Patent ID: 7611574

Claim:
A process for producing an interference pigment, comprising a flake-form inorganic substrate and at least one FeTiO 3 -containing layer thereon, where the FeTiO 3 is present in a proportion of 8-100% by weight, based on the total weight of the layer, and is homogeneously distributed in the layer, and at least one further layer of metal oxides, metal oxide hydrates, MgF 2 or BiOCl, said process comprising the following steps: a flake-form inorganic substrate is suspended in water, a water-soluble inorganic metal compound is added, and a pH at which a corresponding metal oxide hydrate, MgF 2 or BiOCl is deposited on the substrate surface is set and kept constant, a water-soluble inorganic titanium compound and a water-soluble inorganic iron compound in a molar ratio of 1:0.05 to 1:1, based on the oxides TiO 2 and Fe 2 O 3 , are added simultaneously to the suspension at a temperature of 50 to 100° C. and a pH kept constant in the range from 1.4 to 4.0, during which the corresponding oxide hydrates of TiO 2 and Fe 2 O 3 are deposited on the substrate surface as a mixture, the resultant coated substrate is separated off, optionally washed and dried, and thermally treated at temperatures in the range from 500° C. to 1200° C. under reducing conditions.