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.

An anticorrosive pigment comprising an aluminum polyphosphate comprises at least one cerium-based compound and/or one lanthanum-based compound and/or one praseodymium-based compound. An anticorrosive paint incorporating the pigment is also provided.

This invention relates to non-bleeding, non-staining occult particles for use in granular or powdered laundry care compositions such as laundry detergents, laundry aids, and fabric care compositions. The occult particles are comprised of a clay carrier and a coloring agent and are characterized as being substantially indiscernible when contained in the laundry care composition.

In various embodiments, the present invention is directed to a facile one-pot reverse emulsion process to assemble core-shell nanoparticles (CS-SMNPs) into bright and noniridescent photonic supraballs. In one or more embodiments, the present invention is directed to core-shell nanoparticles having an inner high refractive index (RI) core and an outer low RI shell. In one or more embodiment, the present invention includes core-shell nanoparticles using high RI (1.74) melanin cores and low-RI (1.45) silica shells. In various embodiments, these nanoparticles may be self-assembled into bright and noniridescent supraballs using a scalable one-pot reverse emulsion process. According to various embodiments of the present invention, it is possible to generate a full spectrum of structural colors with the combination of only two ingredients, synthetic melanin and silica.

Provided is a black pigment that enables pattern formation of pixel division layer while suppressing generation of development residue. The black pigment comprises (a) a core containing at least one organic black pigment selected from the group consisting of benzodifuranone-based black pigments, perylene-based black pigments, azo-based black pigments, and isomers thereof and (b) a coating layer containing silica and/or a metal oxide and/or a metal hydroxide.

This invention relates to non-bleeding, non-staining occult particles for use in granular or powdered laundry care compositions such as laundry detergents, laundry aids, and fabric care compositions. The occult particles are comprised of a clay carrier and a coloring agent and are characterized as being substantially indiscernible when contained in the laundry care composition.

An electrophoretic medium comprises a plurality of core-shell particles and a non-polar fluid. The core-shell particles comprise an organic pigment particles core and a shell comprising a metal oxide layer and a silane layer. The metal oxide layer may have a thickness of 0.4 to 2 nm. It may be formed using a fluidized bed reactor by inserting the organic pigment into the reactor as a powder bed, contacting the powder bed with a gaseous stream comprising a metal oxide precursor and an inert gas, and contacting the powder bed with a gaseous stream of a reagent and an inert gas. The silane layer is formed from a silane compound comprising a first functional group, wherein the first functional group reacts with the metal oxide.

In various embodiments, the present invention is directed to a supraparticle for use in producing structural colors comprising a plurality of core/shell nanoparticles having a melanin or synthetic melanin core and a silica shell having a plurality of silanol groups on its outer surface and a poly(ethylene glycol) (PEG) crosslinker. In various embodiments, the structure of these crosslinked supra particles is reinforced by hydrogen bonds formed between the silanol groups on the core-shell nanoparticles and mechanical, solution phase, and dry state stability.

An electrophoretic medium comprises a plurality of core-shell particles and a non-polar fluid. The core-shell particles comprise an organic pigment particles core and a shell comprising a metal oxide layer and a silane layer. The metal oxide layer may have a thickness of 0.4 to 2 nm. It may be formed using a fluidized bed reactor by inserting the organic pigment into the reactor as a powder bed, contacting the powder bed with a gaseous stream comprising a metal oxide precursor and an inert gas, and contacting the powder bed with a gaseous stream of a reagent and an inert gas. The silane layer is formed from a silane compound comprising a first functional group, wherein the first functional group reacts with the metal oxide.

The object of the present invention is to provide a method of producing organic pigment microparticles which can surely suppress growth and/or aggregation of particles. The present invention provides a method of producing organic pigment microparticles, comprising the following steps: Step 1 of precipitating organic pigment microparticles by mixing an organic pigment raw material liquid in which an organic pigment raw material is mixed with a solvent, and a precipitation solvent for precipitating the organic pigment microparticles from the organic pigment raw material liquid in a thin film fluid formed by introducing the organic pigment raw material liquid and the precipitation solvent in the space between at least two processing surfaces which are disposed so as to face each other, being capable of approaching to and separating from each other, at least one of which rotates relatively to the other; and Step 2 of coating at least a part of the organic pigment microparticles with an oxide coating; wherein the oxide coating is optically colorless and transparent, and Step 1 and Step 2 are performed out continuously in the thin film fluid, or Step 2 is completed at a predetermined time after Step 1 until the organic pigment microparticles grow and/or aggregate.