JPS6039153B2 - Treatment method for resin surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating a resin surface that can provide a surface coating with excellent adhesion.

For example, polyacetal resin has poor surface activity, so after roughening the resin surface with an acidic or oxidizing etching agent, chemical plating is performed by soaking it in a pretreatment solution and chemical plating solution, or surface treatment such as painting is performed. I was going. However, when a resin molded product is immersed in a conventional etching agent,
Air bubbles form on the surface of the molded product, and the etching agent does not adhere to this area, making it impossible to roughen the surface.Therefore, even if this area is plated, a smooth surface remains, so the surface of the molded product must be sufficiently plated. The disadvantage was that it could not be adhered to the surface of the substrate, and peeling and cracking were likely to occur.

This invention was made with attention to this point, and by adding an acid-resistant surfactant to a mixed solution of phosphoric acid and sulfuric acid, air bubbles generated on the surface of the molded product are removed and a uniform hammered surface is achieved. It was discovered that a plating process with excellent adhesion could be performed, and that a surface coating with even greater adhesion strength could be obtained by sequentially applying a second and third layer of plating after drying. , completed this invention.

That is, the resin surface treatment method according to the present invention involves immersing a resin molded product such as polyacetal resin in an etching solution prepared by adding an acid-resistant surfactant to a mixed solution of phosphoric acid and sulfuric acid.
If necessary, refinement such as neutralization, hot water washing, and water washing is performed, and after the first layer is plated on the resin molded product, this plated layer is dried and subjected to acid activation treatment, and the second and third layers are plated in order. It is distinctive in that it performs processing. According to this invention, by immersing a molded product made of a resin such as polyacetal resin in the etching agent, air bubbles generated on the surface of the molded product are removed, and the molded product is uniformly coated without deteriorating the mechanical strength of the resin material itself. Since it becomes a phase, not only the metal plating layer but also the paint layer,
A strong surface coating can be formed by bonding with other types of resin by fusion or adhesion.

Next, the present invention will be specifically explained using an example in which a metal plating layer is formed on a polyacetal resin.

- First, a large number of polyacetal resin molded articles were degreased for 1 minute in trichlene vapor, and then dried for 30 minutes in air maintained at a temperature of 150 oo.

On the other hand, an etching solution was prepared by mixing the components shown in Table 1 below.

Table 1 Sulfuric acid (95%) 300 μg/sorinic acid (8
5%) 200 upper/lower acid resistant surfactant
0.01 to 5% (fluorine-based or ethylene oxide-based) water, balance, and Table 2 of the above numerous polyacetal resin molded products
The treatment liquid (surfactant) was changed and classified into three types.

Table 2 Type Treatment liquid A Fluorine surfactant B Ethylene oxide surfactant C Phosphoric acid-water Of these, A and B are treated with an etching solution, then neutralization and hot water washing are omitted, and water washing is used. only.

After C was immersed in 85% IJ acid solution, it was neutralized and washed with hot water. The resin molded article was immersed twice in each etching solution, the first time being immersed in a 40 oo solution for 20 minutes, and the second time being immersed in a 50 oo solution for 10 minutes. After the surface roughening of the resin molded product was completed, the resin molded product was subjected to sensitization and activation treatment using a commercially available pretreatment liquid for plastic plating shown in Table 3. Table 3 <Sensitization> Stannous chloride 2 t/so Hydrochloric acid (35%) 5 cc/〆Liquid temperature
25~300○ Bond immersion time
The resin molded article subjected to the above sensitization and activation treatment for 1.5 minutes was treated with a commercially available ammoniacal chemical nickel plating solution, and then the acidic bright steel plating was folded into a 30 μm thick layer. A cut of one skin width was made and the peel strength was examined using a tensile tester.

The results are shown in Tables 3 and 4.

Tables 4 and 5 show the cases where the etching solution temperature was 40q○ and 50ko○, respectively, and the immersion time was 20 minutes and 10 minutes. Table 4 Table 5 As is clear from Tables 4 and 5, both A and B significantly exceeded the practical limit of peel strength of 600 μm/arc, indicating that they had excellent adhesion.

The surface coating obtained in this way also exhibits excellent heat resistance, and after etching the molded product in the same manner as described above, sensitization, kudzu-like treatment, and chemical nickel plating, it is coated with a copper plate of 15 mm. , nickel plated 10mm and chrome plated 0.
Apply 3〃 and leave it at room temperature for 130 minutes - 8 minutes.
A heat resistance test was repeated four times in which one cycle was 0 C6 minutes and left at room temperature, but no blisters or cracks occurred in any of the tests.

Next, the effect of drying after plating on the adhesion strength will be explained.

The test piece used in this test was prepared in the same manner as described above.

That is, the resin molded product was degreased with triclene vapor for 1 minute, dried for 3 minutes at 15°C, and immersed in a 50OO etching solution of a sulfuric acid-phosphoric acid mixture containing 0.1% acid-resistant surfactant. Etching was performed for 10 minutes. Neutralization and hot water washing were omitted, and the neck-faced molded product was washed with water, sensitized and activated, and then immersed in a chemical nickel plating solution to be plated**. 40q of the obtained molded product
After drying in high-temperature air at 80°C, 80°C, and 100°C, oxidation activation treatment was performed with a diluted sulfuric acid solution of about 5%, and pyrophosphate steel strike plating or nickel chloride strike plating was applied.

Furthermore, after cracking 30 piles of acidic bright copper plate, 1
A cut was made to the width of the skin and the peel strength was examined using a tensile tester.
The results are shown in Table 6. Table 6 As is clear from Table 6, by adding a drying step after the plating treatment, the peel strength increases surprisingly and even better adhesion can be obtained.

Since the present invention is as described above, it is possible to apply a surface coating with excellent adhesion strength to resin molded products such as polyacetal resin, and good results can be obtained even if neutralization and hot water washing are omitted after etching treatment. can be obtained, so the surface treatment time can be shortened.

Claims (1)

[Claims] 1. Immerse a resin molded product such as a polyacetal resin in an etching solution made by adding an acid-resistant surfactant to a mixed solution of phosphoric acid and sulfuric acid, and if necessary, perform neutralization, washing with hot water, washing with water, etc. to make the resin molded product. A method for treating a resin surface, which comprises plating the first layer, drying the plating layer and subjecting it to acid activation treatment, and sequentially plating the second and third layers.