Enthone Incorporated

Macdermid Enthone Gmbh

Helmut Horsthemke

Franz-Josef Stark

Ulrich Treuner

Matthias Bentele

An aqueous electrolyte for the deposition of a metal layer on a substrate surface as well as a method for the deposition of a metal layer on a substrate surface by which electrolyte and in which method the formation of airborne emissions above the surface of the electrolyte in a plating tank is significantly reduced or more preferably omitted. The aqueous electrolyte composition according to the invention comprises at least one surfactant in a concentration affecting a dynamic surface tension of the composition of &#x2264;35 mN/m.

Aqueous electrolyte composition having a reduced airborne emission, method and use of this composition

The invention concerns an electrolyte for electroless deposition of metal layers with internal compressive stresses containing a metal base salt, a reducing agent, a complexing agent, an accelerator and a stabilizer. In order to make available an electrolyte of the said kind, from which uniform pore-free and crack-free metal-phosphorus coatings can be deposited with constant layers properties and high phosphorus contents at an elevated deposition rate over a long period of time, it is proposed by means of the invention that the electrolyte contain as metal base salt a metal salt whose anions contain at least one carbon atom and that is present in a starting concentration from 0.01 to 0.3 mol/L. At least one salt consisting of metal acetate, metal formate, metal oxalate, metal propionate, metal citrate and metal ascorbate, especially preferably metal acetate, is used as the metal salt whose anion contains at least one carbon atom. In addition, a method that is especially suitable for the use of the said electrolyte is proposed, where this method advantageously has a closed material circulation. Through the use of the invention especially pore-free and crack-free metal coatings with constant layer properties are uniformly deposited over a long time of use of the bath of at least 14-22 MTO.

Process and electrolytes for deposition of metal layers

The invention relates to a method for the electrolytic coating of materials, in particular metallic materials, whereby a chromium alloy is deposited from an electrolyte, comprising at least chromic acid, sulphuric acid, an isopolyanion-forming metal, a short-chain aliphatic sulphonic acid, the salts and/or halo-derivatives thereof and fluorides. According to the invention, an alloy can be deposited, which can comprise a high proportion of isopolyanion-forming metal as a result of the combined addition of the short-chain aliphatic sulphonic acid with the fluorides and is nevertheless smooth and lustrous. In comparison with the alloy coatings known in the state of the art, in particular chrome/molybdenum alloys the above is a definite advantage. Furthermore, the presence of fluorides in particular leads to the above deposited coatings having a significantly higher hardness.

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Solingen, Germany

Helmut Horsthemke