KR20130006551A - Plating method of acrylonitrile-butadiene-styrene copolymer using manganate salt as etchant - Google Patents

Abstract

PURPOSE: A method for plating ABS(Acrylonitrile-Butadiene-Styrene Copolymer) resins using permanganate as etchant is provided to use the plating of ABS resins by placing with the environmentally-friendly surface treatment without using chromic acid. CONSTITUTION: A method for plating ABS resins comprises a degreasing process, an etching process, an electroless plating process, and an electrolytic nickel plating process. The etching process uses an etchant including permanganate. The etchant is composed of 0.10~0.20 M of the permanganate, 4.0~5.0M of phosphoric acid, and 10~13M of sulfuric acid.

Description

Plating method of Acrylonitrile-Butadiene-Styrene copolymer using manganate salt as etchant}

The present invention relates to a plating method of acrylonitrile-butadiene-styrene copolymer (ABS) resin using permanganate as an etching solution, which is an environmentally friendly surface treatment method capable of plating without using chromic acid, which is a conventionally used environmentally harmful substance. .

With the development of the petrochemical industry, synthetic resins have been applied under the name of plastics. Recently, engineering resins and super engineering plastics have been applied to component materials as products having high strength and chemical resistance with the characteristics of metals and ceramics. However, in order to apply to the industry, it is often applied to give the purpose of functionality and special use by the surface treatment method rather than being applied as a molded article. In particular, ABS resin (Acrylonitrile-Butadiene-Styrene copolymer), which is represented by plastic, is a material that is mostly applied as a plating resin, and has excellent mechanical and thermal properties such as impact resistance.

Restriction of the use of certain Hazardous Substances in electrical and electronic equipment (RoHS), the European Waste Vehicle Treatment Directive (RoHS) ELV: End of Life Vehicles directive (ELV), the existing Regulations for Registration, Evaluation, Authorization and Restriction of Chemical Substances (REACH), including the Regulations on Registration Evaluation Authorization and Restriction of CHemicals. The regulation of substances affecting human and environmental hazards is strictly applied. Along with these problems, the processing of component materials, which are the basis of the industry, is being developed in an environment-friendly and less harmful to human body.

 Etching process, which is essentially applied for plating on the ABS resin, is a process of imparting physical bonding force between the plating layer and the material layer, thereby essentially using chromic acid. The chromic acid applied to the etching process is classified as an environmentally harmful substance because organic matter reacts rapidly with the breathing oxygen and stabilizes as chromium oxide in a short time.

These materials have been essential for the surface treatment process, and as mentioned above, various studies have been made to replace Cr ⁶⁺ materials used in chromic acid etching together with recent environmentally friendly processing methods.

Therefore, the inventors of the present invention have described ABS resin as an optimal etching method using permanganate, which is classified as a strong oxidant to be applied to the surface treatment process of plastic materials, which is classified as an environmentally harmful substance and does not use chromic acid to suppress carcinogenicity and human erosion. The present invention was completed by applying to a plating method.

An object of the present invention is to provide an optimal etching method for applying to the surface treatment process of plastic material with a material that does not use chromic acid in order to suppress carcinogenicity and human erosion.

In order to achieve the above object, the present invention is a plating method of acrylonitrile-butadiene-styrene copolymer (ABS) resin comprising a degreasing process, an etching process, an electroless plating process and an electrolytic nickel plating process, wherein the etching process Provided is a plating method of an ABS resin, characterized by using an etching solution containing silver permanganate.

The etchant may comprise 0.10 to 0.20 M permanganate, 4.0 to 5.0 M phosphoric acid and 10 to 13 M sulfuric acid, preferably the etchant comprises 0.15 M permanganate, 4.7 M phosphoric acid and 12 M sulfuric acid. It may include.

The etching process is preferably etched for 3 to 5 minutes at a temperature of 65 to 70 ℃ using an etching solution containing 0.15M permanganate, 4.7M phosphoric acid and 12M sulfuric acid.

According to one embodiment of the present invention, H ₃ PO _4, H ₂ SO _4, and Experiments were carried out in an etchant mixed with KMnO ₄ , and the results showed that the amounts of H ₃ PO _4, H ₂ SO _4, and KMnO ₄ were 250 mL / L, 650 mL / L, and 25 g / L, respectively, at 70 ° C. for 5 minutes. When etching, it was found that the optimum etching conditions.

As the strong oxidizing agent KMnO ₄ was increased from 5 g / L to 25 g / L, butadiene was oxidized to form carboxyl group and carbonyl group, and when it contained more than 25 g / L, KMnO ₄ was formed. Butadiene and styrene-acrylonitrile (SAN) resin are oxidized at the same time, so that the etching is not performed in the form of a sponge.

In addition, as the amount of H ₂ SO ₄ increases, the bond between the ABS weakens the swelling action, KMnO ₄ was found to make the butadiene easy to oxidize.

In addition, increasing H ₃ PO ₄ shortens the etching time and enables fast etching. It was found that the content of more than 250ml / ℓ also quickly oxidize SAN resin, reducing the overall porous surface.

Identification of the etched porous surface AFM images show that H ₃ PO _4, H ₂ SO _{4, and} KMnO ₄ were etched at 70 ° C. for 5 minutes at 250 ml / l, 650 ml / l and 25 g / l compositions, respectively. A porous surface with uniform unevenness was obtained overall. As the etching time increases, the unevenness increases in size but the overall uneven porosity due to overetching decreases the adhesion in the adhesion test.

XPS analysis showed that the ABS resin was oxidized to form a carboxyl group and a carbonyl group to have hydrophilicity.

In addition, the present invention provides an ABS resin prepared according to the above production method.

The plating method of the ABS resin according to the present invention can be usefully used for the plating of the ABS resin as an environmentally friendly surface treatment capable of plating without using chromic acid which is a conventional environmentally harmful substance.

1 is an analysis result of the ABS resin according to the present invention using FT-IR / ATR,
2 is a schematic view showing an etching apparatus used in the present invention,
3 is a schematic diagram of an electroplating apparatus used in the present invention,
4 is a conceptual diagram showing the entire plating process on the ABS resin,
5 is a conceptual diagram illustrating a method of measuring adhesion to plating;
6 is a SEM photograph of the ABS surface according to the amount of KMnO ₄ ,
7 is a SEM photograph of the ABS surface according to the amount of H ₂ SO ₄ ,
8 is a SEM photograph of the ABS surface according to the amount of H ₃ PO ₄ ,
9 is a SEM photograph of the ABS surface with temperature;
10 is a SEM photograph of the ABS surface according to the etching time,
11 is an AFM photograph of an ABS surface according to etching time,
12 is a comparison of the bonding state before and after etching of the ABS resin through XPS analysis,
13 is a result of adhesion analysis according to the etching time after plating,
14 is a comparison result of SEM photographs according to various etching types.

The present invention will be described in more detail by way of the following examples. However, the present invention is not limited by these examples.

≪ Example 1 >

I. Experimental Method

1. Confirmation of specimen and fabrication of specimen

ABS resin used in this experiment was injected into the plating ABS resin MP-220 produced by LG Chem at 60kg / cm ² at 210 ℃. Specimen identification was confirmed using a far infrared spectrometer (Fourier Transform Infrared Spectrometers; FT-IR / ATR, Thermo Nicolet Nicolet-6700, USA) as shown in FIG. Specimens used for etching were 10 mm x 10 mm x 3 mm plates, and 100 mm x 50 mm x 3 mm plates were used for the adhesion test.

2. Pretreatment and Etching

Degreasing was performed by dissolving 50 g / l NaOH, 30 g / l Na ₃ PO _{4 and} 30 g / l NaCO ₃ in distilled water for 10 minutes at 50 ° C. ABS specimens were treated with KMnO ₄ , H ₂ SO ₄ and Etching was performed on the etching liquids of various compositions of H ₃ PO ₄ given the variables of temperature and time. 2 is a schematic view showing an etching process.

3. Electroless Plating

1) Catalytic Treatment Process

The surface activation process of the etched ABS used a catalyzing-accelerating process. At this time, PdCl ₂ 0.4g / L, SnCl ₂ · 2H ₂ O 40g / L, HCl 200ml / L catalyzed solution was used in the accelerated process to remove the residual Sn components in the catalytic process 100ml / l H ₂ SO ₄ solution was used.

2) Electroless Nickel Plating

The plating apparatus used for electroless plating is the same as the etching process.

The plating bath uses pyrex material to prevent free metal ions from being deposited on the wall of the plating bath, and the plating bath has a capacity of 2 l. The tester was made of aluminum, and a protective film was formed on Teflon tape having excellent corrosion resistance and heat resistance, and was placed in the center of the plating bath. The tester also prevented nickel ions from reducing precipitation during electroless plating on the catalyst Pd ⁰ remaining on the surface during the pretreatment process. The temperature change of the plating liquid has a great effect on the plating speed and the plating structure, so it was plated in a thermostat. The thermostat has a large capacity, can be stirred, and is equipped with a mercury thermostat which can keep the temperature within ± 1 ℃.

The electroless nickel plating experiments were carried out for 10 minutes at 35 ° C. ± 1 ° C. in a Pyrex glass beaker in a thermostat equipped specimens treated with the pretreatment method described above. The composition of the plating bath used in this experiment was 20 g / l NiSO ₄ · 6H ₂ O, 20 g / l NaH ₂ PO ₂ · H ₂ O, 15 g / l C ₆ H ₅ O ₇ Na · 2H ₂ O, pH adjuster Is NaOH and the pH range was 9-9.5. PH correction and agitation were not performed during plating. The plating process of this experiment is shown in Table 1.

No fair Chemical composition Temperature time One Degreasing NaOH 30g / ℓ
Na ₃ PO ₄ 30 g / ℓ
NaCO ₃ 30g / ℓ 50 ℃ 10 min 2 etching KMnO ₄ variable
H ₂ SO ₄ variable
H ₃ PO ₄ variable variable variable 3 Neutralization HCl 50ml / ℓ RT 5min 4 Catalysis PdCl ₂ 0.4g / ℓ
SnCl ₂ 2H ₂ O 40g / ℓ
HCl 200ml / l 35 ℃ 10 min 5 Accelerate H ₂ SO ₄ 100ml / ℓ 40 ℃ 1 min 6 Electroless Nickel Plating NiSO ₄ 6H ₂ O 20 g / ℓ
NaH ₂ PO ₂ H ₂ O 20 g / ℓ
C ₆ H ₅ O ₇ Na ₂ H ₂ O 15 g / ℓ
pH adjusting substance = NaOH
pH: 9-9.5 32-35 ℃ 10 min 7 Activation H ₂ SO ₄ 100ml / ℓ RT 30sec 8 Electrolytic Nickel Plating NiSO ₄ ^. 6H ₂ O 240g / ℓ
NiCl ₂ ^. 6H ₂ O 45g / ℓ
H ₂ BO ₃ 30g / ℓ
Commercial additive 40-45 ℃ 30min

4. Electrolytic Nickel Plating

The plating apparatus used for the electrolytic plating is shown in FIG. The plating bath is made of PVC and has a capacity of 12ℓ to prevent sudden changes in plating composition. The difference from the electroless plating bath is that there is a rectifier for supplying electricity, and a filter is provided to continuously filter the plating liquid to remove impurities on the plating liquid. The composition of the plating liquid used in this experiment was 240 g / l NiSO ₄ · 6H ₂ O, 45 g / l NiCl ₂ · 6H ₂ O, 30 g / l H ₂ BO ₃ , and Ni conc was added as a commercial additive. An experiment was performed for 30 minutes by applying a current to obtain a Ni plating layer having a thickness of about 25 μm.

5. Characterization of ABS Resin

1) Analysis of etching characteristics of ABS resin

The surface was observed using a scanning electron microscope (SEM, Hitachi, S-4800 S-4200, Japan) to confirm the etched degree of the ABS resin.

An X-ray photoelectron spectrometer (XPS, Thermo Fisher Scientific, Multilab-2000, UK) was used to confirm that butadiene on the ABS surface was oxidized to produce carboxyl and carbonyl groups during etching.

Far-infrared spectrometer (Fourier Transform-far Infrared Spectrometers; FT-far IR, Thermo Nicolet, Nicolet-6700, USA) was used to determine whether the ABS resin is suitable for the specimen used in this experiment.

In order to confirm that irregularities were formed on the surface of the ABS resin after etching, a scanning probe microscope (SPM, Digital instruments, Nanoscope II, U.S.A.) was observed in AFM mode. Observed results were calculated root mean square (RMS) roughness value, it is shown in 3D pictures.

2) Plating adhesion measurement

As shown in FIG. 5, the Ni plating layer was peeled off by 1 cm × 1 cm using an adhesion strength tester (AM, LC8405S-K525, Korea).

II Experimental Results

1. Etching Characteristics by Etching Components

1) Microstructure According to the Change of KMnO _{4 Addition}

Through etching experiment of ABS resin, we tried to find the optimum etching conditions for electroless nickel plating in the mixture of KMnO ₄ , H ₂ SO ₄ , H ₃ PO ₄ . The overall process of this experiment is shown in FIG. 4.

KMnO ₄ serves to oxidize butadiene as an oxidizing agent. In order to examine the etching characteristics according to the amount of KMnO _{4, the} amount of H ₂ SO _{4 and} H ₃ PO ₄ was kept constant at 650 ml / l and 250 ml / l, respectively, and the amount of KMnO ₄ was 5 g / l, 15 g / l, The experiments were increased to 25 g / l, 35 g / l, and 45 g / l.

In FIG. 6A, when the surface structure etched at 70 ° C. for 5 minutes in the etching solution in which the amount of KMnO ₄ is dissolved at 5 g / L is observed, the etched surface and the non-etched surface are clearly distinguished. You can see that a round circle is created between the SANs and eroding into the circle. 6 (b) of the experiment with 15 g / l added etching solution, only butadiene was oxidized and eluted at 5 g / l addition. It can be observed that the etching proceeds. 6c to which 25 g / l is added, it can be seen that oxidation proceeds more than 15 g / l is added, and further erodes into the inner side of the material, thereby creating a tissue capable of giving sufficient hook effect during plating. . Compared with the etching process of CrO ₃ , which is a conventional process, the shape of the microstructure shows a significant difference. The etching of CrO _{3 in} FIG. 14 has a dendritic structure as it is eroded into the material direction, but in the etching using KMnO ₄ , a ring structure is formed in which a ring is stacked. Butadiene and SAN (Styrene-Acrylonitrile) in the CrO ₃ etchant is faster than the SAN but the oxidation rate is faster than the overall oxidation, but the oxidation rate of butadiene in the KMnO ₄ etchant compared to the CrO ₃ etchant is SAN oxidation It is much faster than speed, and you can see that it has a ring structure. 6 (d) in which 35 g / l KMnO ₄ is present, it is possible to observe different microsurfaces when increasing from 5 g / l to 25 g / l. If KMnO ₄ is present in excess, butadiene and SAN are oxidized at the same time, there is little donut-like surface, and it can be seen that the erosion is slightly eroded into the rough surface. Butadiene and SAN etch rate is slightly faster than the etching rate of butadiene can be seen that the presence of a circular porous life on the surface.

As shown in FIG. 6E, when 45 g / L KMnO ₄ is dissolved in the etching solution, it is oxidized as a whole without a difference in the rate of etching of butadiene and SAN to form a rough microsurface. It can be seen that the mechanical adhesion to give the hook effect is not obtained.

As the amount of KMnO ₄ increases, the amount of oxidant increases to increase the microporous surface. However, when KMnO ₄ is present in excess of 25 g / L, the etching proceeds as a whole, so that it has no surface with fine roughness that gives mechanical adhesion. Has

2) Microstructure According to Changes in H ₂ SO _{4 Addition}

In order to examine the change according to the amount of H ₂ SO _4, the amount of H ₃ PO ₄ and KMnO ₄ was kept constant at 250 ml / l and 25 g / l, respectively, and the amount of H ₂ SO ₄ was 50 ml / l and 200 ml / l. , 350 ml / l, 500 ml / l, 650 ml / l.

Figure 7 shows the change in the surface microstructure with increasing H ₂ SO ₄ amount by scanning electron microscopy.

Referring to (a) of FIG. 7, when the surface microstructure is observed when 50 ml / l of H ₂ SO ₄ is present in the etching solution, the etching does not occur due to the oxidation reaction. The biggest role of H ₂ SO ₄ in etching is to swell the loosening bonds between the polymers. If the swelling action that weakens the bond between the polymers is not smooth, the strong oxidizing agent KMnO ₄ does not function properly as an oxidizing agent.

In FIG. 7B, in which the amount of H ₂ SO ₄ is increased to 200 ml / L, butadiene does not undergo much oxidation, but the butadiene is slightly oxidized, but little oxidation occurs, such as a slight white spot.

Referring to FIG. 7C, when H ₂ SO ₄ increases to 350 ml / l, a fine porous surface is formed on the ABS resin surface. The etching reaction is very weak because the amount of H ₂ SO ₄ softening and swelling the bonds between the polymers is not sufficient.

In (d) of FIG. 7 in which sulfuric acid is 500 ml / l, swelling reaction occurs more than 350 ml / l, and the amount of porous surface is increased and the size of the circular hole formed by oxidation of butadiene increases. have. Another action of sulfuric acid is to elute oxidized butadiene from the material. If there is not enough sulfuric acid in the etching solution during etching, the swelling and elution is not smooth, but the butadiene is not oxidized well, the etching is not smooth.

It can be seen that when the sulfuric acid is increased by 650 ml / l, potassium permanganese has a sufficient swelling action to oxidize the butadiene resin, resulting in a smooth etching. It can also be observed that oxidized butadiene elutes and erodes deeply from the surface towards the material.

If the amount of sulfuric acid is small, it does not soften the bond between butadiene and SAN, so even if there is enough oxidant, the oxidation reaction does not occur. Has a stacked structure.

3) Microstructure According to Change of H ₃ PO _{4 Addition}

To investigate the change in the amount of _{H 3 PO 4 H 2 SO 4} , KMnO 4 , each amount 650㎖ / ℓ, kept constant at 25g / ℓ and the amount of H ₃ PO ₄ 50㎖ / ℓ, 100㎖ / ℓ , 150 ml / l, 250 ml / l, 300 ml / l.

8 is a surface electron microscopy with changes in the amount of KMnO ₄ is observed by scanning electron microscopy.

When phosphoric acid is present in the etchant 50 ml / l, the texture of the ABS surface is weak but it is observable that the butadiene is oxidized. At 5000 times magnification, fine white spots are spread throughout the surface. If you look at 10000 times, you can see that it is oxidized to produce very small holes. The amount of sulfuric acid swelling and permanganese potassium, which is an oxidizing agent, is sufficient, but the oxidation reaction does not occur rapidly, indicating that phosphoric acid increases the oxidation rate.

As the amount of phosphoric acid increases to 100 ml / l, the small white spots that spread out at 50 ml / l grow to the extent that they are identified as pores, and oxidation proceeds as a whole. Observing at 10000 times, when comparing the microstructure according to the amount of 50ml / l and 100ml / l, the difference in the number of oxidation occurs is not significantly different, but it can be seen that only the size of the hole is increased by etching. . As mentioned above, phosphoric acid has a greater effect on the reaction rate than the direct effect on the swelling and oxidation of butadiene.

Increasing the phosphoric acid to 150ml / l, the pores of the tissue is slightly larger than that of 100ml / l, there is little difference. When phosphoric acid increased to 250ml / l, the etching reaction proceeded rapidly to obtain a donut-shaped porous surface throughout the surface, and chipped deeply from the surface into the material direction to obtain an excellent porosity surface.

When phosphoric acid increases to 300 ml / l, the porous surface disappears and has a mesh-like surface. In the presence of sufficient swelling and excess phosphoric acid to promote the reaction in the presence of an oxidant, the ABS resin is etched entirely and does not form a porous surface. Butadiene is oxidized a little faster than SAN and has a mesh-like surface, but a porous surface cannot be obtained because the etching rate is not significantly different.

As the amount of phosphoric acid increased, the etching reaction rate increased, and the number of sites on which the reaction occurred did not change significantly even if the phosphoric acid increased.

2. Etching Characteristics with Temperature Change

The amount of H ₃ PO _4, H ₂ SO _{4, and} KMnO ₄ was observed to increase the porosity of the surface according to the temperature change during etching at 250 ml / l, 650 ml / l and 25 g / l, respectively.

9 shows the change of microsurface tissue with increasing temperature.

The experiment was conducted at room temperature in a preliminary experiment, but the reaction was weak.

At a temperature of 30 ° C., an oxidation reaction occurred throughout the surface to form a porous surface. Potassium permanganese, swelling and sulfuric acid eluting oxidized butadiene, and phosphoric acid increasing the etching rate are sufficient. Temperature plays an important role in chemical reactions. As the temperature rises, the substance becomes more active and the reaction rate increases. It was observed that butadiene was completely oxidized and etched at 30 ° C., but the etching rate was slow.

Oxidation at 40 ° C occurs throughout the surface of the specimen, and compared with 30 ° C, the site of oxidation does not increase but the pore size of the site of oxidized butadiene increases.

At 50 ℃, the size of the oxidized pores does not change significantly compared to 40 ℃, but it can be observed that the oxidation reaction occurs inside the material.

It can be seen that the reaction oxidizes the entire resin at 60 ° C. The unchanged pore size at 40 ° C and 50 ° C showed that the entire butadiene site was eluted and only SAN remained, but from 60 ° C the entire butadiene and SAN resin were oxidized. Butadiene has a much faster oxidation rate than SAN resin, resulting in a sponge-like structure.

It can be seen that a sponge structure can be formed to impart mechanical adhesion, but a small amount of local etching can be observed by looking at a photograph of 5000 magnification.

Etching at 70 ° C. shows that the etching proceeds uniformly at 5000 magnification. When observed at 10000 magnification, the sponge-like microsurface structure is obtained due to the difference in etching rate between butadiene and SAN.

3. Etching Characteristics According to Etching Time

1) Microstructure according to etching time

The amount of H ₃ PO ₄ , H ₂ SO ₄ , and KMnO ₄ was observed in FIG. 10 to increase porosity of the surface according to the etching time at 250 ml / l, 650 ml / l, and 25 g / l, respectively.

When the etching was performed for 5 minutes, the optimum conditions were confirmed when the amount of potassium permanganate, sulfuric acid and phosphoric acid was changed. In the picture observed at 5000 magnification, the etching proceeded evenly as a whole, and in the picture at 10000 magnification, the etching proceeds in the inner direction of the material, and it has a sponge structure that can give an excellent hook effect.

The photo etched for 10 minutes shows overetching. At 5000 magnifications, the surface is roughened overall, and in 10000 times, the thickness of the ring formed by the elution of butadiene is thinned or broken.

After 15-minute etching, overetching proceeded further, and the size of the ring shape present in the sponge structure was greatly increased compared to that of 5-minute etching. An increase in the size of the ring can be seen in the 5000 times photograph.

At 20 minutes, more overetching can be observed. Observed at 5000 times, the size of the ring was enlarged. Observed at 10000 times, the size of the ring in the depth direction of the material could be observed at the same time.

At 25 minutes, it was confirmed that the ring present in the sponge form appeared large at 5000 magnification. At 10,000 times, it can be seen that when the size of the ring is further increased, a large hole is formed. Compared to the 5-minute etch, overetching is severe and the hook effect is reduced.

2) Fine surface shape according to etching time

H ₃ PO ₄ , H ₂ SO ₄ , KMnO ₄ contents were observed for the surface roughness with the change of etching time at 250ml / l, 650ml / l, 25g / l composition, respectively.

11 is an AFM image of measuring surface roughness.

The surface of the ABS resin before etching is slightly uneven, but exists in a flat state as a whole.

After collecting the AFM image etched for 5 minutes, it can be observed that irregularities are formed evenly on the entire surface. Fine and even irregularities serve to impart mechanical adhesion.

The 10-minute etched AFM image shows that the etching proceeds evenly throughout, but the variation in surface roughness increases locally. It can be seen that the etching proceeded further in the depth direction on the material surface. It can be observed that the variation in etching becomes larger as compared with the 5-minute etching. In other words, etching proceeded locally. This is a factor that inhibits mechanical adhesion.

After 15 minutes of etching, the fine irregularities on the surface are reduced and only large irregularities are locally distributed. If the unevenness is reduced, the mechanical adhesiveness is lowered by decreasing the place to give mechanical adhesion.

If you look at the 20-minute etched image, you can see that the fine roughness is reduced and the etching deviation is bigger compared to the 15-minute etched image. Etching further proceeded in the material depth direction. Compared with the SEM image, it can be seen that the ring shape under the wide-ringed ring shape is enlarged in the picture of 10,000 times magnification and supports the contents of the AFM image.

4. Comparison of bonding state before and after etching of ABS resin

The purpose of etching is largely two to give fine irregularities to the surface for imparting mechanical adhesion, and the other is to impart hydrophilicity to improve the wettability of the plating liquid on the surface so that the plating can be smoothly raised. In order for the resin surface to be hydrophilic, the surface must be polarized. When the butadiene is oxidized during etching, polar carboxyl groups and carbonyl groups are formed, and FIG. 12 confirmed this through XPS analysis.

The etching was performed for 5 minutes at 250 mL / L, 650 mL / L, and 25 g / L compositions of H ₃ PO ₄ , H ₂ SO ₄ , and KMnO ₄ .

12 (a) shows a large peak when the binding energy is 285 eV in the XPS spectrum before etching, and this peak indicates the presence of C-H, C-C, and C = C.

In FIG. 12 (b), which measured the specimen etched for 5 minutes, two peaks were additionally generated in addition to the peaks present at 285 eV. C = O, a carbonyl group produced at 287.5eV, and O = C-O, a carboxyl group produced at 288.5eV. It can be seen that butadiene produced a polycarbonyl group and a carboxyl group due to oxidation, and thus the main peak having C-H, C-C, and C = C decreased after etching.

Analysis by XPS resulted in oxidation, which reduced the amount of carbon from 74.03% before etching to 71.36%. The amount of carbon present in the main peak was reduced to 63.57%. It can be seen that the amount of oxygen increased due to oxidation, increasing from 19.54% to 25.56% before etching.

5. Adhesion Test of Plating Layer According to Etching Conditions

The etching was performed on the specimens etched for 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes at 250 ml / l, 650 ml / l, and 25 g / l, respectively, in amounts of H ₃ PO ₄ , H ₂ SO ₄ , and KMnO ₄ . All processes of 4 were performed.

In order to test the adhesion, the thickness of the plating layer should be at least 20 μm, so that a current of 4ASD was applied for 30 minutes.

For the adhesion test, the Ni-plated layer plated on the specimen was peeled off by 1cm × 1cm and bitten by a load cell.

FIG. 13 shows the results of the adhesion test and showed excellent adhesion at 1.2 kN / m after 5 minutes of etching, and gradually decreased to 1.1 kN at 10 minutes, 0.9 kN at 15 minutes, 0.75 kN at 20 minutes, and 0.6 kN at 25 minutes. . When compared with SEM images according to the etching time, when the etching time is 5 minutes, it has a fine sponge-like etching structure and has a structure to give mechanical adhesion. Compared to the minute etching, the adhesiveness is slightly decreased, and when the etching time is longer, the sponge-like fine roughness is reduced, and the ring shape is increased, so that the adhesive effect is decreased.

When adhesion of the chromic acid etch and simple compared to eoryeowoona CrO _3, when etching 70 ℃, 3 minutes to H ₂ SO ₄ in each of the etching liquid mixture of 400g / ℓ, 400㎖ is 1.5kN / m. Comparing the SEM photograph of FIG. 14, the structure of the microsurface after etching shows a completely different state. Butadiene is oxidized first and local oxidation is the same, but chromic acid is eroded into the whole.

In this experiment, the best adhesion at 5 min etching is 1.2 kN / m.

The microstructure photographs of the two specimens show excellent porosity, but the resin was damaged by the permanganate etch solution and did not reach the expected adhesion.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (5)

In the plating method of acrylonitrile-butadiene-styrene copolymer (ABS) resin including a degreasing process, an etching process, an electroless plating process, and an electrolytic nickel plating process, the etching process uses an etching solution containing permanganate. Plating method of ABS resin characterized in that. The method of claim 1, wherein the etching solution comprises 0.10 to 0.20 M of permanganate, 4.0 to 5.0 M of phosphoric acid, and 10 to 13 M of sulfuric acid. The method of claim 1, wherein the etching solution comprises 0.15 M permanganate, 4.7 M phosphoric acid and 12 M sulfuric acid. The method of claim 1, wherein the etching process using an etching solution containing 0.15M permanganate, 4.7M phosphoric acid and 12M sulfuric acid at a temperature of 65 to 70 ℃ for 3 to 5 minutes of the ABS resin Plating method. ABS resin produced according to the method of any one of claims 1 to 4.

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