JPH03115584A - Method for plating polycarbonate resin - Google Patents

Abstract

PURPOSE:To form a plating film having superior adhesion and fine appearance on polycarbonate resin by successively subjecting the resin to pre-etching with an aq. soln. contg. specified org. substances, etching with an aq. soln. of a mixed acid contg. chromic acid and electroless plating. CONSTITUTION:A polycarbonate resin member to be plated is washed and pre-etched with an aq. soln. contg. 10-500ml/l ketone such as acetone, methylacetone or methyl ethyl ketone and 100-900ml/l ether such as ethylene oxide or propylene oxide or further contg. 0.05-50g/l nonionic surfactant such as octyl phenyl ether or nonyl phenyl ether. The pre-etched member is washed and etched with an aq. soln. contg. CrO3 and H2SO4 or an aq. soln. contg. CrO3, H2SO4 and H3PO4. The etched member is cleaned by washing and plated with Cu or Ni by electroless plating. A plating film having fine appearance is formed on the surface of the polycarbonate resin member with tight adhesion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of plating polycarbonate resin.

Conventional techniques and their problems Conventionally, methods for plating plastics by electroless plating include (a) cleaning treatment, (b) etching treatment, (c) sensitization treatment, (d) activation treatment, A method is known in which the following treatments (e) are sequentially performed: electroless plating treatment. However, with such a method, it is not possible to form an electroless plating film with good adhesion and excellent appearance on polycarbonate resin. Therefore, before the etching process, the main component is an amide such as N,N-dimethylformamide, dimethylacetamide, diethylformamide, etc., which is diluted with lower alcohol such as isopropyl alcohol, polyhydric alcohol such as ethylene glycol, water, etc. A method of treating with a pre-etching solution (Special Publication No. 12996/1989, Japanese Patent Publication No. 1973/1986)
No. 144 and Japanese Patent Publication No. 53-39911) have been proposed, but they have drawbacks such as poor appearance of the formed plating film and variations in the adhesion of the plating film. Therefore, methods such as increasing the sulfuric acid concentration of the chromic acid-sulfuric acid mixture used after pre-etching and immersing it in a high-concentration sulfuric acid aqueous solution after pre-etching have been carried out, but these methods are difficult to obtain sufficient results. Not yet reached.

Means for Solving the Problems In view of the problems described above, the inventor of the present invention has conducted extensive research to find a method for forming a plating film with good adhesion and good appearance on polycarbonate resin. It's here. As a result, the polycarbonate resin was treated with a pre-etching solution consisting of an aqueous solution containing ketones and ethers as main components, etched with a chromic acid mixed acid aqueous solution, and then plated according to a conventional method. We have discovered that it is possible to form a plating film on a resin that has an excellent appearance and high adhesion, and have now completed the present invention.

That is, in the present invention, a polycarbonate resin is treated with a pre-etching solution consisting of an aqueous solution containing 10 to 500 mQ/ff of ketones and 100 to 900 aQ/l of ethers, and then treated with a chromic acid-sulfuric acid aqueous solution or a chromic acid-sulfuric acid-phosphorous solution. The present invention relates to a method of plating polycarbonate resin, which comprises etching the polycarbonate resin with an acid aqueous solution, followed by sequentially performing catalyst application treatment and electroless plating treatment.

In the present invention, any of various polycarbonate resins obtained according to known methods such as the phosgene method and the transesterification method can be used as the object to be treated. Further, copolymers of raw material compounds used in the phosgene method, transesterification method, etc. and other compounds, blend modified products of polycarbonate resins, modified products, etc. can also be used.

In the present invention, first, a polycarbonate resin that has been washed and washed with water according to a conventional method is subjected to a preetching process. As the pre-etching liquid, an aqueous solution containing ketones and ethers is used. Ketones include acetone, methylacetone, methylethylketone, diethylketone, acetonylacetone, acetylacetone, butylketone, methylisobutylketone, ethylacetone,
Propylacetone, diacetone alcohol, cyclohexanone, methylcyclohexanone, etc. can be mentioned, and they can be used alone or in combination. The blending amount of ketones is about 10 to 500IL1271, preferably 2
It is approximately 0 to 200 d/, Q.

Examples of the ethers include cyclic ethers such as ethylene oxide, propylene oxide, and trimethylene oxide, which can be used alone or in combination. The blending amount of ethers is 100-900tQ/f!
degree, preferably about 20 to 800 tQ/l.

The effect of preetching can be further improved by adding a nonionic surfactant to the preetching liquid, if necessary. Examples of nonionic surfactants that can be used include those obtained by adding ethylene oxide to alkylphenyl ethers such as octylphenyl ether, nonylphenyl ether, and dodecylphenyl ether, and those obtained by adding ethylene oxide to polypropylene glycol. ,
The appropriate amount is in the range of about 0.05 to 50 g/R.

The processing conditions for pre-etching vary depending on the type of object to be plated and the concentration of the pre-etching solution, but usually the object to be plated is placed in a pre-etching solution at a temperature of about 15 to 60°C for 1 to 20 minutes. All you need to do is soak it to a certain extent.

After pre-etching, washing with water is performed, followed by etching treatment. For washing, it is preferable to use warm water of about 40 to 50°C.

As the etching solution, a conventionally used chromic acid-sulfuric acid aqueous solution or chromic acid-sulfuric acid-phosphoric acid aqueous solution may be used.
35g/ρ, 98% sulfuric acid 100-950g/R aqueous solution,
(2) Chromic anhydride 50-500g/l, 98% sulfuric acid 1
Chromic acid-sulfuric acid mixture such as 50-900 g/l aqueous solution, (3) dichromate 5-35 g/IJ, 98% sulfuric acid 100-950 g/j2.89% phosphoric acid 50-300
d/R aqueous solution, (4) chromic anhydride 5-35 g/l, 9
8% sulfuric acid 100-950g/l, 89% phosphoric acid 50-950g/l
Examples include a chromic acid-sulfuric acid-phosphoric acid mixed solution such as a 300-7g aqueous solution.

Etching conditions vary depending on the type of material to be plated and the concentration of the etching solution, but usually 5.
The object to be processed is placed in an etching solution at a temperature of 0 to 75°C for 1 to 20 minutes.
Just soak it for about a minute.

Next, by washing with water and, if necessary, acid treatment, the etching solution adhering to the object to be plated is sufficiently removed. Acid treatment may be carried out according to a conventional method, for example, 3
An aqueous solution of 6% hydrochloric acid containing 30 to 100 mQ/g may be used. Furthermore, the treatment effect can be further increased by adding a reducing amine compound such as hydroxylamine hydrochloride or hydroxylamine sulfate to this aqueous hydrochloric acid solution.

Next, according to the conventional method for plating plastics,
Provides catalyst for electroless plating. As the catalyst application method, for example, known methods such as sensitizing/acnavator method, catalyst/accelerator method, etc. may be appropriately employed.

After applying the catalyst, washing with water is performed, and then electroless plating is performed. As the electroless plating solution, known electroless plating solution,
For example, any electroless copper plating solution, electroless nickel plating solution, etc. can be used, and the processing conditions may be according to conventional methods.

After electroless plating, electroplating can be performed as needed, and various types of electroplating can be performed depending on the purpose.

Effects of the Invention According to the method of the present invention, a plating film having an excellent appearance and high adhesion can be formed on a polycarbonate resin, which has conventionally been difficult to form a good plating film on.

Example EXAMPLES The present invention will be explained in more detail with reference to Examples below.

Example 1 Polycarbonate resin square plate molded product (50 x 90 x 3+
+n) at 25°C in an aqueous solution containing 5011 J2/fl of methyl acetone and 100 mu/Ω of ethylene oxide.
Processed for 10 minutes. After washing with water, chromic anhydride 400g/j
65 in an aqueous solution containing 2 and 98% sulfuric acid 400 g/Ω
Etching treatment was performed at ℃ for 10 minutes. After washing with water, it was immersed in an aqueous solution of 50 tQ/l of 36% hydrochloric acid for 2 minutes at room temperature. After washing with water, palladium chloride 0.5g/jL stannous chloride 50g/
, Q and 36% hydrochloric acid 15 g/IJ at 25°C for 3 minutes, and after washing with water, 98% sulfuric acid 100
It was immersed in an aqueous solution of mN/Ω at 40°C for 3 minutes. After washing with water,
In addition, nickel sulfate 25 g/l, citric acid 20 g/g, sodium hypophosphite 15 g/l and ammonium chloride 5
It was immersed in an electroless nickel plating solution of pH 8.5 to 9.5 consisting of an aqueous solution of tr/R at 40° C. for 8 minutes. After washing with water,
Copper sulfate 200g/R.

Plating was carried out for 90 minutes using an electrolytic copper plating solution consisting of 98% sulfuric acid (50 g/Il) at a current density of 3 AldI12 and a solution temperature of 25°C.

Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Example 2 The same resin as Example 1 was mixed with acetonyl acetone 30d/, Q
and propylene oxide at 30° C. for 5 minutes in an aqueous solution containing 200 rd2/fJ. After washing with warm water at 50° C., etching and subsequent treatments were carried out in the same manner as in Example 1. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Example 3 The same resin as Example 1 was mixed with methyl ethyl ketone 100aQ/
The sample was immersed in an aqueous solution containing 100 d/Ω of I and ethylene oxide at 25° C. for 10 minutes.

The etching process and subsequent processes were carried out in the same manner as in Example 1.

Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Example 4 The same resin as in Example 1 was mixed with 5 M/g of acetylacetone, 200 mQ/D of trimethylene oxide, and 0.5 tr/D of nonionic surfactant (Noniball #85, polyoxyethylene alkylphenyl ether, manufactured by Sanyo Chemical Co., Ltd.). It was immersed in the containing aqueous solution at 30° C. for 5 minutes. After washing with water, the catalyst application step was carried out in the same manner as in Example 1, and then copper sulfate 1
2g/l.

Rossel salt 22g/II, sodium hydroxide 15g/l
, α, α' dipyridyl 5 vrrg/l and paraformaldehyde 15 g/ff in an electroless copper plating solution for 15 minutes at 25°C. After washing with water, the same treatment as in Example 1 was carried out. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Example 5 The same resin as Example 1 was mixed with acetonyl acetone 50d/1
, butyl ketone 50tQ/R, ethylene oxide 150
d/42 and nonionic surfactant (Noniball #85
)0.5g/l) at 35°C for 3 minutes. The etching process and subsequent processes were carried out in the same manner as in Example 1. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Example 6 The same resin as Example 1 was mixed with methyl ethyl ketone 150d/ρ
, 50-7 g of methyl isobutyl ketone and 200-/II of trimethylene oxide at 40°C.
Soaked for minutes. After washing with warm water, the etching process and subsequent processes were carried out in the same manner as in Example 4. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Example 7 The same resin as in Example 1 was immersed in an aqueous solution containing 100 d/g of butyl ketone, 100 d/1 of propylene oxide and 200 flLcl/, Q of trimethylene oxide at 40° C. for 2 minutes. After washing with warm water, the etching process and subsequent processes were carried out in the same manner as in Example 1. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Example 8 The same resin as in Example 1 was mixed with 50 aQ/l of acetone, 200 mQ/fJ of methylacetone and 150 mQ/fJ of propylene oxide.
It was immersed in an aqueous solution containing d/42 at 25° C. for 10 minutes. The etching process and subsequent processes were carried out in the same manner as in Example 1. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Comparative Example 1 The same resin as in Example 1 was mixed with N,N-dimethylformamide 7
00aQ/, Q and ethylene glycol 200 ad/
It was immersed in an aqueous solution containing 1 at 35° C. for 5 minutes. 50℃
After washing with warm water, the etching process and subsequent processes were carried out in the same manner as in Example 1. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Comparative Example 2 The same resin as in Example 1 was mixed with N,N-dimethylacetamide 8
00rs! Q/I) and ethylene glycol 100t
It was immersed in an aqueous solution containing Q/1 at 40°C for 10 minutes.

The etching process and subsequent processes were carried out in the same manner as in Example 1.

Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

Comparative Example 3 The same resin as in Example 1 was mixed with N,N-dimethylformamide 7
50-/R and isopropyl alcohol 250tQ/,
It was immersed in an aqueous solution containing Q at 40°C for 5 minutes. The etching process and subsequent processes were carried out in the same manner as in Example 1. Table 1 shows the appearance evaluation after pre-etching and the plating adhesion strength after electrolytic plating.

The adhesion strength was measured by the following method.

Adhesion strength measurement method After electroless plating, copper sulfate plating was performed at a current density of 3A/da2.
．． After drying at 25°C for 90 minutes, drying at 80°C for 2 hours, and leaving at room temperature, the plated product was cut into 10III1 widths and the plating film was tested using a tensile tester (Autograph 5D-100-C, manufactured by Shimadzu Corporation). The adhesion force was measured by pulling it perpendicularly to the resin.

Claims (2)

[Claims] (1) Ketones 10-500ml/l and ethers 1
The polycarbonate resin is treated with a pre-etching solution consisting of an aqueous solution containing 00 to 900 ml/l, and then the polycarbonate resin is etched with a chromic acid-sulfuric acid aqueous solution or a chromic acid-sulfuric acid-phosphoric acid aqueous solution, and then a catalyst imparting treatment is performed. and a method for plating polycarbonate resin, characterized by sequentially performing electroless plating treatment. (2) The pre-etching solution further contains 0.05 to 50 g/l of a nonionic surfactant (
The plating method described in 1).