Abstract: Highly heat-resistant anatase-type titanium oxide particles stably retard an anatase-type crystal phase having excellent reactivity in a temperature range of 700° C., and have fine particles and a uniform particle size distribution. The highly heat-resistant anatase-type titanium oxide includes titanium oxide particles having a content of an anatase crystal phase in the total crystal phases of 85% or more and a modification layer provided on the surfaces of the titanium oxide particles. The modification layer is obtained by modifying an organic acid having a molecular weight of 200 or less with an acidic solution containing 1.5×10?4 mol/L or more and 0.12 mol/L or less. The pH of the acidic solution is 0.2 to 5.

Abstract: The present invention provides a method of producing titanium oxide capable of maintaining a high content of an anatase form crystal phase at a low cost even under a high temperature environment. The method of producing titanium oxide includes a step of synthesizing titanium oxide by using an aqueous solution obtained by dissolving titanium tetrachloride and an ?-hydroxycarboxylic acid having 3 carboxy groups as a reaction liquid and bringing the reaction liquid to a reaction temperature of 60° C. or higher and the boiling point of the reaction liquid or lower, wherein the ratio of the amount (mol) of the ?-hydroxycarboxylic acid to the amount (mol) of Ti in the reaction liquid is 0.006 or more and 0.017 or less, and the concentration of Ti in the reaction liquid is 0.07 mol/L or more and 0.70 mol/L or less.

Abstract: Provided is a method of producing a titanium oxide in which titanium tetrachloride is hydrolyzed using a liquid-phase method. This method includes a step of adding an aqueous titanium tetrachloride solution to warm water having a higher temperature than the aqueous titanium rachloride solution, in which in the step, the temperature of the warm water is 30° C. to 95° C. and the aqueous titanium tetrachloride solution is added to the warm water such that an increase rate of titanium atomic concentration in the warm water is 0.25 mmol/L/min to 5.0 mmol/L/min, and a titanium atomic concentration in the warm water after the step is 280 mmol/L or lower.

Abstract: Provided is a method of producing a titanium oxide in which titanium tetrachloride is hydrolyzed using a liquid-phase method. This method includes a step of adding an aqueous titanium tetrachloride solution to warm water having a higher temperature than the aqueous titanium rachloride solution, in which in the step, the temperature of the warm water is 30° C. to 95° C. and the aqueous titanium tetrachloride solution is added to the warm water such that an increase rate of titanium atomic concentration in the warm water is 0.25 mmol/L/min to 5.0 mmol/L/min, and a titanium atomic concentration in the warm water after the step is 280 mmol/L or lower.

Abstract: A liquid phase method for producing titanium oxide sol by hydrolysis of titanium tetrachloride, which includes mixing an aqueous titanium tetrachloride solution into water at a temperature of 80° C. or higher within 60 seconds while maintaining the mixed solution at the temperature and cooling it to less than 60° C. within 15 minutes after the mixing is completed. Also disclosed is a titanium oxide sol obtained by the method, having an average primal particle diameter (DBET) of 3 to 8 nm, a cumulative 50% volume particle diameter (D50DLS) and DBET have the relationship represented by D50DLS=k×DBET where k is 1 or more and less than 5, and an anatase content of 70% or more; a particulate titanium oxide obtained by drying the titanium oxide sol; and a production method and application thereof to solar cells, lithium ion battery electrodes and dielectric materials.

Abstract: A liquid phase method for producing titanium oxide sol by hydrolysis of titanium tetrachloride, which includes mixing an aqueous titanium tetrachloride solution into water at a temperature of 80° C. or higher within 60 seconds while maintaining the mixed solution at the temperature and cooling it to less than 60° C. within 15 minutes after the mixing is completed. Also disclosed is a titanium oxide sol obtained by the method, having an average primal particle diameter (DBET) of 3 to 8 nm, a cumulative 50% volume particle diameter (D50DLS) and DBET have the relationship represented by D50DLS=k×DBET where k is 1 or more and less than 5, and an anatase content of 70% or more; a particulate titanium oxide obtained by drying the titanium oxide sol; and a production method and application thereof to solar cells, lithium ion battery electrodes and dielectric materials.