Abstract: Red iron oxide pigments with improved coloring properties wherein the isoelectric point of the pigments is greater than 7.

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: Magnetically attractable particles comprise a core of magnetic material encapsulated in a metal oxide coating. They may be made by emulsifying an aqueous solution or dispersion of the magnetic material or precursor, and an aqueous solution or sol of a coating inorganic oxide or precursor, in an inert water-immiscible liquid. The aqueous droplets are gelled, e,g. by ammonia or an amine., recoverd, and heated at 250.degree.-2000.degree. C. The resulting particles are generally smooth spheres below 100 microns in diameter and often of sub-micron size.

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: The pigment comprises a mixture of crystalline phase and an amorphous phase in which the crystalline phase represents from 10 to 70 wt % of the mixture and is constituted by zinc phosphate in the form of substantially spheroidal particles having a maximum size of between 0.5 to 5 microns and the amorphous phase represents from 30 to 90 wt % and comprises ferric phosphate and ferrous phosphate in a mole ratio lying between 1:001 and 1:03.The process comprises a reaction giving ferrous phosphate, partial oxidation thereof and association with zinc phosphate.

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: A luster pigment is described which is made up of a metal oxide film on a colored platelet-like support. The support is a pigment having a length of 3-150 .mu.m, a width of 3-150 .mu.m, and a thickness of 0.1-2 .mu.m. A process is described for the preparation of the pigment in which an organic platelet-like pigment is coated with a metal-oxide film by chemical vapor deposition. The preferred platelet-like organic pigment is .beta.-copper phthalocyanine.

Abstract: Pigments for printing inks and magnetic toners are iron oxide pigments with a rhombic dodecahedral form and an average particle diameter of from 0.05 to 3.0 .mu.m with a standard deviation of the particle size distribution of .+-.30%.

Abstract: Thermostable pigments for coloring stoving lacquers, coil coat lacquers, plastics, sand granulates, lime sandstone, enamel or ceramic glazes are zinc ferrite color pigments containing from 0.01 to 0.5% by weight of lithium.

Abstract: Flaky colored pigment comprising fine flaky powder as base material, and zinc oxide and an inorganic color pigment attached to the surface thereof.

Abstract: A pigment dispersion of enhanced viscosity and heat stability characteristics for use in coating systems is provided. The pigment dispersions generally comprise a pigment carrier, a pigment of the type having a hydrophilic surface, and a surfactant functional as a dispersant in a relatively non polar matrix and which is present on the surface of the pigment in an effective amount. Pigment carriers include water-based carriers and organic solvent-based carriers. Finished coatings having improved viscosity and heat stability are also provided. The finished coatings comprise a coating base and the surfactant treated pigments. Such pigments include iron oxide pigments yellow iron oxide pigment, black iron oxide pigment, divalent ferrite pigments, zinc ferrite pigment, and magnesium ferrite pigment. Such surfactants include trimethylol propane, and trimethylol ethane.

Abstract: Magnetic iron oxide pigments useful in magnetic signal recordings having a dependence of coercivity on temperature in the temperature range of from 76K to 298K of less than 0.13 kA/mK and having a coercivity on powder compressed to 0.9 g/cm.sup.3 of greater than 51 kA/m are prepared by coating a magnetic iron oxide core material having the composition FeO.sub.x where x is a number from 1.33 to 1.5 in a first step with a compound containing divalent and trivalent iron having a ratio of Fe(III): Fe(II) from 0.01 to less than 2, and then in a second step coating the pre-coated core with a second coating of a cobalt compound.

Abstract: Magnetic iron oxide pigments having a monomolecular coating of a cobalt compound useful in magnetic signal recordings having a dependence of coercivity on temperature in the temperature range of from 76 K to 298 K of less than 0.13 kA/mK and having a coercivity on powder compressed to 0.9 g/cm.sup.3 of greater than 51 kA/m are prepared applying a preliminary coating of Fe.sub.3 O.sub.4 or a bertholloid compound to a magnetic iron oxide core material having the composition FeO.sub.x where x is a number from 1.33 to 1.55 and then covering the preliminary coating with a cobalt compound.

Abstract: Iron oxide red pigments comprise clusters of a plurality of pigment particles, preferably at least five intergrown spherical particles, are prepared by conducting nuclear formation of iron oxide yellow .alpha.-FeOOH in the presence of compounds of the elements, B, Al, Ga, Si, Ge, Sn or mixtures thereof in quantities of from 0.05 to 10% by weight, calculated as tri- or tetravalent oxides and based on the arithmetically calculated precipitated .alpha.-FeOOH nuclei, separating brine from the resulting yellow slurry to isolate an iron oxide yellow paste, drying and annealing the paste to form iron oxide red pigment and grinding the red pigment, which pigment is useful in coloring foodstuffs, lacquers, plastics and building materials.

Abstract: A pigment which comprises crystallites of iron oxide having an average particle size of less than 100 nanometers doped with from 10% to 80% by weight of aluminium as Al.sup.3+ based on the weight of iron, having the general formula (Al.sub.x Fe.sub.2-x)O.sub.3, where x=0.34 to 1.24 and having an orange color with the following color measurements:L (Lightness)>45.degree.C (Strength)>40.degree.H (Hue) 50.degree. to 60.degree.A pigment precursor composition is also provided which, on firing, produces the pigment as defined above.

Abstract: Plateletlike pigments based on iron oxide and having a spinel structure of the composition:Mn.sub.u Al.sub.v Fe.sub.[3-(u+v)]-z O.sub.4-z,whereu is from 0.01-0.09,v is from 0-0.3 andz is from 0-1.The pigments can be used for producing decorative coatings, in particular in paints, plastics, prints and cosmetics, for producing electromagnetic screens, as substrates for coatings and as pigments having magnetic properties.

Abstract: A plateletlike two-phase pigment which has a core with a hematite structure of the compositionAl.sub.x Fe.sub.2-x O.sub.3where x is from 0.02 to 0.5, and an outer layer with a spinal structure of the compositionAl.sub.y Fe.sub.3-y O.sub.4+zwhere y is from 0.03 to 0.75 and z is from 0 to 0.5, can be prepared by a hydrothermal treatment of plateletlike Al.sub.x Fe.sub.2-x O.sub.3 pigments (x from 0.02 to 0.5) in the presence of a reducing agent dissolved in the aqueous phase.

Abstract: Lamellar pigments are based on iron oxide of the general formula Mn.sub.X Al.sub.Y Fe.sub.2 -(X+Y)O.sub.3, where X is from 0.01 to 0.06 and Y is from 0 to 0.2. The pigments are prepared by hydrothermal treatment of an aqueous suspension which contains an iron hydroxide or iron oxide hydroxide,and an alkali metal hydroxide and/or alkali metal carbonate, in the presence of a manganese compound which is soluble in the reaction medium and in the presence or absence of an aluminum compound.The pigments are used for pigmenting coatings, printing inks, finishes, plastics, ceramic surfaces, glasses and cosmetic products.

Abstract: Fillers comprising a composition in which 50-90 wt. % or iron oxides and 10-30 wt. % of silica are contained, at least 50 wt. % of the iron oxides being present in the form of iron oxide silicate, and the content of alkali metal oxides or alkaline earth metal oxides is 10 wt. % or less in total, are suitable as fillers for the fabrication of noise insulating materials. Noise insulating materials obtained by using said fillers are excellent in flexibility and processibility and moreover are large in surface density, thus exhibiting excellent noise insulating ability.

Abstract: The invention relates to platelet-shaped pigments of the formula Al.sub.x Fe.sub.2-x O.sub.3-y, wherein x has a value from 0.02 to 0.5 and y has a value from 0.3 to 1.0, which are optionally coated with further oxides.

Abstract: Finely divided magnetic particles of hexaferrite pigments with a W-structure having the compositionE.sub.x M.sub.m (I) M.sub.n (II) Fe.sub.18 -(m+n)O.sub.27-y D.sub.ywhereinE is at least one element from the group comprising alkaline earth metals, alkali metals, lanthanides or lead,M(I) and M(II) are independently at least element from the group comprising metals or semi-metals andD is at least one element from the group of halogens and chalcogens and0.8.ltoreq.x.ltoreq.1.2,1.0.ltoreq.m.ltoreq.3.0,0.ltoreq.n.ltoreq.8.0,0.ltoreq.y.ltoreq.5.

Abstract: A storable magnesium oxide/phosphate based cement having a delayed set time is provided by heating iron-containing magnesium oxide particles at an elevated temperature to provide magnesium ferrate in a gradient that increases to a maximum at the external particle surface.