Bayer Aktiengesellschaft

Henning Erfurth

Franz Hund

Peter Woditsch

Jakob Rademachers

Friedrich Kindervater

Willi Hennings

Bernd Holle

Wilhelm Holznagel

Jacob Rademachers

Wilhelm Schnell

A temperature-stable inorganic yellow pigment of the composition Fe.sub.2 TiO.sub.5 .multidot. x TiO.sub.2, where x is from 0 to about 15, with a particle diameter of less than about 1 micron is produced by forming an aqueous suspension of at least one finely divided iron compound selected from the group consisting of iron oxide, iron oxide hydroxide, iron hydroxide and iron carbonate and at least one finely divided titanium compound selected from the group consisting of titanium dioxide and titanium dioxide oxide hydrate, the iron and titanium compounds being present in accordance with the stoichiometric composition Fe.sub.2 TiO.sub.5 .multidot. x TiO.sub.2 where x is from 0 to about 15, removing the aqueous phase from the mixed suspension, and calcining the residue at a temperature from about 600.degree. C to 1100.degree. C.

Temperature-stable inorganic yellow pigments

In the production of temperature-stable inorganic pigment of pseudobrookite-titanium dioxide structure having the composition Fe.sub.2 TiO.sub.5.sup.. x TiO.sub.2, wherein x is from 0 to about 15, by preparing a suspension of finely divided titanium dioxide or titanium dioxide hydrate and at least one of finely divided iron oxide, iron oxide hydroxide, iron hydroxide and iron carbonate, removing the aqueous phase of the suspension from a solid residue and calcining the residue at a temperature in the range of about 600.degree. to 1100.degree.C, the improvement which comprises including in the suspension or in the solid residue at least one compound of a metal selected from the group consisting of lithium, sodium, potassium, magnesium, zinc, calcium, aluminum, copper, vanadium, chromium, manganese, cobalt and nickel, the compound being present in a quantity to provide about 0.1 to 10 % by weight of metal based on the pigment. With the addition of compounds of lithium, sodium, potassium, magnesium, zinc, calcium or aluminum even in small amounts a much purer yellow color results.

Metal additions to pigments of pseudobrookite-titanium dioxide structure

A process for the production of basic aluminum nitrate solutions by reacting metallic aluminum with nitric acid, comprising establishing a body of metallic aluminum, supplying additional aluminum to said body, supplying to said body countercurrent to the supply of the additional aluminum nitric acid of a concentration of about 5 to 30% by weight having basic aluminum nitrate dissolved therein and a pH of about 1 to 4, maintaining said body at a temperature of from about 30.degree.C up to the boiling point of the nitric acid, whereby the aluminum reacts with the nitric acid, and removing solution containing reaction product adjacent the point of supply of the additional aluminum and remote from the point of supply of the nitric acid.

Production of basic aluminium nitrate solution

Growing community of inventors

Krefeld, Germany

Henning Erfurth