The present invention relates to coated metal oxide particles, to a process for preparing such coated particles by means of flame spray pyrolysis technology, to metal oxide particles derived from such a process, to the compositions comprising such particles and also to the uses thereof.

An electron beam curable paint comprises: a dispersion solution of inorganic nanomaterial, a dispersion solution of inorganic nanoultraviolet absorbent, a polyfunctional monomer and an acrylate prepolymer, wherein the dispersion solution of the inorganic nanomaterial is selected from one or two of a dispersion solution of silicon dioxide and a dispersion solution of aluminum oxide, and the dispersion solution of the inorganic ultraviolet absorbent is a dispersion solution of titanium dioxide or a dispersion solution of zinc oxide. The silicon dioxide, the aluminum oxide, the titanium dioxide and the zinc oxide are respectively surface modified and are dissolved in acrylate monomer to form the dispersion solution of the inorganic material without agglomeration.

Surface-modified zinc oxide particles which have a silane coupling agent having an alkoxy group on surfaces thereof, in which d50 when measured with a laser diffraction/scattering type particle size distribution-measuring instrument by the following measurement method is 4 μm or less. (Measurement method) 10 g of the surface-modified zinc oxide particles, 88 g of cyclopentasiloxane, and 2 g of polyglyceryl-3 polydimethylsiloxyethyl dimethicone are mixed to obtain a liquid mixture, a dispersion treatment is performed on the obtained liquid mixture at 9,500 rpm for 5 minutes using a homogenizer to obtain a liquid dispersion, the liquid dispersion is diluted with cyclopentasiloxane so that a content of the surface-modified zinc oxide particles in the obtained liquid dispersion is 0.01% by mass to produce a measurement solution, and d50 is measured with the laser diffraction/scattering type particle size distribution-measuring instrument using the obtained measurement solution.

Provided is a dispersion liquid for sealing a light-emitting element containing metal oxide particles having a refractive index of 1.7 or higher and a surface-modifying material at least partially attached to the metal oxide particles, in which a particle diameter D50 of the metal oxide particles when a cumulative percentage of a scattering intensity distribution obtained by a dynamic light scattering method is 50% is 30 nm or more and 100 nm or less, and a content of the surface-modifying material not attached to the metal oxide particles is 60% by mass or less with respect to a total content of the metal oxide particles and the surface-modifying material.

Porous metal oxide microspheres are prepared via a process comprising forming a liquid dispersion of polymer nanoparticles and a metal oxide; forming liquid droplets of the dispersion; drying the droplets to provide polymer template microspheres comprising polymer nanospheres; and removing the polymer nanospheres from the template microspheres to provide the porous metal oxide microspheres. The porous microspheres exhibit saturated colors and are suitable as colorants for a variety of end-uses.

The present invention is a composition comprising an aqueous dispersion of metal oxide pigment particles coated with an organosilane polymer comprising structural units of an alkyltrihydroxysilane or a salt thereof, a dialkyldihydroxysilane or a salt thereof, and an ancillary alkylsilane triol. The composition of the present invention provides hydrophobicity to pigment particles, thereby imparting water resistance, and allows for high loadings of pigment in water without increased viscosity. The dispersion is further useful for providing stain and corrosion resistance in coatings arising from paints.

A coated powder comprises (a) particles, and (b) a coating on the surface of the particles including (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties. The amount by weight in SiO.sub.2 equivalents of the organo oxysilane moieties and the silica moieties is at least 0.0625% of the total coated powder weight per m.sup.2/g of the specific surface area of the particle to be coated.

The present invention relates to a process for preparing coated zinc oxide particles by means of flame spray pyrolysis technology, to coated zinc oxide particles, and to a composition comprising said particles. The present invention also relates to specific zinc oxide particles derived from such a process, to the compositions comprising such particles and also to the uses thereof.

A coated powder comprises (a) particles, and (b) a coating on the surface of the particles including (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties. The amount by weight in SiO.sub.2 equivalents of the organo oxysilane moieties and the silica moieties is at least 0.0625% of the total coated powder weight per m.sup.2/g of the specific surface area of the particle to be coated.

Porous metal oxide microspheres are prepared via a process comprising forming a liquid dispersion of polymer nanoparticles and a metal oxide; forming liquid droplets of the dispersion; drying the droplets to provide polymer template microspheres comprising polymer nanospheres; and removing the polymer nanospheres from the template microspheres to provide the porous metal oxide microspheres. The porous microspheres exhibit saturated colors and are suitable as colorants for a variety of end-uses.