Sakai Chemical Industry Co., Ltd.

Kenichi Nakagawa

Takanori Morita

Atsushi Nomura

The invention provides a dispersion of zirconium oxide having a content as high as 20% by weight or more, but a low viscosity, and having a high transparency, which has a transmittance of 35% or more at a wave length of 400 nm, a transmittance of 95% or more at a wave length of 800 nm, and a viscosity of 20 mPa&#xb7;s or less at a temperature of 25&#xb0; C. Such a dispersion of zirconium oxide can be obtained by reacting a zirconium salt with an alkali in water to obtain a slurry of particles of zirconium oxide; filtering, washing, and repulping the slurry; adding an organic acid to the resulting slurry in an amount of one mole part or more per mole part of the zirconium in the slurry; hydrothermally treating the slurry at a temperature of 170&#xb0; C. or higher; and washing and concentrating the resulting aqueous dispersion of particles of zirconium oxide.

Dispersion of zirconium oxide, process for producing the same, and resin composition containing the same

The invention provides a process for producing an aqueous dispersion of zirconium oxide that includes: reacting a zirconium salt with an alkali in water to obtain a slurry of particles of zirconium oxide; filtering, washing, and repulping the slurry; adding an organic acid to the resulting slurry in an amount of one mole part or more per mole part of the zirconium in the slurry; hydrothermally treating the resulting mixture at a temperature of 170&#xb0; C. or higher; and washing the resulting aqueous dispersion of particles of zirconium oxide.

Dispersion of zirconium oxide and process for producing the same

The invention provides a dispersion of particles of rutile titanium oxide wherein the particles of rutile titanium oxide have a D50 in a range of 1 to 15 nm and a D90 of 40 nm or less in particle size distribution as determined by a dynamic light scattering method; a specific surface area in a range of 120 to 180 m/g as determined by a BET method; and a rate of weight loss of 5% or less as obtained by heating the particles of rutile titanium oxide from 105&#xb0; C. to 900&#xb0; C. Such a dispersion of particles of rutile titanium oxide is obtained by a process according to the invention, which comprises: a first step in which an aqueous titanium tetrachloride solution is heated and hydrolyzed to obtain a slurry containing the precipitated particles of rutile titanium oxide; a second step in which the slurry obtained in the first step is filtered and washed with water to remove water-soluble salts dissolved therein from the slurry; a third step in which the slurry obtained in the second step is subjected to a hydrothermal reaction in the presence of an organic acid; a fourth step in which the slurry obtained in the third step is filtered and washed with water; a fifth step in which an acid is added to the slurry obtained in the fourth step, and the resulting mixture is subjected to a wet dispersion treatment, thereby obtaining a dispersion; and a sixth step in which excess acid and water-soluble salts are removed from the dispersion obtained in the fifth step.

Dispersion of particles of rutile titanium oxide, process for producing the same, and use of the same

The invention provides a process for producing an aqueous dispersion of particles of rutile titanium oxide, which comprises:

Process for producing dispersion of particles of rutile titanium oxide

The invention provides a process for producing an aqueous dispersion of zirconium oxide comprising: reacting a zirconium salt with an alkali in water to obtain a slurry of particles of zirconium oxide; filtering, washing, and repulping the slurry; adding an organic acid to the resulting slurry in an amount of one mole part or more per mole part of the zirconium in the slurry; hydrothermally treating the resulting mixture at a temperature of 170&#xb0; C. or higher; and washing the resulting aqueous dispersion of particles of zirconium oxide.

Growing community of inventors

Sakai, Japan

Kenichi Nakagawa