Abstract: The present invention relates to a pigment water dispersion containing pigment-containing water-insoluble crosslinked polymer A particles, a water-soluble basic compound and water, in which a water-insoluble crosslinked polymer A constituting the particles has a carboxy group and a crosslinked structure containing an ester group derived from a water-insoluble crosslinking agent, a saponification value of the water-insoluble crosslinked polymer A is from 170 to 300 mgKOH/g, and the water-soluble basic compound contains a water-soluble amine compound; a process for producing the pigment water dispersion; a water-based ink for ink-jet printing which contains the pigment water dispersion; and an ink-jet printing method using the water-based ink.

Abstract: The present invention relates to a water-based pigment dispersion containing a polymer dispersant and a pigment, the polymer dispersant being prepared by crosslinking a carboxy group-containing water-insoluble polymer (A) with a water-insoluble polyfunctional epoxy compound, in which carboxy groups of the water-insoluble polymer (A) are at least partially neutralized by an alkali metal compound, and the water-based pigment dispersion satisfies the following conditions 1 to 3. The water-based pigment dispersion of the present invention can exhibit excellent redispersibility capable of suppressing solidification of the pigment or the polymer in ink ejection nozzles and can ensure good storage stability under high-temperature conditions.

Abstract: The present invention relates to a water-based pigment dispersion having not only excellent storage stability capable of suppressing solidification of a pigment or the like in ink ejection nozzles, but also excellent ejection properties and fixing properties, while maintaining good water resistance of the pigment dispersion as an advantage attained by using the pigment therein.

Abstract: The present invention relates to a water-based pigment dispersion containing a polymer dispersant and a pigment, the polymer dispersant being prepared by crosslinking a carboxy group-containing water-insoluble polymer (A) with a water-insoluble polyfunctional epoxy compound, in which carboxy groups of the water-insoluble polymer (A) are at least partially neutralized by an alkali metal compound, and the water-based pigment dispersion satisfies the following conditions 1 to 3. The water-based pigment dispersion of the present invention can exhibit excellent redispersibility capable of suppressing solidification of the pigment or the polymer in ink ejection nozzles and can ensure good storage stability under high-temperature conditions.

Abstract: The present invention relates to a water-based pigment dispersion having not only excellent storage stability capable of suppressing solidification of a pigment or the like in ink ejection nozzles, but also excellent ejection properties and fixing properties, while maintaining good water resistance of the pigment dispersion as an advantage attained by using the pigment therein.

Abstract: The present invention relates to a pigment water dispersion containing pigment-containing water-insoluble crosslinked polymer A particles, a water-soluble basic compound and water, in which a water-insoluble crosslinked polymer A constituting the particles has a carboxy group and a crosslinked structure containing an ester group derived from a water-insoluble crosslinking agent, a saponification value of the water-insoluble crosslinked polymer A is from 170 to 300 mgKOH/g, and the water-soluble basic compound contains a water-soluble amine compound; a process for producing the pigment water dispersion; a water-based ink for ink-jet printing which contains the pigment water dispersion; and an ink-jet printing method using the water-based ink.

Abstract: The invention relates to an ink jet recording medium, in which at least one of a substrate and an ink receiving layer contains a compound of the general formula (1): wherein R1 and R2 are individually a hydrogen atom, a hydroxyl group, a linear or branched alkyl group or a substituted or unsubstituted aryl group, with the proviso that R1 and R2 may be the same or different from each other, R3 is a linear or branched alkylene group or arylene group, and X is an acidic solubilizing group.

Abstract: The invention provides an ink jet recording medium excellent in light fastness, gas fastness and uniform ink absorption. The ink jet recording medium has a substrate and an ink receiving layer provided on at least one surface of the substrate. The ink receiving layer contains a compound represented by the general formula (1): wherein R1, R2 and R3 are individually a linear or branched alkyl group having 1 to 20 carbon atoms, with the proviso that at least one of R1, R2 and R3 has a hydroxyl group.

Abstract: An ink jet recording medium comprising a substrate and an ink receiving layer which is provided on at least one surface of the substrate and contains inorganic fine particles having an average secondary particle size of 1-4 ?m as measured by a Coulter counter method in an amount of 0.2-2.0 g/m2 in terms of solid content mass. The ink receiving layer satisfies the following conditions with respect to a pore distribution curve as determined by a nitrogen adsorption method: (1) total pore volume in a pore size range of 10-30 nm is 0.25 ml/g or more, (2) total pore volume in a pore size range of 30-70 nm is 0.1 ml/g or more, and (3) volume ratio of the total pore volume in the pore size range of 10-30 nm to the total pore volume in the pore size range of 30-70 nm is from 1:0.4 to 1:1.

Abstract: The invention provides an ink jet recording medium excellent in light fastness, gas fastness and uniform ink absorption. The ink jet recording medium has a substrate and an ink receiving layer provided on at least one surface of the substrate. The ink receiving layer contains a compound represented by the general formula (1): wherein R1, R2 and R3 are individually a linear or branched alkyl group having 1 to 20 carbon atoms, with the proviso that at least one of R1, R2 and R3 has a hydroxyl group.

Abstract: The invention relates to an ink jet recording medium, in which at least one of a substrate and an ink receiving layer contains a compound of the general formula (1): wherein R1 and R2 are individually a hydrogen atom, a hydroxyl group, a linear or branched alkyl group or a substituted or unsubstituted aryl group, with the proviso that R1 and R2 may be the same or different from each other, R3 is a linear or branched alkylene group or arylene group, and X is an acidic solubilizing group.

Abstract: “A high-molecular compound or high-molecular antioxidant obtained by reacting at least three compounds of (A) a sulfur-containing organic compound having at least two active hydrogen atoms, (B) a polyisocyanate compound having at least two isocyanate groups and (C) an amine compound having at least two active hydrogen atoms and then cationizing with an acid at least some of amino groups in a resultant reaction product” or “a high-molecular antioxidant obtained by reacting at least three compounds of (A) a sulfur-containing organic compound having at least two active hydrogen atoms, (B) a polyisocyanate compound having at least two isocyanate groups and (E) a nonionic polyol compound having at least two active hydrogen atoms” and a recording medium obtained by using the high-molecular antioxidant.

Abstract: The invention provides an ink jet recording medium which attains the prevention of the bronzing of cyan ink and the prevention of the migration of magenta ink at the same time and is excellent in image characteristics. The ink jet recording medium comprises a substrate and an ink-receiving layer provided with at least an upper layer as the outermost layer and a lower layer as a layer lying just under the upper layer, both layers having a porous structure formed of an alumina hydrate and a binder, wherein both of the upper and lower layers contain an alkylsulfonic acid and only the lower layer contains a cationic polymer.

Abstract: A polymer compound comprises a unit composed of a sulfur-containing compound (A) having at least two active hydrogen groups, a unit composed of a compound (B) having at least two isocyanate groups and a unit composed of an amine compound (C) having at least two active hydrogen groups, and having an average particle size of 200 nm or smaller. The polymer compound can be used in a recording medium.

Abstract: An ink jet recording medium comprising a substrate and an ink receiving layer which is provided on at least one surface of the substrate and contains inorganic fine particles having an average secondary particle size of 1-4 ?m as measured by a Coulter counter method in an amount of 0.2-2.0 g/m2 in terms of solid content mass. The ink receiving layer satisfies the following conditions with respect to a pore distribution curve as determined by a nitrogen adsorption method: (1) total pore volume in a pore size range of 10-30 nm is 0.25 ml/g or more, (2) total pore volume in a pore size range of 30-70 nm is 0.1 ml/g or more, and (3) volume ratio of the total pore volume in the pore size range of 10-30 nm to the total pore volume in the pore size range of 30-70 nm is from 1:0.4 to 1:1.

Abstract: The invention provides an ink jet recording medium which attains the prevention of the bronzing of cyan ink and the prevention of the migration of magenta ink at the same time and is excellent in image characteristics. The ink jet recording medium comprises a substrate and an ink-receiving layer provided with at least an upper layer as the outermost layer and a lower layer as a layer lying just under the upper layer, both layers having a porous structure formed of an alumina hydrate and a binder, wherein both of the upper and lower layers contain an alkylsulfonic acid and only the lower layer contains a cationic polymer.

Abstract: “A high-molecular compound or high-molecular antioxidant obtained by reacting at least three compounds of (A) a sulfur-containing organic compound having at least two active hydrogen atoms, (B) a polyisocyanate compound having at least two isocyanate groups and (C) an amine compound having at least two active hydrogen atoms and then cationizing with an acid at least some of amino groups in a resultant reaction product” or “a high-molecular antioxidant obtained by reacting at least three compounds of (A) a sulfur-containing organic compound having at least two active hydrogen atoms, (B) a polyisocyanate compound having at least two isocyanate groups and (E) a nonionic polyol compound having at least two active hydrogen atoms” and a recording medium obtained by using the high-molecular antioxidant.

Abstract: Disclosed herein are a polymer compound comprising a unit composed of a sulfur-containing compound (A) having at least two active hydrogen groups, a unit composed of a compound (B) having at least two isocyanate groups and a unit composed of an amine compound (C) having at least two active hydrogen groups, and having an average particle size of 200 nm or smaller, and a recording medium containing this polymer compound.