Particulate titanium dioxide

Patent metadata

Field	Value
Publication number	US-9682869-B2
Application number	US-201013515208-A
Country	US
Kind code	B2
Filing date	Dec 22, 2010
Priority date	Dec 23, 2009
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A particulate titanium dioxide has a median volume particle diameter of greater than 70 nm. The titanium dioxide can be produced by calcining precursor particles. The titanium dioxide has enhanced UVA efficacy. The particulate titanium dioxide can be used to form dispersions. The particulate titanium dioxide or dispersions can be used to produce sunscreen products having a UV protection which is at least one third of the label SPF value.

First claim

The invention claimed is:

1. A particulate titanium dioxide having:
i) an E524 of less than 9 l/g/cm, an E360 of 25 to 50 l/g/cm, and an E360/E308 ratio of 0.5 to 1.0;
ii) a median volume particle diameter of 85 to 175 nm, as measured by a particle sizer in centrifugation mode using X-ray detection;
iii) a BET specific surface area in a range from 22 to 40 m 2 g −1 ; and
iv) a mean aspect ratio of 1.2 to 2.0:1.

2. The titanium dioxide according to claim 1 wherein the median volume particle diameter is 100 to 160 nm.

3. The titanium dioxide according to claim 1 having a mean length of 30 to 75 nm and a mean aspect ratio of 1.3 to 1.8:1.

4. A dispersion comprising a dispersing medium and particulate titanium dioxide as defined in claim 1 .

5. The dispersion according to claim 4 comprising at least 30% by weight of the titanium dioxide particles.

6. The dispersion according to claim 4 , wherein the dispersing medium is an organic liquid.

7. A sunscreen product comprising the titanium dioxide particles as defined in claim 1 .

8. The sunscreen product of claim 7 , wherein the sunscreen product has an SPF/UVA PF ratio in a range from 1 to 5.

9. The sunscreen product of claim 7 , wherein the defined titanium dioxide particles are essentially the only ultraviolet light attenuator present.

10. A sunscreen product comprising the dispersion of claim 4 .

11. The sunscreen product of claim 10 , wherein the sunscreen product has an SPF/UVA PF ratio in a range from 1 to 5.

12. The sunscreen product of claim 10 , wherein the defined titanium dioxide particles are essentially the only ultraviolet light attenuator present.

13. A particulate titanium dioxide having:
i) an E524 of less than 9 l/g/cm, an E360 of 25 to 50 l/g/cm, and an E360/E308 ratio of 0.5 to 1.0;
ii) a median volume particle diameter of 115 to 150 nm, as measured by a particle sizer in centrifugation mode using X-ray detection;
iii) a BET specific surface area in a range from 22 to 40 m 2 g −1 ; and
iv) a mean aspect ratio of 1.2 to 2.0:1.

14. A particulate titanium dioxide having:
i) an E524 of less than 9 l/g/cm, an E360 of 25 to 50 l/g/cm, and an E360/E308 ratio of 0.5 to 1.0;
ii) a median volume particle diameter of 125 to 140 nm, as measured by a particle sizer in centrifugation mode using X-ray detection;
iii) a BET specific surface area in a range from 22 to 40 m 2 g −1 ; and
iv) a mean aspect ratio of 1.2 to 2.0:1.

15. The titanium dioxide according to claim 2 having a mean length of 30 to 75 nm and a mean aspect ratio of 1.3 to 1.8:1.

16. The titanium dioxide according to claim 13 having a mean length of 30 to 75 nm and a mean aspect ratio of 1.3 to 1.8:1.

17. The titanium dioxide according to claim 14 having a mean length of 30 to 75 nm and mean aspect ratio of 1.3 to 1.8:1.

18. The titanium dioxide according to claim 1 having a mean aspect ratio of 1.4 to 1.6:1.

19. The titanium dioxide according to claim 2 having a mean aspect ratio of 1.4 to 1.6:1.

20. The titanium dioxide according to claim 13 having a mean aspect ratio of 1.4 to 1.6:1.

21. The titanium dioxide according to claim 14 having a mean aspect ratio of 1.4 to 1.6:1.

Assignees

• Tooley Ian Robert
• Sayer Robert Michael
• Staniland Paul Martin
• Croda Int Plc

Inventors

• Tooley Ian Robert
• Sayer Robert Michael
• Staniland Paul Martin

Classifications

• C01P2004/54

  Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension · CPC title

• A61Q17/04

  Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations · CPC title

• A61K8/29

  Titanium; Compounds thereof · CPC title

• A61K8/0241

  Containing particulates characterized by their shape and/or structure (see also A61K8/04, A61K8/11, and A61K8/14, further aspects are classified in A61K2800/40 and subcodes) · CPC title

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title