An object of the present invention is to provide a method for producing a pigment composition that can achieve both a reduction in the number of coarse particles that may be contained in the pigment composition and improvement in the production efficiency of the pigment composition. The present invention relates to a method for producing a pigment composition in which a pigment is dispersed in a liquid medium by a pigment dispersion resin by undergoing step 1 in which a raw material composition containing the pigment, the pigment dispersion resin, and the liquid medium is processed with a dispersing machine, the dispersing machine being a dispersing machine including a configuration allowing the raw material compositions to collide with each other.

An ink set including an ink containing water, a pigment, a pigment dispersion polymer A, and a water-soluble polymer B, and a treatment liquid containing water and at least one selected from the group consisting of a polyvalent metal salt, an acidic compound, and a cationic polymer, in which the pigment dispersion polymer A contains a specific acid group and an aromatic ring, and the water-soluble polymer B contains a specific acid group and a constitutional unit represented by General Formula (1), and in the ink, a mass ratio of a content concentration of the water-soluble polymer B to a content concentration of the pigment dispersion polymer A in a liberated polymer is 1.6 or more, and an image recording method. R.sup.1 represents a hydrogen atom or a monovalent substituent, Y.sup.1 represents a monovalent substituent, A.sup.1 represents —O—, and L.sup.1 is a divalent linking group.

##STR00001##

A metal fine particle-containing ink that contains metal fine particles dispersed therein with a polymer dispersant, a low-molecular weight carboxylic acid and an aqueous solvent, wherein the polymer dispersant contains a constitutional unit derived from an acid group-containing monomer; a content of the low-molecular weight carboxylic acid C in the ink is not less than 1% by mass and not more than 15% by mass. A boiling point (C) of the low-molecular weight carboxylic acid and a boiling point (D) of the aqueous solvent satisfy the following relational formula (I); and an acid dissociation exponent pKa (C) of the low-molecular weight carboxylic acid and an acid dissociation exponent pKa (B) of an acid group in the polymer dispersant satisfy the following relational formula (II):

boiling point (C)>boiling point (D)   (I), and

pKa (C)<pKa (B)   (II).

A metal fine particle-containing ink that contains metal fine particles dispersed therein with a polymer dispersant, a low-molecular weight carboxylic acid and an aqueous solvent, wherein the polymer dispersant contains a constitutional unit derived from an acid group-containing monomer; a content of the low-molecular weight carboxylic acid C in the ink is not less than 1% by mass and not more than 15% by mass. A boiling point (C) of the low-molecular weight carboxylic acid and a boiling point (D) of the aqueous solvent satisfy the following relational formula (I); and an acid dissociation exponent pKa (C) of the low-molecular weight carboxylic acid and an acid dissociation exponent pKa (B) of an acid group in the polymer dispersant satisfy the following relational formula (II):

boiling point (C)>boiling point (D)   (I), and

pKa (C)<pKa (B)   (II).

An object of the present invention is to provide a method for producing a pigment composition that can efficiently reduce the number of coarse particles in a pigment composition such as an aqueous pigment dispersion. The inventors of the present invention have achieved this object by a method of producing a pigment composition for ink, including a processing step of crushing or cracking a pigment component in a raw material composition containing the pigment component and a liquid medium using a rotor-stator processing machine 100.

An object of the present invention is to provide a method for producing a pigment composition that can efficiently reduce the number of coarse particles in a pigment composition such as an aqueous pigment dispersion. The inventors of the present invention have achieved this object by a method of producing a pigment composition for ink, including a processing step of crushing or cracking a pigment component in a raw material composition containing the pigment component and a liquid medium using a rotor-stator processing machine 100.

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

A dispersion comprising a solid particulate component such as a pigment, a dispersing agent and one or more solvents is disclosed. The dispersing agent comprises a reaction product of (a) an epoxidised carboxylic acid ester; (b) a compound including at least one reactive alcohol and/or amino functional group; and (c) a derivatising agent. Such a dispersion shows excellent long-term stability. A method of producing such a dispersion having long-term stability, and a use of the dispersing agent to provide a dispersion having long-term stability are also described.

A dispersion comprising a solid particulate component such as a pigment, a dispersing agent and one or more solvents is disclosed. The dispersing agent comprises a reaction product of (a) an epoxidised carboxylic acid ester; (b) a compound including at least one reactive alcohol and/or amino functional group; and (c) a derivatising agent. Such a dispersion shows excellent long-term stability. A method of producing such a dispersion having long-term stability, and a use of the dispersing agent to provide a dispersion having long-term stability are also described.

An aqueous pigment dispersion includes at least one dispersing agent having the general formula: ##STR00001## The aqueous pigment dispersion can be used in an aqueous inkjet ink which is useful for printing on textile fabrics.