The present invention relates to [1] a process for producing pigment-containing modified polymer particles, including the step of reacting pigment-containing polymer particles (A) containing a functional group and a compound (B) containing a reactive group capable of reacting with the functional group of the polymer particles (A) in a medium under such a condition that a ratio [(B)/(A)] of total moles of the reactive group of the compound (B) to total moles of the functional group of the polymer particles (A) is from 0.10 to 0.62; [2] a pigment water dispersion including an aqueous medium and the modified polymer particles produced by the aforementioned process which are dispersed in the aqueous medium; and [3] an ink including the aforementioned pigment water dispersion and an organic solvent. The modified polymer particles are free from formation of coarse particles upon production of pigment particles, so that an ink obtained by using the modified polymer particles can be prevented from suffering from increase in viscosity thereof when the ink is being concentrated by evaporation of water from the ink, and is excellent in rub fastness when printed on a low-water absorbing recording medium.

The invention relates to aqueous binder-free pigment dispersions containing (A) at least one organic and/or inorganic pigment, (B) one or more dispersing agents and/or surfactants, (C) at least one base of formula (I), where R.sup.1 is H, C.sub.1-C.sub.4-alkyl, CH.sub.2CH.sub.2OH or CH.sub.2CH(CH.sub.3)OH, (D) optionally, one or more polyalkylene glycols, (E) optionally, other additives commonly used for making aqueous pigment dispersions, and (F) water.

##STR00001##

Subject matter are aqueous, low-VOC/SVOC universal pigment preparations comprising a pigment component; a water-soluble, nonionic, surface-active additive comprising a copolymer formed from a vinyl monomer and from an ethylenically unsaturated monomer selected from the group consisting of monocarboxylic esters, dicarboxylic esters, monocarboxamides, and dicarboxamides, the vinyl monomer and/or the ethylenically unsaturated monomer containing an N-containing group with pigment affinity; a phosphoric or phosphonic ester, and optionally customary additives. The aqueous pigment preparations are suitable for the coloring of inks, paints, and renders, especially in metering systems at the point of sale or in in-plant tinting systems.

Subject matter are aqueous, low-VOC/SVOC universal pigment preparations comprising a pigment component, a water-soluble, anionic, surface-active additive from the group of the homo- and copolymers of ethylenically unsaturated monocarboxylic or dicarboxylic acids, which may further comprise, in copolymerized form, vinyl monomers containing no acid function, and of the salts of these homo- and copolymers, the homo- and copolymers being at least partly esterified with a polyether alcohol or a derivative thereof, and comprising a phosphoric or phosphonic ester, and optionally customary additives. The aqueous pigment preparations are suitable for the coloring of inks, paints, and renders, especially in metering systems at the point of sale or in in-plant tinting systems.

A method of making a liquid electrophotographic (LEP) paste is disclosed herein. A base paste is made by forming a dispersion of a pigment and a non-polar carrier, adding a transparent resin dispersion to the pigment dispersion to form a dispersion mixture, and homogenizing the dispersion mixture. The transparent resin dispersion includes a polymer dispersed in a non-aqueous carrier. The homogenizing may be accomplished by agitating the dispersion mixture at a frequency of less than 1 kHz, thereby forming the paste.

Provided are a pigment dispersant, a pigment dispersion, and an aqueous ink composition for inkjet that satisfactorily inhibit a magenta pigment from aggregating and makes it possible to obtain an aqueous ink applicable by printing in an inkjet system. The pigment dispersant of the present invention is a pigment dispersant for dispersing a magenta pigment, wherein a copolymer composed of a polymer alcohol and an ester, or an acrylic dispersant is dispersed in a dispersion medium, and the copolymer composed of the polymer alcohol and the ester, and the acrylic dispersant have an acid value.

Disclosed herein is a pigment preparation including at least one organic and/or inorganic pigment and/or filler. The pigment preparation further includes at least one anionic copolymer as dispersant, containing 40 to 95 mol % of structural units of an anionic monomer selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, 2-carboxyethylacrylic acid, maleic acid, mixtures thereof and their respective salts, and further containing 5 to 60 mol % of structural units of a monomer having repeat units of formula (B1)

##STR00001##

where R11, R12 and R13 are, independently, selected from the group consisting of H, methyl and ethyl; R4 is H or an alkyl group having 1 to 4 carbon atoms; X is selected from the group consisting of O, COO, CONH, CH.sub.2O and CH.sub.2CH.sub.2O; Y is an ethylene group; Z is a propylene group, a butylene group or a phenylethylene group; m is an integer from 0 to 100; n is an integer from 1 to 100; and m+n is greater than 5. The pigment preparation also includes at least one nonionic copolymer, containing at least one structural unit having aromatic groups and at least one structural unit having polyethylene glycol groups. The pigment preparation also includes water.

The invention relates to a colorant composition comprising at least one compound of the formula (I) and at least one pigment, in which the compounds of the formula (I) have the following formula:

##STR00001##

in which R.sup.0 is C.sub.1-C.sub.6-alkyl or CF.sub.3; R.sup.1 is sulfo, carboxyl, C.sub.1-C.sub.4-alkylenesulfo, C.sub.1-C.sub.4-alkylenecarboxy, CONH.sub.2, CONH(C.sub.1-C.sub.4-alkyl) or CN, R.sup.2 is C.sub.1-C.sub.18-alkyl, C.sub.2-C.sub.18-alkenyl, hydroxy-C.sub.1-C.sub.18-alkyl, or (C.sub.1-C.sub.6-alkylene-O).sub.mR where R is defined as H, C.sub.1-C.sub.16-alkyl or hydroxy-C.sub.1-C.sub.16-alkyl and m is a number from 1 to 20, R.sup.3 is H, sulfo, carboxyl, C.sub.1-C.sub.6-alkyl or C.sub.1-C.sub.6-alkoxy, R.sup.4 is H, C.sub.1-C.sub.6-alkyl or C.sub.1-C.sub.6-alkoxy, R.sup.5 is OH, OM, C.sub.1-C.sub.6-alkyl, unsubstituted C.sub.6-C.sub.10-aryl or C.sub.1-C.sub.6-alkyl-, halogen- (e.g. F, Cl, Br), carboxyl- or sulfo-substituted C.sub.6-C.sub.10-aryl,
where the compounds of the formula (I) contain at least one anionic radical from the group of sulfo and carboxyl having the countercation M.sup.+, where M.sup.+ is an alkali metal cation or an organic cation.

The colorant compositions are especially suitable for use in color filters.