JPS6039152B2 - 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, with conventional etching agents, when a resin molded product is immersed,
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, bubbles generated on the surface of the molded product are removed and a uniform surface roughening is achieved. It is possible to perform plating treatment with excellent adhesion, and after further plating treatment, it is possible to obtain a surface coating with even greater adhesion strength by drying at a temperature of 40 oo or more and less than the resin deformation temperature. After seeing this, he came up with the idea and 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 mixture of IJ acid and sulfuric acid, and then neutralizing and hot water if necessary. The method is characterized in that after washing, washing with water, etc. and plating the resin molded product, it is heated and dried at a temperature of 40 qo or higher and lower than the deformation temperature of the resin.

According to this invention, by immersing a resin molded product such as polyacetal resin in the etching agent, air bubbles generated on the surface of the molded product are removed, and the molded product can be uniformly removed without deteriorating the mechanical strength of the resin material itself. Since the surface is roughened, it is possible to form not only a metal plating layer but also a strong surface coating such as a coating layer by painting, or bonding with another type 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 3 minutes in air maintained at a temperature of 15,000 °C.

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

Table 1 Sulfuric acid (95%) 300 [/phosphoric acid (
85%) 200 Otsu/So acid-resistant surfactants
0.01-5% (fluorine-based or ethylene oxide-based) water. The remainder was classified into three types by changing the treatment liquid (surfactant) as shown in Table 2 for the numerous polyacetal resin molded products mentioned above.

Table 2 Treatment liquid A Furohata-based surfactant B Ethylene oxide-based surfactant C Phosphoric acid-water Of these, A and B are treated with an etching solution, then neutralization and scratch cleaning are omitted. I only washed with water.

After C was immersed in 85% phosphoric acid solution, neutralization and wound cleaning were performed. The resin molded product was immersed twice in each etching solution;
000 solution for 1 powder. 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/final liquid temperature
25-30q0 bond immersion time
1.5 minutes <activation> palladium chloride
0.15 t/chloric acid
2cc/Solution temperature 25~
3000 immersion time: 1.8 minutes The resin molded product subjected to the above sensitization and activation treatment was treated with a commercially available ammoniacal chemical nickel plating solution, and then acidic bright steel plating was deposited in a layer of 30 mm thick. After rubbing, 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 4000 and 50 CO, respectively, and the immersion time was 20 minutes and 1 minute. Table 5 (Units: Thailand) Table 4 (Units: Yujika) As is clear from Tables 4 and 5, both A and B significantly exceeded the practical limit value of peel strength of 600 Yu/Ki.
It can be seen that it has excellent adhesion.

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 at 150 qo for 30 minutes, and immersed in a 5000 etching solution of sulfuric acid-phosphoric acid mixture containing 0.1% acid-resistant surfactant for 10 minutes. Etched. Neutralization and scratch cleaning were omitted, and the roughened molded product was washed with water, sensitized and activated, and then immersed in a chemical nickel plating solution for plating. 4000 pieces of the obtained molded product
, after drying in high temperature air at 8000 and 100 degrees Celsius,
Oxidation activation treatment was performed using a diluted sulfuric acid solution of approximately 5%, and pyrophosphate steel strike plating or nickel chloride strike plating was then applied.

Furthermore, after polishing 30 pieces of acidic bright steel plating, l
A cm-wide cut was made and the peel strength was examined using a tensile tester. The results are shown in Table 6. Table 6 (Unit name) As is clear from Table 6, by adding a drying step after plating, the peel strength increases surprisingly and even better adhesion can be obtained.

Claims (1)

[Claims] 1. Immerse a resin molded product such as polyacetal resin in an etching solution containing a mixture of phosphoric acid and sulfuric acid with an acid-resistant surfactant added, and if necessary, neutralize and wash the resin molded product by washing with hot water or water. A method for treating a resin surface, which comprises, after plating, heating and drying at a temperature of 40°C or higher and lower than the deformation temperature of the resin.