Abstract: The present invention relates to very durable bismuth-based inorganic pigments with a light vivid yellow to orange color corresponding to the following general formula: BiV(1−n)XnO(4−3n) in which X is a halogen or a mixture of halogens and n can vary from 0 to 1. The invention also relates to the process for the manufacture of such pigments.

Abstract: The present invention relates to a pigment based on bismuth vanadate with a bright vivid yellow to orange color exhibiting improved resistance, in particular an improved resistance to heat, characterized in that it is coated with several layers of inorganic compounds in several successive stages, the last layer being based on a zinc and boron compound. The present invention also relates to the process for producing this pigment and to its application.

Abstract: The present invention is directed to a transparent pigmentary composition for use as a colorant in printing inks. The composition is manufactured by coupling a mixture of diazonium salts obtained from about 98 to about 85% in moles of 2-methoxy-4-nitroaniline and about 2 to about 15% in moles of 4-chloro-2-nitroaniline with acetylaceto-2-anisidide.

Abstract: A process for preparing a pigment based on bismuth vanadate by reacting an acidic solution of bismuth nitrate with a basic solution of ammonium metavanadate to form a precipitate in a very acidic reaction mixture with a pH value of between 1 and 2. The pH of the reaction mixture is brought to a value of about 7, and the temperature of the reaction mixture is established at 80.degree. C. or higher for a period of about 30 minutes. The reaction mixture is stirred for a period of time of at least one half hour until a pH of approximately 6.5 is reached, and then the precipitate is filtered from the reaction mixture. Finally, the precipitate is washed and dried to obtain a dried pigment.

Abstract: The invention relates to an organic pigment, preferably an azoic pigment, characterized in that it has been treated with polyalkylene imine with a view to improving its characteristics when used in painting. This treatment can be carried out both on an organic pigment treated by known methods and on an untreated pigment. A treated pigment is generally preferred, however, particularly if maximum opacity is desired.

Abstract: A bismuth vanadate based yellow inorganic pigment is disclosed together with a process for making bismuth based yellow inorganic pigments.