JPH0238578A - Surface treatment of polyphenylene oxide/polyamide alloy resin molded product - Google Patents

Abstract

PURPOSE:To form a plating film having fine luster and superior adhesion by electroless plating on a polyphenylene ether/polyamide alloy resin molded product by roughening the surface of the product by etching with an etching soln. having a specified compsn., sensitizing and activating the roughened surface and immersing the product in an electroless plating soln. CONSTITUTION:The surface of a polyphenylene oxide/polyamide alloy resin molded product is cleaned and roughened by immersion in an etching soln. prepd. by adding a cationic, anionic or nonionic surfactant and an inorg. salt such as condensed phosphate to a CrO3-free aq. soln. of a mineral acid such as hydrochloric acid. The product is immersed in an acidic aq. soln. of an inorg. or org. acid and further immersed in a soln. contg. Pd. Pd acting as catalytic nuclei for electroless plating is adsorbed on the surface of the product to sensitize and activate the surface. The product is then immersed in an electroless Ni plating soln. to form a lustrous Ni plating film and it is further electroplated as required.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for surface treatment of polyphenylene ether/polyamide alloy resin (hereinafter referred to as PPE-PA resin) molded articles.

[Conventional technology]

Conventionally, ABS is the material for plastic plated products.
Resin is often used. However, ABS resin has poor physical properties, particularly heat resistance and impact resistance, and cannot be used in products that require mechanical strength and heat resistance. On the other hand, PPE-PA resin is a resin with excellent physical properties such as rigidity, heat resistance, and impact resistance, and is used for various purposes, but surface treatment such as plating is difficult, and good plated products cannot be obtained. The current situation is that it has not been obtained.

Generally, when plating plastics, processes such as surface roughening (etching), sensitization treatment, and activation treatment are required before imparting conductivity to the resin surface using electroless plating.

For example, a surface treatment method for ABS resin includes the steps of degreasing, etching, sensitization, activation, electroless plating, and electroplating. A mixed solution of chromic acid and sulfuric acid is used as the etching solution. If PPE-PA resin is etched with this chromic acid-sulfuric acid mixture, the resin will dissolve or only a plating film with poor adhesion strength will be obtained. Also,
When PPE-PA resin is plated in the same process as ABS resin, chromium remains on the resin surface, which tends to cause a non-plating phenomenon (skip) during electroless plating.

[Problem to be solved by the invention]

Therefore, an object of the present invention is to provide a method for plating a PPE-PA resin molded product with excellent adhesion and an excellent appearance, especially for products such as automobile parts that require mechanical strength and heat resistance. An object of the present invention is to provide a method for plating PPE-PA resin parts.

[Means to solve the problem]

The present invention provides a method for surface treatment of polyphenylene ether/polyamide alloy resin molded articles in which etching treatment, sensitization/activation treatment, electroless plating treatment, and optionally further electroplating treatment are applied in this order to the polyphenylene ether/polyamide alloy resin molded article. , a method for surface treatment of polyphenylene ether/polyamide alloy molded articles, which is characterized by using an aqueous solution of a mineral acid that does not contain chromic acid.

In the present invention, the etching solution may further contain at least one selected from the group consisting of surfactants and inorganic salts. Furthermore, according to a preferred embodiment of the present invention, the molded article is immersed in an acidic aqueous solution after the etching treatment and before the sensitization/activation treatment.

In the present invention, polyphenylene ether/polyamide alloy resin refers to JP-A-60-58463, JP-A-60-6K2.
1146, 6], -120855, 6l-296 (
16L 62-81449, 62-127339, 62-240354, 62-250050, 62-
257962, 62-270654, 62-273
256, 63-10655, special publication 59-50077
Polyphenylene oxide/polyamide alloy resin (hereinafter P
Polyphenylene ether such as P○-PA resin)
Refers to polyamide alloy resin.

The method of the present invention will be explained in detail below in the order of its steps.

In the method of the present invention, first, a PPE-PA resin molded article is washed according to a conventional method and then subjected to an etching treatment. As the mineral acid used in the etching process, mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid can be used, and hydrochloric acid is particularly preferable.
Hydrochloric acid at a concentration of mβ/1 (preferably containing 36% HCl).

The resin surface is dissolved by these mineral acids, and irregularities are formed on the resin surface that provide close contact between the resin and the plating film.

The etching solution used in the present invention preferably contains a cationic, nonionic or anionic surfactant. Examples of the cationic surfactant include octadecyltrimethylammonium chloride, tetradenyldimethylbenzylammonium chloride, oxyethylenedodecylamine, and octadecylamine acetate. Examples of nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene oleyl ether, and polyoxyethylene monolaurate. Examples of anionic surfactants include ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, and sodium dioctylsulfosuccinate. It is preferable to mix cationic and nonionic surfactants, with cationic surfactants ranging from 0.01 to 5
A concentration of 0 g/I+nonionic 0.01 to 50 g/R is preferred. By containing these surfactants,
It is possible to prevent the melted resin from re-adhering and further improve the adhesion and appearance of the plating film.

Furthermore, it is possible to promote the adsorption of palladium, which will serve as a catalyst nucleus for electroless plating in a subsequent process, onto the resin, thereby preventing non-adherence (skip) of electroless plating.

Preferably, the etching solution used in the present invention further contains an inorganic salt. As an inorganic salt, condensed phosphate (
Examples include sodium tripolyphosphate, sodium pyrophosphate, etc.), sodium sulfate, and sodium chloride. Preferred concentrations are 1-100 g/R. These inorganic salts further promote the effect of the surfactant.

Add the material to this etching solution at 10 to 60℃, preferably at 20℃.
By dipping at ~40°C for 1 to 30 minutes, preferably 5 to 20 minutes, the surface is roughened to provide a plating film with good adhesion and good appearance.

After surface roughening, the material is preferably immersed in mineral acid, organic acid, or a mixed solution of mineral acid and organic acid. Examples of mineral acids include hydrochloric acid, sulfuric acid, and nitric acid; examples of organic acids include acetic acid, formic acid, and lactic acid. Preferably, a hydrochloric acid solution is used, with a concentration of 10 to 1
50mβ/β (36% HC41!) 'a degree,
It is desirable to process at 10 to 40°C for 1 to 10 minutes. This treatment prevents the re-assimilation of the resin that has melted and adhered to the material surface, further improving the adhesion and appearance of the plating film.

After washing with water, the material undergoes sensitization and activation treatment. This process is a process in which palladium, which serves as the catalyst nucleus for electroless plating, is adsorbed onto the resin surface.
Any of the Catalyst → Accelerate method and Sensixizer → Activate method used in Plasdinox plating such as BS resin, or Palladium solution immersion → Reducing solution immersion method used in plating polyamide resin, through-hole substrates, etc. can be used. The catalyst referred to here is a solution prepared by diluting a colloid of palladium and soot with a chloride such as hydrochloric acid or sodium chloride, or a mixed aqueous solution thereof.The treatment conditions include palladium chloride 3
0 mg/β or more, stannous chloride 1 p/f! , above, hydrochloric acid 3
0 mβ/, &(36%HCj2) or immersion in sodium chloride at a concentration of 10 g/β or higher at 20° C. or higher for 1 minute or longer. After washing with water, immerse in accelerator solution.

As the accelerator solution, a mineral acid aqueous solution such as hydrochloric acid or sulfuric acid, or a mixed aqueous solution thereof, or an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide, or a mixed aqueous solution thereof can be used.

As for the treatment conditions, the hydrochloric acid solution is 30 to 150 mβ/β(
36% HCjl'), 20-50°C, 1-10 minutes, sulfuric acid solution 50-150 mR/R (98% H2S,),
It is best to soak at 30-60°C for 1-10 minutes. In addition, when an acidic aqueous solution accelerator is used, the adhesion of electroless plating to the resin can be further improved by immersing the product in an aqueous solution, rinsing it with water, and then immersing it in an alkaline aqueous solution (post-accelerator).

As the post-accelerate solution, an aqueous solution of water, sodium oxide, potassium hydroxide, etc. can be used, and the processing conditions are 5-50g/f2.10-40℃, 0.5-50g/f2.
It is best to soak for 5 minutes. The conditions for using an alkaline aqueous solution accelerator are 5 to 50 g/f of sodium hydroxide or potassium hydroxide! Preferably, the treatment is carried out at 10 to 50°C for 1 to 10 minutes.

The processing conditions for Sentizer → Activator are as follows:
Sentizer is made by dissolving 0.5 to 50 g/β of stannous chloride in 0.5 to 100 mβ/l of hydrochloric acid (36% HC, i?), adjusting to 11 with water, and then heating at 10 to 40°C to 0.5 ~1
Soak for 0 minutes. After washing with water, it is immersed in Akujibake, but as an accelerator, palladium chloride 005 to Ig/
β with hydrochloric acid 0.05-100m, Il'/β (36%H
Dissolve in CI) and adjust to 1β with water, then heat at 10 to 50°C.
, it is preferable to soak for 0.5 to 10 minutes.

The palladium solution used in the palladium solution immersion → reduction solution immersion method includes an inorganic or organic palladium salt dissolved in a mineral acid such as hydrochloric acid or nitric acid or an organic acid such as acetic acid or citric acid, or a palladium chelating agent. It can be used dissolved in an alkaline solution. After washing with water, it is immersed in a reducing solution, and an aqueous solution of a reducing agent such as hypophosphorous acid, aminoborane, boron hydride, hydrazine, formalin, or a salt thereof can be used as the reducing solution.

As preferable conditions, palladium chloride 005 to 1 g/
l, hydrochloric acid 005-200mβ/β, 20-40℃, 1-
After soaking for 10 minutes and washing with water, add hypophosphorous acid (50% solution) 5 to 2
00+nn/β, 20-40°C, immersion for 1-10 minutes is preferable.

After the sensitization and activation, washing with water is performed, and electroless plating is performed to impart conductivity to the resin surface. All electroless plating solutions currently used include alkaline and neutral copper plating solutions, alkaline, neutral, and acidic nickel plating solutions, and electroless copper-nickel plating solutions. can. When performing electroplating after electroless plating if necessary, it is desirable to perform heat drying after electroless plating or after electroplating. This treatment further improves adhesion. As a preferable condition, 50~
It is best to dry at 150°C for 0.5 to 20 hours.

When dried at room temperature after plating, it takes a considerable amount of time (about 2 months) for the adhesion to increase and become constant. Until the adhesion strength reaches a certain level (0.5kg/cm)
It is preferable to carry out the above-mentioned heat drying because the slight impact easily causes flakes and scratches on the plated product, making it difficult to handle.

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

Example I PPE-PA resin [Remalloy: 10100 manufactured by Mitsubishi Yuka ■
A 100X3 flat plate (2 dm'T, P, )] was immersed in an ethanol solution for 3 minutes at room temperature, dried, and used as a test piece.

The above test piece was etched at 30°C using the following etching solution.
Etched for 10 minutes.

[Etching treatment liquid]

Hydrochloric acid (36% HCj 260mj!/42
Sodium tripolyphosphate 5g/β Sodium chloride 10g/β tap water
The remaining sample was then immersed in a solution of 60 mβ/1 hydrochloric acid at 25°C for 1 minute, and after washing with water, it was immersed in a palladium solution having the composition below at 30°C for 3 minutes.

[Palladium solution]

Palladium chloride 0.2g/j2hydrochloric acid (
36% HCjri 60mR/R tap water
After washing the remaining portion with water, it was immersed in a reducing solution having the following composition at 30° C. for 3 minutes.

[Reducing solution]

Dimethylaminoborane 1g/l tap water
After washing with water, electroless nickel plating was performed at 40° C. for 10 minutes using an electroless nickel plating solution having the following composition.

[Electroless nickel plating solution]

Nickel sulfate 2.0g/l Ammonium citrate '20g/'It Sodium hypophosphite 20g/l Tap water
Adjust the pH to 9.5 with the remaining ammonia water. After washing with water, activate with a 50ml sulfuric acid solution (98% H2So4) at room temperature for 30 seconds, and then wash with water.
Copper plating of 20 μm was applied using an electro-acidic bright copper sulfate plating solution, and then nickel plating was applied in the order of electro-semi-bright nickel plating → electro-bright nickel plating, each having a thickness of 10 μm. Next, chromium plating was applied to a thickness of 043 μm using an electrochromium plating solution. However, the treatment method between each electroplating was carried out according to a conventional method. Next, the plated test piece was dried with hot air at 70° C. for 10 hours.

The plated product thus obtained was free of pits and stardust, had good gloss, and had an excellent appearance.

Further, the adhesion strength was 2.2 kg/cm. This adhesion strength was measured according to the adhesion test method described in JIS H8630 Annex 6.

Example 2 PPE-PA resin (Remalloy; 2dm'T manufactured by Mitsubishi Yuka)
: P, ) was previously immersed in an ethanol solution at room temperature for 3 minutes, dried, and used as a test piece.

The above test piece was etched at 30°C using the following etching solution.
Etched for 10 minutes.

[Etching treatment liquid]

Sulfuric acid (98% H2SO4”) 180mn/j!
Anionic surfactant 30g/l (ammonium lauryl sulfate) Sodium tripolyphosphate 5 g/l Sodium sulfate 20g/R tap water
The remaining plating process is as in Example 1.
I did the same thing.

After plating, hot air drying was performed at 100°C for 5 hours.

The resulting plated product had an adhesion strength of 1.8 kg/cm (pins), no stardust, good gloss, and excellent appearance.

Example 3 PPE-PA resin (Remalloy Mitsubishi Yuka side type (2d, m
'T, P, ) was previously immersed in an ethanol solution for 3 minutes at room temperature, dried, and used as a test piece.

The above test piece was etched at 40°C using the following etching solution.
Etched for 15 minutes.

[Etching treatment liquid]

Hydrochloric acid (36%HCA) 150mf2/A Sodium sulfate 50g/β tap water
The remaining plating steps were performed in the same manner as in Example 1.

After plating, the plated product was dried with hot air at 120° C. for 3 hours. The adhesion strength of the plated product was 1.8 kg/cm, and the plated product had no pits or stardust, had good gloss, and had an excellent appearance.

Example 4 PPE-PA resin (Remalloy: 2dm'T manufactured by Mitsubishi Yuka ■)
, P, ) was previously immersed in an ethanol solution at room temperature for 3 minutes, dried, and used as a test piece.

The above test piece was etched at 20°C using the following etching solution.
Etching was performed for 20 minutes.

[Etching treatment liquid]

Hydrochloric acid (36%HC, i! > 300mR/R
Sodium pyrophosphate 20g/j2 Sodium tripolyphosphate 20g/β Sodium chloride 30g/β tap water
The remaining plating steps were performed in the same manner as in Example 1.

After plating, the plated product was dried with hot air at 100° C. for 5 hours. The adhesion strength of the plated product was 1.9 kg/cm, and the plated product had no focus or stardust, had good gloss, and had an excellent appearance.

Example 5 PPE-PA fat loss (Remalloy/Mitsubishi Yuka ■ 2dm'T
, 'P,) was previously immersed in an ethanol solution for 3 minutes at room temperature, dried, and used as a test piece.

The above test piece was etched at 40°C using the following etching solution.
Etched for 5 minutes.

[Etching treatment liquid]

Sulfuric acid (98% H2SO4) 300mfl/ff
The following plating steps were performed in the same manner as in Example 1.

After plating, the plated product was dried with hot air at 70° C. for 10 hours. The adhesion strength of the plated product was 1.9 kg/cm, and the plated product had no focus or stardust, had good gloss, and had an excellent appearance.

Example 6 PPE-PA resin (2dm'T made by Remalloy Mitsubishi Yuka)
, P, ) was previously immersed in an ethanol solution at room temperature for 3 minutes, dried, and used as a test piece.

The above test piece was etched at 30°C using the following etching solution.
Etched for 10 minutes.

[Etching treatment liquid]

Hydrochloric acid (36% HCβ) 400mj2/j! Sodium sulfate tap water 80g/jl! Remaining sodium sulfate tap water 80g/β Remaining plating process was performed in the same manner as in Example 1.

After plating, the plated product was dried with hot air at 100° C. for 5 hours. The adhesion strength of the plated product was 1.9 kg/cm, and the plated product had no pits or stardust, had good gloss, and had an excellent appearance.

Example 7 After etching at 20°C for 15 minutes using the same test piece and etching solution as in Example 1, formic acid (85%) 2
It was immersed in a solution of 0 m7/β at 20°C for 1 minute. After washing with water,
It was immersed in a catalyst solution having the following composition at 30°C for 3 minutes.

[Catalyst solution]

Palladium chloride 0.1g/j2 stannous chloride ゛10g/β hydrochloric acid (36% HCβ)
100mA/A Sodium Chloride
100g/β tap water After washing with remaining water, add hydrochloric acid (36% HCI 1. OOmj!/j
! The solution was subjected to an accelerator treatment of immersion at 30° C. for 3 minutes. After washing with water, sodium hydroxide 10g/l, 20℃
After performing a post-acceleration treatment for 2 minutes, the specimen was washed with water, and electroless plating was performed at 25° C. for 10 minutes using an electroless copper plating solution having the following composition.

[Electroless copper plating solution]

Copper sulfate 15g/f! .

Rossell salt 30g/β-paraformaldehyde 20g/A sodium hydroxide -
1 (Ig/j!Tap water After washing with remaining water, immerse in 3.0 m*/1 solution of sulfuric acid (98% H2S○4) for 30 seconds at room temperature and then washing with water.Electroplating after electroacidic bright copper sulfate plating The processing conditions were the same as in Example 1. After drying with hot air at 120°C for 3 hours, the adhesion strength was measured to be 1.8 kg/cm. There were no pits or stardust, and the gloss was good and the appearance was good. It was an excellent plated product.

Example 8 PPC)-PA resin [:/! J Le GTX: EPL
@150X150X3mm flat plate (4,5 drri'T
, P, , ) ] was previously immersed in ethanol at room temperature for 3 minutes to dry, and then used as a test piece.

The above test piece was plated in the same manner as in Example 1, and then the plated test piece was dried with hot air at 100° C. for 5 hours. The plated product thus obtained was free of pits and stardust, had good gloss, and had an excellent appearance. Further, the adhesion strength was 2.0 kg/cm.

Example 9 A test piece similar to Example 8 was plated in the same manner as Example 2. After plating, the adhesion strength of the plated product was 1.8 kg/cm, which was dried with hot air at 70°C for 10 hours.
The plated product was free of stardust, had good gloss, and had an excellent appearance.

Example 10 A test piece similar to that in Example 8 was prepared in the same manner as in Example 7. After plating, the adhesion strength of the plated product, which was dried with hot air at 120℃ for 3 hours, was 1.8 kg/cm.
The plated product was free of stardust, had good gloss, and had an excellent appearance.

Example 11 PPE-PA resin (Remalloy: 2dm'T manufactured by Mitsubishi Yuka ■)
, P,) was previously immersed in an ethanol solution for 3 minutes at room temperature, dried, and used as a test piece.

The above test piece was etched at 30°C using the following etching solution.
Etched for 10 minutes.

[Etching treatment liquid]

Hydrochloric acid (36% HC, 1 liter 26Qmjl!/j
2 Tap water The remaining plating treatment steps were performed in the same manner as in Example 1.

After plating, the plated product was dried with hot air at 70° C. for 10 hours. The adhesion strength of the plated product was 1.6 kg/cm, and the plated product had no pits or stardust, had good gloss, and had an excellent appearance.

Example 12 PPC)-PA resin (/Lil GTX: EPL@J
4.5 dm'T, P, ) was previously immersed in an ethanol solution at room temperature for 3 minutes, then dried and used as a test piece.

The above test piece was etched at 30°C using the following etching solution.
Etched for 10 minutes.

[Etching treatment liquid]

Salt N (36% HCI) 260mA/j! Tap water The remaining plating steps were performed in the same manner as in Example 1.

After plating, the plated product was dried with hot air at 70° C. for 10 hours. The adhesion strength of the plated product was 1.2 kg/cm, and the plated product had no pits or stardust, had good gloss, and had an excellent appearance.

Comparative Example 1 A test piece similar to Example] was etched at 68° C. for 10 minutes with an etching solution having the following composition.

The etching method and processing conditions are the same as those for commonly used ABS resin etching processing.

[Etching treatment liquid]

Chromic anhydride 4DOg/12 sulfuric acid (9
8%) 400 g/β tap water
After washing the remaining water, add to a solution of hydrochloric acid (36% H(1) 50 mβ/1,
It was immersed at 25° C. for 2 minutes, and then immersed in the palladium solution of Example 1 in a water washer under the same conditions. The following processing steps were performed in the same manner as in Example 1.

After chrome plating, hot air drying was performed at 70°C for 10 hours, and the adhesion strength was measured, and it was 0.2 to 0.4 kg/cm.
Only a moderate adhesion strength was obtained. In addition, the plated product had many pits and stardust and had a poor appearance.

Comparative example 2 The conditions up to the etching treatment were the same as in Comparative Example 1.

After washing with water, add hydrochloric acid (36% H) to a solution of 50 mn/A.
It was immersed at 25° C. for 2 minutes and subjected to a cacrystal treatment under the same conditions as in Example 7 in a water washer. After washing with water, it was also subjected to an accelerator treatment under the same conditions as in Example 7. After washing with water, electroless nickel plating was performed under the same conditions as in Example 1.
Even after immersion for υ minutes, the plating did not completely cover the resin (50% precipitation), so electroplating could not be performed.

This plating treatment method is the same as the usual plating process for ABS resin.

Comparative Example 3 Using the same test piece as in Example 1, etching was carried out at 68° C. for 10 minutes with an etching solution having the following composition. The etching method and conditions are the same as those for ABS resin plating.

[Etching treatment solution]

Sulfuric acid (98%) 900 g/i' Chromic anhydride 15 g/β tap water
When the remaining resin was etched under the above conditions, the resin surface was completely dissolved and subsequent processing was impossible.

Comparative Example 4 A test piece similar to Example 8 was plated in the same manner as Comparative Example 1. After plating, the adhesion strength was measured by drying with hot air at 70°C for 10 hours, and the adhesion strength was only about 0.4 to 0.6 kg/cm, indicating that the plated product had many pits and stardust and had a poor appearance. Ta.

Comparative Example 5 The same test piece as in Example 8 was plated in the same manner as in Comparative Example 2, but the plating did not completely adhere to the resin even after being immersed in electroless nickel plating for 15 minutes. Therefore, electroplating could not be performed.

Comparative Example 6 When a test piece similar to Example 8 was etched using the same etching solution composition and conditions as Comparative Example 3, the resin surface was completely dissolved and subsequent processing was impossible.

The electroplating solution composition and conditions used in each example and comparative example are as follows.

○Electro-acidic bright copper sulfate plating solution・Copper sulfate 225g/ffl・Sulfuric acid (98% H2S○,) 56g/β・Tap water・Temperature・Current density remaining 25'c 2,5 A/d m' ○Electric semi-gloss Nickel plating solution, nickel sulfate 250g//2, nickel chloride 40g/A, boric acid
40g/β・Tap water・Temperature・Current density ○Electro-bright nickel plating solution・Nickel sulfate・Nickel chloride・Boric acid Remaining 52℃ 3 A/d m' 250 g/ll 50g/β ・Tap water・Temperature・Current density○Electrochromium plating solution・Chromic anhydride・Trivalent chromium remaining 55℃ 3 A/d m' 250g/β L2g/β・Sulfuric acid (98% H2S 04) 2.5 g/
β・Tap water Remaining [Effect of the invention] According to the present invention, a polyphenylene ether/polyamide alloy resin molded product is plated without pits or stardust, has a glossy appearance, and has good adhesion. A film can be formed.

Claims (3)

[Claims] (1) In a surface treatment method for a polyphenylene ether/polyamide alloy resin molded product, in which etching treatment, sensitization/activation treatment, and electroless plating treatment are performed in this order, the etching solution is a mineral acid that does not contain chromic acid. A method for surface treatment of polyphenylene ether/polyamide alloy molded products, characterized by using an aqueous solution of. (2) The method according to claim 1, wherein the etching solution further contains at least one selected from the group consisting of a surfactant and an inorganic salt. (3) The method according to claim 1, characterized in that the molded article is immersed in an acidic aqueous solution after the etching treatment and before the sensitization/activation treatment.