Environmentally friendly electroplating method for plastic workpieces

Abstract

The present application relates to an environmentally friendly electroplating method for plastic workpieces, which includes internal stress removal, alkaline washing and oil removal, roughening, sensitization and activation treatment, chemical nickel deposition, water-plated metal coating, coating of surface treatment agent, wire drawing and vacuum nickel plating. The present application has the following advantages and effects: a metal layer is plated on the plastic workpiece by combining water plating and vacuum plating to meet the requirements for color variability, and the coating is thicker and has strong adhesion; trivalent chromium is used to replace hexavalent chromium with high toxicity to reduce damage to the ecological environment; a microporous structure is formed by roughening, sensitizing and activation treatment in sequence, and the molecules on the surface are activated, so that the coating is easier to adhere and has higher adhesion strength; a surface treatment agent layer is coated and formed between the water-plated coating and the vacuum-plated coating to improve the relative adhesion between each coating and assist in improving the overall coating adhesion strength of the plastic workpiece surface, so as to achieve the purpose of improving the overall performance of the product.

Description

Technical Field

[0001] The present application relates to the technical field of electroplating, and in particular to an environmentally friendly electroplating method for plastic workpieces. Background Art

[0002] Compared with metal parts, plastic electroplating products can not only achieve a good metallic texture, but also reduce the weight of the products. While effectively improving the appearance and decorativeness of plastics, it also improves their electrical, thermal and corrosion resistance performance. Due to the structural advantages of plastic workpieces, they not only have excellent comprehensive performance and are easy to process and form, but also the surface of plastic workpieces is easy to erode and obtain a higher coating bonding strength, so they are currently widely used in electroplating.

[0003] With respect to the above-mentioned related technologies, the inventors believe that the current plastic workpieces have low adhesion of the coating after electroplating, which causes the coating to fall off easily, and therefore still need to be improved. Summary of the Invention

[0004] In order to improve the coating adhesion of a plastic workpiece, the present application provides an environmentally friendly electroplating method for a plastic workpiece.

[0005] The present application provides an environmentally friendly electroplating method for plastic workpieces using the following technical solutions:

[0006] An environmentally friendly electroplating method for a plastic workpiece comprises the following steps:

[0007] S1. Remove internal stress: Dry the plastic workpiece at 65±2℃ for 3 hours to remove the internal stress during the product molding process;

[0008] S2. Alkaline washing and degreasing;

[0009] S3. Roughening; soak in a roughening solution, remove and rinse with anhydrous ethanol;

[0010] S4. Sensitization and activation treatment: spraying with sensitizing solution and activation solution respectively;

[0011] S5 electroless nickel deposition; treated in a nickel treatment solution, pH 8-10, temperature 25-45 ℃, soaked 5-8min to obtain a conductive nickel layer;

[0012] S6. Water-plated metal coating; sequentially performing copper plating, acid copper plating, and trivalent chromium plating;

[0013] S7 coating surface treatment agent; coating the surface treatment agent on the metal coating of S6, and then drying and curing at 90-100 ℃ for 15-20min;

[0014] S8. Wire drawing: using mechanical friction to produce a pattern of straight, random, spiral, wavy, or swirl lines;

[0015] S9. Vacuum nickel plating; spray UV primer, bake the primer, vacuum nickel plating, then spray UV topcoat, and finally dry at 100-120℃ for 10-15 minutes.

[0016] By adopting the above technical solution, on the one hand, a metal layer is plated on the plastic workpiece by combining water plating and vacuum plating, achieving a thicker coating with strong adhesion. Vacuum plating meets the demand for surface color variability, allowing the development of more different colors, while water plating meets the coating thickness requirements of the wire drawing process. Trivalent chromium is used to replace the highly toxic hexavalent chromium, reducing damage to the ecological environment. On the other hand, internal stress of the plastic workpiece is removed to avoid the problem of cracking and easy shedding of the coating due to the increase in volume caused by internal stress release after electroplating. The roughening treatment causes small molecules on the surface of the plastic workpiece to degrade and dehydrate, and the small molecules fall off the surface of the plastic workpiece to form a microporous structure, increasing the surface roughness of the plastic workpiece and improving the adhesion of the coating. The sensitization and activation treatment increases the microporous structure of the plastic workpiece surface and activates the surface molecules, making the coating easier to adhere and having higher adhesion strength. A surface treatment agent layer is applied and formed between the water-plated and vacuum-plated coatings to improve the relative adhesion between the individual coatings and help improve the overall coating adhesion strength of the plastic workpiece surface, thereby achieving the purpose of improving the overall performance of the product.

[0017] Preferably, in S7, the surface treatment agent includes the following components in parts by weight:

[0018] 30-40 parts of epoxy acrylate;

[0019] 4-5 parts of ethyl orthosilicate;

[0020] 10-12 parts ethanol;

[0021] 0.4-0.6 parts of butyl titanate;

[0022] 2-3 parts of tert-amyl perbenzoate;

[0023] 0.6-0.8 parts of octyl propionate;

[0024] 0.1-0.2 parts KOH;

[0025] 1-2 parts dispersant;

[0026] 2-3 parts of curing agent.

[0027] By adopting the above technical solution, ethyl orthosilicate can be used to siliconize the metal surface, so ethyl orthosilicate has good adhesion and permeability to the metal coating. Under the catalysis of butyl titanate, a silicone emulsion can be prepared from epoxy acrylate containing hydroxyl groups, ethyl orthosilicate and ethanol under ultrasonic dispersion. The silicone emulsion has strong adhesion and low surface tension, which improves the wettability of the surface treatment agent on the metal coating surface. Under the catalysis of KOH, tert-amyl peroxybenzoate and octyl propionate undergo an ester exchange reaction, and the product carries hydrophobic phenyl groups and long carbon chain groups, which helps to reduce surface energy. , making the vacuum coating stronger in bonding strength; and KOH is easily soluble in ethanol, and the components can further catalyze the occurrence of ester exchange reaction after blending; the viscosity is increased by hydrophobic association between hydrophobic groups, and the further compounding of the dispersant isotridecanol polyoxyethylene ether makes the surface treatment agent have a certain viscosity while maintaining fluidity, so that the surface treatment agent can be evenly solidified on the surface of the metal coating, and firmly bonded to the metal coating in a physical and chemical bonding manner; isotridecanol polyoxyethylene ether improves the dispersion efficiency, and good dispersibility can make the surface treatment agent layer smoother and the vacuum coating easier to cover.

[0028] Preferably, the surface treatment agent further comprises 4-6 parts by weight of tetradecyl methacrylate.

[0029] By adopting the above technical solution, in the presence of KOH, the epoxy acrylate emulsion can be modified by further adding tetradecyl methacrylate. The introduced long carbon chain hydrophobic groups will avoid contact with water and be adsorbed on the air-liquid interface, which helps to reduce surface tension and makes the vacuum coating easier to adsorb. In addition, the association between the hydrophobic groups of tetradecyl methacrylate and the hydrophobic groups of the ester exchange product of tert-amyl perbenzoate and octyl propionate is enhanced, forming a supramolecular structure dominated by intermolecular association, increasing the mechanical volume of the fluid and further playing a viscosity-increasing role, so that the surface treatment agent forms a good interface between the water-plated metal coating and the vacuum coating, thereby improving the firmness of the coating on the surface of the plastic workpiece and achieving the effect of improving adhesion.

[0030] Preferably, the surface treatment agent further comprises 1-2 parts of monooctyl maleate and 3-4 parts of deionized water, by weight.

[0031] By adopting the above technical solution, in aqueous solution, monooctyl maleate can also ionize to produce carboxylate chelating functional groups, which assist in chemical bonding with metals; the polar groups in monooctyl maleate are tightly adsorbed on the metal surface by virtue of charge action, thereby improving the stable bonding force between the surface treatment agent and the water-plated metal coating and the vacuum nickel coating.

[0032] Preferably, the preparation method of the surface treatment agent is:

[0033] First, epoxy acrylate, ethyl orthosilicate, ethanol and butyl titanate are stirred at 90-100°C for 2-3 hours, and then ultrasonically dispersed for 10-15 minutes to obtain an emulsion;

[0034] Blend tert-amyl perbenzoate, octyl propionate and KOH, and stir to react at 80-90°C for 35-45 minutes; then add emulsion, dispersant and curing agent, and continue stirring for 50-60 minutes.

[0035] Preferably, tert-amyl peroxybenzoate, octyl propionate and KOH are mixed and stirred at 80-90° C. for 35-45 minutes; then 4-6 parts of tetradecyl methacrylate and the emulsion are added, and the mixture is kept warm and stirred for 40-55 minutes; then a mixed solution of 1-2 parts of monooctyl maleate and 3-4 parts of deionized water is added, and then a dispersant and a curing agent are added, and the mixture is stirred for 50-60 minutes.

[0036] Preferably, the dispersant is isotridecanol polyoxyethylene ether; and the curing agent is polyamide.

[0037] Preferably, in S4, the sensitizing solution is an aqueous solution containing 10-20 g / L stannous chloride, 5-10 g / L sodium stannate and 25-30 mL / L hydrochloric acid; the activating solution is an aqueous solution containing 5-10 g / L silver nitrate and 6-10 ml / L ammonia.

[0038] Preferably, the nickel treatment solution of S5 comprises 15-20 g / L nickel hypochlorite, 2-3 g / L sodium citrate, 8-12 ml / L ammonia water and 2-3 g / L accelerator DA-222.

[0039] In summary, this application has the following beneficial technical effects:

[0040] 1. A combination of water plating and vacuum plating is used to coat the plastic workpiece with a metal layer, meeting the requirements for color variability, and the coating is thick and has strong adhesion. Trivalent chromium is used to replace the highly toxic hexavalent chromium to reduce damage to the ecological environment. A microporous structure is formed through roughening, sensitization, and activation treatments, activating the surface molecules to make the coating easier to adhere and with higher adhesion strength. A surface treatment agent layer is applied between the water-plated and vacuum-plated coatings to improve the relative adhesion between the coatings and help improve the overall coating adhesion strength of the plastic workpiece surface, thereby improving the overall performance of the product.

[0041] 2. Under the catalysis of butyl titanate, hydroxyl-containing epoxy acrylate, ethyl orthosilicate, and ethanol can be ultrasonically dispersed to produce a silicone emulsion with strong adhesion and low surface tension, thereby improving the wettability of the surface treatment agent on the metal coating surface. Under the catalysis of KOH, tert-amyl peroxybenzoate and octyl propionate undergo an ester exchange reaction. The product carries hydrophobic phenyl groups and long carbon chain groups, which helps to reduce the surface energy and enhance the bonding strength of the vacuum coating. KOH is easily soluble in ethanol, and the components can further catalyze the ester exchange reaction after blending. Hydrophobic association occurs between the hydrophobic groups to increase viscosity. The further compounding of the dispersant isotridecanol polyoxyethylene ether gives the surface treatment agent a certain viscosity while maintaining fluidity. As a result, the surface treatment agent can be uniformly solidified on the surface of the metal coating, firmly bonding to the metal coating through physical and chemical bonding.

[0042] 3. In the presence of KOH, the epoxy acrylate emulsion can be modified by further adding tetradecyl methacrylate. The introduced long carbon chain hydrophobic groups will avoid contact with water and adsorb on the air-liquid interface, helping to reduce surface tension and making vacuum coating easier to adsorb. The hydrophobic groups of tetradecyl methacrylate and the hydrophobic groups of the transesterification product of tert-amyl peroxybenzoate and octyl propionate enhance the association effect, forming a supramolecular structure dominated by intermolecular association, increasing the mechanical volume of the fluid and further enhancing viscosity. This allows the surface treatment agent to form a good interface between the water-plated metal coating and the vacuum-plated coating, improving the firmness of the coating on the surface of the plastic workpiece and achieving the effect of improving adhesion.

[0043] 4. The polar groups in monooctyl maleate are tightly adsorbed on the metal surface by means of charge, thereby improving the stable bonding force between the surface treatment agent and the water-plated metal coating and the vacuum nickel coating. DETAILED DESCRIPTION

[0044] The application is described in further detail below.

[0045] In this application, epoxy acrylate is produced by Hubei Xinmingtai Chemical Co., Ltd.; isotridecanol polyoxyethylene ether is produced by Jiangsu Hai'an Petrochemical Plant, model E-1306; and polyamide curing agent is produced by Tianjin Ningping Chemical Products Co., Ltd.

[0046] Unless otherwise specified, the raw materials used in the following embodiments can be obtained from common commercial sources. Example

[0047] Example 1

[0048] This embodiment discloses an environmentally friendly electroplating method for a plastic workpiece, comprising the following steps:

[0049] S1. Remove internal stress; dry the plastic workpiece at 63°C for 3 hours to remove internal stress during the product molding process;

[0050] S2. Alkaline washing and degreasing;

[0051] S3 coarsening; containing 380g / L concentrated sulfuric acid and 380g / L of chromic anhydride aqueous solution as a roughening treatment solution, soaked at 65 ° C for 8min, removed and washed with anhydrous ethanol;

[0052] S4 sensitization and activation treatment; respectively, with sensitizing solution and activation solution spray treatment; sensitizing solution is an aqueous solution containing 10g / L stannous chloride, 5g / L sodium stannate and 25mL / L hydrochloric acid; activation solution is an aqueous solution containing silver nitrate concentration of 5g / L, ammonia concentration of 6ml / L;

[0053] S5 electroless nickel deposition; in a nickel treatment solution comprising 15g / L nickel chloride, 2g / L sodium citrate, 8ml / L ammonia and 2g / L accelerator DA-222, pH 8, temperature 25 ℃, soaked for 5min to obtain a conductive nickel layer;

[0054] S6. Water-plated metal coating; sequentially performing copper plating, acid copper plating, and trivalent chromium plating;

[0055] S7 coating surface treatment agent; coating the surface treatment agent on the metal coating of S6, and then drying at 90 ℃ for 15min to cure;

[0056] S8. Wire drawing: using mechanical friction to produce a pattern of straight, random, spiral, wavy, or swirl lines;

[0057] S9. Vacuum nickel plating; spray UV primer, bake the primer, vacuum nickel plating, spray UV topcoat, and finally dry at 100℃ for 10 minutes.

[0058] In S7, the surface treatment agent includes the following components: epoxy acrylate, tetraethyl orthosilicate, ethanol, butyl titanate, tert-amyl peroxybenzoate, octyl propionate, KOH, a dispersant and a curing agent, wherein the dispersant is isotridecanol polyoxyethylene ether and the curing agent is polyamide. The content of each component is shown in Table 1 below.

[0059] The surface treatment agent was prepared as follows: first, epoxy acrylate, ethyl orthosilicate, ethanol, and butyl titanate were stirred at 90° C. for 2 h, and then ultrasonically dispersed for 10 min to obtain an emulsion;

[0060] T-amyl peroxybenzoate, octyl propionate and KOH were mixed and stirred at 80° C. for 35 minutes; then, the emulsion, dispersant and curing agent were added and the stirring was continued for 50 minutes.

[0061] In addition, the surface tension of water is 72.099 mN / m; the surface tension of the ultrasonically dispersed emulsion of epoxy acrylate, ethyl orthosilicate, ethanol, and butyl titanate in Example 1 was tested, and the surface tension was measured to be 50.128 mN / m.

[0062] Example 2

[0063] This embodiment discloses an environmentally friendly electroplating method for a plastic workpiece, comprising the following steps:

[0064] S1. Remove internal stress; dry the plastic workpiece at 67°C for 3 hours to remove internal stress during the product molding process;

[0065] S2. Alkaline washing and degreasing;

[0066] S3 coarsening; containing 400g / L concentrated sulfuric acid and 410g / L of chromic anhydride aqueous solution as a roughening treatment solution, soaked at 70 ° C for 15min, removed and washed with anhydrous ethanol;

[0067] S4 sensitization and activation treatment; respectively, with sensitizing solution and activation solution spray treatment; sensitizing solution is an aqueous solution containing 20g / L stannous chloride, 10g / L sodium stannate and 30mL / L hydrochloric acid; activation solution is an aqueous solution containing silver nitrate concentration of 10g / L, ammonia concentration of 10ml / L;

[0068] S5 electroless nickel deposition; in a nickel treatment solution comprising 20g / L nickel chloride, 3g / L sodium citrate, 12ml / L ammonia and 3g / L accelerator DA-222, pH 10, temperature 45 ℃, soaked for 8min to obtain a conductive nickel layer;

[0069] S6. Water-plated metal coating; sequentially performing copper plating, acid copper plating, and trivalent chromium plating;

[0070] S7 coating surface treatment agent; coating the surface treatment agent on the metal coating of S6, and then drying at 100 ℃ for 20min to cure;

[0071] S8. Wire drawing: using mechanical friction to produce a pattern of straight, random, spiral, wavy, or swirl lines;

[0072] S9. Vacuum nickel plating; spray UV primer, bake the primer, vacuum nickel plating, spray UV topcoat, and finally dry at 120℃ for 15 minutes.

[0073] In S7, the surface treatment agent includes the following components: epoxy acrylate, tetraethyl orthosilicate, ethanol, butyl titanate, tert-amyl peroxybenzoate, octyl propionate, KOH, a dispersant and a curing agent, wherein the dispersant is isotridecanol polyoxyethylene ether and the curing agent is polyamide. The content of each component is shown in Table 1 below.

[0074] The surface treatment agent was prepared as follows: epoxy acrylate, ethyl orthosilicate, ethanol, and butyl titanate were stirred at 100°C for 3 h, and then ultrasonically dispersed for 15 min to obtain an emulsion;

[0075] T-amyl peroxybenzoate, octyl propionate and KOH were mixed and stirred at 90° C. for 45 minutes; then, the emulsion, dispersant and curing agent were added and the stirring was continued for 60 minutes.

[0076] Example 3

[0077] This embodiment discloses an environmentally friendly electroplating method for a plastic workpiece, comprising the following steps:

[0078] S1. Remove internal stress; dry the plastic workpiece at 65°C for 3 hours to remove internal stress during the product molding process;

[0079] S2. Alkaline washing and degreasing;

[0080] S3. Roughening; an aqueous solution containing 390g / L concentrated sulfuric acid and 400g / L chromic anhydride was used as a roughening treatment solution, soaked at 68 ° C for 12min, removed and washed with anhydrous ethanol;

[0081] S4 sensitization and activation treatment; respectively, with sensitizing solution and activation solution spray treatment; sensitizing solution is an aqueous solution containing 15g / L stannous chloride, 8g / L sodium stannate and 27mL / L hydrochloric acid; activation solution is an aqueous solution containing silver nitrate concentration 8g / L, ammonia concentration of 8ml / L;

[0082] S5 electroless nickel deposition; in a nickel treatment solution comprising 18g / L nickel chloride, 2.5g / L sodium citrate, 10ml / L ammonia and 2.5g / L accelerator DA-222, pH 9, temperature 35 ℃, soaked for 7min to obtain a conductive nickel layer;

[0083] S6. Water-plated metal coating; sequentially performing copper plating, acid copper plating, and trivalent chromium plating;

[0084] S7 coating surface treatment agent; coating the surface treatment agent on the metal coating of S6, and then drying at 95 ℃ for 18min to cure;

[0085] S8. Wire drawing: using mechanical friction to produce a pattern of straight, random, spiral, wavy, or swirl lines;

[0086] S9. Vacuum nickel plating; spray UV primer, bake the primer, vacuum nickel plating, spray UV topcoat, and finally dry at 110℃ for 13 minutes.

[0087] In S7, the surface treatment agent includes the following components: epoxy acrylate, tetraethyl orthosilicate, ethanol, butyl titanate, tert-amyl peroxybenzoate, octyl propionate, KOH, a dispersant and a curing agent, wherein the dispersant is isotridecanol polyoxyethylene ether and the curing agent is polyamide. The content of each component is shown in Table 1 below.

[0088] The surface treatment agent was prepared as follows: epoxy acrylate, ethyl orthosilicate, ethanol, and butyl titanate were stirred at 95°C for 2.5 hours and then ultrasonically dispersed for 13 minutes to obtain an emulsion;

[0089] T-amyl peroxybenzoate, octyl propionate and KOH were mixed and stirred at 85° C. for 40 minutes; then, the emulsion, dispersant and curing agent were added and the stirring was continued for 55 minutes.

[0090] Example 4

[0091] The difference from Example 1 is that in S7, the surface treatment agent includes the following components: epoxy acrylate, tetraethyl orthosilicate, ethanol, butyl titanate, tert-amyl perbenzoate, octyl propionate, KOH, a dispersant, a curing agent, tetradecyl methacrylate, monooctyl maleate and deionized water, wherein the dispersant is isotridecyl polyoxyethylene ether and the curing agent is polyamide. The content of each component is shown in Table 1 below.

[0092] The surface treatment agent was prepared as follows: first, epoxy acrylate, ethyl orthosilicate, ethanol, and butyl titanate were stirred at 90° C. for 2 h, and then ultrasonically dispersed for 10 min to obtain an emulsion;

[0093] t-Amyl peroxybenzoate, octyl propionate and KOH were mixed and stirred at 80°C for 35 minutes; then tetradecyl methacrylate and emulsion were added, kept warm and stirred for 40 minutes; then a mixed solution of monooctyl maleate and deionized water was added, followed by a dispersant and a curing agent, and stirred for 50 minutes.

[0094] Example 5

[0095] The difference from Example 2 is that in S7, the surface treatment agent includes the following components: epoxy acrylate, tetraethyl orthosilicate, ethanol, butyl titanate, tert-amyl perbenzoate, octyl propionate, KOH, a dispersant, a curing agent, tetradecyl methacrylate, monooctyl maleate and deionized water, wherein the dispersant is isotridecyl polyoxyethylene ether and the curing agent is polyamide. The content of each component is shown in Table 1 below.

[0096] The surface treatment agent was prepared as follows: epoxy acrylate, ethyl orthosilicate, ethanol, and butyl titanate were stirred at 100°C for 3 h, and then ultrasonically dispersed for 15 min to obtain an emulsion;

[0097] t-Amyl peroxybenzoate, octyl propionate and KOH were mixed and stirred at 90°C for 45 minutes; then tetradecyl methacrylate and emulsion were added, and the mixture was kept warm and stirred for 55 minutes; then a mixed solution of monooctyl maleate and deionized water was added, and then a dispersant and a curing agent were added, and the mixture was stirred for 60 minutes.

[0098] Example 6

[0099] The difference from Example 3 is that in S7, the surface treatment agent includes the following components: epoxy acrylate, tetraethyl orthosilicate, ethanol, butyl titanate, tert-amyl perbenzoate, octyl propionate, KOH, a dispersant, a curing agent, tetradecyl methacrylate, monooctyl maleate and deionized water, wherein the dispersant is isotridecyl polyoxyethylene ether and the curing agent is polyamide. The content of each component is shown in Table 1 below.

[0100] The surface treatment agent was prepared as follows: epoxy acrylate, ethyl orthosilicate, ethanol, and butyl titanate were stirred at 95°C for 2.5 hours and then ultrasonically dispersed for 13 minutes to obtain an emulsion;

[0101] t-Amyl peroxybenzoate, octyl propionate and KOH were mixed and stirred at 85°C for 40 minutes; then tetradecyl methacrylate and emulsion were added, kept warm and stirred for 50 minutes; then a mixed solution of monooctyl maleate and deionized water was added, followed by a dispersant and a curing agent, and stirred for 55 minutes.

[0102] Example 7

[0103] The difference from Example 1 is that the surface treatment agent further includes tetradecyl methacrylate, and the content of each component is shown in Table 2 below.

[0104] Example 8

[0105] The difference from Example 7 is that tetradecyl methacrylate is replaced by acrylic acid. The contents of each component are shown in Table 2 below.

[0106] Example 9

[0107] The difference from Example 1 is that the contents of epoxy acrylate, ethyl orthosilicate, ethanol, and tetradecyl methacrylate are as shown in Table 2 below, in parts by weight.

[0108] Example 10

[0109] The difference from Example 1 is that the surface treatment agent further includes monooctyl maleate and deionized water, and the content of each component is shown in Table 2 below.

[0110] Example 11

[0111] The difference from Example 10 is that monooctyl maleate is replaced by polyethylene. The contents of each component are shown in Table 2 below.

[0112] Example 12

[0113] The difference from Example 1 is that the surface treatment agent is styrene-butadiene latex.

[0114] Example 13

[0115] The difference from Example 1 is that the dispersant is lauryl alcohol polyether.

[0116] Example 14

[0117] The difference from Example 1 is that the curing agent is dicyandiamide. Comparative Example

[0118] Comparative Example 1

[0119] The difference from Example 1 is that the electroplating method does not include S7, that is, no surface treatment agent is applied.

[0120] Comparative Example 2

[0121] The difference from Example 1 is that tetraethyl orthosilicate is replaced by ethyl acetate.

[0122] Comparative Example 3

[0123] The difference from Example 1 is that t-amyl peroxybenzoate is replaced by ethanol, and octyl propionate is replaced by acetic acid.

[0124] Table 1 Component contents of Examples 1-6

[0125] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Epoxy acrylate 30 40 35 30 40 35 Tetraethyl orthosilicate 4 5 5 4 5 5 ethanol 10 12 11 10 12 11 Butyl Titanate 0.4 0.6 0.5 0.4 0.6 0.5 tert-Amyl perbenzoate 2 3 2 2 3 2 Octyl propionate 0.6 0.8 0.7 0.6 0.8 0.7 KOH 0.1 0.2 0.2 0.1 0.2 0.2 dispersants 1 2 2 1 2 2 curing agent 2 3 2 2 3 2 Tetradecyl methacrylate / / / 4 6 5 Monooctyl Maleate / / / 1 2 2 Deionized water / / / 3 4 3

[0126] Table 2 Component contents of Examples 7-11

[0127] Example 7 Example 8 Example 9 Example 10 Example 11 Epoxy acrylate 30 30 36 30 30 Tetraethyl orthosilicate 4 4 6 4 4 ethanol 10 10 12 10 10 Butyl Titanate 0.4 0.4 0.4 0.4 0.4 tert-Amyl perbenzoate 2 2 2 2 2 Octyl propionate 0.6 0.6 0.6 0.6 0.6 KOH 0.1 0.1 0.1 0.1 0.1 dispersants 1 1 1 1 1 curing agent 2 2 2 2 2 Tetradecyl Methacrylate / Acrylic Acid 4 4 6 / / Monooctyl maleate / polyethylene / / 1 1 1 Deionized water / / 3 3 3

[0128] Performance testing

[0129] Test method: A 100-grid knife test was performed on the electroplated plastic workpieces of each embodiment and comparative example. A 100-grid test knife was used to scratch 100 grids with a length and width of 1 mm on the surface of the plastic workpiece to be tested. 3M610# adhesive tape was applied to the scratched surface of the plastic workpiece to be tested. The air was expelled, and the edge of the adhesive tape was lifted and quickly torn off at a 90° angle with a force of 1 kg. This was repeated three times. The adhesion of the scratching results was graded from 0 to 5 according to the standard ISO grade, with grade 0 being the best, indicating a completely smooth cut edge without any peeling of the grid edge. The test results are shown in Table 3 below.

[0130] Table 3 Performance test results of various embodiments and comparative examples

[0131] Adhesion grade Example 1 2 Example 2 1 Example 3 1 Example 4 1 Example 5 0 Example 6 1 Example 7 1 Example 8 2 Example 9 1 Example 10 1 Example 11 2 Example 12 3 Example 13 2 Example 14 2 Comparative Example 1 4 Comparative Example 2 3 Comparative Example 3 3

[0132] This specific implementation manner is merely an explanation of the present application and is not intended to limit the scope of protection of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by patent law.

Claims

1. An environmentally friendly electroplating method for plastic workpieces, characterized by: The steps include: S1. Remove internal stress: Dry the plastic workpiece at 65±2℃ for 3 hours to remove the internal stress during the product molding process; S2. Alkaline washing and degreasing; S3. Roughening; soak in a roughening solution, remove and rinse with anhydrous ethanol; S4. Sensitization and activation treatment: spraying with sensitizing solution and activation solution respectively; S5 electroless nickel deposition; treated in a nickel treatment solution, pH 8-10, temperature 25-45 ℃, soaked 5-8min to obtain a conductive nickel layer; S6. Water-plated metal coating; sequentially performing copper plating, acid copper plating, and trivalent chromium plating; S7 coating surface treatment agent; coating the surface treatment agent on the metal coating of S6, and then drying and curing at 90-100 ℃ for 15-20min; S8. Wire drawing: using mechanical friction to produce a pattern of straight, random, spiral, wavy, or swirl lines; S9. Vacuum nickel plating; spray UV primer, bake the primer, vacuum nickel plating, then spray UV topcoat, and finally dry at 100-120 ° C for 10-15 minutes; In said S7, the surface treatment agent comprises the following components in parts by weight: 30-40 parts of epoxy acrylate; 4-5 parts of ethyl orthosilicate; 10-12 parts of ethanol; 0.4-0.6 parts of butyl titanate; 2-3 parts of tert-amyl peroxybenzoate; 0.6-0.8 parts of octyl propionate; 0.1-0.2 parts of KOH; 1-2 parts of dispersant; 2-3 parts of curing agent; 4-6 parts of tetradecyl methacrylate; 1-2 parts of monooctyl maleate; and 3-4 parts of deionized water. The preparation method of the surface treatment agent is: First, epoxy acrylate, ethyl orthosilicate, ethanol and butyl titanate are stirred at 90-100°C for 2-3 hours, and then ultrasonically dispersed for 10-15 minutes to obtain an emulsion; Blend tert-amyl perbenzoate, octyl propionate and KOH, and stir to react at 80-90°C for 35-45 minutes; then add emulsion, dispersant and curing agent, and continue stirring for 50-60 minutes.

2. The environmentally friendly electroplating method for a plastic workpiece according to claim 1, characterized in that: Blend tert-amyl perbenzoate, octyl propionate and KOH, stir and react at 80-90°C for 35-45 minutes; then add 4-6 parts of tetradecyl methacrylate and emulsion, keep warm and continue stirring for 40-55 minutes; then add a mixed solution of 1-2 parts of monooctyl maleate and 3-4 parts of deionized water, then add dispersant and curing agent, and stir for 50-60 minutes.

3. The environmentally friendly electroplating method for a plastic workpiece according to claim 1, characterized in that: The dispersant is isotridecanol polyoxyethylene ether; and the curing agent is polyamide.

4. The environmentally friendly electroplating method for a plastic workpiece according to claim 1, characterized in that: In the S4, the sensitizing solution is an aqueous solution containing 10-20 g / L stannous chloride, 5-10 g / L sodium stannate and 25-30 mL / L hydrochloric acid; the activating solution is an aqueous solution containing 5-10 g / L silver nitrate and 6-10 ml / L ammonia.

5. The environmentally friendly electroplating method for a plastic workpiece according to claim 1, characterized in that: The nickel treatment solution of S5 includes 15-20 g / L nickel hypochlorite, 2-3 g / L sodium citrate, 8-12 ml / L ammonia water and 2-3 g / L accelerator DA-222.