Production of pigments
AssigneeCiba-Geigy Corporation
InventorsDavid T. Pechey, John H. Coy
Life of this patent
Estimating the term…
Abstract
A process for producing monoazo or disazo pigments, which process comprises: (a) adding to a solution of a diazonium and/or tetrazonium salt of an aromatic or heterocyclic amine a solution or suspension containing 0.1-50% by weight of the theoretically required total weight of one or more coupling components, and (b) using the product from step (a) as an additive in the production of a monoazo pigment, a disazo pigment or a mixture of monoazo and disazo pigments. Compared with products produced by conventional methods, the pigments produced in the manner described above have a greater coloring strength, improved transparency, improved flow properties, and a higher degree of dispersibility.
Claims16
A process for producing monoazo or disazo pigments, which comprises
- (a) adding to a solution of a diazonium and/or tetrazonium salt of an aromatic or heterocyclic amine a solution or suspension containing 0.1-50% by weight of the theoretically required total weight of one or more coupling components, and
- (b) using the product from step (a) as an additive in the production of a monoazo pigment, a disazo pigment or a mixture of monoazo and disazo pigments.
A process for producing monoazo or disazo pigments, which process comprises
- (a) adding to a solution of a diazonium and/or tetrazonium salt of an aromatic or heterocyclic amine a solution or suspension containing 0.1-50% by weight of the theoretically required total weight of one or more coupling components, and
- (b) completing the coupling reaction by adding the partially coupled product obtained according to step (a) to a solution or suspension of one or more coupling components identical to or different from those used in step (a).
Dependencies are inferred from the claim text.