Abstract: Bismuth vanadate pigments IBi.sub.x Fe.sub.y E.sub.v V.sub.(1-w) P.sub.w O.sub.z Iwith the following meanings of the variables:E denotes calcium, zinc, cerium, praseodymium, and/or silicon;x is a value from 0.8 to 1.2;y is greater than 0 to 0.1 when v is greater than 0 or is greater than or equal to 0.035 to 0.1 when v is equal to 0;v is greater than or equal to 0 to 0.2;w is greater than 0 to 0.1;z denotes the number of oxygen atoms required to satisfy the valence requirements of the cations.and the preparation and use of said pigments for dyeing coating compositions, printing inks, and plastics.

Abstract: Bismuth vanadate pigments haveBi.sub.x E.sub.v Si.sub.y V.sub.(1-z) P.sub.z O.sub.wwhere x is from 0.8 to 1.2, y is from 0 to 4, z is from 0 to 0.2, v is from >0 to 0.5, and w is the number of oxygen atoms for satisfying the valence requirements of the cations, with the following provisos:a) when y=0, then z is from >0 to <0.05 and E is calcium or a mixture of calcium and zinc and/or magnesium in which the molar ratio of calcium to zinc and/or magnesium is .gtoreq.1,b) when 0<y<1, then z is from 0 to 0.2 and E is calcium or a mixture of calcium and zinc and/or magnesium in which the molar ratio of calcium to zinc and/or magnesium is .gtoreq.1,c) when y.gtoreq.1, then z is from 0 to 0.2 and E is zinc, magnesium, calcium,, lithium, aluminum or mixtures thereof.

Abstract: An essentially monoclinic bismuth vanadate of the formula Bi[V.sub.1-x P.sub.x)O.sub.4 ] where x is from 0 to 0.1 has a chroma of .gtoreq.85, a lightness of .gtoreq.80, a hue angle of from 89 to 95 and a photochromism with a .DELTA.E value of .ltoreq.2 under the CIELAB system.

Abstract: Thermostable bismuth vanadate/molybdate pigments are prepared by precipitating onto a pigment, obtained by calcination, of the formulaBi VO.sub.4 .cndot.Bi.sub.2 Mo O.sub.6where n is 0.2-2.5, in aqueous suspension at 70.degree.-100.degree. C. within the pH range from 4 to 9.5 a first SiO.sub.2 -containing layer using an alkali metal silicate solution of a magnesium hexafluorosilicate solution, maintaining the suspension at 70.degree.-100.degree. C. for not less than 1 hour, producing a thick coating on the precoated pigment by adding further alkali metal silicate solution, magnesium hexafluorosilicate solution or a mixture of the two within the pH range from 4 to 9.5, and finally depositing wax on the SiO.sub.2 -containing layer by means of a waxing emulsion/dispersion, the products showing, compared with the starting pigment, an appreciably improved thermal stability in plastics.

Abstract: Thermostable rutile mixed phase pigments of the ternary system titanium, antimony and chromium contain from 0.1 to 2.0% by weight of magnesium.

Abstract: Thermally stable lead chromate pigments or pigments containing lead chromate, which have high color strength and are provided with a precipitated coating containing silicon dioxide, are prepared by a process in which an aqueous pigment suspension is mixed once or several times with an aqueous MgSiF.sub.6 solution, the pH being maintained at 4.5-9.5 and the temperature at 50.degree.-95.degree. C., and the pigment is then separated off and worked up, these steps being carried out in a conventional manner.

Abstract: Blue iron hexacyanoferrate-III pigments are produced by a process wherein complex iron-II hexacyanoferrate-II (Berlin white) is prepared by electrolysis of an aqueous catholyte solution containing (a) an iron-II salt, (b) an alkali metal salt, an ammonium salt or a mixture of these, and (c) hydrogen cyanide, in an electrolysis cell in which the anode chamber and cathode chamber are separated by an ion exchange membrane, using an electrically conductive aqueous liquid in the anode chamber, and the iron-II hexacyanoferrate-II obtained is then converted to the blue pigment.The process gives Berlin white, which is substantially free from salt, in high yield and high purity. Pollution caused by the process is very low, since only a small amount of salt is produced. Compared with the corresponding blue pigments produced by prior art processes, the pigments obtained give purer colorations with better gloss, and are of higher color strength.

Abstract: Blue iron hexacyanoferrate-III pigments (I) are prepared by anodic oxidation of metallic iron in hydrogen cyanide, or a reaction medium containing hydrogen cyanide, at pH<7 and at an anode potential of .ltoreq.0.76 V (measured against a standard hydrogen electrode) to complex iron-II hexacyanoferrate-II compounds (II), which are then oxidized to (I) in a conventional manner. The oxidation of (II) is advantageously carried out with air or oxygen at pH 0-4 and at from 70 to 95.degree. C., but can also be carried out at pH>8.The process gives readily dispersible pigments (I) which are of high color strength and give brilliant, glossy colorations.

Abstract: Pigment compositions including nickel titanium yellow or chromium titanium yellow as an inorganic component together with an organic pigment component impart better gloss and/or hiding power to organic coatings containing 10% or more of the compositions if the compositions are prepared by subjecting a suspension of the components in a liquid medium to intense shearing stresses and thereafter separating the mixed pigments from the medium.