Abstract: The invention relates to a method and digital storage medium and a computer system for multilingual associative searching. The method, medium or system provides for input of the search text in a first language, the search text is automatically translated into a second language, the search text translated into the second language is transferred to an associative search module, the associative search module including a neural network or a predefined algorithm which is designed to search on the basis of a search text in the second language.

Abstract: The present invention relates to iron oxide pigments with an Fe(II) content of at least 5 wt. %, calculated as FeO, which have at least one inorganic after-treatment layer and at least one organic after-treatment coating, a process for preparing these iron oxide pigments and their use.

Abstract: This invention relates to new pure-colored iron oxide direct red pigments, to a process for their production and to their use for pigmenting lacquers, plastics, building materials and ceramics.

Abstract: A process for preparing red ceramic molded bodies by rapid firing is disclosed, wherein low Si-content iron oxides are employed. The process produces molded bodies having improved colouristic properties.

Abstract: The invention relates to transparent iron oxide pigments having an average particle size, based on the longest needle axis, of less than 0.1 .mu.m, to processes for their production and to their use for pigmenting lacquers and plastics.

Abstract: Iron oxide pigments are made stable against oxidation and discoloration by a coating process. Preferred coating compounds are maleic acid hydrazide and phthalic acid.

Abstract: Boron-containing iron-oxide pigments as disclosed which are prepared by a nitrobenzene reduction process. The boron is present in the pigments in a homogeneously doped form in amounts of 0.02 to 0.13% by weight, based on iron oxide. Preparation of the pigments is also described.

Abstract: A temperature-resistant black pigment which is a mixed oxide of manganese and iron with the structure of hematite and having a manganese content of 3 to 35% by weight, and with absolute color values in colorimetric testing in paint systems, expressed in CIELAB units, in the lightened form (Blend of 10 parts titaniumdioxide and 1 part of black pigment) of 60 to 70 for L*, -0.5 to 1.9 for a* and -4 to -6.5 for b* useful for coloring autoclave-cured building materials and for pigmenting heat-resistant paint systems is obtained by preparing a precursor material of manganese and iron oxides or hydroxides, which contains the phase with the structure of spinel and calcining that precursor material in an oxidizing atmosphere at 500.degree. to 1,000.degree. C.

Abstract: Building materials such as plaster, lime-sand bricks, fiber cement parts, cast stones, roof tiles, flagstone and paving setts are colored by incorporating therein in organic granules produced from a suspension of one or more inorganic pigmenting agents and a hydrolyzed or poorly soluble compound of one or more ion types present per se as an essential constitutent in one or more pigments.

Abstract: Isometric iron oxide pigments are prepared by an improved process by precipitation of aqueous solutions containing iron (II) salts with alkaline precipitating agents followed by oxidation of the precipitate at temperatures of from 20.degree. C. to 100.degree. C., wherein the improvement comprises adjusting the iron (III) content to 1 to 25 mol %, based on the total iron, before precipitation.

Abstract: A black manganese/iron oxide pigment having a spinel structure and having the composition Mn.sub.x Fe.sub.3-x O.sub.4 wherein x has a value from 0.1 to 0.9, is prepared by the steps:a) oxidizing iron(II) salts or mixtures of iron(II) salts and manganese(II) salts, in solution or after reaction with alkaline precipitants, with manganese dioxide or other compounds containing manganese in high valency,b) additionally oxidizing the salts of (a) to establish an Fe(III) content therein with another oxidizing agent, andc) filtering, washing, drying and grinding the pigment;and the pigment is useful for pigmenting building materials to a black color.

Abstract: Building materials such as concrete can be colored by a black pigment which consists essentially of manganese ferrite of the composition Mn.sub.1+x Fe.sub.2-x O.sub.4 with a spinel structure wherein x has a numerical value from -0.1 to 0.1 and the pigment is prepared by a process whereina) soluble manganese (II) salts and soluble iron (II) salts are precipitated from a solution of metal salts by reaction with alkaline precipitating agents in an approximately stoichiometric ratio,b) the precipitate from a) is reacted with an oxidizing agent to form a pigment, andc) the pigment is filtered, washed, dried and ground.

Abstract: A black manganese/iron oxide pigment having a spinel structure and having the composition Mn.sub.x Fe.sub.3-x O.sub.4 wherein x has a value from 0.1 to 0.9, is prepared by the steps:a) oxidizing iron(II) salts or mixtures of iron(II) salts and manganese(II) salts, in solution or after reaction with alkaline precipitants, with manganese dioxide or other compounds containing manganese in high valency,b) additionally oxidizing the salts of (a) to establish an Fe(III) content therein with another oxidizing agent, andc) filtering, washing, drying and grinding the pigment;and the pigment is useful for pigmenting building materials to a black color.

Abstract: Pigments having the color of natural uncalcined umber contain more than 85% by weight of iron oxides, expressed as Fe.sub.2 O.sub.3, and less than 0.1% by weight of crystalline silica are obtained by mixing iron oxides of spinel structure and/or hematite structure with or without iron oxide yellow and said pigments are useful in coloring paints, lacquers and building materials.

Abstract: An improved process is disclosed for preparing iron yellow pigments from iron--(II) salt solutions, in the presence of iron scrap, by injection of air at elevated temperatures. After formation of the pigment, the reaction suspension is stirred without additional gas injection, whereby lighter, purer yellow pigments are obtained.

Abstract: A heat-stable iron oxide black pigment resistant to hydrothermal treatment in air at temperatures above 180.degree. C. and which has a specific BET surface of 0.5 to 5 m.sup.2 /g is useful as a coloring agent for building materials, paints, cements, bricks and so forth and is prepared by reacting an aqueous solution of FeOOH, iron (II) salts and alkalis at elevated temperature and precipitating iron oxide from the solution with Na.sub.2 CO.sub.3 at temperatures in the range from 80.degree. C. to the boiling point of the solution.

Abstract: A pigment useful for coloring building materials such as bricks is a heat-stable isometric iron oxide brown pigment of .gamma.-Fe.sub.2 O.sub.3 structure which has a silicon content, expresed as SiO.sub.2, of 0.1 to 12% and an Al content, expressed as Al.sub.2 O.sub.3, of 0.02 to 5%.

Abstract: A process for the production of iron oxide yellow pigments by the Penniman-Zoph process from the raw materials iron (II) sulfate, sodium hydroxide and metallic iron, is disclosed in which iron (II) is oxidized to iron (III) by gassing with air in the presence of goethite nuclei, the iron (III) sulfate is dissolved to form iron (II) and the goethite nuclei are built up to iron oxide yellow pigments, characterized in that the gassing with air and dissolving of the metal are carried out in separate vessels.

Abstract: Acicular magnetic iron oxide pigments are disclosed which have a Co content of 1 to 5% by weight and an FeO content of 5 to 12% by weight. The pigments may optionally contain an additional dopant selected from zinc, phosphate and SiO.sub.2. The pigments are useful in magnetic recording media such as video tapes.

Abstract: Highly-coercive isometric iron oxide useful in magnetic toners for electrostatic photo-copying processes or for magnetic printers is produced by(a) subjecting Fe.sub.3 O.sub.4 pigment produced in a wet process to oxidation and(b) subsequently reducing the oxidized pigment from (a) to produce highly-coercive Fe.sub.3 O.sub.4 pigment.