Bayer Aktiengesellschaft

Peter Panek

Peter Woditsch

Eckhard Bayer

Heribert Stutgens

Walter Gutsche

Wolfgang Ritter

Peter Tacke

Dieter Rade

Hilmar Rieck

Rolf Michael Braun

Horst Bornefeld

Werner Kannchen

A modified hydrophobic colored or magnetic pigment or filler comprising a hydrophobic pigment or filler containing from 0.05 to 10% by weight, based on the weight of the pigment or filler, of an organopolysiloxane corresponding to the formula ##STR1## wherein x=0 to 500,

Hydrophobic pigments and fillers for incorporation in synthetic resins

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

In the process wherein a titanium-containing material is subjected to react with sulphuric acid to form a solid reaction mass from which the titanium values are recovered in solution by digestion with water or dilute sulphuric acid leaving behind a reaction residue and the reaction residue is thereafter treated to recover at least part of the titanium contained therein, the improvement wherein the treatment of the reaction residue is effected by contacting with sulphuric acid of a concentration greater than 86% a mixture by weight comprising about 5 to 95% of the reaction residue and 95 to 5% of a slag having a TiO.sub.2 content 60% by weight and a Ti(III) content of about 5 to 40% by weight, and thereafter eventually adding water, steam or dilute sulphuric acid to the mass to start the reaction.

Treating hydrolysis residues from preparation of titanium dioxide

A process for the production of a hydrolyzable titanyl sulphate solution comprising contacting sulphuric acid of about 86% concentration with a mixture of slag and ilmenite, the ratio of H.sub.2 SO.sub.4 to TiO.sub.2 in the mixture ranging from about 1.7:1 to 2.2:1 and the mol ratio of Ti(III) to Fe(III) in the mixture ranging from about 25:1 to 1.4:1, the slag having a TiO.sub.2 content of &gt;80% and a Ti(III) content of about 22 to 40% calculated as TiO.sub.2, and the ilmenite having a Fe(III) to Fe(II) ratio from about 1:1 to 10:1, and adding water if necessary to bring the concentration of sulphuric acid to from about 86 to 96%.

Production of hydrolyzable titanyl sulphate solution

A process for the preparation of a hydrolyzable titanyl sulphate solution comprising adding sulphuric acid having a concentration greater than about 86% to a ternary mixture of two slags and an ilmenite to bring the proportion by weight of H.sub.2 SO.sub.4 to TiO.sub.2 to from about 1.7:1 to 2.2:1 and adding water, dilute sulphuric acid or oleum in amount sufficient to bring the H.sub.2 SO.sub.4 concentration to from about 86 to 96%, thereby to form the titanyl sulphate solution, the first slag having a TiO.sub.2 content greater than about 80% and a Ti(III) content of about 22 to 40%, the second slag having a TiO.sub.2 content of about 60 to 80% and a Ti(III) content of about 5 to 15%, and the ilmenite having a ratio of Fe(III) to Fe(II) of from about 1:1 to 10:1, the slags and ilmenite being present in such proportions that the ternary mixture of raw materials obtained has a molar ratio of Ti(III) to Fe(III).gtoreq.1.4.

Hydrolyzable titanyl sulphate solutions by decomposition of ternary raw

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.

Stabilizing titanium dioxide pigments with vanadates

A pigmented high-impact plastic comprising by weight about

Growing community of inventors

Krefeld, Germany

Peter Panek