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 [1] a water-based pigment dispersion formed by dispersing a pigment in a water-based medium with a polymer dispersant, in which the dispersant contains an acid group-containing (meth)acrylic resin (A) and a polyurethane resin (B); the resin (A) is crosslinked with a crosslinking agent (C), and a crosslinking degree of the resin (A) is from 0.12 to 0.65; and a mass ratio of the pigment [pigment/whole solid components of water-based pigment dispersion] is from 0.25 to 0.75, and [2] a process for producing a water-based pigment dispersion, including step 1 of subjecting a pigment mixture containing a pigment, an acid group-containing (meth)acrylic resin (A) and a polyurethane resin (B) to dispersion treatment to obtain a dispersion; and step 2 of subjecting the dispersion obtained in the step 1 to crosslinking treatment with a crosslinking agent (C).

Abstract: The present invention relates to [1] a water-based pigment dispersion formed by dispersing a pigment in a water-based medium with a polymer dispersant, in which the polymer dispersant contains a (meth)acrylic resin (A) and a resin (B); and the resin (B) is at least one resin selected from the group consisting of a polyester resin (B1), an acid-modified polyolefin resin (B2) and a vinyl chloride-based resin (B3), and [2] a process for producing a water-based pigment dispersion, including the following steps 1 and 2: Step 1: subjecting a pigment mixture containing a pigment, an acid group-containing (meth)acrylic resin (A), and a resin (B) which is at least one resin selected from the group consisting of a polyester resin (B1), an acid-modified polyolefin resin (B2) and a vinyl chloride-based resin (B3) to dispersion treatment to obtain a dispersion; and Step 2: subjecting the dispersion obtained in the step 1 to crosslinking treatment with a crosslinking agent (C).

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: In a light emitting diode package or a light emitting diode, a cover body having an opening with a reflecting surface is attached on an upper portion of a base body on which a light emitting diode element is mounted. The base body is formed of alumina ceramics having a pore diameter of 0.10 to 1.25 ?m or a porosity of 10% or more, and a thermal via is formed in the base body. Accordingly, it is possible to improve luminance and heat radiating characteristics of the light emitting diode package and the light emitting diode which uses alumina ceramics.