The invention provides dispersed inorganic mixed metal oxide pigment compositions utilizing a carboxylic acid, containing dispersant and a mixed metal oxide pigment. The metal oxide pigment is of the type used to colour ceramic or glass articles. The dispersant, in addition to at least one carboxylic acid group, comprises at least one 300-3000 g/mole solubilizing chain of repeating units from hydrocarbylene or repeating units from C3 or C4 alkylene ethers or mixtures of said ethers. A milling process using beads is also described to reduce the mixed metal oxide particle size to the desired range. A method of using the mixed metal oxide dispersion to digitally print an image on a ceramic or glass article using the dispersion jetted through a nozzle and firing the coloured article is also described.

A highly efficient method is provided for producing a water-based ink for ink jet recording with which the number of coarse particles in a water-based pigment dispersion liquid is significantly reduced, dispersed particles are made finer, the dispersion stability is improved, the storage stability is improved, and high discharge stability is achieved when a water-based ink for ink jet recording is produced. Particularly, provided is a method for producing a water-based pigment dispersion liquid, the method including kneading a mixture containing a quinacridone type pigment (a), a styrene-acrylic acid type copolymer (c), a basic compound (d), and a polyoxyalkylene glycol or its derivative (e) to prepare a pigment dispersion that is solid at room temperature and mixing a aqueous medium and the pigment dispersion to decrease the viscosity and liquefy the pigment dispersion.

The present invention provides [1] a process for producing a fine organic pigment having a very small primary particle size, and a fine organic pigment produced by the process; a process for producing a dispersion using the fine organic pigment, and a dispersion produced by the process; and a process for producing an ink using the dispersion. The present invention relates to [1] a process for producing a fine organic pigment, including step 1 of kneading a mixture prepared by blending (A) a raw material organic pigment containing an oxygen atom and a nitrogen atom bonded to a hydrogen atom in a molecule thereof, (B) a water-soluble inorganic salt, (C) a water-soluble organic solvent, (D) water and (E) a water-soluble basic compound with each other, in which the water (D) is blended in an amount of not less than 0.6 part by mass and not more than 7.0 parts by mass on the basis of 100 parts by mass of the water-soluble inorganic salt, and the water-soluble basic compound (E) is blended in an amount of not less than 1.5 parts by mass and not more than 35 parts by mass on the basis of 100 parts by mass of the raw material organic pigment.

A C.I. Pigment Yellow 74 as an insoluble azo pigment is provided. This C.I. Pigment Yellow 74 is crystalline particles. The ratio (26.6/11.7) of a diffraction intensity of a peak at 26.6 to a diffraction intensity of a peak at 11.7 in terms of Bragg angle (20.2) as measured by powder X-ray diffraction using CuK -radiation is 0.85 to 1.12, and the average primary particle size is 20 to 130 nm. The use of this C.I. Pigment Yellow 74 as a colorant in a coloring composition enables to provide the coloring composition with excellent dispersibility and good particle size stability and storage stability compared with conventional pigments. The use of this coloring composition enables the formation (recording) of images having excellent clarity and transparency of such high levels that have not been achievable by conventional technologies.

A coloring composition includes colorants, polymerizable compounds, and a resin, in which a ratio P/M of a mass P of the colorants to a mass M of the polymerizable compounds is 0.05 to 0.35, a content of the polymerizable compounds is 25 to 65 mass % with respect to a total solid content of the coloring composition, a ratio A/B of a minimum value A of an absorbance in a wavelength range of 400 nm or longer and shorter than 580 nm to a minimum value B of an absorbance in a wavelength range of 580 nm to 770 nm is 0.3 to 3, and a ratio C/D of a minimum value C of an absorbance in a wavelength range of 400 nm to 750 nm to a maximum value D of an absorbance in a wavelength range of 850 nm to 1300 nm is 5 or higher.