Bayer Aktiengesellschaft

Lanxess Deutschland Gmbh

Bayer Chemicals Ag

Ulrich Meisen

Gerhard Auer

Eckhard Bayer

Werner Schuy

G&uuml;nter Lailach

Rolf-Michael Braun

Leslaw Mleczko

Wolfgang Korschen

Gunter Buxbaum

Horst Brunn

Holger Friedrich

Carsten Rosenhahn

Ralph Weber

Jürgen Kischkewitz

Krzysztof Chlopek

Juergen Kischkewitz

Georg Lamp

Christine Kathrein

Florian Haberey

Karl-Heinz Van Bonn

Kai Buetje

Peter Koehler

Udo Julius

Kai Bütje

Ralf Gerhard Koenig

Ralf Gerhard Konig

Ralf Gerhard KÖNIG

Peter KÖHLER

Aluminium-containing iron oxide pigments of the formula FeAlOwith x values from 0.01 to 0.25, characterized in that they possess an a* value of 30.5 to 32.5 CIELAB units and a b* value of 25.5 to 30.5 CIELAB units, measured in each case as full shade in the alkyd resin according to DIN EN ISO 787-25:2007.

Iron oxide pigments containing Al

Coated pigments for plastics, as well as processes for production of the pigments, the use thereof for colouring polyvinyl chloride (PVC), processes for colouring PVC, PVC coloured with such coated pigments, and also plastics products including such coated pigments, may include inorganic pigments coated with of at least one of hydroxides of magnesium, hydroxides of calcium, oxides of magnesium, and oxides of calcium.

Coated pigments for coloring PVC

The invention relates to iron oxide pigments comprising an average solid body diameter of 0.1 to 500 &#x3bc;m, and to the production and use thereof.

Iron oxide pigments

Iron Oxide pigment containing greater than 99% iron oxide, having a chloride content of less than 0.1% and a mean solid diameter of 10 to 500 &#x3bc;m and methods of making the same are disclosed.

The present invention relates to a process for preparing yellow iron oxide pigments by the precipitation method from iron(II) chloride or iron(II) sulphate raw material and calcium carbonate precipitant.

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The invention relates to a process for the preparation of magnetite particles and to their use.

Process for the preparation of magnetite particles and their use

The invention relates to a toner containing low-silicon magnetite particles.

Toner containing magnetite particles

This invention relates to a process for producing magnetite particles having a coercivity of 6.366 kA/m to 10.345 kA/m (&equals;80 to 130 Oe) and an octahedral particle shape, comprising heating an alkaline component and an iron(II) component in the form of an aqueous solution to a temperature of 50&deg; C. to 100&deg; C., whereby the molar ratio of iron(II) component to one equivalent of alkaline component is 0.38 to 0.45, and treating the suspension with an oxidizing agent at a rate of oxidation of 20 to 50 mol. % Fe(II)/h until the iron compound has an Fe(III) content of more than 65 mol. %, and then again adding an Fe(II) component in the form of an aqueous solution at a molar ratio of Fe(II) to one equivalent of total alkaline component used is 0.47 to 0.49, and treating the suspension with an oxidizing agent, at a rate of oxidation is 20 to 50 mol. % Fe(II)/h until the iron compound has an Fe(III) content of more than 65 mol. %, and filtering the suspension, and washing, drying and grounding the residue.

Process for producing magnetite particles

Process for producing yellow iron oxide pigments

This invention relates to magnetite particles with a mean particle size of 0.1 to 0.3 &mgr;m, a specific surface area of 6 to 9 m /g, a coercive force of 80 to 110 Oe, a residual magnetization of 13 to 20 nTm /g, a pH of 7 to 10 and a bulk density of 0.6 to 0.9 g/cm , by heating an aqueous solution of an alkaline component under inert gas, to a precipitation temperature of 65-85&deg; C., adding iron (II) and iron (III) components and oxidizing the suspension with an oxidizing agent at a speed of 7-25 mol % Fe (II)/h.

Magnetites and their use in producing toners

Process for the production of yellow iron oxide

Process for the preparation of iron oxide pigments from the waste acid resulting from the preparation of titanium dioxide by the sulfate process, characterized in that in a first stage a partial neutralization of the sulfuric acid contained in the waste acid is performed with compounds from the group comprising metallic iron and/or iron compounds, the sulfuric acid is optionally further neutralized with a further alkaline compound, the precipitate containing Ti, Al, Cr and V compounds is separated from the resultant reaction product and an iron oxide yellow pigment or iron oxide black pigment is precipitated from the resultant iron sulfate-containing solution by addition of alkaline compounds as well as an oxidizing agent, each pigment being able to be baked to form an iron oxide red pigment.

Method for producing iron oxide pigments from waste acid resulting from TiO2 production

The invention relates to a method of preparing an aluminium-containing iron oxide nucleus with an &agr;-FeOOH crystal structure from FeCl . This nucleus is a suitable starting material for the preparation of iron oxide yellow and for use as a yellow coloring pigment.

Method of preparing an aluminum-containing iron oxide nucleus

The present invention relates to a process for the production of an aluminum-containing iron oxide crystallization nucleus with a &agr;-FeOOH crystal structure from FeCl . This nucleus is suitable as starting material for the production of iron oxide red (&agr;-Fe O ) via &agr;-FeOOH as an intermediate product.

Process for the production of an aluminium-containing iron oxide crystallization nucleus

Process for the production of gypsum and also of an iron-oxide pigment from the waste acid that accumulates in the course of the production of titanium dioxide in accordance with the sulfate process, characterized in that in a first stage a partial neutralization of the waste acid is effected with a calcium compound subject to precipitation and optionally direct separation of gypsum, subsequently the remaining solution is neutralized further in a second stage subject to precipitation of a deposit containing Ti, Al, Cr, V and optionally Fe(III) and from the solution containing iron sulfate that is obtained after separation of the solids an iron-oxide pigment is produced in a third stage by addition of alkaline compounds and also of an oxidizing agent.

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Kall, Germany

Ulrich Meisen