Gerhard Collardin Gmbh

Manfred Breuer

Reinhard Opitz

The invention relates to a process for phosphatizing metal surfaces with an acidic phosphatizing solution containing zinc ions, calcium ions, phosphate ions and accelerators and, optionally, other additives, characterized in that, after degreasing and without activation, the metal surfaces are brought into contact at 30.degree. to 65.degree. C. with solutions which contain Zn.sup.2+, Ca.sup.2+, PO.sub.4.sup.3- and, as accelerators, nitrate and/or nitrite and/or chlorate ions and/or an organic nitro compound and/or H.sub.2 O.sub.2 or an inorganic peroxide and which have a pH-value of from 2.2 to 3.8, a ratio of free acid to toal acid of from 1:10 to 1:60 and a ratio by weight of (Ca.sup.2+ +Zn.sup.2+) to PO.sub.4.sup.3- of from 1:&gt;8 to 1:40, and to the use of this process for pretreating the metal surfaces for painting by electrodeposition, particularly by cathodic electrodeposition.

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Pulheim, Germany

Manfred Breuer