Bayer Aktiengesellschaft

Eckhard Bayer

Peter Woditsch

Heribert Stutgens

Ulrich Meisen

Rolf-Michael Braun

Gunter Lailach

Peter Panek

Klaus Kohler

Klaus Nollen

Hans Sander

Jorg Krekel

Gerhard Wiederhoft

Wolfgang D Muller

Bernd-Michael Holle

The present invention relates to iron oxide red pigments, a process for the production of iron oxide red pigments by calcining iron oxide yellow pigments or iron oxide black pigments, and the use thereof.

Iron oxide red pigments, process for the production of iron oxide red pigments and use thereof

The present invention relates to iron oxide yellow pigments, to a method of producing iron oxide yellow pigments by a precipitation method from iron(II) chloride and an alkaline component, and to the use thereof.

Iron oxide yellow pigments, a method of producing iron oxide yellow

The present invention relates to a process for the preparation of iron oxide yellow pigments by the process of precipitation from iron(II) chloride and from an alkaline component as well as the use thereof.

Process for the preparation of iron oxide yellow pigments and the use

The present invention relates to a process for the production of titanium dioxide pigments and the use thereof.

Process for the thermal treatment of titanium dioxide in a circulating

A process for the preparation of an improved quality TiO.sub.2 pigment by hydrolysis of titanyl sulphate, isolation of the hydrolysis product form the waste acid produced during the hydrolysis, washing of the hydrolysis product and calcination of the hydrolysis product to form the TiO.sub.2 pigment, wherein the hydrolysis of the titanyl sulphate is carried out using separately produced hydrolysis nuclei which have been produced by a reaction of titanium salts with alkaline reagents, and in which waste acid and/or wash liquid containing waste acid is added after at least 50% of the total duration of the hydrolysis process.

Process for the recorvery of sulphuric acid in the production of

A process for the production of TiO.sub.2 pigments by the sulfate process by digestion of titanium-containing raw materials with sulfuric acid, hydrolysis of the titanyl sulfate formed, purification of the hydrolyzate and calcination of the hydrolyzate in rotary kilns, wherein the calcination conditions are regulated through adjustment of the SO.sub.2 content of the waste gases issuing from the rotary kilns used for calcination.

Process for the production of titanium dioxide pigments

The production of titanium dioxide pigments with improved chalking resistance and gloss retention by coating with an oxide and/or phosphate of zirconium and of titanium, aluminum and/or silicon, the improvement which comprises coating with zirconium by adding to an aqueous alkaline suspension of the titanium dioxide pigment of alkali metal or ammonium zirconium carbonate complex and slowly precipitating the zirconium by adding a dissolved compound of at least one of titanium, aluminum, silicon and phosphorus.

Process for the production of titanium dioxide pigments with high

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

A process for the production of a light-stable and weather-stable titanium dioxide pigment comprising precipitating onto the pigment in aqueous suspension a colorless vanadate of at least one of zinc, magnesium, calcium, strontium and barium at a pH-value above 7 in about 0.01 to 5% by weight, expressed as V.sub.2 O.sub.5, based on TiO.sub.2. Advantageously the pigment either before or after precipitation of the vanadate is coated with at least one oxide, oxide hydrate or phosphate of titanium, silicon, aluminum or zirconium.

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Krefeld, Germany

Eckhard Bayer