Titanium hydroxide and photocatalytic coating agent

• US 6,645,460 B2
• Filed: 03/29/2001
• Issued: 11/11/2003
• Est. Priority Date: 05/24/2000
• Status: Expired due to Fees

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Ando, Hiroyuki, Sakatani, Yoshiaki, Koike, Hironobu
• Primary Examiner(s): Silverman, Stanley S.
• Assistant Examiner(s): Johnson, Edward M.
• Application Number:
  US09/820,363
• Publication Number:
  US 20010056037A1
• Time in Patent Office: 957 Days
• Field of Search: 423/384, 423/608, 423/610, 502/350
• US Class Current: 423/608
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 37/031 Precipitation
• CPC Class Codes: C01G 23/04 Oxides; Hydroxides
• CPC Class Codes: C01G 23/053 Producing by wet processes, e.g. hydrolysing titanium salts
• CPC Class Codes: C01P 2002/70 defined by measured X-ray, neutron or electron diffraction data

Abstract

There is provided a titanium hydroxide having a nitrogen content of 2.3% by weight or more in terms of nitrogen atom based on the titanium hydroxide and/or having a nitrogen content of about 3.3% by weight or more in terms of nitrogen atom based on the titanium oxide obtained after calcining the titanium hydroxide in air at about 400° C. The titanium hydroxide may be utilized as a raw material for producing a photocatalyst which exhibits a superior photocatalytic activity by irradiation of visible light.

Claims

1. A titanium hydroxide having a nitrogen content of 2.3% by weight or more in terms of nitrogen atom based on the titanium hydroxide and/or having a nitrogen content of about 3.3% by weight or more in terms of nitrogen atom based on the titanium oxide obtained after calcining the titanium hydroxide in air at about 400°

C.

2. A titanium hydroxide according to claim 1, which has (i) an X-ray photoelectron spectrum which has a peak at a binding energy within the range of from 458 eV to 460 eV and (ii) an index X₁ calculated by the equation below of about 0.76 or more,

3. A titanium hydroxide according to claim 1 or 2, which has an amorphous phase.

5. A photocatalyst produced by calcining a titanium hydroxide according to claim 1 or 2.

6. A photocatalytic coating agent comprising a titanium hydroxide according to claim 1 or 2 and a solvent.

4. A process for producing a titanium hydroxide having a nitrogen content of 2.3% by weight or more in terms of nitrogen atom based on the titanium hydroxide and/or having a nitrogen content of about 3.3% by weight or more in terms of nitrogen atom based on the titanium oxide obtained after calcining the titanium hydroxide in air at about 400°

C., which comprises the step of adding an ammonia solution or an ammonium compound into an aqueous solution of titanium compound.