Degussa Aktiengesellschaft

Everhard Gratzfeld

Eva Clausen

Helmut Reinhardt

Hans Schaefer

Heinrich Winkeler

Iron blue characterized by an ammonium content of .+-.5.5 weight %, a potassium content of &lt;0.1 weight %, a sodium content of &lt;0.1 weight %, a color strength in a toluene intaglio printing ink up to 15% greater than the standard Vossen blue 705/80 (calculated in accordance with DIN 53 234) and the color spacings (determined in accordance with DIN 6174 relative to Vossen blue 705/80 as standard) of

Iron blue pigment, process for its pigmentation and use

Iron blue pigment (DIN 55 906) is produced by white paste precipitation and subsequent oxidation of the white paste. Alakli or alkali metal ions i.e. sodium and potassium ions, cyanide or complex iron cyanide ions and iron ions are used as raw materials. The iron blue pigment according to the invention is characterized by a potassium content of 0.5-4.5% by weight, preferably 0.5-2.0% by weight, a sodium content of 0.2-1.0% by weight, an ammonium content of 2.0-4.5% by weight, preferably 3.0-4.5% by weight, a coloring power in accordance with DIN 53 204 and DIN 53 234 of 5-15% above the Vossen Blue 705 Standard and the following color intervals (determined in accordance with DIN 53 204 and DIN 53 234 in conjunction with DIN 6174, in relation to Vossen Blue 705 as standard):

Iron blue pigment, process for making the same and use

Iron blue pigment (DIN 55 906) is produced by white paste precipitation and subsequent oxidation of the white paste. Alkali or alkali metal ions i.e. sodium and potassium ions, cyanide or complex iron cyanide ions and iron ions are used as raw materials. The iron blue pigment according to the invention is characterized by a potassium content of 7.0-9.0% by weight, preferably 7.6-9.0% by weight, a sodium content of 0.5-2.0% by weight, preferably 0.5-1.5% by weight, a coloring power according to DIN 53 204 and DIN 53 234 of 5-15% above the Vossen Blue 705 Standard and the following color intervals (determined in accordance with DIN 53 204 and DIN 53 234 in conjunction with DIN 6174, in relation to Vossen Blue 705 as standard):

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Wesseling, Germany

Everhard Gratzfeld