A method for coating the surface of a substrate, such as inorganic particles, with a metal oxide. A suspension is formed containing the substrate, a polyvalent anion and a metal ion where the molar ratio of the polyvalent anion to the metal ion is greater than three and the metal ion is precipitated onto the substrate as a metal oxide. Preferably, the method is used to coat titanium dioxide pigment particles with aluminum oxide.

A method to coat oxide-based color pigments with an ultrasound-assisted coating of nanofiber or other nanostructures in order to enhance heat-fastness and color performance to said color pigments is presented. In particular, the present invention provides a method to coat oxide-based color pigments with nano-coating materials, including but not limited to, alumina and/or silica at different dosage levels, with nanospike, nanoneedle, nanoplate, and/or nanoflower morphology towards enhancing the heat-fastness and color performance of said color pigments.

In an ultraviolet-shielding particle coated with silicon oxide of the present invention, a surface of the ultraviolet-shielding particle is coated with a silicon oxide coat, at least one functional group selected from the group consisting of an alkyl group, an alkenyl group, and a cycloalkyl group is present on a surface of the silicon oxide coat, and a content of the functional group is 0.0001% by mass or more and 0.30% by mass or less.

The present disclosure provides an example of a white ink. The ink includes an aqueous ink vehicle and from 5 wt % to 60 wt % of a white flocculated colorant mass. The white flocculated colorant mass can include white metal oxide pigment having an average particulate size from 100 nm to 2,000 nm, silica coated on the white metal oxide pigment to form a silica-coated pigment, and a polymeric dispersant associated with a surface of the silica-coated pigment.

The present disclosure provides an example where a white ink can include an aqueous ink vehicle and from 5 wt % to 60 wt % of a white flocculated colorant mass. The white flocculated colorant mass can include white metal oxide pigment, an alumina coating, and polymeric dispersant associated with a surface of the alumina-coated pigment. The white metal oxide pigment can have an average particulate size from 100 nm to 2,000 nm. The alumina coating on the white metal oxide pigment can form an alumina-coated pigment where the alumina coating is predominantly alumina, and the white metal oxide pigment content to alumina content can be from 99:1 to 9:1 by weight.

There is provided an electrostatic ink composition comprising chargeable particles comprising white pigment particles having a basic species on their surface; and a charge director; wherein the white pigment particles are present in an amount of at least 75 wt % based on the total weight of the non-volatile solids in the electrostatic ink composition. A method of manufacturing an electrostatic ink composition and a printed medium are also described.

A titanium dioxide pigment composition comprising a plurality of titanium dioxide particles and a polymer that is associated with the titanium dioxide particles and becomes associated with latex particles in an aqueous based coating formulation to inhibit agglomeration of the titanium dioxide particles while the coating formulation dries is provided. The polymer comprises a water soluble polymer backbone, at least one functional group that is attached to the polymer backbone and has an affinity for titanium dioxide, and at least one hydrophobic functional group that is attached to the polymer backbone and has an affinity for latex. Also provided is a method of manufacturing a titanium dioxide pigment composition.

Provided in one example herein is a liquid electrophotographic ink composition. The composition comprises: a carrier fluid comprising a polymer; ink particles each comprising a non-aqueous polymeric resin and pigment particles distributed in the polymeric resin; and a charge director. The pigment particles comprise a metal oxide and have a hydrophobic surface. The hydrophobic surface comprises at least one of the following: (i) nanoparticles attached to each of the pigment particles, the nanoparticles comprising at least one of an oxide, a phosphate, and a nitrate; (ii) a coating disposed over each of the pigment particles, the coating comprising at least one of an oxide, a phosphate, and a nitrate; and (iii) a coating disposed over each of the pigment particles, the coating comprising at least one of a polymer and an oligomer.

The purpose of the present invention is to provide: a composite pigment, and production method thereof, which can suppress luster of a coating film by modifying an inorganic coloring pigment, and which can be used in various applications such as low-gloss (luster reduction effect) pigments and matte pigments; a paint composition which can achieve both an excellent coating film texture and also the property of having low gloss and luster even when added to a coating film; and a coating film. In this composite pigment, the inorganic coloring pigment is fixed by an inorganic compound, and a plurality of particles of the inorganic coloring pigment are aggregated into granular form through the inorganic compound.

The purpose of the present invention is to provide a composite pigment which can be dispersed and made into paint in a manner that saves labor compared with conventional flat emulsion paints, and which can achieve concealing properties and low glossiness (a luster reduction effect) without separately adding a matting agent. This composite pigment contains an inorganic compound and/or an organic compound, and a fixed extender pigment.