Barrier coatings

September 12, 2011

Chemetall’s new Gardobond® CU 7600 and Gardobond® 7602 technologies allow high-quality copper layers to be applied on substrate materials such as iron, steel, zinc, or die-cast zinc in an electroless and environmentally friendly way.

The process, applied at ambient temperature, enables further processing by galvanic coating for decorative and functional purposes. The products can be used in place of technologies involving copper or nickel electrodeposition.

The processes do not contain any strong complexing agents such as cyanide, EDTA, or HEDTA and, except for copper, also no heavy metals. Moreover, they are free from organic or inorganic stabilizing agents and do not require reducing agents such as formaldehyde, hydrazine, or hypophosphite.

The new technologies operate at ambient temperature and do not need external power input. Because the process operates on the basis of chemical reactions, it also can provide an even, largely constant barrier coating on hollow parts or components with recesses or bores.

Using the coatings does not alter the process sequence in existing plating plants. As both processes are relatively insensitive to extraneous ion carryover, deionized water generally can be omitted in the upstream cleaning processes. Depending on the application, the additional upstream cleaning step for electrolytic degreasing of coating may be obsolete.

The CU 7602 coating generates permanently glossy copper layers, while CU 7600 produces matte surfaces. Both technologies can be used in such industrial sectors as the automotive industry and in the production of welding rods, fittings, jewelry, and electrical and household appliances. The new processes also can be used when producing connecting elements for windows, doors, or furniture.

Chemetall GmbH * 49-69-7165-3605 * www.chemetall.com