JPS585335A - Treatment of resin surface - Google Patents

Abstract

PURPOSE:To roughen the entire surface of a resin molded article such as a polyacetal resin molded article without lowering mechanial strength of said article, by immersing said article in a mixed soln. of phosphoric acid and sulfuric acid, said soln. containing an acid-resistant surfactant added thereto. CONSTITUTION:0.01-5% acid-resistant surfactant such as a fluorine-or ethylene oxide-contg. surfactant is added to a mixed soln. of phophoric acid and sulfuric acid to obtain an etching soln. A resin molded article such as a polyacetal resin molded article is immersed in said etching soln. EFFECT:Bubbles formed on the surface of a molded article can be removed, and the entire surface can be roughened. Thus, a metal-plated layer as well as a firm surface layer such as a coating layer or a joining layer to other resin can be formed by welding or bonding.

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, polyacecool resin has poor surface activity, so after roughening the resin surface with an acidic or oxidizing etching agent, chemical plating is performed by immersing it in a pretreatment solution and a chemical plating solution, or surface treatment such as painting is performed. I was going.

However, when conventional etching agents are immersed in resin moldings, air bubbles are generated on the surface of the molded product, and the etching agent does not adhere to these areas, making it impossible to roughen the surface. However, since a smooth surface remains, the plating cannot be sufficiently adhered to the surface of the molded product, and there is a drawback that peeling and plating are 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 a molded product are removed and a uniform surface roughening is achieved. They discovered that plating treatment with excellent adhesion can be performed and completed this invention.

That is, the resin surface treatment method according to the present invention is a treatment method for etching the surface of a resin such as a polyacetal resin, in which a resin molded article is immersed in an etching solution prepared by adding an acid-resistant surfactant to a mixed solution of phosphoric acid and sulfuric acid. The points are distinctive.

According to this invention, by immersing a resin molded product such as polyacecool resin in the above-mentioned etching agent, air bubbles generated on the surface of the molded product are removed, and the resin W material itself is uniformly etched without deterioration of its mechanical strength. The surface will become rough, so not only the metal plating layer but also the paint! l! It is possible to form strong surface coatings such as bonding with other types of resins by bonding, fusing, 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°C.

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

Table 1 Sulfuric acid (95%) 300m//j! Phosphoric acid (85%) 20
0mj! /j! Acid-resistant surfactant 0.0
1-5% (fluorine-based or ethylene oxide-based) water balance
Table 2 shows the numerous polyacecool resin molded products mentioned above.
The treatment liquid (surfactant) was changed and classified into three types.

Class Treatment liquid 8 Fluorine-based surfactant, agent B Ethylene oxide-based surfactant C phosphoric acid
After treating A and B with an etching solution, neutralization and hot water washing were omitted, and only water washing was performed.

After C was immersed in an 85% phosphoric acid solution, it was neutralized and washed with hot water. The resin molded product was immersed twice in each etching solution, the first time was immersed in a 40°C solution for 20 minutes, and the second time was
It was immersed in a solution at ℃ 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 g/j2 hydrochloric acid (35%)
5 cc / 1 liquid temperature
Immersion time at 25-30℃: 1.5 minutes Activation> Palladium chloride 0.15g/#hydrochloric acid
2 cc/1 liquid temperature
Immersion time at 25 to 30°C: 1.5 minutes The resin molded product subjected to the above sensitization and activation treatment was treated with a commercially available ammonia-based chemical di-Nokel plating solution, and then acidic bright copper plating was applied to a thickness of 30 μm. After the layer was electrodeposited, a cut of 1 cI 1 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 cases where the etching solution temperature was 40° C. and 50° C., and the immersion time was 20 minutes and 10 minutes, respectively.

As is clear from Table 4.5, A and B, that is, those made by the method of this invention, have a practical limit of peel strength of 600 g/
It can be seen that all cases significantly exceed cs and have excellent adhesion.

Although 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 it also provides good results even if neutralization and hot water washing are omitted after etching treatment. can be obtained, so the surface treatment time can be shortened.

Patent applicant: Kokusan Metal Industry Co., Ltd. 309-

Claims (1)

[Claims] A method for etching the surface of a resin such as polyacetal resin, which comprises immersing a resin molded article in an etching solution prepared by adding an acid-resistant surfactant to a mixed solution of phosphoric acid and sulfuric acid.