Abstract: The present invention relates to a process for preparing a coloured effect pigment, comprising: (i) coating aluminium-based substrate particles in an aqueous coating medium with at least one metal oxide layer, wherein the metal oxide is selected from a titanium oxide, an iron oxide, or any mixture thereof, (ii) providing a mixture of the coated aluminium-based substrate particles and a particulate inorganic non-metallic material in the aqueous coating medium by adding the particulate inorganic non-metallic material to the aqueous coating medium, and (iii) separating the mixture of the coated aluminium-based substrate particles and the particulate inorganic non-metallic material from the aqueous coating medium and subjecting the separated mixture to a thermal drying step so as to obtain a dry coloured effect pigment material.

Abstract: Described are thin plane-parallel aluminum flakes illustrated in FIG. 1 having a thickness of up to 200 nm and comprising an inner layer of oxidized aluminium having a thickness of 0.5-30 nm, a process for the manufacture thereof and the use thereof, e.g. in formulations, like paints, electrostatic coatings, printing inks, plastics materials, and cosmetics. Surprisingly, due to the inner layer of oxidized aluminum the aluminum flakes have an improved shear stability as evidenced e.g. by the difference in lightness before and after shear stress.

Abstract: The present invention relates to a process for preparing a coloured effect pigment, comprising the steps of (a) preparing in an aqueous coating medium at least one layer of a hydroxyl-containing metal oxide on a substrate, thereby obtaining in the aqueous coating medium a first coloured pigment material CPM1 comprising the substrate coated with the hydroxyl-containing metal oxide, wherein the substrate is made of aluminium or aluminium alloy which optionally comprises at least one passivating layer, and wherein the hydroxyl-containing metal oxide is a hydroxyl-containing iron oxide or a hydroxyl-containing titanium oxide or a mixture thereof, (b) providing the first coloured pigment material CPM1 in a liquid post-treatment medium comprising one or more high boiling organic liquids, and (c) heating the liquid post-treatment medium to a temperature of at least 90° C. so as to convert the first coloured pigment material CPM1 to a second coloured pigment material CPM2.

Abstract: An iron oxide containing effect pigment, and methods for producing and using the same are discussed. The iron oxide containing effect pigment may include an iron oxide coating in direct contact with a particulate substrate, which may have high levels of hematite, magnetite, or maghemite; and low amounts of toxic metals. A method for producing the pigment may include chemical vapor deposition of iron pentacarbonyl onto a particulate substrate. The iron oxide containing effect pigments may be incorporated into compositions, such as cosmetics.