There are disclosed aqueous pigment dispersions containing dispersant-improving-agents, and methods of preparing and using the same.

A composition including a disperse dye and an aqueous carrier having a first polyol and a second polyol having at least 5 carbon has atoms, wherein the composition has a color fastness to water of at least 3 according to International Organization for Standardization test ISO 105-EO1:2010 when used in direct inkjet printing on a ready-to-print polyester textile.

The present invention provides a compound and a pigment dispersant, each of which improves the dispersibility of various types of pigments in a non-aqueous solvent and also provides a pigment composition, a pigment dispersion, and a toner, each of which has a preferable coloring power. The compound includes a polymer which has a monomer unit having a specific structure and also includes a specific partial structure.

A dispersant is provided comprising a blend of mono- and di-phosphate esters, each phosphate group being substituted with either one or two alkyl or alkenyl alkoxylate groups wherein the alkyl or alkenyl portion is a branched alkyl or alkenyl radical comprising 1-30 carbon atoms, the alkoxylate portion comprises ethoxylate monomers and/or propoxylate monomers, and the dispersant further comprises a basic component selected from an amidopropyldimethylamine, a heterocyclic amine, an ammonium ion, and an alkali metal ion. The dispersant is suitable for dispersing a variety of pigments and other particulate matter in either aqueous or organic media.

This invention relates to a process for the preparation of a dispersion comprising coloured or black particles, such coloured or black particles prepared by the process, the use of the dispersion and the coloured or black particles in electrophoretic fluids, and electrophoretic display devices comprising such fluids.

Provided are a method for producing an aqueous inkjet pigment dispersion, including producing a mixed liquid of water, a pigment, a pigment dispersing polymer, and rosin acid in an amount of from 3% by mass to 30% by mass relative to the total mass of the pigment, and reducing the amount of rosin acid included in the produced mixed liquid, to less than 3.0% by mass relative to the total mass of the pigment; an aqueous inkjet pigment dispersion; and an aqueous inkjet ink.

The present invention provides the following process for producing a fine organic pigment which is capable of producing the fine organic pigment that has a very small primary particle size and is excellent in filtering property even in a cleaning step, and a fine organic pigment produced by the process; a process for producing a dispersion using the fine organic pigment, and a dispersion produced by the process; and a process for producing an ink using the dispersion. The present invention relates to [1] a process for producing a fine organic pigment, including steps 1 and 2: step 1: kneading a mixture prepared by compounding a raw material organic pigment, a water-soluble inorganic salt, a water-soluble organic solvent and a compound represented by the following formula (1) with each other, the compound being compounded in an amount of not less than 0.8 part by mass and not more than 18.0 parts by mass on the basis of 100 parts by mass of the raw material organic pigment: R.sup.1O(PO).sub.m(EO).sub.nA (1); and step 2: subjecting the mixture obtained in the step 1 to cleaning treatment with an aqueous solvent and then to filtration, [2] a fine organic pigment produced by the process according to the above aspect [1], [3] a dispersion produced using the fine organic pigment according to the above aspect [2], [4] a process for producing a paste of a fine organic pigment, including the above step 1 and 2, [5] a process for producing a dispersion, including step 3 of subjecting the paste of the fine organic pigment produced by the process according to the above aspect [4], an organic solvent and water to dispersing treatment, and [6] a process for producing an ink, including step 4 of mixing the dispersion produced by the process according to the above aspect [5] with at least one material selected from the group consisting of water and an organic solvent.

A process for preparing a dispersion comprising the stages: i) providing a dispersion comprising a particulate solid, a liquid medium and a dispersant having cross-linkable groups and a weight averaged molecular weight of from 1,000 to 70,000; and ii) cross-linking the dispersant in the presence of the particulate solid and the liquid medium thereby preparing a dispersion of an encapsulated particulate solid, wherein the cross-linking is performed such that 0.01 to 0.5 mmoles of cross-linkable groups in the dispersant are cross-linked per g of dispersant; said process also comprising at any stage: iii) adding a metal chelating agent to the dispersion; and after stage iii) the stage of: iv) removing at least some of the metal chelating agent from the dispersion.

An alkali-resistant pigment composition is provided comprising (a) a C.I. Pigment Yellow 139 and (b) an adduct containing a compound of formula (II) or a tautomeric form thereof, wherein X is O, S or NR.sup.1; Y is O, S or NR.sup.1; the group -A-B— is selected from the group consisting of —CR.sup.2═CR.sup.3-, —CR.sup.4R.sup.5—CR.sup.6R.sup.7-, —CY—CR.sup.8R.sup.9-, —CX—NR.sup.10-, —CR.sup.11═N—, —CR.sup.12R.sup.13-NR.sup.14- and R.sup.1 is hydrogen, C.sub.1-C.sub.8alkyl, C.sub.3-C.sub.7cycloalkyl, C.sub.6-C.sub.10aryl or C.sub.7-C.sub.10aralkyl; R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9, R.sup.10, R.sup.11, R.sup.12, R.sup.13 and R.sup.14are independently of each other hydrogen, halogen, C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl, or C.sub.6-C.sub.10aryl, or R.sup.2 and R.sup.3 form a benzoannellated ring; and/or a melamine- or pyrimidine-based compound, which is optionally substituted. The pigment composition may be used as colorant in various applications, especially in coloring high molecular weight organic material, for example, coating compositions, paints, printing inks, liquid inks, plastics, films or fibers.

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An electrolytic dye reduction method comprises preparing a catholyte by dispersing a dye in a leucodye comprising electrolyte. In a preferred method the leucodye like leucoindigo is the sole dispersing aid.