Bayer Aktiengesellschaft

Klaus Nollen

Peter Woditsch

Wilfried Burow

Horst Brunn

Eckhard Bayer

Helmut Printzen

Heribert Stutgens

Klaus Kohler

Hans Sander

Iron oxide yellow pigments having a silking effect .DELTA.E.sub.1 *, less than or equal to 0.5, and having color values which range for L* from 52-63, for a* from 8 to 14 and for b* from 40 to 48 CIELAB units are produced by a process by first, forming needle-shaped .alpha.-FeOOH yellow pigment nuclei in the presence of compounds containing the elements B, Al, Ga, Si, Ge, Sn or Pb present in a quantity of from 0.05 to 10% by weight, where the quantity is calculated as the tri- or tetra-valent oxides of the compounds and based on the .alpha.-FeOOH which is precipitated during nucleation, and second, growing iron oxide yellow pigments on the thus formed iron oxide yellow nuclei.

Iron oxide yellow pigments having a low silking effect and a process for

An inorganic pigment exhibiting improved gloss and distribution in lacquer binders, carrying a coating comprising a polyhydrogen siloxane and an alkanolamine. Advantageously the alkanolamine comprises at least one of triethanolamine, triisopropanolamine, diethanolamine, diisopropanolamine and 2-amino-2-methyl-propanol-1, the polyhydrogen siloxane is a polymethylhydrogen siloxane having more than 5 Si atoms, and the pigment comprises TiO.sub.2 or a titanate carrying an inorganic coating, the polyhydrogen siloxane plus alkanolamine ranging from about 0.3 to 1% by weight of the pigment and the ratio by weight of the polyhydrogen siloxane to alkanolamine ranging from about 1:2 to 1:5.

Inorganic pigments with improved gloss and distribution in lacquer

An inorganic pigment exhibiting improved gloss and distribution in lacquer binders, carrying a coating comprising a SiOH-containing organosilicon compound and an alkanolamine. Advantageously the alkanolamine comprises at least one of triethanolamine, triisopropanolamine, diethanolamine, diisopropanolamine and 2-amino-2-methyl-propanol-1, the organosilicon compound is of the formula ##STR1## wherein n&gt;3, R and R.sup.1 each independently is alkyl, cycloalkyl, aryl, alkenyl or a group of the formula ##STR2## wherein m&gt;1, the organosilicon compound having an OH:Si ratio within the range of about 1:1 to 1:20, and the pigment comprises TiO.sub.2 or a titanate carrying an inorganic coating, the organosilicon compound plus alkanolamine ranging from about 0.3 to 1% by weight of the organosilicon compound to alkanolamine ranging from about 1:2 to 1:5.

Inorganic pigments with improved gloss and good distribution in lacquer

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Krefeld, Germany

Klaus Nollen