Merck Patent Gmbh

Merck Patent Gesellschaft MIT Beschrankter Haftung

Doreen Warthe

Johann Dietz

Gerhard Pfaff

Cornelia Foerderer

Sabine Schoen

Ute Honeit

Veronika Hochstein

The present invention relates to pigments which comprise a substrate and an iron(II) silicate-containing coating applied thereto, to a process for the preparation of these pigments, and to the use thereof.

Pigments with an iron silicate-containing coating

Disclosed are yellowing-stable, silver-white effect pigments having high whiteness based on synthetic mica flakes and to the use thereof in paints, lacquers, printing inks, plastics, button pastes, ceramic materials, glasses, for coloring seed, as dopant in laser markings of plastics and papers, as additive for laser welding of plastics, as additive for coloring in the foods and pharmaceuticals sectors and in cosmetic formulations, and for the preparation of pigment compositions and dry preparations.

Effect pigments

Effect pigments having improved optical properties based on SiOflakes coated with one or more layers, where the SiOflakes have a thickness of from 50 nm to 150 nm; processes for the preparation thereof; and use of these pigments in cosmetics, paints, coatings, plastics, films, in security printing, in security features in documents and identity cards, for coloring seed, for coloring foods or in medicament coatings and for the preparation of pigment compositions and dry preparations; are disclosed.

[object Object]

The present invention relates to effect pigments having a color flop comprising metal oxide-coated SiOflakes having a uniform layer thickness, where the color flop runs through all four quadrants of the a,b color coordinate system (CIELAB L,a,b system). The present invention likewise relates to processes for the preparation of these pigments in which SiOflakes having a uniform layer thickness are coated with metal oxides, and to the use of these pigments in cosmetics, paints, coatings, plastics, films, in security printing, in security features in documents and identity papers, for coloring seed, for coloring foods or in medicament coatings and for the preparation of pigment compositions and dry preparations.

Effect pigments having a strong color flop

The present invention relates to intensely colored red effect pigments comprising iron oxide-coated SiOflakes, where the total thickness of the effect pigments is not greater than 500 nm (+/&#x2212;30 nm). The present invention likewise relates to processes for the preparation of these pigments in which SiOflakes are coated with iron oxide, where the thicknesses of the SiOflakes and of the iron-oxide layers are selected in such a way that the total thickness of the red effect pigments is not greater than 500 nm (+/&#x2212;30 nm), and to the use of these pigments in cosmetics, paints, coatings, plastics, films, in security printing, in security features in documents and identity papers, for coloring seed, for coloring foods or in medicament coatings and for the preparation of pigment compositions and dry preparations.

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Griesheim, Germany

Doreen Warthe