JP2003082138A - Plated resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plated resin molding which has a plating layer with high bond strength although it has not been subjected to etching with chromic acid. SOLUTION: The plated resin molding comprises a molded resin containing a polyamide resin and a styrene resin, having a metal plating layer on the surface, and not subjected to etching with an acid containing a heavy metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plated resin molded body having a high plating strength and a method for producing a plated resin molded body which does not require an etching step.

[0002]

2. Description of the Related Art For the purpose of reducing the weight of automobiles, resin moldings such as ABS resin and polyamide resin are used as automobile parts. The resin moldings have a high-class and beautiful appearance. In order to add, copper, nickel, etc. are plated.

Conventionally, when plating a molded body of ABS resin or the like, an etching step of roughening the resin molded body after the degreasing step is essential in order to enhance the adhesion strength between the resin molded body and the plating layer. For example, when plating an ABS resin molded body or a polypropylene molded body, after degreasing treatment, a chromic acid bath (a mixed solution of chromium trioxide and sulfuric acid) is used.
It is necessary to perform etching treatment at ˜70 ° C. for 10 to 15 minutes, and the wastewater contains toxic hexavalent chromate ion.
For this reason, a treatment of reducing hexavalent chromate ions to trivalent ions and then neutralizing and precipitating is essential, and there is a problem during wastewater treatment.

In consideration of the safety at the work site and the effect of waste water on the environment, it is desirable not to carry out etching treatment using a chromium bath. In that case, ABS resin or the like is used. There is a problem that the adhesion strength of the plated layer to the molded body cannot be increased.

The present invention provides a method for producing a plated resin molded body, which has a high adhesion strength between the resin molded body and the plating layer and has a beautiful appearance, and which does not require etching treatment with chromic acid or the like. The challenge is to provide.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have made a resin molded product containing a polyamide resin and a styrene resin so that the resin molded product can be obtained without etching treatment with an acid containing a heavy metal such as chromic acid. The present invention has been completed by finding that the adhesion strength between the plating layer and the plating layer can be increased, and that the adhesion strength can be dramatically increased by adding an additional component to the resin molding.

As a means for solving the above problems, the present invention is a plated resin molded article having a metal plating layer on the surface of a resin molded article containing a polyamide resin and a styrene resin, the resin molded article containing a heavy metal. Provided is a plated resin molded body which is not subjected to etching treatment with an acid.

As another means for solving the above-mentioned problems, the present invention comprises a step of degreasing a resin molding containing a polyamide resin and a styrene resin, and an electroless plating step. Provided is a method for producing a plated resin molded body that does not include an etching step using an acid that contains it.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The plated resin molded article of the present invention is a plated resin molded article having a metal plating layer on the surface of a resin molded article containing a polyamide resin and a styrene resin. It is not etched with an acid containing a heavy metal such as chromic acid.

The polyamide resin that constitutes the resin molding is a polyamide resin formed from diamine and dicarboxylic acid and a copolymer thereof. For example, nylon 66, polyhexamethylene sebacamide (nylon 6.1
0), polyhexamethylene dodecanamid (nylon 6,
12), polidodecamethylene dodecanamid (nylon 1
212), polymeta-xylylene adipamide (nylon M
XD6), polytetramethylene adipamide (nylon 4
6) and mixtures and copolymers thereof; nylon 6/6
Nylon 66/6 with 6,6T content of 50 mol% or less
T (6T: polyhexamethylene terephthalamide), 6I
Nylon 66 / 6I (6
I: polyhexamethylene isophthalamide), nylon 6
Copolymers such as T / 6I / 66, nylon 6T / 6I / 610; polyhexamethylene terephthalamide (nylon 6T), polyhexamethylene isophthalamide (nylon 6I), poly (2-methylpentamethylene) terephthalamide (nylon M5T), poly (2-methylpentamethylene) isophthalamide (nylon M5I), nylon 6T / 6I, nylon 6T / M5T, and other copolymers. In addition, copolymer nylon such as amorphous nylon may be used. Amorphous nylon Examples thereof include a polycondensation product of terephthalic acid and trimethylhexamethylenediamine.

Further, a ring-opening polymerization product of a cyclic lactam, a polycondensation product of an aminocarboxylic acid and a copolymer composed of these components, specifically, nylon 6, poly-ω-undecanamide (nylon 11), poly- Aliphatic polyamide resins such as ω-dodecanamide (nylon 12) and copolymers thereof, copolymers with polyamides comprising diamine and dicarboxylic acid, specifically nylon 6T / 6, nylon 6T
/ 11, nylon 6T / 12, nylon 6T / 6I / 1
2, nylon 6T / 6I / 610/12 and the like, and mixtures thereof.

Among the above, as the polyamide resin, PA (nylon) 6, PA (nylon) 66, and PA (nylon) 6/66 are preferable.

The styrenic resin that constitutes the resin molding is
Examples thereof include polymers of styrene and styrene derivatives such as α-substituted and nucleus-substituted styrene. Further, a copolymer composed mainly of these monomers and a vinyl compound such as acrylonitrile, acrylic acid and methacrylic acid and / or a conjugated diene compound such as butadiene and isoprene is also included. For example, polystyrene, high-impact polystyrene (HIPS) resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, acrylonitrile-styrene copolymer (AS resin), styrene-methacrylate copolymer (MS resin), styrene-butadiene A copolymer (SBS resin) etc. can be mentioned.

Further, the polystyrene resin may contain a styrene copolymer in which a carboxyl group-containing unsaturated compound is copolymerized in order to improve compatibility with the polyamide resin. A styrene-based copolymer in which a carboxyl group-containing unsaturated compound is copolymerized is a carboxyl group-containing unsaturated compound in the presence of a rubbery polymer and, if necessary, another monomer copolymerizable therewith. Is a copolymer obtained by polymerizing. Specific examples of the component include 1) a monomer containing an aromatic vinyl monomer as an essential component or an aromatic vinyl-carboxyl group-containing unsaturated compound in the presence of a rubbery polymer obtained by copolymerizing a carboxyl group-containing unsaturated compound. A graft polymer obtained by polymerizing a monomer containing a saturated compound as an essential component, 2) a monomer containing an aromatic vinyl and a carboxyl group-containing unsaturated compound as essential components in the presence of a rubbery polymer. Graft copolymer obtained by copolymerizing a monomer, 3) a carboxyl group-containing unsaturated compound is not copolymerized rubber-reinforced styrene resin, a carboxyl group-containing unsaturated compound and an aromatic vinyl as essential components A mixture of a monomer with a copolymer, 4) a mixture of 1) and 2) above, a copolymer containing a carboxyl group-containing unsaturated compound and aromatic vinyl, 5) above 1), 2 ), 3), 4) and aromatic vinyl There is a mixture with a copolymer as an essential component.

In the above 1) to 5), styrene is preferable as the aromatic vinyl, and acrylonitrile is preferable as the monomer copolymerized with the aromatic vinyl. The carboxyl group-containing unsaturated compound is preferably 0.1 to 8 mass% in the styrene resin, more preferably 0.2 to
It is 7 mass%.

The content of the polyamide resin in the resin molded product is preferably 90 to 10% by mass, more preferably 80.
To 20% by mass, more preferably 70 to 30% by mass, and the content of the styrene resin is preferably 10 to 90%.
Mass%, more preferably 20 to 80 mass%, still more preferably 30 to 70 mass%.

The plated resin molding of the present invention preferably contains a surfactant and / or a coagulant in the resin molding in order to enhance the adhesion strength of the plating layer. These surfactants and / or coagulants may be those in which the surfactant (emulsifier) used when emulsion polymerization is applied during resin production remains in the resin, and do not use emulsifiers such as bulk polymerization. When the manufacturing method is applied, it may be added separately in the resin. The surfactant and / or the coagulant may be those used in the emulsion polymerization of the resin, and may be other than those used in the emulsion polymerization. The surfactant may be an anionic surfactant, a cationic surfactant, or a nonionic surfactant. An amphoteric surfactant and an amphoteric surfactant are preferable.

The surfactant and / or coagulant is preferably contained in the resin molding in an amount of 20% by mass or less,
The content is more preferably 1.0 × 10 ^{−6 to} 20 mass%, further preferably 1.0 × 10 ^{−2 to} 20 mass%.

The plated resin molding of the present invention has an adhesion strength between the resin molding and the metal plating layer (JIS H8630).
Preferably has a maximum value of 10 kPa or more, more preferably 50 kPa or more, still more preferably 1 or more.
00 kPa or more, particularly preferably a maximum value of 150 kPa
That is all.

The shape of the plated resin molded product of the present invention, the type and thickness of the plated layer, etc. can be appropriately selected according to the application and can be applied to various applications, but particularly bumpers, emblems, wheel caps. Suitable for automobile parts such as interior parts, exterior parts, etc.

Next, the method for producing the plated resin molded article of the present invention will be described step by step. The production method of the present invention comprises a step of degreasing treatment and an electroless plating step, and it is desirable to include a step of treating with a catalyst-imparting liquid at least between the above two steps. The usual processing steps performed by a trader can be appropriately added.

First, a resin molding containing a polyamide resin and a styrene resin is degreased. The resin molded product is obtained by molding it into a desired shape suitable for the purpose by a known method such as injection molding.

The degreasing treatment is carried out with an aqueous surfactant solution containing an alkali such as sodium hydroxide or sodium carbonate or an acid such as sulfuric acid or carbonic acid. In the present invention, after this degreasing treatment, it is possible to move to an electroless plating step or another step, and etching etching with an acid containing a heavy metal such as chromic acid becomes a roughening treatment for increasing the adhesion strength of the plating layer. No steps are required.

After the degreasing treatment, for example, a water washing step, a step of treating with a catalyst application liquid, a water washing step, a step of treating with an activating liquid (activation step) and a water washing step can be performed. The step of treating with the catalyst-applying liquid and the step of treating with the activating liquid can be performed simultaneously.

The treatment with the catalyst-applied liquid is carried out, for example, by using a 35% hydrochloric acid solution of tin chloride (20-40 gl ^-1 ) (10-20 m).
gl ^-1 ) at room temperature for about 1 to 5 minutes. The treatment with the activating solution is performed with palladium chloride (0.1 to 0.3 gl ^-1 ).
It is immersed in a 35% hydrochloric acid solution (3-5 ml ^-1 ) for 1 to 2 minutes at room temperature.

After that, the electroless plating process is performed once or twice or more. As the plating bath, one containing nickel, copper, cobalt, nickel-cobalt alloy, gold or the like and a reducing agent such as formalin or hypophosphite can be used. The pH and temperature of the plating bath are selected according to the type of plating bath used.

When the plating treatment is further performed after the electroless plating, an electroplating process using copper or the like can be added after the activation treatment with acid or alkali.

[0028]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples. In addition, the adhesion test of the plating layer performed in Examples and Comparative Examples and the details of the components used are as follows. (1) Adhesion Test of Plating Layer Using the plated resin moldings obtained in Examples and Comparative Examples,
The adhesion strength (maximum value) between the resin molding and the metal plating layer was measured by the adhesion test method described in JIS H8630 Annex 6. (2) Component (A) used: Polyamide (A-1) Standard molecular weight Polyamide 6 (Number average molecular weight 1
6,000) (B) component: bulk polymerized styrene resin (B-1) 75% by mass of styrene, acrylonitrile 2
5 mass% (B-2) 60 mass% of styrene, acrylonitrile 2
0% by mass, rubber amount 20% by mass (C) component: emulsion polymerized styrene resin (C-1) styrene amount 75% by mass, acrylonitrile 2
5% by mass (C-2) 60% by mass of styrene, acrylonitrile 2
0% by mass, rubber amount 20% by mass (C-3) Styrene amount 45% by mass, acrylonitrile 1
5% by mass, rubber amount 40% by mass (C-4) Styrene amount 30% by mass, acrylonitrile 1
0% by mass, rubber amount 60% by mass (C-5) Styrene amount 40% by mass, acrylonitrile 1
5% by mass, rubber amount 40% by mass, carboxylic acid amount 5% by mass (D) component: surfactant (emulsifier) (D-1) potassium rosinate (D-2) potassium oleate (D-3) lauric acid Potassium (D-4) α olein sulfonate (Liporan PB-8
00: manufactured by Lion Corporation (D-5) α-olein sulfonate (Lipolan PJ-4)
00: manufactured by Lion Co., Ltd. Examples 1 to 19 and Comparative Examples 1 and 2 Compositions having the combinations and ratios shown in Table 1 [(A),
The components (B) and (C) are expressed in mass%, and the component (D) is
(A) to (C) parts by mass relative to 100 parts by mass) are mixed with a V-type tumbler, and then a twin-screw extruder (manufactured by Nippon Steel, TEX30, cylinder temperature 230 ° C.)
And melt-kneaded to obtain pellets. Next, use an injection molding machine (cylinder temperature 240 ° C, mold temperature 60 ° C) to
A molded body of 00 × 50 × 3 mm was obtained, and the molded body was used as a test piece for electroless plating according to the following process sequence to obtain a plated resin molded body. The test results are shown in Tables 1 and 2. (Manufacturing method of plated resin molded body) Degreasing step: The test piece was immersed for 20 minutes in a 50 g / L aqueous solution (liquid temperature 40 ° C) of Aesculin A-220 (manufactured by Okuno Chemical Industries Co., Ltd.).

Catalyst application step: A test piece was mixed with an aqueous solution of 35 mass% hydrochloric acid 150 ml / L and a catalyst C (Okuno Pharmaceutical Co., Ltd.) 40 ml / L aqueous solution (liquid temperature 2
It was immersed in (5 ° C) for 3 minutes.

First activation step: 98% by mass of the test piece
It was immersed in a 100 ml / L sulfuric acid aqueous solution (liquid temperature 40 ° C.) for 3 minutes.

Second activation step: The test piece was immersed in a 15 g / L aqueous solution of sodium hydroxide (solution temperature 40 ° C.) for 2 minutes.

Nickel electroless plating process: A test piece was made of chemical nickel HR-TA (manufactured by Okuno Chemical Industry Co., Ltd.).
A mixed aqueous solution of 150 ml / L and 150 ml / L of chemical nickel HR-TB (manufactured by Okuno Chemical Industries Co., Ltd.) (liquid temperature 40
C.) for 5 minutes.

Acid activation step: The test piece was treated with Topsun (Okuno Pharmaceutical Co., Ltd.) 100 g / L aqueous solution (liquid temperature 2
It was soaked in (5 ° C.) for 1 minute.

Electroplating step of copper: The test piece was immersed in a plating bath (liquid temperature 25 ° C.) having the following composition and electroplated for 120 minutes. (Composition of plating bath) Copper sulfate (CuSO ₄ .5H ₂ O) 200 g / L Sulfuric acid (98%) 50 g / L Chloride ion (Cl ⁻ ) 5 ml / L, Top Lucina 2000MU (manufactured by Okuno Chemical Industries Co., Ltd.) 5
ml / L Top Lucina 2000A (Okuno Pharmaceutical Co., Ltd.)
5 ml / L

[0035]

[Table 1]

[0036]

[Table 2]

As is clear from Tables 1 and 2, the incorporation of the surfactant in the resin molded body dramatically improved the adhesion strength of the plating layer.

[0038]

EFFECTS OF THE INVENTION The plated resin molding of the present invention does not undergo an etching treatment with an acid containing a heavy metal such as chromic acid, but has a plating layer having high adhesion strength. In addition, since the etching treatment with an acid containing a heavy metal such as chromic acid is not performed, wastewater treatment is easy and there is no environmental pollution due to the heavy metal.

Claims (13)

[Claims] 1. A plated resin molded product having a metal plating layer on the surface of a resin molded product containing a polyamide resin and a styrene resin, wherein the resin molded product is not etched with an acid containing a heavy metal. Is a plated resin molding. 2. The plated resin molded article according to claim 1, wherein the resin molded article contains a surfactant and / or a coagulant. 3. The plated resin molded article according to claim 2, wherein the surfactant contains an emulsifier used in emulsion polymerization. 4. The polyamide resin is PA6, PA66,
PA6 / 66, The plating resin molded object of any one of Claims 1-3. 5. The plated resin molded article according to claim 1, wherein the styrene resin is selected from ABS resin, AS resin, acid-modified AS resin, and acid-modified ABS resin. 6. The content of polyamide resin is 90 to 10.
In mass%, the content of styrene resin is 10 to 90 mass%
The plated resin molding according to any one of claims 1 to 5. 7. The plated resin molding according to claim 1, wherein the maximum adhesion strength (JIS H8630) between the resin molding and the metal plating layer is 10 kPa or more. 8. The plated resin molded article according to claim 1, which is used for automobile parts. 9. A plated resin molded body, which comprises a step of degreasing a resin molded body containing a polyamide resin and a styrene resin and an electroless plating step and does not include an etching step with an acid containing a heavy metal. Manufacturing method. 10. The plating according to claim 9, further comprising a step of treating with a catalyst-imparting liquid between a step of degreasing a resin molded body containing a polyamide resin and a styrene resin and an electroless plating step. Manufacturing method of resin molding. 11. The content of polyamide resin is 90 to 1.
The method for producing a plated resin molded article according to claim 9 or 10, wherein the content of the styrene resin is 0% by mass and the content of the styrene resin is 10 to 90% by mass. 12. The plated resin molding has a maximum adhesion strength (JIS H8630) between the resin molding and the metal plating layer of 10 kPa or more, according to any one of claims 9 to 11.
A method for producing the plated resin molded article described. 13. The method for producing a plated resin molded article according to claim 9, which is used for automobile parts.