The present invention relates to [1] a process for producing pigment-containing modified polymer particles, including the step of reacting pigment-containing polymer particles (A) containing a functional group and a compound (B) containing a reactive group capable of reacting with the functional group of the polymer particles (A) in a medium under such a condition that a ratio [(B)/(A)] of total moles of the reactive group of the compound (B) to total moles of the functional group of the polymer particles (A) is from 0.10 to 0.62; [2] a pigment water dispersion including an aqueous medium and the modified polymer particles produced by the aforementioned process which are dispersed in the aqueous medium; and [3] an ink including the aforementioned pigment water dispersion and an organic solvent. The modified polymer particles are free from formation of coarse particles upon production of pigment particles, so that an ink obtained by using the modified polymer particles can be prevented from suffering from increase in viscosity thereof when the ink is being concentrated by evaporation of water from the ink, and is excellent in rub fastness when printed on a low-water absorbing recording medium.

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.

A method for producing a halogenated zinc phthalocyanine pigment includes a step of forming a halogenated zinc phthalocyanine crude pigment into a pigment. The halogenated zinc phthalocyanine crude pigment is obtained by depositing a halogenated zinc phthalocyanine, which is synthesized by using an acidic compound or a compound that generates an acid by reacting with water, and the step includes a pretreatment step of kneading the halogenated zinc phthalocyanine crude pigment along with water.

A method for producing a halogenated zinc phthalocyanine pigment according to one embodiment includes a first step of obtaining a halogenated zinc phthalocyanine crude pigment by deposition by extracting a halogenated zinc phthalocyanine, which is synthesized by using a compound that generates an acid by reacting with water; and a second step of forming the halogenated zinc phthalocyanine crude pigment into a pigment.

An object of the present invention is to provide a method of efficiently producing a colorant that can be used for production of a pigment composition or an aqueous pigment dispersion with a small volume-average particle size of a dispersed substance and with fewer coarse particles. The inventor of the present invention has achieved the object by a method of producing a colorant that includes: step 1 of kneading a composition containing a pigment having a primary particle size of 100 nm or more, a liquid medium, and a water-soluble inorganic salt with a processing machine to produce a kneaded product containing a pigment having a primary particle size in a range of 10 nm or more and less than 100 nm; and step 2-1 of mixing the kneaded product, a resin having an anionic group, and a basic compound.

The present disclosure relates to a solid pigment preparation, including at least one pigment in an aqueous solution including an amine-functional acrylic block copolymer and an amine-functional polymeric dispersant including a polyoxyalkylene moiety, as well as a process for producing the solid pigment preparations and their use in various coloring applications. The solid pigment preparations are particularly universally dispersible in both water- and solvent-based systems. Corresponding dispersions are accordingly also within the scope of the present disclosure.

There is provided a novel halogenated zinc phthalocyanine pigment for a color filter, which can form a green color filter having excellent contrast and high luminance. A halogenated zinc phthalocyanine pigment for a color filter shows, in a Raman spectrum, a peak intensity of 3.0% or more at 716±2.2 cm.sup.−1 when a peak intensity at 650±10 cm.sup.−1 is regarded as 100%.

The invention relates to a method for preparing high-stability liquid blueberry anthocyanins, belonging to the field of food processing. A method for preparing high-stability liquid blueberry anthocyanins comprises the following process steps: adding graphene oxide and chitosan to an MES buffer solution at room temperature, mixing homogeneously and adding EDC and NHS sequentially, reacting to obtain a first solution; adding dry blueberry anthocyanin powder in the first solution, adjusting pH to 4.5 to 5.0 and mixing homogeneously to obtain a second solution, and treating the second solution at 350 to 420 MPa and 2 to 4° C. to obtain the product. The method for increasing the stability of blueberry anthocyanins provided by the present invention uses dry blueberry anthocyanin powder as a raw material and adds graphene oxide combined with chitosan compound as an anthocyanin stabilizer, thereby increasing the stability of blueberry anthocyanins during processing and production.

An aqueous ink jet composition includes a dye component composed of at least one of sublimation dyes and disperse dyes, polyester, 1-(hydroxyalkyl)-2-pyrrolidone, and water, wherein the content (mass %) of the polyester is 4.0 times or more and 300.0 times or less the content (mass %) of the dye component.

A method for preparing a dispersion of nanoparticles of a solid organic dye or pigment in a liquid carrier, the method comprising continuously mixing: at least one solution or slurry containing a reactant precursor for the solid organic dye or pigment in an organic or other solvent with the liquid carrier in a counter current mixing reactor whereby to obtain reaction of the reactant precursor and formation of the solid organic dye or pigment as a dispersion of nanoparticles in the liquid carrier and solvent mixture; optionally, removing unreacted reactant precursor and/or by-product from the dispersion when present; and optionally, concentrating the dispersion.