The invention provides an aqueous ink containing a coloring material, wherein the coloring material is a self-dispersible pigment in which a functional group containing another atomic group and an anionic group such as a carboxylic acid group, a sulfonic acid group, a phosphoric acid group or a phosphonic acid group are bonded to a particle surface of a pigment such as carbon black or an organic pigment, and a standard deviation of an introduced amount of the functional group is 0.0380 or less.

This invention relates to particles comprising a pigment core particle encapsulated by a polymer, a process for their preparation, electrophoretic fluids comprising such particles, and electrophoretic display devices comprising such fluids.

The present invention provides fluid compositions comprising at least one hydrophobic liquid, at least one inorganic pigment, and at least one compatibilization agent comprising at least one phosphate monoester.

Provided are surface-treated fine particles which, when added to coatings for the production of films, exhibit excellent reactivity with respect to organosilicon compounds and resins that are matrix components of the coating films, and thereby allow the films to exhibit excellent performance. Oligomer-modified fine particles include inorganic oxide fine particles having a surface modified with an oligomer, the oligomer being derived from a metal alkoxide represented by Formula (1): R.sub.nM.sub.1(OR).sub.z-n (1) wherein M.sub.1: one or more elements selected from Si, Ti, Zr and Al; R and R: one or more groups selected from alkyl groups of 1 to 8 carbon atoms, aryl groups and vinyl groups; n: an integer of from 0 to (z2); and z: the valence of M.sub.1. The oligomer has a polymerization degree of 3 or more. The oligomer has a weight average molecular weight in the range of 1000 to 10000.

An inkjet ink containing a white pigment, a block polymer-type resin dispersant, an organic solvent, and water, in which the white pigment is titanium oxide particles in which the surface is treated with alumina, excluding particles in which the surface is treated with an organic compound, silica, zirconia, zinc oxide, or magnesium oxide, and titanium oxide particles in which the surface is treated with alumina and an organic compound.

The present invention refers to a process for producing white UV-absorbing surface-reacted calcium carbonate doped with a titanium species, comprising the steps of providing a calcium carbonate-comprising material, a calcium phosphate selected from monocalcium phosphate and/or dicalcium phosphate, and at least one titanium comprising substance, treating the calcium carbonate-comprising material with the calcium phosphate in an aqueous medium to form an aqueous suspension and grinding the aqueous suspension at a pH value of at least 4.2 to form an aqueous suspension of surface-reacted calcium carbonate, wherein the calcium carbonate-comprising material and the calcium phosphate in combination have a calcium ion to phosphate ion molar ratio (Ca.sup.2+:PO.sub.4.sup.3) in the range from 1.75:1 to 100:1, and wherein the at least one titanium comprising substance is added before and/or during and/or after the treatment step and/or before and/or during the grinding step.