Dyes, processes for their manufacture and use as dispersants for the production of dispersions of pigments in organic liquids, for printing inks and dyes

摘要

1343606 Pigment dispersion IMPERIAL CHEMICAL INDUSTRIES Ltd 14 Jan 1972 [11 Feb 1971] 4445/71 Heading B1V [Also in Divisions C3 and C4] A composition suitable for use in the manufacture of paints and printing inks comprises a finely divided dispersion of a pigment having a particle size of less than 20 microns in an organic liquid which contains dissolved therein a dyestuff of the formula D-(Z-O.OCR) n in which D is the radical of a dyestuff which is attached to Z through a carbon atom of an aromatic ring present in D, Z is a divalent bridging group, n is an integer of 1-8 and R is the residue of a carboxy ended polyester RCOOH derived from a hydroxycarboxylic acid of the forumla HO-X-COOH in which X is a divalent saturated or unsaturated aliphatic radical containing at least 8 carbon atoms and in which there are at least 4 carbon atoms between the hydroxy and carboxy acid groups, or from a mixture of such a hydroxycarboxylic acid and a carboxylic acid free from hydroxy groups. D may be an azo, anthraquinone or copper phthalocyanine dye and Z may be -CH 2 -, -NHCH 2 CH 2 -, -NHCH 2 CH OH CH 2 -, -NHCOCH 2 - or -SO 2 NH-CH 2 CH 2 -. Suitable hydroxycarboxylic acids used to prepare the polyester are recinoleic acid, a mixture of 9- and 10-hydroxystearic acids, or 12-hydroxystearic acid preferably containing minor amounts of stearic and palmitic acids, and suitable carboxylic acids free of hydroxy groups are lauric, palmitic stearic and oleic acids. The compositions may be prepared by mixing together the pigment, organic liquid and dyestuff and subjecting the mixture to mechanical treatment, e.g. milling, to reduce the particle size of the pigment. Alternatively an organic liquid solution of the dyestuff may be emulsified into an aqueous phase in the presence of a surface active agent, mixed with an aqueous slurry of the pigment and, after removal of the organic liquid and water, the pigment and dyestuff dispersed in an organic medium. The dispersion may contain 5-70% by weight of the pigment which may be inorganic or organic and 5-50% by weight of the dyestuff based on the weight of the pigment. Suitable organic liquids for use in preparing the dispersion are benzene, toluene, xylene, white spirit, n-hexane, cyclohexane, chlorobenzone, carbon tetrachloride, perchloroethylene, alkyd resins and heat-bodied linseed oils.