Bayer Aktiengesellschaft

Karlheinz Turban

Jakob Rademachers

Gerhard Franz

Werner Fuhr

Bernd Holle

A process for the production of an anisometric yellow-brown zinc ferrite pigment comprising homogeneously mixing zinc oxide having a specific BET surface of more than 2 m.sup.2 /g with needle-shaped .alpha.-FeOOH obtained from an iron salt solution by mixing with alkali and subsequently oxidizing in a nucleation and pigment growth stage, the FeOOH having a specific BET surface of about 15 to 25 m.sup.2 /g, an average needle width of about 0.025 to 0.125 .mu.m and an average needle length of about 0.2 to 0.6 .mu.m, annealing the mixture at a temperature of about 700.degree. to 1000.degree. C., cooling and grinding.

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Krefeld, Germany

Karlheinz Turban