JPS61183473A - Method for metallizing surface of molded polyphenylene sulfide resin - Google Patents

Abstract

PURPOSE:To metallize the surface of a molded resin article having a three- dimensionally ruggedness structure and to improve the bonding strength of the resulting film by roughening the surface of a product consisting of prescribed percentages of polyphenylene sulfide resin and an inorg. filler before plating. CONSTITUTION:A resin composition contg. the inorg. filler of 1-10mum average particle size by 10-250pts.wt. per 100pts.wt. polyphenylene sulfide resin is molded. The surface of the molded product is roughened with the solvent in which the resin is readily soluble, and the plating is carried out. Thus, the surface having three-dimensionally rugged structure is metallized, and the molded resin product having the metallized surface has superior bonding strength to the plated film.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improved method for surface metallization of polyphenylene sulfide resin molded articles.

[Conventional technology]

Conventionally, as a method for metallizing the surface of polyphenylene sulfide molded products, Japanese Patent Publication No. 56-25453 describes
A method has been proposed in which the surface of the molded article to be metallized is mechanically roughened, then etched with a strongly oxidizing aqueous solution mainly consisting of a chromium compound, sulfuric acid and phosphoric acid, and then chemically plated.

[Problems to be solved by the present invention]

However, the method described in the above publication requires mechanical roughening of the surface to be metallized by sand blasting or sandpaper, and is therefore difficult to apply to molded products with three-dimensional irregularities. There are drawbacks. Furthermore, as stated in the publication, the subsequent treatment with a strong oxidizing aqueous solution has no effect on roughening the surface, but the adhesive strength between the resulting metal plating film and the resin molded product is also insufficient, so it cannot be said to be an effective method. do not have.

Therefore, the inventors of the present invention have conducted intensive studies on a method to roughen the surface of a polyphenylene sulfide resin molded product by chemical etching without performing mechanical surface roughening treatment, and to obtain sufficient adhesion strength with the metal plating film. and
A molded product made by blending a specific filler in a specific amount with a polyphenylene sulfide resin is treated with a good polyphenylene sulfide solvent, and then subjected to a normal plating treatment to produce a surface-metalized polyphenylene sulfide with specific plating adhesion. The present invention is based on the fact that a resin molded article can be obtained.

[Means to solve the problem]

That is, the present invention provides polyphenylene sulfide resin 10
After roughening a polyphenylene sulfide resin molded product containing 10 to 250 M parts of an inorganic filler with an average particle size in the range of 1 to 10 μm based on 0 parts by weight using a good solvent for polyphenylene sulfide. , relates to a method for surface metallizing a polyphenylene sulfide resin molded article, which is characterized by plating treatment.

Polyphenylene sulfide (hereinafter pps) used in the present invention
).

A polymer containing 70 mol% or more, more preferably 90 mol% or more of repeating units represented by the structural formula +S+,
If the content of the repeating unit is less than 70 mol%, heat resistance will be impaired, which is not preferable.

Generally, pps is a polymer with relatively small molecular weight obtained by the production method typified by Japanese Patent Publication No. 45-3368, and an essentially linear polymer obtained by the production method typified by Japanese Patent Publication No. 52-12240. There are polymers with relatively high molecular weight, and in the former polymer, the degree of polymerization can be increased by heating in an oxygen atmosphere after polymerization, or by adding a crosslinking agent such as peroxide and heating. - In the present invention, it is possible to use PPS obtained by any method. PP in terms of mechanical properties of the molded product itself and on the plating adhesive surface.
In order to avoid a decrease in the adhesion of the plating film due to the agglomeration and peeling of S, the essentially linear polymer obtained by the production method typified by the above-mentioned Japanese Patent Publication No. 12240/1980 is
It can be used more preferably.

Furthermore, less than 30 mol% of the repeating units of PPS can be composed of repeating units having the following structural formula, etc.

The melt viscosity of PPS used in the present invention is not particularly limited as long as it is possible to obtain a molded article, but in terms of mechanical properties of the molded article, it is 100 poise or more, and in terms of moldability, it is 10. Those of OOO poise or less are more preferably used.

Furthermore, an antioxidant, a heat stabilizer, a copper damage inhibitor, a lubricant, a crystal nucleating agent, an ultraviolet absorber, and a coloring agent can be added to the PPS used in the present invention, and furthermore, the degree of crosslinking of the PPS can be controlled. For this purpose, ordinary peroxidants and JP-A-59-131
Crosslinking promoters such as thiophosphinic acid metal salts described in Publication No. 650 ζζ, or JP-A-58-204045,
It is also possible to incorporate crosslinking inhibitors such as dialkyltin dicarboxylate and aminotriazole described in JP-A-58-204046 and the like.

The inorganic filler used in the present invention can be either soluble or insoluble in a good solvent for PPS used for surface roughening treatment, and does not necessarily have to be spherical, but has an average particle size of 1 to 10 μm. It is important that it is within the range of
More preferably, one having a diameter of 1 to 6 μm is used. By using a filler with a particle size in this range, the uneven structure obtained by treating PPs with a good solvent has a size suitable for an anchoring effect with the metal plating film, and strong plating film adhesion can be obtained. If the average particle diameter is less than 1μ or more than 10μ, the adhesion of the plating film will be small and undesirable;
If it exceeds 0μ, the brightness of the plating will be significantly impaired, which is not preferable. The average particle diameter here is the particle diameter (median number) at which the cumulative frequency determined from the particle size distribution measured by the sedimentation balance method is 5096.

Inorganic fillers used in the present invention include metal oxides such as alumina, silicon oxide, magnesium oxide, zirconia oxide, and titanium oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, and sulfuric acid such as calcium sulfate and barium sulfate. Salt, wollastenite, sericite, kaolin, mica, clay, bentonite, asbestos,
Examples include, but are not limited to, talc, silicates such as alumina silicate, boron nitride, silicon carbide, and Saroyan.

It is also possible to use two or more of these fillers together,
If necessary, it can be used after being pretreated with a silane-based, titanium-based, or other coupling agent.

The blending amount of these inorganic fillers is preferably 10 to 250 parts by weight, particularly 30 to 100 parts by weight, based on 3100 parts by weight of PP. If it is less than 10 parts by weight, the effect of improving the adhesion of the metal plating film is insufficient, and if it exceeds 250 parts by weight, the surface roughness increases and the adhesion of the plating film and the brightness of the plating are impaired, which is not preferable.

In addition, although it is not an essential component in the present invention, in order to improve the mechanical properties of the molded product, a fibrous reinforcing material such as glass fiber or carbon fiber may be added to 5100 parts by weight of PP as an essential component of the present invention. It is possible to mix the above-mentioned inorganic filler and fibrous reinforcing material in such a range that the total amount does not exceed 250 parts by weight. Furthermore, small amounts of other types of polymers may be blended within a range that does not impede the object of the present invention.

The means for blending PPS, inorganic fillers, and other additives is arbitrary and is not limited, but for example, a method of simultaneous mixing using a screw extruder or the like can be adopted.

For producing a molded article from the compound, any conventional thermoplastic resin molding method such as injection molding, extrusion molding, compression molding, or blow molding can be used, and a molded article of a desired shape can be easily obtained.

When performing plating treatment in the present invention, it is important to first perform preliminary treatment such as wiping off an oil film on the surface of the molded article as necessary, and then roughen the surface using a good solvent of PPS. Treatment with acids such as nitric acid, which has an oxidizing effect, is not preferable because it forms an oxide film on the surface. Good solvents for PPS used in the surface roughening treatment include 1-chloronaphthalene, l-bromonaphthalene, triethylenetetramine, tetraethylenepentamine, etc., and mixed solvents containing these. Among them, 1-chloronaphthalene and 1-Bromnaphthalene is preferably used.

The conditions for this surface roughening treatment vary depending on the type of solvent used, but in order to speed up the treatment speed, heating to a high temperature is effective. For example, when using 1-chlornaphthalene, heating to 200 to 220°C It is preferable to immerse the molded article in the solvent for 1 to 30 minutes and then thoroughly wash it.

Furthermore, if the inorganic filler used is insoluble in the solvent used, it is also possible to perform acid or alkali treatment following the surface roughening treatment for the purpose of decomposing or dissolving the inorganic filler.

By applying a commonly known plating treatment to the surface-roughened resin molded product for plating, it is possible to obtain a surface metallized P with extremely excellent plating film adhesion and plating brightness.
A PS resin molded product is obtained. Further, it is also possible to metallize the surface of the molded product subjected to the surface roughening treatment by metal vapor deposition, sputtering, or the like.

The plating process includes, for example, sensitizing with a stannous chloride solution, activating with a palladium chloride solution, and electroless plating of copper or nickel, or catalyst staining, accelerating, and electroless plating. It is possible to continue each step of plating, and furthermore, it is possible to apply a normal plating method consisting of additional electroplating with the same or different metal as the metal used for electroless plating.

In addition, when performing the plating process, by partially shielding the surface of the resin molded product for plating using a commonly known method,
It is also possible to obtain molded articles with a partially metallized surface.

Furthermore, the molded article according to the method of the present invention can be heat-treated at a temperature below the melting point of PPS for the purpose of increasing the degree of crystallinity or crosslinking during any of the steps after molding. It is also possible to perform heat treatment after plating for the purpose of increasing the adhesion of the plating film.

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

〔Example〕

Examples 1-11. Comparative Examples 1 to 4 Melt viscosity 1,200 poise (320°C, breaking speed 100
To 100 parts by weight of powdered pps <1 Rydon #P-4, manufactured by Phillips Petroleum, Inc., USA, various inorganic fillers shown in Table 1 were added in the proportions shown in Table 1. - After blending and melt-mixing using a screw extruder set at 310°C, the mixture was taken in the form of a strand and pelletized using a strand e-cutter.

Next, each pellet was placed in a screw in-line injection molding machine set at 310-320°C (IL, mold temperature 130-320°C).
Under the condition of 140℃, - side is 80th square, thickness is about 3
A test piece of H was molded.

Next, each test piece was heated to 210°C and immersed in 1-chlornaphthalene for 3 minutes, and then thoroughly washed under running water.
A test piece with a roughened surface was obtained.

Each test piece with a roughened surface was subjected to plating treatment by sequentially performing the steps shown below.

(1) Catalyst A-30 Catalyst (Okuno Pharmaceutical Co., Ltd.) It was immersed in an If solution at 25° C. for 3 minutes.

(2) Washing with water (3) Acceleration It was immersed in 10g of 6-sulfuric acid solution at 40°C for 3 minutes.

(4) Water washing 6) Electroless copper plating Copper sulfate (Cu5On115HzO) 1001 and formalin 3596 aqueous solution 400 cc were diluted with water to 11
Plating solution A, potassium sodium tartrate (tetrahydrate 4001, and sodium hydroxide 100f diluted with water to make 11), 200 cc of each were mixed immediately before use, and the plating solution was diluted to 24 with water. The sample was immersed for 8 minutes at room temperature while bubbling air.

(6) Washing with water (7) Electroplating The electroless plated test piece was washed with 50p of concentrated sulfuric acid, 200y of copper sulfate (pentahydrate), and SCB-MU as a brightener.
10 cc, 5CB-11 cc (manufactured by Okuno Pharmaceutical Co., Ltd.) and 1,000 cc of water. Electroplating was performed for 9 minutes to form a copper plating film with a thickness of about 50 μm.

Regarding the obtained surface metallized PPS molded product, the force required to peel off the plating film over a width of 10 ff and a length of 40 ff was evaluated as the adhesion force of the plating film, and the results of evaluating the plating brightness by observing the appearance were evaluated. Shown in Table 1.

Example 121 The test piece used in Example 3 was exactly the same as Example 3, except that instead of being immersed in 1-chloronaphthalene at 210°C, it was immersed in 1-bromnaphthalene at 210°C for 3 minutes. Using this procedure, a PPS molded product with a metallized surface was obtained, and the adhesion of the plating film was evaluated.
/l.

Comparative Examples 5 to 10 Regarding the test pieces used in Example 3 and Example 8, 21
Except that the surface was roughened by applying the following treatments instead of immersion treatment in 1-chloronaphthalene at 0°C.
The plating process was carried out in exactly the same manner as in Example 3, and the adhesion of the plating film was evaluated. The results are shown in Table 2.

(1) Chromium mixed acid treatment A test piece was immersed in a mixed solution of 162F potassium dichromate, 390cc of concentrated sulfuric acid, 99cc of concentrated phosphoric acid, and 999cc of water at 50°C for 3 minutes.

(21 Nitric acid treatment The test piece was immersed in 60% nitric acid at 30°C for 5 minutes, washed with water, and further neutralized with 10% sodium carbonate solution.

(3) Sulfuric acid treatment The test piece was immersed in concentrated sulfuric acid at 150°C for 5 minutes, washed with water, and further neutralized with 1096 sodium carbonate solution.

Table 2 Example 13 To parts of PP5100I used in Example 1, 40 parts by weight of titanium oxide with an average particle size of 2.3μ and 40 parts by weight of glass fiber (TN-100 manufactured by Nippon Electric Glass Co., Ltd.) were melted. A test piece was obtained in exactly the same manner as in Example 1, except that the mixed pellets were used, and further surface roughening treatment and
A plating treatment was performed to obtain a PPS molded product with a metalized surface.

The resulting molded product had good plating brightness and plating film adhesion of 1720 f/tx.

Example 14 A surface metallized PPS molded product was obtained in exactly the same manner as in Example 3, except that PPS obtained by the method shown in Reference Example 1 was used instead of the PPS used in Example 3. Ta.

The resulting molded product had good plating brightness and plating film adhesion of 23501/es.

Reference example 1 (PPS preparation! 1) Sodium sulfide 3.26 # (25
mole, including water of crystallization 4096), sodium hydroxide + Jium 4
y, about 110 mol of sodium acetate trihydrate 136#C)
and N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) 7.94 were added, and the temperature was gradually raised to 205°C while stirring.
Distilled water L506 containing 8 kg of water was removed. 3.7 kg of 1,4-dichlorobenzene was added to the remaining mixture.
Add 5 kq (25,5 mol) and NMP2#,
Heated at 265°C for 4 hours. The reaction product was washed 8 times with hot water and dried under reduced pressure at 80°C for 24 hours to a melt viscosity of 2.5.
Approximately 2 kg of powdered PPS of 00 poise was obtained.

Comparative Example 11 PPS used in Example 14 instead of PPS used in Comparative Example 5
The surface metallized P
A Ps molded product was obtained.

The plating film adhesive strength of the obtained molded product was 190y/cIl.

Example 15 Used in Example 3. Using pellets of pps composition,
Width 50ff x length 80m x height 35fi, thickness 2.5f
A box-shaped molded product of i was molded, and plating was performed in exactly the same manner except that this molded product was used in place of the test piece used in Example 3.

The appearance of the obtained molded product was good.

〔Effect of the invention〕

The method for surface metallizing polyphenylene sulfide resin molded articles of the present invention is carried out without a mechanical roughening process, so it is possible to surface metallize a surface with a three-dimensional uneven structure. The surface-metallized polyphenylene sulfide resin molded product obtained by the method of the present invention has excellent plating film adhesion, surface brightness, and excellent heat resistance, chemical resistance, and mechanical properties derived from PPS, and can be used as a metal substitute. It is useful as various parts including applications and printed wiring boards.

Claims (1)

[Claims] For 100 parts by weight of polyphenylene sulfide resin,
Inorganic filler 10-25 with an average particle diameter in the range of 1-10μ
1. A method for surface metallizing a polyphenylene sulfide resin molded article, which comprises roughening the surface of a polyphenylene sulfide resin molded article containing 0 parts by weight using a good solvent for polyphenylene sulfide, and then subjecting it to plating treatment.