Stir-in pigment compositions
AssigneeCiba Speciality Chemicals Corporation
InventorFridolin Babler
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Abstract
A stir-in pigment composition for coloring high-molecular-weight material, particularly coatings and ink systems, comprises 85 to 99.5 parts by weight of a pigment and 0.5 to 15 parts by weight of an additive comprising a vinylpyrrolidone polymer or copolymer. The stir-in pigment composition is in the form of microgranules and is obtainable by spray drying a high solids content aqueous pigment dispersion containing the pigment and the additive. The new pigment composition powders are easily handled, easily wetted and disperse rapidly to form homogeneous aqueous pigment dispersions which are practically free of larger pigment aggregates and can readily be incorporated into aqueous ink and paint systems as stir-in pigments without a dispersion step in a bead mill.
Claims28
A stir-in pigment composition in the form of microgranules, which comprises 85 to 99.5 parts by weight of a pigment and 0.5 to 15 parts by weight of an additive comprising a vinylpyrrolidone polymer or copolymer, with the proviso that the copolymer is not a copolymer of an ethylenically unsaturated sulfonic acid and N-vinyl-pyrrolidone.
A pigment composition obtained by spray drying an aqueous pigment dispersion which comprises 85 to 99.5 parts by weight of a pigment and 0.5 to 15 parts by weight of an additive comprising a vinylpyrrolidone polymer or copolymer.
Dependencies are inferred from the claim text.