SU755887A1 - Solution for polymeric surface pickling before its metallization - Google Patents

Description

The invention relates to the preliminary preparation of the polymer surface before metallization and can be used in the radio, 5 instrument-making and electrical industries.

The closest to the invention in technical essence and the achieved result is a solution for etching the polymer surface before metallization, containing iodine and potassium iodide [1].

When polymers are treated with this solution, adsorption of saturation of the surface layer with iodine occurs, which leads to an increase in adhesion of the coating to the substrate. However, in this case, the surface still remains smooth, which provides a basis for finding ways to give it a roughness that contributes to an increase in adhesion of the coating to the substrate.

The aim of the invention is to increase the adhesion of the coating to the base. 25

The goal is achieved by the fact that the proposed solution in contrast to the known additionally contains hydrochloric acid πρπ the following ratio of components, g / l:

Iodine 10-15

Potassium iodide 30-45

Hydrochloric acid

(unit weight: 1.17-1.19) 240-360

Hydrochloric acid primes the surface of polyamide, making it rough, and iodine is embedded in the surface layer of plastic. The ratio of components is chosen so that during processing the surface of the plastic is sufficiently etched and at the same time pressed with iodine. The solution is prepared by simple mixing of the components.

The use of the invention can be illustrated by the following examples. Samples of polyamide with an area of 8 cm ^{g were} degreased in gasoline for 5 minutes, dried in air, and treated at room temperature in an etching solution.

Example 1. The solution contains, g / l:

Iodine 10

Potassium iodide 30

Hydrochloric acid

(spd. 1,17-1,19) 240

Processing time 20 min

3

755887

four

PRI and mper 2. The solution contains, g / l:

Iodine 12.5 Potassium iodide 37.5 Hydrochloric acid (unit weight: 1.17-1.19) 300

Processing time 15 min

Example 3. The solution contains

zht, g / l: Iodine 15 Potassium iodide 45 | Λ Hydrochloric acid ιυ (ud.ves.1,17-1,19) 360 Time of processing 10 min

Then the samples were washed in distilled water and they were sensitized in a solution containing 100 g / l of 2–15 tin chloride and 180 ml / l of hydrochloric acid (mp, 1.19) for 5 min. The samples were washed with distilled water and activated in a solution containing 3 g / l of palladium chloride and 20 ml / l of hydrochloric acid (pl.

1,19), for 10 minutes at room temperature, then dried in air, treated in a reducing agent solution containing 30 g / l 25

sodium hypophosphite, for 5 minutes and chemically nickel-plated at 50 ° C in a solution containing, g / l: nickel chloride 10; sodium hypophosphite 20; succinic acid 10, sodium hydroxide 4; sodium fluoride 1, for 10 min.

Tests on the adhesion of nickel to the substrate was carried out after applying a layer of electroplated nickel with a thickness of:

10 μm from solution, g / l: nickel sulphate 250, sodium chloride 15, boric acid 30; 1,4-Butinediol (35% solution) 1 ml / l; chloramine B 2 ml / l; formalin (40% solution)

0.01 ml / l, "Progress" 0.003 ml / l, 40 pH 5, at a current density of 4 A / dm ² and an electrolyte temperature of 50 ° C.

Nickel adhesion to the substrate was evaluated by the number of samples that did not withstand the tests of thermal currents (i.e., the samples were kept for 1 h in water having a temperature of 80 + 5 ° С and 30 s in water having a temperature of 5 ± 0.5 ° С, the cycle was repeated 3 times), and by the number of samples on which the coating was peeled off when the mesh of cuts was applied.

The data obtained are shown in the table.

The test results of nickel-plated polyamide samples

for adhesion

Method test The number of samples with peeling coating,% according to the invention prototype example one example 2 example 3

Drawing

mesh slits. 8 11 9 18

Thermal currents 5 4 3 7

 The test results show that the adhesion of the nickel coating to the surface of the polyamide is 1.5-1.7 times higher than that of the prototype.

Claims (1)

Polypropylene etching solution surfaces before metallization, co. holding iodine and potassium iodide, characterized by the fact that, in order to increase the adhesion of the coating to the substrate, it additionally contains hydrochloric acid in the following ratio of components, g / l: Iodine 10-15 Potassium iodide 30-45 Hydrochloric acid (specific weight: 17.17-1.19) 240-360