The present invention relates to [1] a process for producing a pigment composition, including the step of subjecting a raw material pigment composition containing C.I. Pigment Yellow 74, a specific by-product and water to heat treatment at a temperature of from 160 to 210 C.; and [2] a method of reducing a content of a by-product in a raw material pigment composition containing C.I. Pigment Yellow 74, the specific by-product and water, said method including the step of subjecting the raw material pigment composition to heat treatment at a temperature of from 160 to 210 C.

The method prepares an aqueous pigment dispersion. The method includes the following steps: providing a silica liquid including a hydrophilic fumed silica, potassium hydroxide and ion exchanged water; providing a styrene-acrylic acid copolymer obtained by copolymerizing monomers including a styrene monomer at an amount of 50 to 90 mass %; providing an aqueous medium; mixing a pigment with the styrene-acrylic acid copolymer and the aqueous medium to prepare a first mixture; and subsequently mixing the first mixture with the silica liquid to prepare the aqueous pigment dispersion.

A purpose of the present invention is to provide a fine coated pigment which is inhibited from becoming coarse particles and is easily dispersible. The coated pigment is a pigment, the surface of which has been coated with a resin, wherein the resin is an -olefin copolymer having an acid group and the amount of the resin with which the pigment has been coated is 10-50 parts by mass per 100 parts by mass of the uncoated pigment (X).

A living radical polymer that has a low molecular weight distribution and has a specific functional group at least at one end, and a resin-coated pigment has high dispersibility of a resin composition including the living radical polymer, is excellent in properties such as preservation stability, discharge stability, and color developability in a dispersed state, and is suitably used in a pigment dispersion. A living radical polymer has a specific functional group structure, the living radical polymer includes a polymerization initiator-derived specific organic compound moiety at one end or in a backbone of the living radical polymer and is obtained by reacting a radical generator having a specific functional group with at least any end, for example, an iodine end ascribable to a precursor. A living radical polymer composition includes the same; a resin-coated pigment is obtained by coating with the living radical polymer composition; and a method produces the living radical polymer.

A UV curable inkjet ink containing covert or overt ultraviolet or infrared reactive material. The ultraviolet or infrared reactive materials are processed in acrylate monomer or combination of acrylate monomer and acrylate oligomer media, along with photoinitiators and surfactants to produce an inkjet ink for printing on non-porous substrates such as plastic, glass, ceramic or metal with high adhesion, scratch and chemical resistance and providing a security feature responsive to ultraviolet or infrared radiation.

An object that is to be achieved by the present invention is to provide an azo pigment having excellent transparency, suitable dispersibility, and a low viscosity, an ink, and the like. An azo pigment according to the present invention has a zeta potential of 80 to 30 mV in isopropanol (IPA). The content of a metal element in the azo pigment is preferably 0.05 to 2.00 parts by mass relative to 100 parts by mass of the azo pigment. The metal element is preferably an iron element. The ratio (Fe/C) of the concentration Fe (atomic %) of an iron element in the surfaces of particles of the azo pigment to the concentration C (atomic %) of a carbon element in the surfaces of the particles of the azo pigment which are determined by X-ray photoelectron spectroscopy is preferably 0.20 or less.

This development pertains to polyurethane resins for producing stable pigment dispersions that are compatible with co-solvents and humectants used in aqueous ink jet inks. Inks with improved flow in printhead and penetration of substrate may be obtained.

A composition includes: a metal-free phthalocyanine compound; a red colorant; and a solvent, in which a ratio A/B of an absorbance A at a wavelength of 700 nm to an absorbance B at a wavelength of 810 nm is 10 or higher.

A water-based pigment dispersion including an aluminum lake pigment (A) and a pigment dispersant (B). The pigment dispersant (B) is a polymer containing a constituent unit derived from an anionic group-containing monomer (b-1) and a constituent unit derived from a hydrophilic nonionic monomer (b-2) containing an oxyalkylene group. A water-based ink for ink-jet recording, including the water-based pigment dispersion and a water-soluble organic solvent (C).

The present disclosure is drawn to pigment dispersions including from 5 wt % to 30 wt % of a pigment having an amide group, a styrene acrylic polymer having a weight average molecular weight from 3,000 Mw to 30,000 Mw and having a weight ratio to the pigment of from 1:1 to 1:10, a lactam co-solvent having a weight ratio to the pigment of from 10:1 to 1:10, and water. The lactam co-solvent can be co-milled with the pigment and an at least 5 wt % portion of the lactam co-solvent can be adsorbed on the pigment via van der waals interaction with the amide group.