Method for electrolytic surface modification of flat metal workpieces in copper-sulfate treatment liquid containing sulfate-metallates

Abstract

The invention relates to a method for the electrolytic surface modification of a flat workpiece by the deposition of copper aggregates. The invention also relates to flat metal workpieces that can be produced using this method and to the use of said metal workpieces as substrates for the formation of secure adhesive bonds comprising a plurality of materials.

Description

[0001]The present invention relates to a method for the electrolytic surface modification of a flat metal workpiece by deposition of copper aggregates. The invention further relates to the flat metal workpieces produced with this method and to the use of the metal workpieces as substrate for the formation of strong adhesive bonds with a plurality of materials.[0002]The production of a large and rough surface is regarded as a prerequisite for a binder-free pressing of surfaces made of different materials. Depending on the combination of materials, the surfaces are first of all cleaned and then structured. Structuring is effected in the case of metal-metal bonds by dry brushing or grinding. In the case of metal-plastic bonds, which are generally produced by extruding a plastic onto a metal surface, the metal surface is pre-treated, e.g. by conversion, such as phosphating, chromating among other things, or the metal surface is modified by deposition of a deeply structured (“rough”) sur...

AI Technical Summary

Benefits of technology

This patent aims to provide a method for improving adhesion to metal surfaces, particularly in sensitive and challenging bond systems. By using as few components as possible and depositing a copper layer doped with rare earth elements, the method can minimize the release of disruptive substances and increase the adhesive strength of flat metal workpieces. The technical effects of this patent are improved adhesion to metal surfaces and a more robust and reliable bonding mechanism.

Problems solved by technology

The technical difficulties of the methods used—degreasing, electrolytic cleaning, pickling, coating—consist in the insufficiently uniform edging of the surface of foils and strips.

However, for applications in which good adhesion to another material is required, a smooth surface may be undesirable.

If this is not or is not sufficiently the case, the adhesion deteriorates.

Thus, poor adhesion between a metal surface and the same or a different material, for example a lacquer layer, a paint layer or an adhesive can lead to products which are of inferior quality or even unusable.

However, anodizing is limited to a few metal materials, such as for example aluminium, titanium and alloys thereof.

For example, through the length of the aggregates, the adhesive bond is substantially dependent on the flow behaviour of the plastics to be pressed on, in particular when the flow behaviour is so poor that the plastic does not reach the base of the treatment and only undercuts form on the tips of the aggregates.

Even if such an adhesive bond is sufficiently good, there remain cavities in the bond at the base of the conventional aggregates of the treatment, into which aggressive chemicals can penetrate and can damage or destroy the adhesive bond through corrosion.

Images