UV-protective compositions and their use

Patent metadata

Field	Value
Publication number	US-10675229-B2
Application number	US-201715714723-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Mar 24, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Disclosed are compositions comprising inorganic UV-absorbing agents and the use of such compositions, in particular for protecting a subject or the surface of an inanimate object against a harmful effect of ultraviolet radiation.

First claim

We claim:

1. A UV-protective composition comprising nanoparticles of at least one inorganic UV-absorbing agent selected from the group consisting of (i) barium titanate (BaTiO3) and (ii) bismuth vanadate (BiVO4); and a dispersant associated with said nanoparticles, wherein a weight ratio of said dispersant to said inorganic UV-absorbing agent is within a range of 1:2.5 to 2.5:1, and wherein said dispersant includes a neutralized polyacrylic acid;
wherein said inorganic UV-absorbing agent has a median particle diameter, on a particle number basis (DN50), of at most 80 nm;
wherein a critical wavelength of said inorganic UV-absorbing agent is within a range of 330 to 400 nm;
and wherein a UV absorbance selectivity is defined by
R AUC=100%·(AUC 280-400 )/(AUC 280-700 )

wherein:
RAUC is said UV absorbance selectivity;
AUC 280-400 is a UV-absorbance by the composition or by said inorganic UV-absorbing agent, over a wavelength range of 280 nm to 400 nm; and
AUC 280-700 is a UV-absorbance by the composition or by said inorganic UV-absorbing agent, over a wavelength range of 280 nm to 700 nm;
and wherein said UV absorbance selectivity of said inorganic UV-absorbing agent is at least 60%.

2. The UV-protective composition of claim 1 , wherein said UV absorbance selectivity of said inorganic UV-absorbing agent is at least 70%.

3. The UV-protective composition of claim 1 , wherein said UV absorbance selectivity of said inorganic UV-absorbing agent is at least 75%.

4. The UV-protective composition of claim 1 , wherein said inorganic UV-absorbing agent comprises said barium titanate, and wherein said UV absorbance selectivity of said barium titanate is at least 80%.

5. The UV-protective composition of claim 1 , wherein a polydispersity index (PDI) of said inorganic UV-absorbing agent is within a range of 0.13 to 0.30.

6. The UV-protective composition of claim 1 , wherein said D N 50 is within a range of 15 nm to 70 nm.

7. The UV-protective composition of claim 1 , wherein said D N 50 is within a range of 15 nm to 60 nm.

8. The UV-protective composition of claim 5 , wherein said D N 50 is within a range of 25 nm to 50 nm.

9. The UV-protective composition of claim 1 , wherein said inorganic UV-absorbing agent comprises said bismuth vanadate, and wherein said UV absorbance selectivity of said bismuth vanadate is at least 65%.

10. The UV-protective composition of claim 1 , wherein said inorganic UV-absorbing agent comprises said bismuth vanadate, and wherein said UV absorbance selectivity of said bismuth vanadate is at least 70%.

11. The UV-protective composition of claim 1 , wherein said weight ratio of said dispersant to said inorganic UV-absorbing agent is within a range of 1:2.0 to 2.0:1.

12. The UV-protective composition of claim 1 , wherein at least a portion of said dispersant at least partially envelops said inorganic UV-absorbing agent.

13. The UV-protective composition of claim 1 , wherein said critical wavelength of said inorganic UV-absorbing agent is at least 345 nm.

14. The UV-protective composition of claim 1 , wherein said critical wavelength of said inorganic UV-absorbing agent is at least 360 nm.

15. A UV-protective composition comprising nanoparticles of at least one inorganic UV-absorbing agent selected from the group consisting of (i) barium titanate (BaTiO3) and (ii) bismuth vanadate (BiVO4), and a dispersant associated with said nanoparticles, wherein a weight ratio of said dispersant to said inorganic UV-absorbing agent is within a range of 1:2.5 to 2.5:1, and wherein said dispersant includes a neutralized polyacrylic acid;
wherein said inorganic UV-absorbing agent has a median particle diameter, on a particle number basis (DN50), of at most 80 nm;
wherein a critical wavelength of said inorganic UV-absorbing agent is within a range of 330 to 400 nm;
wherein an area under the curve formed by UV-absorption of a particular one of said inorganic UV-absorbing agent, as a function of wavelength in a range of 280 nm to 400 nm (AUC 280-400 ), is at least 75% of the AUC formed by said particular one of said inorganic UV-absorbing agent, at the same concentration, in a range of 280 nm to 700 nm (AUC 280-700 ), and wherein an overall polydispersity index (PDI) of said inorganic UV-absorbing agent is within a range of 0.13 to 0.30.

16. The UV-protective composition of claim 15 , wherein a weight ratio of said dispersant to said inorganic UV-absorbing agent is within a range of 1:2 to 2:1.

17. A UV-protective composition comprising nanoparticles of an inorganic UV-absorbing agent selected from the group consisting of (i) barium titanate (BaTiO3) and (ii) bismuth vanadate (BiVO4), and a dispersant associated with said nanoparticles, wherein a weight ratio of said dispersant to said inorganic UV-absorbing agent is within a range of 1:2.5 to 2.5:1, and wherein said dispersant includes a neutralized polyacrylic acid;
wherein said inorganic UV-absorbing agent has a median particle diameter, on a particle number basis (DN 50 ), of at most 80 nm;
and wherein a critical wavelength of said inorganic UV-absorbing agent is within a range of 330 to 400 nm.

18. The UV-protective composition of claim 17 , wherein said weight ratio of said dispersant to said inorganic UV-absorbing agent is within a range of 1:2.0 to 2.0:1.

Assignees

• Landa Labs 2012 Ltd

Inventors

• Landa Benzion
• Abramovich Sagi
• Dor Snir

Classifications

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C08K3/22

  of metals · CPC title

• C08K2201/011

  Nanostructured additives · CPC title

• C01P2002/50

  Solid solutions · CPC title

• C01P2002/84

  by UV- or VIS- data · CPC title