Electrophoretic coating method

Abstract

The present invention relates to the field of electrophoretic technology, and more specifically, to a coating method for an electrophoretic component. The coating method comprises a mixing step: mixing a zirconizing agent, a borate, and a complexing agent in a mass ratio of (2-6): (1-4): 1 to obtain a zirconium-based conversion solution; and a zirconization step: immersing the electrophoretic component in the zirconium-based conversion solution to form a zirconized film on the surface of the electrophoretic component. The coating method comprises mixing a zirconizing agent, a borate, and a complexing agent in a mass ratio of (2-6): (1-4): 1 to obtain a zirconium-based conversion solution, and then immersing the electrophoretic component in the zirconium-based conversion solution to form a zirconized film with a dense structure on the surface of the electrophoretic component. The addition of the borate facilitates film formation and increases the density of the film, thereby strengthening the adhesion of the zirconized film to the surface of the electrophoretic component and reducing the risk of the zirconized film shedding, thereby helping the zirconized film enhance the corrosion resistance and wear resistance of the electrophoretic component.

Description

Technical Field

[0001] The present invention relates to the field of electrophoresis technology, and in particular to a coating method for an electrophoresis component. Background Art

[0002] Electrophoretic components require surface treatment prior to electrophoretic processing. Typically, a zirconium film is formed on the surface to improve the component's corrosion resistance and wear resistance. However, in related technologies, the zirconium film formed after soaking the component easily falls off, resulting in corrosion resistance and wear resistance that fail to meet application requirements. Therefore, a coating method for electrophoretic components is urgently needed. Summary of the Invention

[0003] In response to the above technical problems, the present invention provides a coating method for electrophoretic parts, which can form a zirconium film with a dense structure on the surface of the electrophoretic part, thereby enhancing its adhesion to the surface of the electrophoretic part and reducing the probability of the zirconium film falling off, thereby improving the corrosion resistance and wear resistance of the electrophoretic part.

[0004] An embodiment of the present invention provides a coating method for an electrophoretic element, the coating method comprising:

[0005] Mixing step: mixing the zirconating agent, borate and complexing agent in a mass ratio of (2-6): (1-4): 1 to obtain a zirconium-based conversion solution;

[0006] Zirconization process: immersing the electrophoretic element in the zirconium-based conversion solution to form a zirconization film on the surface of the electrophoretic element.

[0007] According to any of the aforementioned embodiments of the present invention, the mass ratio of the zirconizing agent, the borate and the complexing agent is (3-5): (2-3): 1.

[0008] According to any of the aforementioned embodiments of the present invention, the mass concentration of the zirconizing agent in the zirconium-based conversion solution is 0.8 g / L to 1.5 g / L.

[0009] According to any of the aforementioned embodiments of the present invention, the zirconizing agent includes fluorozirconate and / or fluorozirconic acid.

[0010] According to any of the aforementioned embodiments of the present invention, the fluorozirconate includes at least one of potassium fluorozirconate, sodium fluorozirconate and ammonium fluorozirconate.

[0011] According to any of the aforementioned embodiments of the present invention, the fluorozirconate includes potassium fluorozirconate and sodium fluorozirconate, and the mass ratio of the potassium fluorozirconate to the sodium fluorozirconate is (3-5):1.

[0012] According to any of the aforementioned embodiments of the present invention, the borate comprises at least one of sodium borate, potassium borate, potassium tetrafluoroborate and sodium tetrafluoroborate.

[0013] According to any of the aforementioned embodiments of the present invention, the complexing agent includes at least one of sodium citrate, sodium tartrate, sodium hexametaphosphate, sodium acetate, oxalic acid and sodium aminotricarboxylate.

[0014] According to any of the aforementioned embodiments of the present invention, the pH of the zirconium-based conversion solution is 4-5.

[0015] According to any of the aforementioned embodiments of the present invention, the electrophoretic element is immersed in the zirconium-based conversion solution for a time period of 5 min to 20 min.

[0016] An embodiment of the present invention provides a coating method for an electrophoretic component. The method comprises mixing a zirconizing agent, a borate, and a complexing agent in a mass ratio of (2-6): (1-4): 1 to obtain a zirconium-based conversion solution. The electrophoretic component is then immersed in the zirconium-based conversion solution to form a zirconized film with a dense structure on the surface of the electrophoretic component. The addition of the borate can facilitate film formation and increase the density of the film, thereby strengthening the adhesion of the zirconized film to the surface of the electrophoretic component and reducing the occurrence of zirconized film shedding, thereby helping the zirconized film enhance the corrosion resistance and wear resistance of the electrophoretic component. Therefore, the coating method for an electrophoretic component provided by an embodiment of the present invention can form a zirconized film with a dense structure on the surface of the electrophoretic component. This can enhance its adhesion to the surface of the electrophoretic component and further reduce the probability of zirconized film shedding, thereby improving the corrosion resistance and wear resistance of the electrophoretic component.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those skilled in the art by reading the detailed description of the preferred embodiment below. The accompanying drawings are only for the purpose of illustrating the preferred embodiment and are not to be considered as limiting the present invention. In the accompanying drawings:

[0019] Figure 1 A schematic flow chart of a coating method for an electrophoretic element provided in some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0020] The above summary of the invention is not intended to describe every disclosed embodiment or every implementation of the present invention. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided by a series of examples, which can be used in various combinations. In each example, the enumeration is intended only as a representative group and should not be construed as exhaustive.

[0021] In this article, the electrophoretic part refers to a workpiece to be processed whose surface is coated with electrophoretic technology. The workpiece to be processed can be a component for a vehicle or a metal component for other industrial fields.

[0022] See also Figure 1 As shown, an embodiment of the present invention provides a coating method for an electrophoretic element, and the coating method for an electrophoretic element includes:

[0023] S100, a mixing step of mixing a zirconating agent, a borate, and a complexing agent in a mass ratio of (2-6): (1-4): 1 to obtain a zirconium-based conversion solution;

[0024] S200 , a zirconization process, immersing the electrophoretic component in a zirconium-based conversion solution to form a zirconization film on the surface of the electrophoretic component.

[0025] The coating method for an electrophoretic component provided in an embodiment of the present invention comprises mixing a zirconizing agent, a borate, and a complexing agent in a mass ratio of (2-6): (1-4): 1 to obtain a zirconium-based conversion solution, and then immersing the electrophoretic component in the zirconium-based conversion solution to form a zirconized film with a dense structure on the surface of the electrophoretic component. The addition of the borate can facilitate film formation and increase the density of the film, thereby strengthening the adhesion of the zirconized film to the surface of the electrophoretic component, reducing the occurrence of zirconized film shedding, and thus helping the zirconized film enhance the corrosion resistance and wear resistance of the electrophoretic component. Therefore, the coating method for an electrophoretic component provided in an embodiment of the present invention can form a zirconized film with a dense structure on the surface of the electrophoretic component, thereby strengthening its adhesion to the surface of the electrophoretic component, and further reducing the probability of zirconized film shedding, thereby improving the corrosion resistance and wear resistance of the electrophoretic component.

[0026] In some possible embodiments of the present invention, the mass ratio of the zirconizing agent, borate, and complexing agent is (3-5):(2-3):1. Within this mass ratio range, the zirconizing agent, borate, and complexing agent can better cooperate with each other to further improve the density of the zirconized film and reduce its shedding, thereby further enhancing the corrosion resistance and wear resistance of the electrophoretic component.

[0027] For example, the mass ratio of the zirconizing agent, the borate and the complexing agent can be, but is not limited to, 2:1:1, 2:2:1, 3:2:1, 3:3:1, etc.

[0028] Furthermore, in the zirconium-based conversion solution, selecting appropriate components and their contents can help form a zirconium film with a dense structure and enhance the adhesion between the zirconium film and the surface of the electrophoretic component, thereby improving the corrosion resistance and wear resistance of the electrophoretic component.

[0029] In some possible embodiments of the present invention, the mass concentration of the zirconizing agent in the zirconium-based conversion solution is 0.8 g / L to 1.5 g / L. A mass concentration of the zirconizing agent within this range can increase the formation rate of zirconium oxide and the modulus of the zirconized film, thereby facilitating the formation of a dense zirconized film and improving the corrosion and wear resistance of the electrophoretic component.

[0030] Illustratively, the mass concentration of the zirconizing agent in the zirconium-based conversion solution can be, but is not limited to, 0.8 g / L, 0.81 g / L, 0.82 g / L, 0.83 g / L, 0.84 g / L, 0.85 g / L, 0.86 g / L, 0.87 g / L, 0.88 g / L, 0.89 g / L, 0.9 g / L, 0.91 g / L, 0.92 g / L, 0.93 g / L, 0.94 g / L, 0.95 g / L, 0.96 g / L, 0.97 g / L, 0.98 g / L, 0.99 g / L, 1 g / L, 1.1 g / L, 1.2 g / L, 1.3 g / L, 1.4 g / L, 1.5 g / L, or a range consisting of any two of the above values.

[0031] In some possible embodiments of the present invention, during the coating process, the pH of the chemical conversion solution is 4-5. A pH within this range can increase the amount of zirconium film formed, thereby facilitating the formation of a dense zirconium film and improving the corrosion resistance and wear resistance of the electrophoretic component.

[0032] Illustratively, the pH of the chemical conversion solution may be, but is not limited to, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, or a range consisting of any two of the foregoing values.

[0033] In some possible embodiments of the present invention, the zirconating agent includes fluorozirconate and / or fluorozirconic acid.

[0034] In some possible embodiments of the present invention, the fluorozirconate includes at least one of potassium fluorozirconate, sodium fluorozirconate, and ammonium fluorozirconate.

[0035] In some possible embodiments of the present invention, the fluorozirconate includes potassium fluorozirconate and sodium fluorozirconate, with the mass ratio of potassium fluorozirconate to sodium fluorozirconate being (3-5):1. The zirconizing agent contains different cations, which can repel each other and reduce agglomeration, thereby helping to form smaller zirconium oxide particles and further improving the density of the zirconized film.

[0036] In some possible embodiments of the present invention, the borate includes at least one of sodium borate, potassium borate, potassium tetrafluoroborate and sodium tetrafluoroborate.

[0037] In some possible embodiments of the present invention, the complexing agent includes at least one of sodium citrate, sodium tartrate, sodium hexametaphosphate, sodium acetate, oxalic acid, and sodium aminotricarboxylate.

[0038] In an embodiment of the present invention, the pH of the zirconium-based conversion solution can be adjusted by adding an acid solution, such as acetic acid, phosphoric acid, etc.

[0039] Furthermore, in some possible embodiments of the present invention, the electrophoretic component is immersed in the zirconium-based conversion solution for 5 to 20 minutes. Immersing the electrophoretic component in the zirconium-based conversion solution for a time within this range can help form a zirconium film of appropriate thickness and enhance the adhesion between the zirconium film and the electrophoretic component, thereby improving the corrosion resistance and wear resistance of the electrophoretic component.

[0040] In the above embodiment, the electrophoretic member is generally a metal plate for vehicles, such as a cold-rolled plate.

[0041] The following embodiments describe the present disclosure in more detail, and these embodiments are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are by mass, and all reagents used in the embodiments are commercially available or synthesized according to conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0042] Example 1

[0043] This embodiment provides a coating method for an electrophoretic element, comprising:

[0044] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 0.6 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.4 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.2 g / L.

[0045] Example 2

[0046] This embodiment provides a coating method for an electrophoretic element, comprising:

[0047] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 0.8 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.4 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.2 g / L.

[0048] Example 3

[0049] This embodiment provides a coating method for an electrophoretic element, comprising:

[0050] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 0.8 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.2 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.2 g / L.

[0051] Example 4

[0052] This embodiment provides a coating method for an electrophoretic element, comprising:

[0053] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 0.9 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.6 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.3 g / L.

[0054] Example 5

[0055] This embodiment provides a coating method for an electrophoretic element, comprising:

[0056] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 1.2 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.4 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.2 g / L.

[0057] Example 6

[0058] This embodiment provides a coating method for an electrophoretic element, comprising:

[0059] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 1.5 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.3 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.3 g / L.

[0060] Example 7

[0061] This embodiment provides a coating method for an electrophoretic element, comprising:

[0062] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes sodium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of sodium fluorozirconate in the zirconium-based conversion solution is 1.5 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.3 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.3 g / L.

[0063] Example 8

[0064] This embodiment provides a coating method for an electrophoretic element, comprising:

[0065] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, sodium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 1.2 g / L, the mass concentration of sodium fluorozirconate in the zirconium-based conversion solution is 0.3 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.3 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.3 g / L.

[0066] Example 9

[0067] This embodiment provides a coating method for an electrophoretic element, comprising:

[0068] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, sodium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 1.25 g / L, the mass concentration of sodium fluorozirconate in the zirconium-based conversion solution is 0.25 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.3 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.3 g / L.

[0069] Example 10

[0070] This embodiment provides a coating method for an electrophoretic element, comprising:

[0071] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, sodium fluorozirconate, potassium tetrafluoroborate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 1.25 g / L, the mass concentration of sodium fluorozirconate in the zirconium-based conversion solution is 0.25 g / L, the mass concentration of potassium tetrafluoroborate in the zirconium-based conversion solution is 0.3 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.3 g / L.

[0072] Example 11

[0073] This embodiment provides a coating method for an electrophoretic element, comprising:

[0074] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, sodium fluorozirconate, potassium tetrafluoroborate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 1.25 g / L, the mass concentration of sodium fluorozirconate in the zirconium-based conversion solution is 0.25 g / L, the mass concentration of potassium tetrafluoroborate in the zirconium-based conversion solution is 0.2 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.1 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.3 g / L.

[0075] Comparative Example 1

[0076] This comparative example provides a coating method for an electrophoretic component, comprising:

[0077] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 0.8 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.2 g / L.

[0078] Comparative Example 2

[0079] This comparative example provides a coating method for an electrophoretic component, comprising:

[0080] The cold-rolled sheet is immersed in a zirconium-based conversion solution for 10 minutes to form a zirconium film on the surface of the electrophoretic part, wherein the pH of the zirconium-based conversion solution is 4, and the zirconium-based conversion solution includes potassium fluorozirconate, potassium borate, acetic acid and sodium citrate, the mass concentration of potassium fluorozirconate in the zirconium-based conversion solution is 0.7 g / L, the mass concentration of potassium borate in the zirconium-based conversion solution is 0.1 g / L, and the mass concentration of sodium citrate in the zirconium-based conversion solution is 0.1 g / L.

[0081] Test section

[0082] 1) Zirconium oxide particle size test in zirconium film

[0083] The particle size of zirconium oxide in the zirconium film was measured using a nanoparticle tracking analyzer.

[0084] 2) Porosity test

[0085] The porosity of the zirconium membrane was tested according to the standard "GB / T 24586-2009 Iron Ore - Determination of Apparent Density, True Density and Porosity," using helium as the test gas. The test results are shown in Table 1. The smaller the porosity, the denser the zirconium membrane structure.

[0086] 3) Adhesion test

[0087] The adhesion of the coating is measured according to GB / T 9286. The specific method is as follows:

[0088] Use an NT knife to score 6x6 lines (25 1mm² squares) on the coated aluminum surface, keeping the test surface as flat as possible. Apply adhesive tape (tape adhesion greater than or equal to 5.3N) to the specimen surface and press it firmly with a rubber eraser to ensure full contact between the tape and the test surface. Allow the tape to rest for 3 minutes. Quickly remove the tape at a 90-degree angle. Visually inspect the test surface and grade it according to ISO standards.

[0089] ISO standard rating:

[0090] Level 0: 5B, the edges of the cut are completely smooth, and there is no peeling on the edges of the lattice.

[0091] Level 1: 4B, there is small peeling at the intersection of the cuts, and the actual damage in the grid area is less than or equal to 5%.

[0092] Level 2: 3B, there is peeling at the edge or intersection of the incision, and the area is 5%-15%.

[0093] Level 3: 2B, there is partial peeling or large-scale peeling along the edge of the incision, or part of the grid is peeled off as a whole, and the peeling area is 15%-35%.

[0094] Level 4: 1B, the cut edge is larger than peeling or some squares are partially or completely peeled off, and the area is 35%-65%.

[0095] Level 5: 0B, there are pieces of paint falling off at the edges and intersections of the lines, and the total falling area is greater than 65%.

[0096] 4) Anti-corrosion performance test

[0097] The test was carried out in accordance with the national standard GB / T 2423.17-2008, wherein the salt water concentration was 5%, the temperature in the salt spray chamber was controlled at 35°C~37°C, the salt spray test time was 450h, and after the salt spray test, the surface of the cold-rolled sheet was observed for rust.

[0098] 5) Wear resistance test

[0099] Wear resistance was tested using a UMT friction and wear testing system. The specific method is as follows: friction and wear testing was performed in a linear reciprocating motion across the width of the zirconized coating on the cold-rolled sheet. The test parameters were as follows: a 3mm diameter GCr15 steel ball, a friction speed of 20mm / s, a load of 6N, and a test duration of 15 minutes. The test results are shown in Table 1. Smaller wear scar width and depth indicate better wear resistance.

[0100] Table 1 Test results of Examples 1-11 and Comparative Examples 1-2

[0101]

[0102] According to Table 1, a comparison of the test results of Examples 1-11 and Comparative Examples 1-2 shows that in the coating method for an electrophoretic component provided by the present invention, a zirconizing agent, a borate, and a complexing agent are mixed in a mass ratio of (2-6): (1-4): 1 to obtain a zirconium-based conversion solution. This can reduce the particle size of the formed zirconium oxide, and the zirconized film has good density, that is, a small porosity, which in turn makes the formed zirconized film have strong adhesion to the surface of the electrophoretic component, thereby improving the corrosion resistance and wear resistance of the electrophoretic component.

[0103] From the comparison of the test results of Examples 1 to 11 and Comparative Example 1, it can be seen that no borate was added in Comparative Example 1, which resulted in an increase in the porosity of the zirconium oxide film formed therein and an increase in the particle size of zirconium oxide in the film, thereby reducing its adhesion to the electrophoretic component, causing the zirconium oxide film to easily fall off, and the corrosion resistance and wear resistance of the electrophoretic component are far inferior to those of Examples 1 to 11.

[0104] From the test results of Examples 1 to 11 and Comparative Example 2, it can be seen that the mass ratio of the zirconizing agent, borate and complexing agent in Comparative Example 2 is not set within the range of (2 to 6): (1 to 4): 1, resulting in an increase in the porosity of the zirconized film formed therein and an increase in the particle size of zirconium oxide in the film, which in turn reduces its adhesion to the electrophoretic component, causing the zirconized film to easily fall off, and the corrosion resistance and wear resistance of the electrophoretic component are far inferior to those of Examples 1 to 11.

[0105] From the test results of Examples 1 and 2 to 11, it can be seen that the mass concentration of the zirconizing agent in the zirconium-based conversion liquid is in the range of 0.8 g / L to 1.5 g / L, which can help form zirconium oxide with smaller particle size and a zirconized film with good density, thereby enhancing the adhesion between the zirconized film and the electrophoretic part, thereby improving the corrosion resistance and wear resistance of the electrophoretic part.

[0106] Comparing the tests of Examples 2 and 4 with those of Examples 3, 5 and 6, it can be seen that when the mass ratio of the zirconizing agent, borate and complexing agent is in the range of (3-5): (2-3): 1, zirconium oxide with smaller particle size and a zirconized film with good density can be formed.

[0107] Comparing the test results of Examples 6, 7, 8 and 9, it can be seen that adding two or more zirconizing agents with a mass ratio within the range of (3-5):1 can help form zirconium oxide with smaller particle size and a zirconized film with good density.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A coating method for an electrophoretic component, characterized in that: The coating method of the electrophoretic element includes: Mixing step: mixing a zirconizing agent, a borate, and a complexing agent in a mass ratio of (3-5):(2-3):1 to obtain a zirconyl-based conversion liquid; the mass concentration of the zirconizing agent in the zirconyl-based conversion liquid is 0.8 g / L-1.5 g / L; the zirconizing agent is a fluorozirconate; the fluorozirconate includes potassium fluorozirconate and sodium fluorozirconate, and the mass ratio of the potassium fluorozirconate to the sodium fluorozirconate is (3-5):1; Zirconization process: immersing the electrophoretic element in the zirconium-based conversion solution to form a zirconization film on the surface of the electrophoretic element.

2. The electrophoretic element coating method according to claim 1, characterized in that: The borate includes at least one of sodium borate and potassium borate.

3. The electrophoretic element coating method according to claim 1, characterized in that: The complexing agent includes at least one of sodium citrate, sodium tartrate, sodium hexametaphosphate, sodium acetate, oxalic acid and sodium aminotricarboxylate.

4. The electrophoretic element coating method according to claim 1, characterized in that: The pH of the zirconium-based conversion solution is 4-5.

5. The electrophoretic element coating method according to claim 1, characterized in that: The electrophoretic element is immersed in the zirconium-based conversion solution for 5 minutes to 20 minutes.

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