Method for producing barium titanate powder

Patent metadata

Field	Value
Publication number	US-2016200588-A1
Application number	US-201414912732-A
Country	US
Kind code	A1
Filing date	Aug 22, 2014
Priority date	Aug 23, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

The invention provides a method for producing barium titanate powder comprising the steps of: adding an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 to 400 m 2 /g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of time shorter than 24 hours to provide barium titanate particles.

First claim

1 . A method for producing barium titanate powder comprising the steps of:
adding an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 to 400 m 2 /g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of time shorter than 24 hours to provide barium titanate particles.

2 . The method according to claim 1 , wherein in the step of subjecting the barium titanate precursor to hydrothermal treatment to provide barium titanate, the hydrothermal treatment is performed at a temperature of 250° C. or less.

3 . The method according to claim 1 comprising the steps of:
adding an aqueous solution of titanium tetrachloride and an aqueous solution of an alkali to water maintained at a temperature of 45 to 65° C. at the same time while maintaining the temperature of the resulting reaction mixture in the range of 45 to 65° C. and maintaining the pH thereof in the range of 1.5 to 3.5 to simultaneously neutralize the titanium tetrachloride with the alkali thereby to provide an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 to 400 m 2 /g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction;
adding the aqueous slurry of anatase hydrous titanium oxide to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide solution at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and
subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of time shorter than 24 hours to provide barium titanate particles.

4 . The method according to claim 3 , wherein in the step of subjecting the barium titanate precursor to hydrothermal treatment to obtain barium titanate, the hydrothermal treatment is performed at a temperature of 250° C. or less.

Assignees

• Sakai Chemical Industry Co

Inventors

• Yamanaka Kazumi
• Baba Yuji
• Yoneda Minoru
• Kuniyoshi Yukihiro
• Ogama Shinji

Classifications

• C01G23/006 Primary

  Alkaline earth titanates · CPC title

• C04B2235/6582

  Hydrogen containing atmosphere · CPC title

• C04B2235/5409

  expressed by specific surface values · CPC title

• H01G4/1227

  based on alkaline earth titanates · CPC title

• C04B35/4682

  based on BaTiO3 perovskite phase · CPC title