Storage-stable formulations of water-insoluble or sparingly water-soluble dyes with electrolyte-sensitive thickeners: polyacrylic acid
AssigneeCiba-Geigy Corporation
InventorsMarc Burglin, Roland Putzar
Life of this patent
Estimating the term…
Abstract
The invention relates to storage-stable aqueous formulations of water-insoluble or sparingly water-soluble solids which contain an electrolyte-sensitive thickener in addition to a dispersant. During storage, even for considerable periods of time, these formulations form no sediment and can be diluted by stirring in a small amount of electrolyte (e.g. a salt) and are then ready for use.
Claims15
A storage-stable aqueous formulation of a water-insolable or sparingly water-soluble dye which dye has a particle size of less than 50 millimicrons, which formulation contains the dye, an electrolyte-sensitive thickener selected from the group consisting of polyacrylic acid having a molecular weight 1.multidot.10.sup.5 to 1.multidot.10.sup.7, a polyacrylamide, polymethacrylamide or a homo- or copolymer of acrylamide and methacrylamide or acrylic acid having a molecular weight of 1.multidot.10.sup.5 to 1.multidot.10.sup.7, or a copolymer of malieic anhydride and ethylene having a molecular weight of 1.multidot.10.sup.3 to 1.multidot.10.sup.7, and mixtures of such thickeners.
A storage-stable aqueous formulation of a water-insoluble or sparingly water-soluble dye having a particle size of less than 10 millimicrons, which formulation contains the dye, an electrolyte-sensitive thickener selected from the group consisting of polyacrylic acid having a molecular weight of 5.multidot.10.sup.5 to 6.multidot.10.sup.6, polyacrylamide, polymethacrylamide or homo- or copolymer of acrylamide and methacrylamide or acrylic acid having a molecular weight of 1.multidot.10.sup.6 to 4.multidot.10.sup.6, or a copolymer of maleic anhydride and ethylene having a molecular weight of 8.multidot.10.sup.3 to 1.multidot.10.sup.6, and mixtures of such thickeners, and a non-ionic dispersant.
A process for the preparation of a dye formulation, which comprises converting a water-insoluble or sparingly water-soluble dye in the presence of a non-ionic, amphoteric, cationic or anionic dispersant, or of a mixture of such dispersants, into a finely dispersed form and adding an elecroyte-sensitive thickener, or adding an electrolyte-sensitive thickener to a finely disperse dye formulation which contains a dispersant, the electrolyte-sensitive thickener being selected from the group consisting of polyacrylic acid having a molecular weight of 1.multidot.10.sup.5 to 1.multidot.10.sup.7, a polyacrylamide, polymethacrylamide or a homo- or copolymer of acrylamide and methacrylamide or acrylic acid having a molecular weight of 1.multidot.10.sup.5 to 1.multidot.10.sup.7, or a copolymer of maleic anhydride and ethylene having a molecular weight of 1.multidot.10.sup.3 to 1.multidot.10.sup.7, and mixtures of such thickeners.
Dependencies are inferred from the claim text.