Bayer Aktiengesellschaft

Heinz P Hemmerich

Hans J Rosenkranz

Peter Rasche

Werner Schulte-Huermann

Jurgen Spille

Dietmar Kranz

In a process for the preparation of an N-alkylated aromatic amine by contacting an aromatic amine with an aliphatic or cycloaliphatic alcohol at an elevated temperature and under increased pressure, in the presence of catalysts, the improvement wherein the reaction is carried out in the presence of a phosphorus oxyhalide.

Process for the preparation of N-alkylated aromatic amines

The application relates to a process for the preparation of pigment concentrates, preferably pulverulent pigment concentrates, which is characterized in that the polymer present in an intimate mixture, free from non-ionic surface-active agents, of an aqueous pigment suspension and an aqueous latex of a polymer or polycondensate containing carboxyl groups, or an aqueous solution of a polymer or polycondensate containing carboxyl groups, is coagulated by adding an electrolyte, while thoroughly mixing intensively, and the coagulate containing the pigment is then separated off in a known manner and optionally dried. The pigment concentrates are suitable for pigmenting aqueous media and printing pastes for pigment printing of textiles.

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Krefeld, Germany

Heinz P Hemmerich