The present invention relates to [1] a process for producing a colored fine particle dispersion by subjecting a raw material monomer containing a crosslinkable monomer to emulsion polymerization in the presence of a pigment in which an amount of the crosslinkable monomer compounded in the raw material monomer is from 0.1 to 10% by mass, said process including the step 1 of mixing and emulsifying the raw material monomer with a surfactant A and water to obtain a pre-emulsion; and the step 2 of conducting the emulsion polymerization while supplying the pre-emulsion obtained in the step 1 to a pigment pre-dispersion containing the pigment and water to thereby obtain the colored fine particle dispersion, and [2] a process for producing a water-based ink, including the step of mixing the colored fine particle dispersion that is produced by the process according to the aforementioned [1], and an organic solvent.

The present invention provides a pigment dispersion and a method of producing the pigment dispersion. The pigment dispersion includes: water; a pigment; a pigment dispersing polymer; and a rosin acid that includes at least one selected from the group consisting of abietic acid, salts of abietic acid, dihydroabietic acid and salts of dihydroabietic acid, and a total content of abietic acid, salts of abietic acid, dihydroabietic acid and salts of dihydroabietic acid is 50% by mass or higher with respect to a total mass of the rosin acid contained in the pigment dispersion. The pigment dispersion is excellent in terms of dispersibility, storage stability after dispersion, and jettability when used for an inkjet recording ink.

An aqueous dispersion comprising a surface-modified hydrophilic mixed oxide powder comprising silicon and aluminum and water, characterized in that

a) the surface of the particles has Si and Al atoms and
b) the surface modification has an Si atom bonded to a hydrocarbon radical via a C atom, and
c) the carbon content of the surface-modified mixed oxide powder is 3-25% by weight.

The present invention provides [1] a process for producing a colored fine particle dispersion including the step of subjecting a dispersion including a pigment, a polymerizable monomer, a surfactant, a polymerization initiator and water to emulsion polymerization, the pigment being a pigment having a quinacridone skeleton; the surfactant being an anionic or nonionic surfactant; and the polymerization initiator including an anionic or nonionic azo-based compound, [2] a colored fine particle dispersion including colored fine particles having an average particle size of not less than 10 nm and not more than 300 nm, and [3] a process for producing a water-based ink for ink-jet printing, including the step of mixing the obtained colored fine particle dispersion and an organic solvent B.

The present disclosure provides an aqueous composition comprising a quaternary amine compound neutralized with a polycarboxylic acid. The aqueous composition is particularly useful for inerting clay in cement compositions as well as compatibilzing pigments in pigment dispersions.

A colored fine particle dispersion including emulsified particles including a pigment and a polymer containing a constitutional unit derived from a compound (A) represented by formula (I) and a constitutional unit derived from a polymerizable monomer component including a hydrophobic vinyl-based monomer: ##STR00001##
wherein BO is a butyleneoxy group; EO is an ethyleneoxy group; M is a cation; m represents an average molar number of addition of BO and is a number of not less than 1 and not more than 10; and n represents an average molar number of addition of EO and is a number of not less than 4 and not more than 25; a process for producing the colored fine particle dispersion; a water-based ink for ink-jet printing including the colored fine particle dispersion; and a use of the colored fine particle dispersion as a colorant for a water-based ink for ink-jet printing.

A method for forming a pigmented aqueous slurry includes a step of combining a dispersant having pigment affinic groups with water to form an aqueous dispersant mixture. Pigment is added to the aqueous dispersant mixture to form an aqueous pigment mixture. The aqueous pigment composition is ground until the average particle size is less than 30 microns to form a pigmented aqueous slurry.

The present invention provides an aqueous pigment dispersion including a pigment, an anionic group-containing organic polymer compound, and bio-nanofibers having an average diameter of 1 nm or more and 100 nm or less and an aspect ratio of 100 or more, and also provides an aqueous ink using the aqueous pigment dispersion. The bio-nanofibers are preferably cellulose nanofibers or chitosan nanofibers. The anionic group-containing organic polymer compound is preferably at least one selected from the group consisting of acrylic resins having anionic groups, polyurethane resins having anionic groups, and polysaccharide derivatives having anionic groups.

Provided is a method for producing an aqueous pigment dispersion including a step of dispersing a mixture containing a pigment, an anionic group-containing organic polymer compound, a basic compound, and from 1% to 500% by mass of alkylene oxide adduct having a polyamine structure with respect to the pigment into water. The step of dispersing includes Step 1 of kneading a mixture which contains a pigment, an anionic group-containing organic polymer compound, a basic compound, and from 1% to 500% by mass of alkylene oxide adduct having a polyamine structure with respect to the pigment, and which contains no water or water equal to or less than 30% by mass with respect to a solid content thereof, and Step 2 of dispersing a kneaded material obtained in Step 1 into water.

The present invention relates to the use of a haematite pigment whose sum of the a* values in full shade and with reduction in the surface coating test is from 58.0 to 61.0 CIELAB units, preferably from 58.0 to 60.0 CIELAB units, more preferably from 58.5 to 61.0 CIELAB units, more preferably from 58.5 to 60.0 CIELAB units, particularly preferably from 59.0 to 61.0 CIELAB units, more particularly preferably from 59.0 to 60.0 for producing an aqueous, titanium dioxide-containing preparation.