Gerhard Collardin Gmbh

Henkel Kommanditgesellschaft Auf Aktien

Gerhard Collardin Gesellschaft MIT Beschraenkter Haftung

Reinhard Opitz

Kurt Hosemann

Heinz Portz

Karl-Heinz Gottwald

Lutz Schellenberg

Manfred Breuer

Corrosion inhibitors containing a mixture of one or more water soluble tetraborate salts and one or more water soluble condensed phosphate salts are non-toxic and are more effective than either of the components alone. These compositions containing both tetraborates and condensed phosphates are also more effective than such prior art inhibitors as nitrites and ethanolamine-based inhibitors.

Anticorrosive agents and use thereof

The present invention relates to a process for phosphating metal surfaces, and more specifically of surfaces of iron, zinc, and aluminum and the alloys thereof as a pretreatment for cold working wherein the surfaces without previous activation are contacted in a temperature range of from 30.degree. C. to 70.degree. C. with an aqueous solution containing

Process for phosphating metal surfaces

A method for activating a metal surface during a phosphating process by treating the surface with an activating solution containing titanium ions, phosphate ions, and borate ions, after initial cleaning and rinsing but before phosphation.

Method for activating metal surfaces prior to zinc phosphation

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.

Process for the zinc/calcium phosphatizing of metal surfaces at low

A composition for the after-passivation of phosphated metal surfaces and a method for its use, the composition containing at least one water soluble salt of tetravalent titanium or divalent manganese, cobalt, nickel or copper.

After-passivation of phosphated metal surfaces

A process for phosphating metal surfaces, particularly iron, steel and zinc-plated steel, by treating them with aqueous, acidic zinc phosphate baths at only moderately elevated temperatures in the range of from 22.degree. to 38.degree. C. The baths used have 2 to 6 g/l of Zn; 4 to 23 g/l of PO.sub.4.sup.3- ; a free acid content of 0.05 to 0.4 points; and a pH-value of 3.0 to 4.0. The ratio of Zn to PO.sub.4.sup.3- is preferably in the range from 1:2 to 1:11. The baths can advantageously contain nickel-(II)-ions, with a nickel content not exceeding a Zn:Ni ratio of 1:0.5. This process gives iron-containing zinc phosphate layers having an iron content of from 5 to 20% by weight and is particularly useful for pretreatment for subsequent cathodic electro-dip-lacquering.

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Dueren, Germany

Reinhard Opitz