperature is 3℃, voltage is 80V, and pulse power supply current density is 3.0A / dm³. 2 The oxidation time is 60 min.

[0029] S4: A wear-resistant and antibacterial coating is sprayed onto the inner surface of the aluminum-based non-stick pan blank after step S3, and then baked at 320°C for 15 minutes to obtain the non-stick pan with the wear-resistant and antibacterial coating. The thickness of the coating is 25 μm.

[0030] This embodiment presents a wear-resistant and antibacterial coating, which is a modified polytetrafluoroethylene coating with an interpenetrating network structure. It is prepared from raw materials including pyridinium salt-modified polyimide and polytetrafluoroethylene. The specific preparation method includes the following steps: First, 200g of polytetrafluoroethylene is swollen in 100mL of ethylenediamine under the action of supercritical carbon dioxide (operating temperature 35℃, operating pressure 72.9atm). Then, hexafluorodianhydride is added for polycondensation. Simultaneously, during the reaction, fluorinated pyridinium salt diamine is added stepwise to participate in the polycondensation reaction. The molar ratio of ethylenediamine to hexafluorodianhydride and fluorinated pyridinium salt diamine is 4:2:1. After the reaction is completed for 3 hours, appropriate amounts of acetic anhydride and triethylamine are added as dehydrating agent and catalyst, respectively. Under normal pressure, the temperature is raised to 300℃ for an imidization reaction for 1 hour, finally obtaining the modified polytetrafluoroethylene coating material with an interpenetrating network structure.

[0031] In this embodiment, the fluoropyridinium salt diamine was obtained by a substitution reaction of 4-trifluoromethyl-2,6-pyridinium diamine and bromohexane in a molar ratio of 1:1.

[0032] Example 2

[0033] This embodiment describes a method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating, the method comprising the following steps:

[0034] S1: Extruding aluminum or aluminum alloy substrates, followed by pre-treatment operations such as turning the opening, chamfering the bottom corners, degreasing, hot re-beating, shaping the bottom of the pot or turning the bottom shape with a tungsten carbide tool, to obtain an aluminum-based non-stick pot blank;

[0035] S2: Place the aluminum-based non-stick pan blank after step S1 into a centrifugal steel shot machine and use silicon carbide ceramic as shot blasting material to roughen it by shot blasting, so that an uneven raised structure is formed on the inner surface of the pan.

[0036] S3: After cleaning the aluminum-based non-stick pan blank processed in step S2, perform hard anodizing treatment to form an oxide film layer on the surface of the non-stick pan blank, and then clean it for later use. The hard anodizing treatment is carried out using a sulfuric acid solution with added oxalic acid. The mass concentration of the sulfuric acid solution is 30%, and the mass ratio of oxalic acid to sulfuric acid solution is 1:8. The operating conditions are as follows: temperature is 3℃, voltage is 80V, and pulse power supply current density is 3.0A / dm³. 2 The oxidation time is 60 min.

[0037] S4: A wear-resistant and antibacterial coating is sprayed onto the inner surface of the aluminum-based non-stick pan blank after the treatment in step S3, and then baked at 360°C for 20 minutes to obtain the non-stick pan with the wear-resistant and antibacterial coating. The thickness of the coating is 30 μm.

[0038] This embodiment presents a wear-resistant and antibacterial coating, which is a modified polytetrafluoroethylene coating with an interpenetrating network structure. It is prepared from raw materials including pyridinium salt-modified polyimide and polytetrafluoroethylene. The specific preparation method includes the following steps: First, 200g of polytetrafluoroethylene is swollen in 120mL of ethylenediamine under the action of supercritical carbon dioxide (operating temperature 35℃, operating pressure 72.9atm). Then, hexafluorodianhydride is added for polycondensation. Simultaneously, during the reaction, fluorinated pyridinium salt diamine is added stepwise to participate in the polycondensation reaction. The molar ratio of ethylenediamine to hexafluorodianhydride and fluorinated pyridinium salt diamine is 7:3:2. After the reaction is completed for 3 hours, appropriate amounts of acetic anhydride and triethylamine are added as dehydrating agent and catalyst, respectively. Under normal pressure, the temperature is raised to 300℃ for an imidization reaction for 1 hour, finally obtaining the modified polytetrafluoroethylene coating material with an interpenetrating network structure.

[0039] In this embodiment, the fluoropyridinium salt diamine was obtained by a substitution reaction of 5-(trifluoromethyl)-2,3-pyridinium diamine and bromoheptane in a molar ratio of 1:1.05.

[0040] Example 3

[0041] This embodiment describes a method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating, the method comprising the following steps:

[0042] S1: Extruding aluminum or aluminum alloy substrates, followed by sequential pretreatment operations such as turning the opening, chamfering the bottom corners, degreasing, cold refinishing the bottom, shaping the bottom of the pot, or turning the bottom shape with a tungsten carbide tool, to obtain an aluminum-based non-stick pot blank;

[0043] S2: Place the aluminum-based non-stick pan blank after step S1 into a centrifugal steel shot machine and use silicon carbide ceramic as shot blasting material to roughen it by shot blasting, so that an uneven raised structure is formed on the inner surface of the pan.

[0044] S3: After cleaning the aluminum-based non-stick pan blank processed in step S2, perform hard anodizing treatment to form an oxide film layer on the surface of the non-stick pan blank, and then clean it for later use. The hard anodizing treatment is carried out using a sulfuric acid solution with added tartaric acid. The mass concentration of the sulfuric acid solution is 30%, and the mass ratio of tartaric acid to sulfuric acid solution is 1:12. The operating conditions are as follows: temperature is 3℃, voltage is 80V, and pulse power supply current density is 3.0A / dm³. 2 The oxidation time is 60 min.

[0045] S4: A wear-resistant and antibacterial coating is sprayed onto the inner surface of the aluminum-based non-stick pan blank after step S3, and then baked at 410°C for 30 minutes to obtain the non-stick pan with the wear-resistant and antibacterial coating. The thickness of the coating is 35 μm.

[0046] This embodiment presents a wear-resistant and antibacterial coating, which is a modified polytetrafluoroethylene coating with an interpenetrating network structure. It is prepared from raw materials including pyridinium salt-modified polyimide and polytetrafluoroethylene. The specific preparation method includes the following steps: First, 200g of polytetrafluoroethylene is swollen in 100mL of ethylenediamine under the action of supercritical carbon dioxide (operating temperature 35℃, operating pressure 72.9atm). Then, hexafluorodianhydride is added for polycondensation. Simultaneously, during the reaction, fluorinated pyridinium salt diamine is added stepwise to participate in the polycondensation reaction. The molar ratio of ethylenediamine to hexafluorodianhydride and fluorinated pyridinium salt diamine is 4:2:1. After the reaction is completed for 3 hours, appropriate amounts of acetic anhydride and triethylamine are added as dehydrating agent and catalyst, respectively. Under normal pressure, the temperature is raised to 300℃ for an imidization reaction for 1 hour, finally obtaining the modified polytetrafluoroethylene coating material with an interpenetrating network structure.

[0047] In this embodiment, the fluoropyridinium salt diamine was obtained by a substitution reaction of 3-fluoro-5-methyl-2,6-pyridinium diamine and 1-bromooctane in a molar ratio of 1:1.1.

[0048] Example 4

[0049] This embodiment describes a method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating. The coating materials and manufacturing steps are basically the same as in Embodiment 1. The difference is that in this embodiment, 2,5,6-trifluoro-3,4-pyridinediamine is used instead of 4-trifluoromethyl-2,6-pyridinediamine, and bromoheptane is used instead of bromohexane.

[0050] Example 5

[0051] This embodiment has a method for making a non-stick pan with a wear-resistant and antibacterial coating. The coating raw materials and manufacturing steps are basically the same as those in Embodiment 1. The difference is that in this embodiment, 2-fluoro-6-methoxy-3,5-pyridinediamine is used instead of 4-trifluoromethyl-2,6-pyridinediamine, and 1-bromooctane is used instead of bromohexane.

[0052] Example 6

[0053] This embodiment describes a method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating. The coating materials and manufacturing steps are basically the same as in Embodiment 1. The difference is that in this embodiment, 6-fluoro-3,4-pyridinediamine is used instead of 4-trifluoromethyl-2,6-pyridinediamine, and bromoheptane is used instead of bromohexane.

[0054] The non-stick pans with wear-resistant and antibacterial coatings prepared in Examples 1-6 were subjected to performance tests, and the performance results are shown in Tables 1 and 2:

[0055] Table 1

[0056]

[0057] Table 2

[0058]

[0059]

[0060] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating, characterized in that, The manufacturing method includes the following steps: S1: Extruding aluminum or aluminum alloy substrate and then performing pretreatment to obtain aluminum-based non-stick pan blank; S2: Place the aluminum-based non-stick pan blank after step S1 into a centrifugal steel shot machine and use silicon carbide ceramic as shot blasting material to roughen it by shot blasting, so that an uneven raised structure is formed on the inner surface of the pan. S3: After cleaning the aluminum-based non-stick pan blank processed in step S2, perform hard anodizing treatment and then clean it for later use. S4: Apply a wear-resistant and antibacterial coating to the inner surface of the aluminum-based non-stick pan blank after step S3, and bake it at 320-410℃ for 10-20 minutes to obtain the non-stick pan with wear-resistant and antibacterial coating. The wear-resistant and antibacterial coating is a modified polytetrafluoroethylene coating with an interpenetrating network structure, which is made from raw materials including pyridinium salt modified polyimide and polytetrafluoroethylene; the pyridinium salt modified polyimide is obtained by polycondensation and imidization reaction of hexafluorodianhydride and a diamine including fluorinated pyridinium salt diamine and ethylenediamine.

2. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 1, characterized in that, The pretreatment operation includes at least one of the following steps: machine mouth, chamfering, degreasing, hot re-beating, cold re-beating, pot bottom shaping, or tungsten carbide tool bottom shaping.

3. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 1, characterized in that, The hard anodizing process is performed using a sulfuric acid solution with added organic acids.

4. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 3, characterized in that, The organic acid is at least one of oxalic acid, aminosulfonic acid, tartaric acid, malic acid, and ascorbic acid.

5. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 1, characterized in that, The operating conditions for the hard anodizing treatment are: temperature -5 to 7°C, voltage 60 to 100V, and pulse power supply current density 2.0 to 4.0 A / dm³. 2 The oxidation time is 30–80 min.

6. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 1, characterized in that, The fluorinated pyridinium salt diamine is obtained by a substitution reaction between a fluorinated pyridinium diamine and a long-chain bromoalkane.

7. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 6, characterized in that, The fluorinated pyridine diamine is at least one selected from 4-trifluoromethyl-2,6-pyridine diamine, 5-(trifluoromethyl)-2,3-pyridine diamine, 3-fluoro-5-methyl-2,6-pyridine diamine, 5-fluoro-2,3-pyridine diamine, 2-fluoro-3,4-pyridine diamine, 6-fluoro-3,4-pyridine diamine, 6-fluoro-2,3-pyridine diamine, 2,5,6-trifluoro-3,4-pyridine diamine, 3-fluoro-2,4-pyridine diamine, 3,5-difluoro-4-methyl-2,6-pyridine diamine, 2-fluoro-6-methoxy-3,5-pyridine diamine, and 3-fluoro-2,6-pyridine diamine.

8. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 6, characterized in that, The long-chain bromoalkane is at least one of 1-bromooctane, bromoheptane, and bromohexane.

9. The method for manufacturing a non-stick pan with a wear-resistant and antibacterial coating as described in claim 1, characterized in that, The modified polytetrafluoroethylene coating with an interpenetrating network structure is first prepared by swelling polytetrafluoroethylene in ethylenediamine under the action of supercritical carbon dioxide, followed by the addition of hexafluorodianhydride for polycondensation reaction; simultaneously, fluorinated pyridinium salt diamine is added stepwise during the reaction to participate in the polycondensation reaction; after the reaction is completed, an imidization reaction is carried out to finally obtain the modified polytetrafluoroethylene coating material with an interpenetrating network structure.

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