Condorcoat EC 980: new chrome free pretreatment for galvanized steel

On November 23rd and 24th the autumn congress of ECCA (European Coil Coating Association) took place in Brussels.
During the convention, Mrs Rocco Emanuela, from Condoroil's R&D department, presented a paper about chrome free pretreatments for galvanized steel in colour coating lines. Here below a short abstract:

In the coil coating industry, corrosion resistance and aesthetic properties are essential for the quality of the product. To guarantee both the requirements along all the supply chain not only the paint step is important, but also the pre-treatment step plays a key role.

The pre-treatment step converts the metal surface in order to improve its resistance to corrosion and to enhance the adhesion of the paint to the metal. Application of the product can be done in traditional spray tunnels or by chemical coater.

In the application by chemical coater products containing organic film polymers (like Condorcoat EC 940 and EC960) are predominantly used. In spray applications, instead, traditional products based on hexavalent chromium, complex oxides (nitrocobalt) or again crystalline phosphating can be still found. In some cases there could be lines adopting nanotechnologic formulations already used in the chemical coater. Indeed the organic products are very foamy when used in spray applications. The resin has tendency to soil ramps, rollers and areas where the liquid is spryed and it can be very difficult to get a uniform deposit of the substrate. Moreover, since polymers are very susceptible to the pH, especially when in emulsion, the working bath has to be constantly monitored to avoid sludge formation.

In order to eliminate the disadvantages given by a resins based product, designed to be used with the chemical coater, Condoroil studied and formulated a product dedicated to spray lines called Condorcoat EC 980.

With Condorcoat EC980 the conversion of the surface is achieved in one step and does not require further rinse. The product is chrome, cobalt and phosphate free and complies with environmental regulations.
The formulation provides corrosion protection and paint adhesion combining the inorganic passivating effect of acidity and zirconium salts with the functionality of the organosilane additives.

Pre-treatment products overview
Condoroil offers three different passivating products for substrate pre-treatment. All the products are chrome free.

PRODUCT BASIC COMPOSITION Operative pH Rinse Applicator CONDORCOAT EC940 Esafluotitanic acid, organic polymers 2,9 ± 0.5 NO COATER CONDORCOAT EC960 Esafluotitanic acid, organic polymers. It produces a 
coloured coating 2.9± 0.5 NO COATER CONDORCOAT EC980 Esafluozirconic acid and silane additives 5 ± 1.0 NO SPRAY