KR20200144716A - Wet surface treatment method of nonconductive plastic - Google Patents

Abstract

According to the present invention, a wet surface treatment method of nonconductive plastic comprises: a step of performing a surface modification treatment on the nonconductive plastic; a pre-dipping step of treating the surface-modified nonconductive plastic surface with hydrochloric acid, and controlling the surface pH and surface charge; a step of using at least one between an activation solution containing a precious metal colloid and an ionogenic precious metal activation solution on the surface of the pre-dipped nonconductive plastic to metalize the surface of the nonconductive plastic; and a step of plating the metalized surface of the nonconductive plastic to give conductivity to the surface of the nonconductive plastic.

Description

Wet surface treatment method of non-conductive plastics{WET SURFACE TREATMENT METHOD OF NONCONDUCTIVE PLASTIC}

The present invention relates to a method for wet surface treatment of non-conductive plastics.

Plastic materials are widely used in our daily lives, but there are not many surface treatment technologies that can enhance products.

Electrodeposition coating can be applied to enhance the quality of plastic. Electrodeposition coating requires a plating process that imparts conductivity to the non-conductive plastic surface.

Until recently, plastic plating was mainly applied only to ABS materials and PC/ABS materials with relatively easy chemical etching, and much research has not been conducted on materials such as PET, PU, PE, PS, PVC, PP, PC, and PMMA. .

In addition, as chromium plating used for surface treatment of existing plastic materials reveals environmental pollution problems and high production cost limitations, there is a growing demand for a new method instead of chromium plating for plastic materials.

Dry surface treatment technology, which is one of the new methods, has the advantage of being able to control the thickness of the metal film layer to be thinner than that of the existing method, and its application range is gradually increasing.

However, in the metallization process of a polymer film material using dry surface treatment technology, there are disadvantages such as non-uniformity of the deposited metal particles, defects due to pore formation, and relatively low productivity and expensive equipment investment due to the dualization of the production process.

Republic of Korea Patent Publication No. 2011-0029602 (published on March 23, 2011)

It is an object of the present invention to provide a method for wet surface treatment of non-conductive plastics.

The present invention provides a method for plating a non-conductive plastic, comprising: a cleaning step of removing foreign substances from the surface of the non-conductive plastic; Surface-treating the non-conductive plastic with at least one etching solution after the cleaning step; Metallizing the surface-treated non-conductive plastic surface using at least one of an active solution containing a noble metal colloid and an ionic noble metal active solution; And plating the metallized surface of the non-conductive plastic to impart conductivity to a plating method for improving surface properties of a non-conductive plastic.

The cleaning step may include sequentially treating the non-conductive plastic in an acid bath and an alkali bath; And after treatment in the acid bath (Acid bath) and alkali bath (Alkali bath), it may include the step of ultrasonic treatment.

The acid bath treatment is performed in a solution containing sulfuric acid and a surfactant, and the alkali bath treatment is performed in a solution containing sodium hydroxide, sodium carbonate, trisodium phosphate, and a surfactant. I can.

The surface treatment step may include performing a primary etching treatment on the cleaned non-conductive plastic with an etching solution; And performing a second etching treatment with an etching solution containing a metal salt on the non-conductive plastic subjected to the first etching treatment.

The etching solution used in the first etching treatment may include (i) at least one acid; And (ii) an alkali metal permanganate and an alkaline earth metal permanganate.

The etching solution used in the secondary etching treatment may include at least one metal salt selected from the group consisting of FeCl3, FeCl2, TiCl3, CaCl2, CuCl2, CrCl3, ZnCl2, MgCl2, MnCl2, and Cr(NO3)3. .

After the surface treatment step, a pre-dip step of controlling the surface pH and surface charge by treating the non-conductive plastic surface with hydrochloric acid may be further included.

The metallization step may include: a first metallization step of adsorbing tin (Sn) on the surface of the non-conductive plastic; A second metallization step of adsorbing palladium (Pd) after the first step treatment; And a third metallization step of removing the tin (Sn) adsorbed on the surface of the non-conductive plastic and metallizing palladium (Pd).

The plating treatment step may be performed by an electroless plating process.

The non-conductive plastics are polyethylene terephthalate (PET), polyurethane (PU), polyethylene (PE), polycarbonate (PC), polyvinyl chloride (PVC), polystyrene (PS), polymethyl methacrylate (PMMA) And at least one of polypropylene (PP).

According to the present invention, there is provided a wet surface treatment method capable of providing conductivity and improving adhesion by forming a uniform metal film layer according to the wet surface treatment of a non-conductive plastic.

1 shows a wet surface treatment method of a non-conductive plastic according to an embodiment of the present invention,
2 is an experimental example of observing the surface texture of polypropylene (PP) according to the wet surface treatment (etching treatment) according to the first embodiment of the present invention with an electron microscope,
3 shows the results of evaluation of bonding strength (adhesion) according to the wet surface treatment of polypropylene (PP) according to the first embodiment of the present invention,
4 is an experimental example of observing the surface structure of polypropylene (PP) according to the wet surface treatment (etching treatment) according to the second embodiment of the present invention with an electron microscope,
5 shows the results of evaluation of bonding strength (adhesion) according to the wet surface treatment of polypropylene (PP) according to the second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present embodiment is not limited to the embodiments disclosed below, but may be implemented in various forms, only this embodiment makes the disclosure of the present invention complete, and the scope of the invention to those of ordinary skill It is provided to be fully informed. The shape of elements in the drawings may be exaggerated for more clear explanation, and elements indicated by the same reference numerals in the drawings mean the same elements.

1 shows a wet surface treatment method of a non-conductive plastic according to an embodiment of the present invention.

In the method for improving the surface characteristics of a non-conductive plastic according to an embodiment of the present invention (hereinafter referred to as “the method of the present invention”), the target plastic is polyethylene terephthalate (PET), polyurethane (PU), Polyethylene (PE), polycarbonate (PC), polyvinyl chloride (PVC), polystyrene (PS), polymethyl methacrylate (PMMA), and at least one of polypropylene (PP).

In the wet surface treatment method of a non-conductive plastic, first, a surface modification treatment step (S1) for surface modification of the non-conductive plastic is performed.

The surface modification treatment step (S1) includes a cleaning step (S1-1) of removing contaminants from the surface of the non-conductive plastic; An etching treatment step of etching with an etching solution after the cleaning step (S1-2); And a surface roughness adjusting step (S1-3) of adjusting the surface roughness of the etched non-conductive plastic.

The cleaning step (S1-1) corresponds to a pretreatment process of removing by-products present in the material manufacturing process or contaminants on the surface during handling, and non-conductive plastics are sequentially treated in an acid bath and an alkali bath. Processing step (S1-1-1); It is carried out through a step (S1-1-2) of ultrasonic treatment after treatment in an acid bath and an alkali bath.

Acid bath treatment may be performed in a solution containing sulfuric acid (H ₂ SO ₄ ) and a surfactant (Surfactant) at 30 to 100° C. for 10 to 40 minutes. Specifically, an aqueous solution in which 400 to 600 ml/L of sulfuric acid (H ₂ SO ₄ ) and 0.5 to 3 g/L of a surfactant are mixed may be prepared and treated at 50 to 85°C for 15 to 30 minutes.

After the acid bath treatment, the non-conductive plastic is treated in an alkali bath, and the alkali bath treatment is performed with sodium hydroxide (NaOH), sodium carbonate (Na ₂ CO ₃ ), and trisodium phosphate (Na _3). FO ₄ ) and in a solution containing a surfactant at 30 to 100° C., it may be performed for 10 to 40 minutes. Specifically, sodium hydroxide (NaOH) 25 to 45 g/L, sodium carbonate (Na ₂ CO ₃ ) 20 to 40 g/L, trisodium phosphate (Na ₃ FO ₄ ) 20 to 40 g/L, and surfactant 3 to 7 An aqueous solution containing g/L may be prepared and treated at 50 to 85°C for 15 to 30 minutes.

After sequentially treating the non-conductive plastic in an acid bath and an alkali bath, a cleaning step (S1-1-2) using ultrasonic waves is performed.

The cleaning step using ultrasonic waves is carried out in an ultrasonic bath, and is carried out for 1 to 30 minutes, preferably 2 to 20 minutes and more preferably 5 to 15 minutes.

The ultrasonic bath is a power in the range of 40 to 60 watts/L and removes foreign matter from the surface of the non-conductive plastic at a temperature of 40 to 60°C.

Treatment with an aqueous rinse solution after ultrasonic cleaning (though not shown) may be additionally performed.

The aqueous rinse solution contains an organic solvent, and the content of the organic solvent may be 2% to 15% by weight.

The organic solvent may be a known polar water-miscible solvent such as alcohol or dimethyl sulfoxide (DMSO), or may be a water-miscible alcohol such as methanol, ethanol or propanol.

In another embodiment, when the surface condition of the non-conductive plastic is good, the cleaning step may be replaced with only simple washing with ethanol or acetone. In addition, instead of using ultrasonic waves, washing water may be sprayed to increase the cleaning effect, or the washing step may be performed by vibrating agitation simultaneously with the washing water injection.

After the cleaning step, an etching treatment step (S1-2) of etching the non-conductive plastic with an etching solution is performed.

The etching treatment step (S1-2) is to impart hydrophilicity by chemically creating functional groups such as carboxyl groups or amine groups on the surface of non-conductive plastics, and physically swelling or surface roughening An adsorption site is provided so that more metal ions can be adsorbed on the non-conductive plastic surface through (anchoring).

The etching treatment step (S1-2) is to treat the etching solution on the non-conductive plastic from which foreign matters on the surface have been removed through the cleaning step (S1-1), and includes chromic acid (CrO ₃ ) and sulfuric acid (H ₂ SO ₄ ). It can be carried out for 10 to 60 minutes at 30 to 100 ℃ in an aqueous solution. For example, an aqueous solution of chromic acid (CrO ₃ ) 30 to 60 g/L and sulfuric acid (H ₂ SO ₄ ) 300 to 600 ml/L is prepared and carried out at 50 to 85° C. for 25 to 35 minutes. .

In order to improve the moistening of the non-conductive plastic surface to be etched, the etching solution may further contain a wetting agent. The concentration of the wetting agent can be appropriately adjusted and used by a person skilled in the art.

In one embodiment of the present invention, etching is performed using a solution containing chromic acid (CrO ₃ ) and sulfuric acid (H ₂ SO ₄ ) as an etching solution, but in another embodiment, (i) at least one acid; And/or (ii) an etching solution containing at least one permanganate selected from alkali metal permanganate and alkaline earth metal permanganate.

When an acid is used, an inorganic acid is used, and the inorganic acid is at least one selected from the group consisting of sulfuric acid, nitric acid, and phosphoric acid.

When using a permanganate, the alkali metal permanganate may be any one of potassium permanganate, sodium permanganate, lithium permanganate, and rubidium permanganate, and in particular, potassium permanganate or sodium permanganate may be used. As alkaline earth metal permanganate, magnesium permanganate and calcium permanganate are used.

After the etching treatment step (S1-2), a surface roughness adjusting step (S1-3) of adjusting the surface roughness of the non-conductive plastic surface is performed.

In the surface roughness adjustment step (S1-3), the etched plastic surface is swelled or the plastic surface is anchored to adjust the roughness of the plastic surface.

By the surface roughness control step (S1-3), a functional group, specifically, a hydrophilic functional group such as a hydroxyl group or a carboxyl group, is given to the surface of the plastic, facilitating the adsorption of metal ions, and at the same time creating a fine cavity on the plastic surface. It is formed to increase the surface roughness to improve the adhesion between the deposited metal film and the plastic surface.

After the surface treatment step (S1), a pre-dip step (S2) of controlling the surface pH and surface charge is performed by treating the surface of the non-conductive plastic with hydrochloric acid.

Contaminants are removed from the plastic surface through the surface treatment step (S1), hydrophilicity is imparted by etching, and the plastic surface is modified by adjusting the surface roughness. At this time, most of the modified surface has alkali, which causes instability of the subsequent process.

In the pre-dip step (S2), the non-conductive plastic surface is treated with hydrochloric acid to resolve this instability, and the pH and surface charge of the surface are adjusted.

By controlling the surface pH and surface charge according to the pre-dip step (S2), the stability of the noble metal catalyst is provided and the adsorption efficiency of the catalyst particles can be increased.

The concentration of hydrochloric acid treated for pre-dip includes 200 to 400 g of hydrochloric acid per liter of non-ionized water, and a compound of sodium chloride or potassium chloride, and the treatment conditions may be 1 to 5 minutes at room temperature.

After the pre-dip step (S2), a step (S3) of metallizing the non-conductive plastic surface using at least one of an active solution containing a noble metal colloid and an ionic noble metal active solution (S3) is performed. Is done.

The metallization step (S3) may include a first metallization step (S3-1) of adsorbing tin (Sn) on the non-conductive plastic surface; A second metallization step (S3-2) of adsorbing palladium (Pd) after the first step treatment; And a third metallization step (S3-3) of removing the tin (Sn) adsorbed on the non-conductive plastic surface and metallizing palladium (Pd).

The metallization step (S3) refers to a catalytic treatment process (catalyst activation process), and is to smoothly perform the formation of a plating layer, which is a subsequent process. It is carried out by the process of adsorbing the same precious metal.

The first metallization step (S3-1) is to adsorb tin (Sn) on the surface of a non-conductive plastic, in an aqueous solution containing tin chloride (SnCl ₂ ), hydrochloric acid (HCl), and sulfuric acid (H ₂ SO ₄ ). At to 100 ℃, it can be carried out for 10 minutes to 60 minutes. For example, a mixture of tin chloride (SnCl ₂ ) 30 to 60 g/L, hydrochloric acid (HCl) 30 to 60 ml/L and sulfuric acid (H ₂ SO ₄ ) 10 to 40 ml/L was prepared, and 50 At -80°C, the immersion treatment is performed for 35 to 45 minutes.

The second metallization step (S3-2) is to adsorb palladium (Pd) on the non-conductive plastic surface, in an aqueous solution containing palladium chloride (PdCl ₂ ) and hydrochloric acid (HCl) at 10 to 35°C, pH 2 to 5 And 5 to 30 minutes. For example, an aqueous solution of palladium chloride (PdCl ₂ ) 1 to 5 g/L and hydrochloric acid (HCl) 55 to 95 ml/L is immersed at 15 to 25°C and pH 2.5 to 4.5 for 10 to 20 minutes. .

The third metallization step (S3-3) removes tin (Sn), which is an impurity present in the adsorption process of the metal component through the second metallization step (S3-2), and metallizes palladium (Pd), This is a process in which only Pd ⁰ is present on the plastic surface to act as a metal catalyst in the subsequent plating process step. At this time, in a sulfuric acid (H ₂ SO ₄ )-based solution to remove tin (Sn), it is treated at 20 to 35° C. for 1 to 10 minutes.

After the metallization step (S3), a plating treatment step (S4) for imparting conductivity to the non-conductive plastic surface is performed. The plating treatment step S4 is performed by an electroless plating process.

The electroless plating process includes forming a first plating layer made of a first metal on a surface of a non-conductive plastic (S4-1); Forming at least one or more second plating layers made of a second metal on the first metal plating layer (S4-2); And drying the non-conductive plastic on which the plating layer is formed (S4-3).

In the step of forming the first plating layer (S4-1), the first metal is nickel and/or copper, and only nickel may be used.

The first metal plating layer is a plating solution consisting of 50ml/L EN800NB-M (Youngjin Plachem, Korea), 50ml/L EN8000NB-N (Youngjin Plachem, Korea) and 50ml/L EN8000NB-B (Youngjin Plachem, Korea). It can be formed by electroless plating at 60 to 90° C. for 1 to 20 minutes. The first metal plating layer functions as a base metal layer.

In the step of forming the second metal plating layer (S4-2), the second metal plating layer is formed on the first metal plating layer. The second metal is at least one selected from the group consisting of nickel, copper, zinc, and chromium, and specifically, nickel may be used.

The second metal plating layer is a process for controlling the surface roughness of the finally obtained plastic. Preferably, at least two or more plating layers are formed by using an electroless metal plating process.

For example, the second plating layer is a plating solution consisting of 60ml/L ENCHEM M-2001-A (Winstar Korea, Korea) and 150ml/L ENCHEM M-2001-B (Winstar Korea, Korea) at 60 to 90°C. , It can be formed by electroless plating for 1 minute to 20 minutes.

Drying the plastic (S4-3) is performed by drying the non-conductive plastic on which the plating layer is formed by hot air at 80 to 90°C for 30 to 60 minutes.

In the case of another embodiment in which electroplating (direct plating) is used for metallization of the plastic surface, after applying the catalyst with the catalyst-imparting treatment liquid, the activation treatment liquid containing copper ions having a pH of 7 or more, preferably pH 12 or more. Treated with

The treatment liquid containing copper ions may be copper sulfate. In order to treat the plastic surface with the activation treatment liquid, the temperature of the activation treatment liquid is set to 0 to 60°C, preferably 30 to 50°C, and the plastic is immersed for 1 to 20 minutes, preferably 2 to 5 minutes.

According to the present invention, there is provided a wet surface treatment method capable of providing conductivity and improving adhesion by forming a uniform metal film layer according to the wet surface treatment of a non-conductive plastic. Therefore, the plastic obtained by the present invention can be used when a metal surface is required on the surface of electronic, telecommunication parts, sound image parts, automobile parts and mechanical parts.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are merely illustrative to aid understanding of the present invention, and the scope of the present invention is not limited by the following examples.

Example 1

The surface was treated for surface modification of polypropylene (PP) (manufactured by Japan Polychem, Inc.). Surface treatment was sequentially prepared an aqueous solution in which sulfuric acid (H ₂ SO ₄ ) 500 ml/L, water (H ₂ O) 500 ml/L, and surfactant 1 to 2 g/L were mixed, and at 70° C., 20 minutes During the acid bath (Acid bath) treatment. After this, a solution of 35 g/L of sodium hydroxide (NaOH), 30 g/L of sodium carbonate (Na ₂ CO ₃ ), 30 g/L of trisodium phosphate (Na ₃ FO ₄ ) and 5 g/L of a surfactant was prepared. And, at 70° C., an alkali bath was treated for 20 minutes. After treatment with an acid bath and an alkali bath, washing was performed using ultrasonic waves at 50 watts/L and 50° C. for 10 minutes. Contaminants (foreign substances) on the plastic surface were removed by the above cleaning step.

Next, a mixture of chromic acid (CrO ₃ ) 38 g/L, water (H ₂ O) 550 ml/L and sulfuric acid (H ₂ SO ₄ ) 450 ml/L was prepared, and the temperature was 76° C. for 30 minutes. Etched. The surface treatment step was completed by controlling the roughness of the plastic surface by swelling the etched plastic surface or anchoring the plastic surface. The surface structure according to the wet surface treatment (etching treatment) of polypropylene (PP) was observed with an electron microscope, and it is shown in FIG. 2.

As shown in FIG. 2, as a result of observing the surface texture after the etching treatment, the surface roughening was uniformly formed in a net shape such as a fiber structure.

After the surface treatment, the surface of the plastic in which the cleaning, etching, and roughness were adjusted was treated with hydrochloric acid to perform pre-dip to control the surface pH and surface charge. For pre-dip, 300 g of hydrochloric acid per 1 liter of non-ionized water and a compound of sodium chloride or potassium chloride were treated, and the treatment conditions were performed at room temperature for 3 minutes.

To metallize the surface of pre-dip plastic plastic, tin chloride (SnCl ₂ ) 40 g/L, hydrochloric acid (HCl) 40 ml/L, sulfuric acid (H ₂ SO ₄ ) 20 ml/L and An aqueous solution in which 900 ml/L of water (H ₂ O) was mixed was prepared, and a first metallization step of immersion treatment was performed at 70° C. for 40 minutes.

After the first metallization step, a mixture of palladium chloride (PdCl ₂ ) 3 g/L, hydrochloric acid (HCl) 75 ml/L and water (H ₂ O) 922 ml/L was prepared, and a temperature of 20° C., pH A second metallization step of 3.5 and 15 minutes immersion was performed.

After the second metallization step was performed, in order to remove tin (Sn), which is an impurity present in the adsorption process of the metal component, in a sulfuric acid (H ₂ SO ₄ )-based solution at 30°C for 5 minutes. 3 metallization steps)

50ml/L EN800NB-M (Youngjin Plachem, Korea), 50ml/L EN8000NB-N (Youngjin Plachem, Korea) and 50ml/L EN8000NB-B (Youngjin Pla-Chem, Korea) on the surface of the plastic that has been metallized by the above steps. Chem, Korea) was subjected to an electroless plating process at 80° C. for 10 minutes to form a nickel base plated layer. As a follow-up process, a plating solution consisting of 60ml/L ENCHEM M-2001-A (Winstar Korea, Korea) and 150ml/L ENCHEM M-2001-B (Winstar Korea, Korea) was applied at 80℃ to 10 A secondary nickel plating layer was formed by performing an electroless plating process for minutes. It dried with hot air at 85 degreeC for 40 minutes.

Finally, in order to confirm the bonding strength (adhesion) according to the wet surface treatment of polypropylene (PP), it was tested according to the evaluation methods of KS-D 0254 (2001) and KS-M ISO 2409 (2013), and the results were confirmed. . This is shown in FIG. 3.

As shown in Fig. 3, both showed good bonding strength (adhesion) in the results of the adhesion test (KS-D 0254) of the plating through the hardened steel scraper and the evaluation of plating peeling according to the peel test (KS-M ISO 2409). .

Example 2

Polypropylene (PP) was subjected to wet surface treatment in the same manner as in Example 1. However, the other conditions were the same, and in the etching treatment step, the treatment time of the etching solution was set differently. Specifically, a mixture of chromic acid (CrO ₃ ) 38 g/L, water (H ₂ O) 550 ml/L and sulfuric acid (H ₂ SO ₄ ) 450 ml/L was prepared in the etching step, and a temperature of 76° C., It was etched for 5 minutes.

4 shows that the surface texture of the polypropylene (PP) according to the wet surface treatment (etching treatment) according to Example 2 was observed with an electron microscope, and the wet surface treatment of the polypropylene (PP) according to Example 2 The result of evaluation of bonding strength (adhesion) is shown in FIG. 5.

4 and 5, as a result of observing the surface texture after the etching treatment, the surface roughening was uniformly formed in a net shape such as a fiber structure, and an adhesion test of plating through a hardened steel scraping mechanism (KS-D 0254) and In the results of plating peeling evaluation (KS-M ISO 2409) according to the peel test, all showed good bonding strength (adhesion).

Embodiments of the present invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those of ordinary skill in the technical field of the present invention can improve and change the technical idea of the present invention in various forms. Therefore, such improvements and changes will fall within the scope of protection of the present invention as long as it is apparent to those of ordinary skill in the art.

Claims (10)

In the wet surface treatment method of non-conductive plastic,
Surface-modifying the non-conductive plastic;
Pre-dip step of treating the surface-modified non-conductive plastic surface with hydrochloric acid to control surface pH and surface charge;
Metallization using at least one of an active solution containing a noble metal colloid and an ionic noble metal active solution on the surface of the pre-dip non-conductive plastic; And
A wet surface treatment method of a non-conductive plastic comprising the step of plating to impart conductivity to the surface of the metallized non-conductive plastic. In claim 1,
The surface modification treatment step,
A cleaning step of removing contaminants from the surface of the non-conductive plastic;
An etching treatment step of etching with an etching solution after the cleaning step; And
A wet surface treatment method of a non-conductive plastic comprising the step of controlling a surface roughness of the etched non-conductive plastic. In paragraph 2,
The cleaning step,
Sequentially treating the non-conductive plastic in an acid bath and an alkali bath; And the acid bath treatment is performed in a solution containing sulfuric acid and a surfactant, and the alkali bath treatment is performed in a solution containing sodium hydroxide, sodium carbonate, trisodium phosphate, and a surfactant. do.
After treatment in the acid bath and the alkali bath, the method of treating a non-conductive plastic with an ultrasonic wave. In paragraph 2,
In the etching treatment step, a solution containing chromic acid and sulfuric acid is used,
The surface roughness adjusting step is a wet surface treatment method of a non-conductive plastic, characterized in that after etching treatment, swelling treatment or anchoring of the plastic surface. In claim 1,
The pre-dip step is a wet surface treatment method of a non-conductive plastic, characterized in that performed for 1 to 10 minutes at 10 ~ 50 ℃. In claim 1,
The metallization step,
A first metallization step of adsorbing tin (Sn) on the non-conductive plastic surface;
A second metallization step of adsorbing palladium (Pd) after the first step treatment; And
And a third metallization step of removing the tin (Sn) adsorbed on the surface of the non-conductive plastic and metallizing palladium (Pd). In claim 1,
The plating treatment step,
A wet surface treatment method of a non-conductive plastic, characterized in that carried out by an electroless plating process. In clause 7,
The electroless plating process,
Forming a first plating layer made of a first metal on the surface of the non-conductive plastic;
Forming at least one or more second plating layers made of a second metal on the first metal plating layer; And
A wet surface treatment method of a non-conductive plastic comprising the step of drying the non-conductive plastic on which the plating layer is formed. In clause 8,
The first metal and the second metal are each,
Non-conductive plastic wet surface treatment method comprising at least one selected from the group consisting of nickel, copper, zinc and chromium. In claim 1,
The non-conductive plastic,
Polyethylene terephthalate (PET), polyurethane (PU), polyethylene (PE), polycarbonate (PC), polyvinyl chloride (PVC), polystyrene (PS), polymethyl methacrylate (PMMA) and polypropylene (PP) Non-conductive plastic wet surface treatment method comprising at least one of.

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