Titanium oxide particles and method for producing same

Patent metadata

Field	Value
Publication number	US-2024239683-A1
Application number	US-202218289825-A
Country	US
Kind code	A1
Filing date	Apr 28, 2022
Priority date	May 17, 2021
Publication date	Jul 18, 2024
Grant date	—

Abstract

Titanium oxide particles, a method for their production, and a slurry, dispersion, composition and dielectric starting material that include the titanium oxide particles. The D90 (LD)/D50 (LD) ratio of the titanium oxide particles is greater than 1.0 and 2.0 or lower, and the particle concentration of coarse particles having a size exceeding 16 times the D50 (SEM)(16× the D50 (SEM)), for primary particles, is 20 ppm or lower. For their production, a source gas and oxidizing gas are introduced into a reaction tube and reacted, with a purge medium blowing outlet being provided on the inner wall of the reaction tube, and the blowout angle and the blowout flow velocity (B) of the purge medium from the inner wall of the reaction tube being such that the purge medium is introduced in a swirling manner along the inner wall of the reaction tube.

First claim

1 . Titanium oxide particles, wherein the D90 (LD)/D50 (LD) ratio of the titanium oxide particles as measured by laser diffraction/scattering analysis is greater than 1.0 and 2.0 or lower, and the particle concentration of coarse particles whose primary particle size exceeds 16 times the size of D50 (SEM) of primary particles of the titanium oxide particles as observed under a field emission scanning electron microscope is 20 ppm or lower (based on the number of particles).

2 . Titanium oxide particles according to claim 1 , wherein the D90 (SEM)/D50 (SEM) ratio of primary particles of the titanium oxide particles as observed under a field emission scanning electron microscope is greater than 1.0 and 2.0 or lower.

3 . Titanium oxide particles according to claim 1 , wherein the [D90 (SEM)−D10 (SEM)]/D50 (SEM) ratio of primary particles of the titanium oxide particles as observed under a field emission scanning electron microscope is 0.82 or lower.

4 . Titanium oxide particles according to claim 1 , wherein the D99 (SEM)/D50 (SEM) ratio of primary particles of the titanium oxide particles as observed under a field emission scanning electron microscope is greater than 1.0 and 2.0 or lower.

5 . Titanium oxide particles according to claim 1 , wherein the D90 (DLS)/D50 (DLS) ratio of the titanium oxide particles as measured by dynamic light scattering is greater than 1.0 and 2.0 or lower.

6 . Titanium oxide particles according to a claim 1 , wherein the D90 (DLS)/D90 (SEM) ratio, as the ratio of the D90 (DLS) for the titanium oxide particles as measured by dynamic light scattering and the D90 (SEM) for primary particles of the titanium oxide particles as observed under a field emission scanning electron microscope, is 2.2 or lower.

7 . Titanium oxide particles according to claim 1 , wherein the D90 (LD) for the titanium oxide particles as measured by laser diffraction/scattering analysis is 3000 nm or lower.

8 . Titanium oxide particles according to claim 1 , wherein the D90 (DLS) for the titanium oxide particles as measured by dynamic light scattering and the D90 (SEM) for primary particles of the titanium oxide particles as observed under a field emission scanning electron microscope, are 200 nm or lower, and the D50 (SEM) is 10 to 150 nm.

9 . Titanium oxide particles according to claim 1 , wherein the anatase content is 70% or greater.

10 . Titanium oxide particles according to claim 1 , wherein the BET specific surface area is 5 to 200 m 2 /g.

11 . Titanium oxide particles according to claim 1 , wherein the Cl content of the titanium oxide particles as measured by silver nitrate potentiometric titration is 0.2% or lower.

12 . Titanium oxide particles according to claim 1 , wherein the Na, Al, S, Fe, Ni, Cr, Nb and Zr contents are each 10 ppm by mass or lower, and the Si and C contents are each 500 ppm by mass or lower.

13 . A method for producing titanium oxide particles wherein, for a step in which a source gas comprising titanium tetrachloride and an inert gas, and an oxidizing gas comprising either or both of oxygen gas and water vapor in addition to an inert gas, are introduced into a reaction tube and are reacted and then cooled to produce titanium oxide particles, a blowing outlet for a purge medium is provided on the inner wall of the reaction tube and the purge medium is introduced in a swirling manner along the inner wall of the reaction tube, with the blowout angle α of the purge medium from the inner wall of the reaction tube being 50° or greater with respect to a line connecting the blowing outlet of the purge medium and the center axis line of the reaction tube, on a plane projected onto a cross-section of the reaction tube that is perpendicular to the axis line of the reaction tube, and the blowout flow velocity (B) of the purge medium being 35 m/s or greater.

14 . The method for producing titanium oxide particles according to claim 13 , wherein the blowout angle β of the purge medium from the inner wall of the reaction tube with respect to the direction of the axis line of the reaction tube, on a plane projected onto a longitudinal section of the reaction tube that includes the axis line of the reaction tube, is 60° or greater, where 0° is the downstream side of the reaction gas flow.

15 . The method for producing titanium oxide particles according to claim 13 , wherein the purge medium is introduced so that the ratio B/A is 0.5 or greater, where A is the flow velocity of the reaction gas formed from the source gas and the oxidizing gas in the reaction tube and B is the blowout flow velocity of the purge medium.

16 . A slurry that includes titanium oxide particles according to claim 1 .

17 . A dispersion that includes titanium oxide particles according to claim 1 .

18 . A composition that includes titanium oxide particles according to claim 1 .

19 . A dielectric starting material that includes titanium oxide particles according to claim 1 .

Assignees

• Resonac Corp

Inventors

• Furumoto Yoshiyasu
• Kayama Susumu
• Kogoi Hisao

Classifications

• B01J21/063

  Titanium; Oxides or hydroxides thereof · CPC title

• C01P2004/45

  Aggregated particles or particles with an intergrown morphology · CPC title

• C01P2002/30

  Three-dimensional structures · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2006/80

  Compositional purity · CPC title