Aqueous dispersion containing a hydrophilic metal oxide powder comprising a metal oxide and a surface modification of the metal oxide, wherein a) the metal oxide is selected from the group consisting of TiO.sub.2, ZrO.sub.2, SiO.sub.2, Al.sub.2O.sub.3, Fe.sub.2O.sub.3, Fe.sub.3O.sub.4, Sb.sub.2O.sub.3, WO.sub.3, CeO.sub.2 and mixed oxides thereof and b) the surface modification b1) comprises silicon atoms and aluminum atoms and b2) the silicon atoms are at least partly bonded to a hydrocarbon radical via a C atom and b3) the Al/Si molar ratio of the surface modification is 1:2-1:20.

The invention provides a method for producing an organic solvent dispersion of titanium oxide particles in an organic solvent except methanol and ethanol, comprising: (a) a surface treating process for surface treating an alcohol dispersion of titanium oxide particles in at least one alcohol solvent selected from the group consisting of methanol and ethanol with a surface treating agent comprising a silane coupling agent and 12-hydroxystearic acid thereby surface treating the titanium oxide particles; and (b) a solvent replacing process for replacing the alcohol solvent that is a dispersion medium of the alcohol dispersion of titanium oxide particles by the organic solvent except methanol and ethanol, wherein the silane coupling agent has the general formula (I)
(RO).sub.nSiX.sub.4-n(I)
wherein R is an alkyl group having carbon atoms of 1-4, n is 2 or 3, X is an alkyl, a fluoroalkyl, a vinyl or a (meth)acryloyloxyalkyl group.

The present invention aims to provide a method of producing a fine particulate inorganic oxide dispersion, which makes it possible to easily disperse a fine particulate inorganic oxide while reducing the amount of dispersant used. The present invention relates to a method of producing a fine particulate inorganic oxide dispersion, the method including mixing the following components (A) to (D): (A) at least one fine particulate inorganic oxide selected from the group consisting of zirconium oxide (ZrO.sub.2), titanium oxide (TiO.sub.2), and barium titanate (BaTiO.sub.3), (B) a dispersant, (C) an alkoxysilane compound, and (D) a solvent having the following Hansen solubility parameters: a hydrogen bonding component (dH) of 11 or less and a polar component (dP) of 4 or more; and wet grinding the resulting mixture.

A method of recovering an inorganic pigment from a coating composition, the method comprising a step of adding polyethylene glycol to the coating composition. The invention also concerns a coating composition comprising an inorganic pigment composition recovered according to the method, and the use of polyethylene glycol in the recovery of inorganic pigment from a coating composition.

The present disclosure provides an example where a non-Newtonian white ink can include an aqueous ink vehicle, from 5 wt % to 60 wt % of white colorant, and from 0.1 wt % to 5 wt % of amphoteric alumina particles dispersed in the aqueous ink vehicle. The white colorant can include white metal oxide pigment having an average particulate size from 100 nm to 2,000 nm, an alumina coating on the white metal oxide pigment forming an alumina-coated pigment, and a polymeric dispersant associated with a surface of the alumina-coated pigment. The amphoteric alumina particles can have an average particles size from 2 nm to less than 100 nm.

The present invention relates to a process for the production of titanium dioxide (TiO.sub.2) nanoparticles with desired ratio of anatase phase and rutile phase, the method comprising (a) reacting titanium trichloride (TiCl.sub.3) solution with a flower extract (b) drying the reaction mixture obtained in step (a) at high temperature to powder form and (c) calcination of the powder obtained in step (b) at high temperatures.

Methods for of synthesizing a polymer functionalized nanoparticle are provided. The method can comprise: attaching an anchoring compound to a nanoparticle; attaching a RAFT agent to the anchoring compound; and polymerizing a plurality of butadiene-derived monomers on the anchoring compound to form a polymeric chain covalently bonded to the nanoparticle via the anchoring compound. Polymer functionalized nanoparticles are also provided that include a nanoparticle defining a surface; a butadiene-derived polymeric chain covalently bonded to the surface of the nanoparticle. Nanocomposites are also provided that include a plurality of such polymer functionalized nanoparticles dispersed within a polymeric matrix.

The invention provides a method for producing an organic solvent dispersion of titanium oxide particles in an organic solvent except methanol and ethanol, comprising: (a) a surface treating process for surface treating an alcohol dispersion of titanium oxide particles in at least one alcohol solvent selected from the group consisting of methanol and ethanol with a surface treating agent comprising a silane coupling agent and 12-hydroxystearic acid thereby surface treating the titanium oxide particles; and (b) a solvent replacing process for replacing the alcohol solvent that is a dispersion medium of the alcohol dispersion of titanium oxide particles by the organic solvent except methanol and ethanol, wherein the silane coupling agent has the general formula (I)

(RO).sub.nSiX.sub.4-n(I)

wherein R is an alkyl group having carbon atoms of 1-4, n is 2 or 3, X is an alkyl, a fluoroalkyl, a vinyl or a (meth)acryloyloxyalkyl group.

The invention provides an organic solvent dispersion of titanium oxide particles in a content of 10% by weight or more in an organic solvent except methanol and ethanol,

wherein the titanium oxide particles are surface-treated with a surface treating agent comprising a silane coupling agent having the general formula (I)

(RO).sub.nSiX.sub.4-n (I)

wherein R is an alkyl group having carbon atoms of 1-4, n is 2 or 3, X is an alkyl, a fluoroalkyl, a vinyl or a (meth)acryloyloxyalkyl group, and 12-hydroxystearic acid, and

wherein the titanium oxide particles in the organic solvent have a D50 in a range of 1 to 30 nm, and

wherein the organic solvent dispersion has a transmittance of 2% or more at a wavelength of 500 nm and a transmittance of 70% or more at a wavelength of 800 nm, a viscosity of 10 mPa.Math.s or less at a temperature of 25 C. immediately after production while the increase in the viscosity is 40 mPa.Math.s or less seven days after production as compared to that of the dispersion immediately after production.

Metal oxide-polymer composite particles have a median particle size D50 of 40-75 nm or 100-150 nm and an average RTA of at least 0.06. Alternatively or in addition, metal oxide-polymer composites comprise two or more populations of metal oxide particles differing in size, particle size distribution, or shape. Alternatively or in addition, the use of a multicomponent hydrophobizing system including an alkylsilane to fabricate metal oxide-polymer composite particles increases the tribocharge of the composite particles.