A process for producing pigments having a defined size and shape and also pigments produced by this process. The process has the steps: a) production of a three-dimensional surface structure on a substrate, with surface regions which are in each case partly bounded by a plurality of three-dimensional structural elements and are arranged in gaps being formed; b) application of a pigment material layer to the surface structure; c) detachment of the pigment material layer from the surface structure and production of pigments.

Pearlescent pigments including a largely transparent platelet-shaped substrate having a density ρ.sub.S and at least one optically active coating having a density ρ.sub.M, the substrate having an average size d.sub.50 of 3 to 8 μm and an average height h.sub.S of 40 to 110 nm. The disclosure further relates to a method for producing the pearlescent pigments, and also to the use thereof.

The present invention is directed to a coated bismuth oxy halide-based pigment having a coating comprising an anti-oxidant, said antioxidant is being a phenol based, a phosphite or phosphonate based, or a thioether based stabilizer, and the coating comprising an inner coating and an outer coating, wherein the outer coating comprises the antioxidant, and wherein the inner coating comprises a first layer consisting of one or more salts, or one or more oxides, heteropolyacids, organic acids, sulphites, sulfides, sulfates, phosphates, pyrophosphates, polyphosphates, hydrates, carbonates, or a combination thereof, selected from the group of alkali-earth metals, metals, non-metals, transition metals or lanthanides. Further, the present invention is directed to a composition comprising a paint, a lacquer, an ink, a cosmetic, a resin, a plastisol or a polymer formulation, and such pigment. In addition, the present invention is directed to a method for manufacturing a coated bismuth oxy halide-based pigment, said method comprising the steps of: —providing a dispersion of a bismuth oxy halide-based pigment, —adding a dispersion of an antioxidant, —mixing and drying.

An article including a reflector having a first surface and a second surface opposite the first surface; a first selective light modulator layer external to the first surface of the reflector; a second selective light modulator layer external to the second surface of the reflector; a first absorber layer external to the first selective light modulator layer; and a second absorber layer external to the second selective light modulator layer; wherein each of the first and second selective light modulator layers include a host material is disclosed herein. Methods of making the article are also disclosed.

Optical effect pigment comprising a plurality of layers and a magnetic element, the layers can be arranged in two stacks of asymmetric layers or in a single stack of layers and comprise at least an absorber layer and at least a dielectric layer and can further comprise a reflector layer. The magnetic element presents a magnetisation which is out-of-plane, i.e. predominantly perpendicular to the plane of the pigment, which allows a deposition on the printing substrate whereby the face of the pigment lying up or down on the substrate can be predetermined. Such effect pigment has applications in many fields and specifically in security printing, where due to controlled deposition for instance a double-stack pigment will produce a different optical effect on each of its faces.

The present invention provides a magnetic multilayer pigment flake and a magnetic coating composition that are relatively safe for human health and the environment. The pigment flake includes one or more magnetic layers of a magnetic alloy and one or more dielectric layers of a dielectric material. The magnetic alloy is an iron-chromium alloy or an iron-chromium-aluminum alloy, having a substantially nickel-free composition. The coating composition includes a plurality of the pigment flakes disposed in a binder medium.

The present invention relates to an effect pigment having optically active layers consisting of a flake of a highly reflective material with directly adjacent on one side or on both sides a layer of a semiconducting material having a bandgap of 0.1 to 3.5 eV. The effect pigment may be further coated with a coating which is optically non-active in the visible wavelength region.

The present invention relates to effect pigments which are based on flake-form substrates having a circular form factor of 1.2-2 and are coated with at least one high-refractive-index layer, and to the use thereof, inter alia in paints, coatings, printing inks, plastics and in cosmetic formulations.

The present invention is directed to effect pigments with solvochromic properties. These effect pigments have a structure comprising a substrate in platelet form and a coating applied to the substrate, wherein the coating comprises: optionally a layer (1) comprising or consisting of at least one of tin oxide, tin hydroxide and/or tin oxide hydrate, a layer (2) comprising at least one of metal oxide, metal hydroxide and/or metal oxide hydrate, and a layer (3) comprising at least one of metal oxide, metal hydroxide and/or metal oxide hydrate, wherein the layers (2) and (3) comprise in their metal oxide, metal hydroxide and/or metal oxide hydrate in a majority two different metal ions from the group consisting of Ti, Fe, Sn or Zr and a further spacer layer (4) being located in between layers (2) and (3), wherein layer (4) has a porous structure comprising cavities and connectors. The solvochromic properties denote to the effect pigment having a first interference color under ambient atmosphere which changes reversibly to a second interference color, when the effect pigment comes into contact with a solvent.

An optical device includes a reflector layer having a first surface, a second surface opposite the first surface; a third surface, and a fourth surface opposite the third surface; and a first selective light modulator layer external to the first surface of the reflector layer; in which at least one of the third surface and the fourth surface includes an azimuthal modulator layer. A method of making an optical device is also disclosed.