Three-coating and one-baking electrosilvering coating as well as preparation method and application thereof

Abstract

The invention discloses a three-coating and one-baking electrosilvering coating and a preparation method and application thereof, and relates to the field of electrosilvering coatings, the three-coating and one-baking electrosilvering coating comprises an electrosilvering black paint layer, an electrosilvering layer and an electrosilvering coating varnish layer; a silver electroplating layer is sprayed on the surface of the silver electroplating black paint layer, and a silver electroplating coating varnish layer is sprayed on the surface of the silver electroplating layer; the electroplated silver black paint layer comprises the following components in percentage by weight: 40-60% of special polyester resin, 5-15% of barium sulfate, 1-5% of a dispersing agent, 0.5-1% of a flatting agent and 20-30% of a mixed solvent. According to the three-coating and one-baking electrosilvering coating and the preparation method and application thereof, the construction process of the three-coating and one-baking electrosilvering coating is simple, when the three-coating and one-baking electrosilvering coating is used, powder primer is sprayed on the surface of a metal hub, then baking is carried out, then three-time spraying is carried out, the electrosilvering black paint layer, the electrosilvering layer and the electrosilvering finishing varnish layer are sequentially carried out, and after the three-layer spraying is completed, the three-coating and one-baking electrosilvering coating is formed. And the performance test of the three-coating and one-baking electrosilvering coating meets and exceeds the requirement of the automobile hub industry on the performance of a coating film.

Description

Technical Field

[0001] This invention relates to the field of electroplating silver coating technology, specifically to a three-coat, one-bake electroplating silver coating, its preparation method, and its application. Background Technology

[0002] Electroplated silver coating is a type of coating containing silver powder particles. It is primarily used to provide excellent adhesion, corrosion resistance, and decorative effects. It forms a protective layer on metal surfaces, thereby protecting the metal materials and extending their service life. For example, in the automotive wheel industry, it ensures the longevity of the wheels.

[0003] In existing technologies, the spraying process for electroplating silver materials is quite complicated, involving many steps and is time-consuming and labor-intensive.

[0004] To overcome the above shortcomings, Chinese patent (publication number CN118256148A) discloses a two-component electroplating silver coating and its application. By weight, the first component comprises the following raw materials: 35-55 parts of electroplating silver resin, 10-25 parts of hydroxyl acrylic resin, 3-8 parts of aluminum silver paste, 0.1-2 parts of leveling agent, and 15-30 parts of organic solvent. The mass ratio of the hydroxyl acrylic resin to the electroplating silver resin in the first component is (1.4-3):1. The second component includes a curing agent. The coating film produced by the two-component electroplating silver coating exhibits good silver plating effect, abrasion resistance, chemical resistance, and water resistance. The patent also provides an application of the two-component electroplating silver coating in household appliances and automotive interior parts.

[0005] While existing technologies can overcome the shortcomings mentioned above, other problems still exist in their operation: existing metallic coatings, such as wheel coatings, require three coats, each requiring separate baking after drying, followed by another coat. This process is time-consuming and labor-intensive, potentially impacting wheel production efficiency. Furthermore, they have a fatal flaw in corrosion resistance, failing to meet the corrosion resistance requirements of the automotive wheel industry, such as the 1000h neutral salt spray test and 240h CASS test standards. Summary of the Invention

[0006] The purpose of this invention is to provide a three-coat, one-bake electroplated silver coating, its preparation method, and its application, to solve the problems mentioned in the background art. Existing metal coatings, such as wheel hub coatings, require three coats, each requiring separate baking after each coat. After baking, another coat is needed, which is time-consuming and labor-intensive, easily affecting the production efficiency of wheel hubs. Furthermore, they have fatal defects in corrosion resistance, failing to meet the requirements for corrosion resistance of coating films in the automotive wheel hub industry, such as the testing standards of 1000h neutral salt spray and 240h CASS test.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a three-coat, one-bake electroplated silver coating and its preparation method and application, comprising an electroplated silver black paint layer, an electroplated silver layer, and an electroplated silver clear coat layer;

[0008] Its characteristic is that: the surface of the electroplated silver black paint layer is sprayed with an electroplated silver layer, and the surface of the electroplated silver layer is sprayed with an electroplated silver clear varnish layer;

[0009] The electroplated silver-black paint layer comprises, by weight percentage, 40-60% special polyester resin, 5-15% barium sulfate, 1-5% dispersant, 0.5-1% leveling agent, and 20-30% mixed solvent, with the sum of the quantities of each component equal to 100%.

[0010] The electroplated silver layer comprises, by weight percentage, 80% electroplating silver resin, 10-15% ethyl acetate, 1-2% adhesion promoter, 0.5-1% leveling agent, 0.5-1% ultraviolet absorber, and 3% silver powder, with the sum of the quantities of each component equal to 100%.

[0011] The electroplated silver clear varnish layer comprises, by weight percentage, 50-70% special acrylic resin, 15-30% solvent, 0.1-0.5% leveling agent, 0.1-0.3% defoamer, 1-2% ultraviolet absorber, 0.5-1% light stabilizer, and 1-2% adhesion promoter, with the sum of the quantities of each component equal to 100%.

[0012] Furthermore, the special resin of the electroplated silver-black paint layer is a special polyester resin, the dispersant is dispersant BYK-163, the leveling agent is leveling agent BYK-331, and the mixed solvent is xylene.

[0013] Furthermore, the electroplating silver resin of the electroplated silver layer is an electroplating silver resin containing metal paste, ethyl acetate is the solvent, the adhesion promoter is a silane coupling agent, the leveling agent is a polyether-modified siloxane, and the ultraviolet absorber is UV-326.

[0014] Furthermore, the ethyl acetate can adjust the viscosity, the leveling agent can eliminate orange peel effect, improve surface smoothness, and ensure spray leveling, while the ultraviolet absorber prevents yellowing and aging caused by long-term exposure to light.

[0015] Furthermore, the electroplated silver layer comprises, by weight percentage, 75-85% electroplating silver resin, 10-15% ethyl acetate, 1-2% adhesion promoter, 0.5-1% leveling agent, 0.5-1% ultraviolet absorber, and 3% silver powder, and the sum of the quantities of each component is equal to 100%.

[0016] Furthermore, the solvent of the electroplated silver clear coat is xylene, the leveling agent is BYK-333, the defoamer is BYK-066N, the ultraviolet absorber is UV-327, and the light stabilizer is HALS.

[0017] Furthermore, the preparation method of the coating is also disclosed, specifically including the following steps:

[0018] Electroplated silver-black paint layer: Mix 50% of the total amount of special polyester resin and dispersant, stir at low speed for 10 minutes, grind to fineness ≤20μm through a sand mill, control the temperature ≤40℃, add the remaining anti-rust pigment, filler and talc powder to the dispersion tank, disperse at high speed for 30 minutes, add leveling agent, anti-settling agent and remaining solvent, stir at medium speed for 15 minutes, and avoid bubbles.

[0019] Furthermore, for the electroplated silver layer, 80% of the electroplating silver resin is mixed with 11% ethyl acetate, stirred at 600 rpm for 10 minutes, then switched to 400 rpm to avoid agglomeration of the metallic pigments. 1% adhesion promoter, 0.7% leveling agent, and 0.7% UV absorber are added sequentially, stirred for 30 minutes, and allowed to stand to defoam. The electroplating silver resin needs to be premixed with the solvent to avoid direct contact with the high-viscosity resin, which could lead to uneven dispersion.

[0020] Furthermore, for the electroplated silver clear varnish layer, special acrylic resin and some solvent such as xylene are added to the reaction vessel and stirred at low speed until uniform to form a base material. The mixture is then switched to high-speed shear dispersion and stirred for 20-30 minutes to form a stable slurry. The stirring speed is then reduced to medium-low speed and stirred for 10-15 minutes. Defoamer, leveling agent, ultraviolet absorber and adhesion promoter are added in sequence.

[0021] Furthermore, the application of this coating was disclosed, specifically including the following application steps:

[0022] S1: Pre-treatment, which involves pre-treating the wheel hub substrate;

[0023] S2: Powder primer application: Spray a layer of powder primer onto the pre-treated wheel hub surface, and bake and keep it warm after spraying.

[0024] S3: Electroplated silver spraying. After the wheel hub is preheated, the electroplated silver black paint layer, electroplated silver layer and electroplated silver clear coat layer are sprayed in sequence, and then baked once.

[0025] S2: When applying the powder primer, bake at 220°C for 30 minutes;

[0026] S3: The electroplated silver black paint layer, electroplated silver layer and electroplated silver clear coat layer are mixed in advance, and the wheel hub temperature is preheated to 70-80℃. They are sprayed in sequence, and after spraying, they are baked at a temperature between 140-160℃ and kept warm for 30-40 minutes.

[0027] After preparing the electroplated silver black paint layer, electroplated silver layer, and electroplated silver clear coat layer in sequence, the wheel hub is pre-treated. After the pre-treatment is completed, the car wheel hub is heated to a suitable temperature, and then the electroplated silver black paint layer, electroplated silver layer, and electroplated silver clear coat layer are sprayed onto its surface. After the dry film is formed, it is baked.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. The three-coat, one-bake electroplating silver coating process is simple. When using it, spray the powder primer on the surface of the metal wheel hub and then bake it. Then spray three coats in the order of electroplating silver black paint layer, electroplating silver layer and electroplating silver clear coat layer. After the three coats are completed, bake it once. The process is simple and convenient.

[0030] Furthermore, it is highly efficient, with three layers of electroplated silver applied and baked in one go, eliminating the need for three separate baking processes and frequent baking. It also features low energy consumption, low labor costs, and minimal waste.

[0031] 2. The formulation of the electroplated silver layer ensures adhesion and high temperature resistance. The electroplating silver resin containing metal paste can enhance the metal reflection effect. The setting of ethyl acetate solvent can ensure the leveling of the spray coating. The silane coupling agent setting with adhesion promoter can optimize the interface structure and reduce the risk of peeling.

[0032] Furthermore, the polyether-modified siloxane setting in the electroplating silver leveling agent can prevent excessive leveling from causing metal sedimentation, and the setting of ultraviolet absorbers provides long-lasting anti-yellowing and is suitable for outdoor use environments.

[0033] 3. The performance test of the three-coat one-bake electroplated silver coating meets and exceeds the requirements of the automotive wheel industry for coating film performance, such as the test standards of 1000h neutral salt spray and 240h CASS test. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall process of the present invention.

[0035] Figure 2 This is a schematic diagram of the electroplating silver spraying process of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1: As Figures 1-2 The technical solution shown is a three-coat, one-bake electroplated silver coating. In order to solve the problem of the cumbersome and time-consuming one-coat, one-bake process, the following is disclosed: an electroplated silver black paint layer, an electroplated silver layer, and an electroplated silver clear varnish layer; the electroplated silver black paint layer, the electroplated silver layer, and the electroplated silver clear varnish layer; the surface of the electroplated silver black paint layer is sprayed with an electroplated silver layer, and the surface of the electroplated silver layer is sprayed with an electroplated silver clear varnish layer.

[0038] The electroplated silver-black paint layer comprises, by weight percentage, 40-60% special polyester resin, 5-15% barium sulfate, 1-5% dispersant, 0.5-1% leveling agent, and 20-30% mixed solvent, with the sum of the quantities of each component equal to 100%.

[0039] The electroplated silver layer comprises, by weight percentage, 80% electroplating silver resin, 10-15% ethyl acetate, 1-2% adhesion promoter, 0.5-1% leveling agent, 0.5-1% ultraviolet absorber, and 3% silver powder. The sum of the quantities of each component is equal to 100%.

[0040] The electroplated silver clear coat comprises, by weight percentage, 50-70% special acrylic resin, 15-30% solvent, 0.1-0.5% leveling agent, 0.1-0.3% defoamer, 1-2% ultraviolet absorber, 0.5-1% light stabilizer, and 1-2% adhesion promoter, with the sum of the quantities of each component equal to 100%.

[0041] The special resin for the electroplated silver-black paint layer is a special polyester resin, the dispersant is BYK-163, the leveling agent is BYK-331, and the mixed solvent is xylene.

[0042] The silver plating resin for the silver plating layer is a silver plating resin containing metal paste. Ethyl acetate is the solvent, the adhesion promoter is a silane coupling agent, the leveling agent is a polyether-modified siloxane, and the ultraviolet absorber is UV-326.

[0043] Ethyl acetate can adjust viscosity, leveling agents can eliminate orange peel effect in spraying, improve surface smoothness, and ensure spraying leveling, while UV absorbers prevent yellowing and aging caused by long-term exposure to light.

[0044] The electroplated silver layer comprises, by weight percentage, 80% electroplating silver resin, 10-15% ethyl acetate, 1-2% adhesion promoter, 0.5-1% leveling agent, 0.5-1% ultraviolet absorber, and 3% silver powder. The sum of the quantities of each component equals 100%.

[0045] The solvent for the electroplated silver clear coat is xylene, the leveling agent is BYK-333, the defoamer is BYK-066N, the ultraviolet absorber is UV-327, and the light stabilizer is HALS.

[0046] Example 2: Figures 1-2 The technical solution shown also discloses a method for preparing the coating, based on Example 1:

[0047] Electroplated silver-black paint layer: Mix 50% of the total amount of special polyester resin and dispersant, stir at low speed for 10 minutes, grind to fineness ≤20μm through a sand mill, control the temperature ≤40℃, add the remaining anti-rust pigment, filler and talc powder to the dispersion tank, disperse at high speed for 30 minutes, add leveling agent, anti-settling agent and remaining solvent, stir at medium speed for 15 minutes, and avoid bubbles.

[0048] For the silver plating layer, mix 80% silver plating resin with 11% ethyl acetate, stir at 600 rpm for 10 minutes, then switch to 400 rpm to avoid agglomeration of metallic pigments. Add 1% adhesion promoter, 0.7% leveling agent, and 0.7% UV absorber in sequence, stir for 30 minutes, and let stand to defoam. The silver plating resin needs to be premixed with the solvent to avoid direct contact with high-viscosity resin, which may lead to uneven dispersion.

[0049] For the electroplated silver clear varnish layer, special acrylic resin and some solvents such as xylene are added to the reaction vessel and stirred at low speed until uniform to form a base material. Then, the mixture is switched to high-speed shear dispersion and stirred for 20-30 minutes to form a stable slurry. The stirring speed is then reduced to medium-low speed and stirred for 10-15 minutes. Defoamer, leveling agent, UV absorber and adhesion promoter are added in sequence.

[0050] Example 3: Figures 1-2 The technical solution shown, based on Embodiment 2, also discloses the application steps of the coating:

[0051] S1: Pre-treatment, which involves pre-treating the wheel hub substrate;

[0052] S2: Powder primer application: Spray a layer of powder primer onto the pre-treated wheel hub surface, and bake and keep it warm after spraying.

[0053] S3: Electroplated silver spraying. After the wheel hub is preheated, the electroplated silver black paint layer, electroplated silver layer and electroplated silver clear coat layer are sprayed in sequence, and then baked once.

[0054] S2: When applying the powder primer, bake at 220℃ for 30 minutes; S3: Prepare the electroplated silver black paint layer, electroplated silver layer and electroplated silver clear coat layer in advance, and preheat the wheel hub temperature to 70-80℃ in advance. Spray them in sequence, and bake them uniformly after spraying. The baking temperature is between 140-160℃ and the temperature is maintained for 30-40 minutes.

[0055] After preparing the electroplated silver black paint layer, electroplated silver layer, and electroplated silver clear coat layer in sequence, the wheel hub is pre-treated. After the pre-treatment is completed, the car wheel hub is heated to a suitable temperature, and then the electroplated silver black paint layer, electroplated silver layer, and electroplated silver clear coat layer are sprayed onto its surface. After the dry film is formed, it is baked.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A three-coat, one-bake electroplating silver coating, comprising an electroplated silver black paint layer, an electroplated silver layer, and an electroplated silver clear coat layer; Its features are: The surface of the electroplated silver black paint layer is coated with an electroplated silver layer, and the surface of the electroplated silver layer is coated with an electroplated silver clear varnish layer. The electroplated silver-black paint layer comprises, by weight percentage, 40-60% special polyester resin, 5-15% barium sulfate, 1-5% dispersant, 0.5-1% leveling agent, and 20-30% mixed solvent, with the sum of the quantities of each component equal to 100%. The electroplated silver layer comprises, by weight percentage, 75-85% electroplating silver resin, 10-15% ethyl acetate, 1-2% adhesion promoter, 0.5-1% leveling agent, 0.5-1% ultraviolet absorber, and 3% silver powder, with the sum of the quantities of each component equal to 100%. The electroplated silver clear varnish layer comprises, by weight percentage, 50-70% special acrylic resin, 15-30% solvent, 0.1-0.5% leveling agent, 0.1-0.3% defoamer, 1-2% ultraviolet absorber, 0.5-1% light stabilizer, and 1-2% adhesion promoter, with the sum of the quantities of each component equal to 100%.

2. The three-coat, one-bake electroplating silver coating according to claim 1, characterized in that: The special resin for the electroplated silver-black paint layer is a special polyester resin, the dispersant is BYK-163, the leveling agent is BYK-331, and the mixed solvent is xylene.

3. The three-coat, one-bake electroplating silver coating according to claim 1, characterized in that: The electroplating silver layer uses an electroplating silver resin containing metal paste, with ethyl acetate as the solvent, an adhesion promoter as a silane coupling agent, a leveling agent as a polyether-modified siloxane, and an ultraviolet absorber as UV-326.

4. The three-coat, one-bake electroplating silver coating according to claim 3, characterized in that: The ethyl acetate can adjust the viscosity, the leveling agent can eliminate orange peel effect, improve surface smoothness, and ensure spray leveling, while the ultraviolet absorber prevents yellowing and aging caused by long-term exposure to light.

5. The three-coat, one-bake electroplating silver coating according to claim 4, characterized in that: The electroplated silver layer comprises, by weight percentage, 80% electroplating silver resin, 10-15% ethyl acetate, 1-2% adhesion promoter, 0.5-1% leveling agent, 0.5-1% ultraviolet absorber, and 3% silver powder, with the sum of the quantities of each component equal to 100%.

6. The three-coat, one-bake electroplating silver coating according to claim 1, characterized in that: The solvent for the electroplated silver clear coat is xylene, the leveling agent is BYK-333, the defoamer is BYK-066N, the ultraviolet absorber is UV-327, and the light stabilizer is HALS.

7. The three-coat, one-bake electroplating silver coating according to claim 1, characterized in that, The preparation method of the coating was also disclosed, specifically including the following steps: Electroplated silver-black paint layer: Mix 50% of the total amount of special polyester resin and dispersant, stir at low speed for 10 minutes, grind to fineness ≤20μm through a sand mill, control the temperature ≤40℃, add the remaining anti-rust pigment, filler and talc powder to the dispersion tank, disperse at high speed for 30 minutes, add leveling agent, anti-settling agent and remaining solvent, stir at medium speed for 15 minutes, and avoid bubbles.

8. The method for preparing a three-coat, one-bake electroplating silver coating according to claim 7, characterized in that: The electroplated silver layer is prepared by mixing 80% electroplating silver resin with 11% ethyl acetate, stirring at 600 rpm for 10 minutes, switching to 400 rpm to avoid agglomeration of metallic pigments, and then adding 1% adhesion promoter, 0.7% leveling agent, and 0.7% ultraviolet absorber in sequence, stirring for 30 minutes and letting it stand to defoam. The electroplating silver resin needs to be premixed with the solvent to avoid direct contact with high-viscosity resin, which may lead to uneven dispersion.

9. The method for preparing a three-coat, one-bake electroplating silver coating according to claim 8, characterized in that: The electroplated silver clear varnish layer is prepared by adding special acrylic resin and some solvents such as xylene into a reaction vessel, stirring at low speed until uniform to form a base material, switching to high-speed shear dispersion, and continuing for 20-30 minutes to form a stable slurry, reducing the stirring speed to medium-low speed, stirring for 10-15 minutes, and adding defoamer, leveling agent, ultraviolet absorber and adhesion promoter in sequence.

10. The three-coat, one-bake electroplating silver coating according to claim 1, characterized in that: The application of the coating was also disclosed, including the following application steps: S1: Pre-treatment, which involves pre-treating the wheel hub substrate; S2: Powder primer application: A layer of powder primer is sprayed onto the pre-treated wheel hub surface, and then baked and kept warm after spraying. S3: Electroplated silver spraying. After the wheel hub is preheated, the electroplated silver black paint layer, electroplated silver layer and electroplated silver clear coat layer are sprayed in sequence, and then baked once. S2: When applying the powder primer, bake at 220°C for 30 minutes; S3: The electroplated silver black paint layer, electroplated silver layer and electroplated silver clear coat layer are mixed in advance, and the wheel hub temperature is preheated to 70-80℃. They are sprayed in sequence, and after spraying, they are baked at a temperature between 140-160℃ and kept warm for 30-40 minutes. After preparing the electroplated silver black paint layer, electroplated silver layer, and electroplated silver clear coat layer in sequence, the wheel hub is pre-treated. After the pre-treatment is completed, the car wheel hub is heated to a suitable temperature, and then the electroplated silver black paint layer, electroplated silver layer, and electroplated silver clear coat layer are sprayed onto its surface. After the dry film is formed, it is baked.

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