Coating compositions, process and luminescent coated articles
View Patent ↗The invention is directed to a composition having a carrier matrix, and a particulate luminescent composition dispersed therein, the particulate luminescent composition comprising a rare-earth-doped solid-state solution of alkaline earth fluorides represented by the chemical formula RE x (Ca a Sr b Ba c ) 1−x F 2+x−2y O y wherein RE represents a three-valent rare-earth element, 0.005≦x≦0.20, and 0≦y≦0.2, a+b+c=1, with the proviso at least two of a, b, and c are not equal to zero; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths. It is further directed to a process by contacting a surface with the composition and articles made therefrom.
1. A composition comprising a carrier matrix, and a particulate luminescent composition dispersed therein, the particulate luminescent composition comprising a rare-earth-doped solid-state solution of alkaline earth fluorides represented by the chemical formula
RE x (Ca a Sr b Ba c ) 1−x F 2+x−2y O y
wherein RE represents a three-valent rare-earth element, 0.005≦x≦0.20, and 0≦y≦0.2, a+b+c=1, with the proviso at least two of a, b, and c are not equal to zero; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths.
2. The composition of claim 1 wherein at least one pair of the plurality of peaks exhibits an intensity ratio with respect to one another that differs by at least 5% from the corresponding peak intensity ratio of the corresponding reference composition.
3. The composition of claim 1 wherein RE is Eu +3 , Tb +3 or Er +3 .
4. The composition of claim 1 wherein c=0.
5. The composition of claim 1 wherein 0.01≦x≦0.10.
6. The composition of claim 2 wherein the intensity ratios differ by at least 10%.
7. The composition of claim 1 wherein the carrier matrix comprises a liquid.
8. The composition of claim 7 wherein the liquid is water.
9. The composition of claim 1 wherein the carrier matrix comprises a polymer.
10. The composition of claim 7 wherein the polymer is dissolved in the liquid.
11. The composition of claim 9 wherein the polymer is ethyl cellulose.
12. A process comprising contacting a surface with a composition comprising a carrier matrix, and a particulate luminescent composition dispersed therein, the particulate luminescent composition comprising a rare-earth-doped solid-state solution of alkaline earth fluorides represented by the chemical formula
RE x (Ca a Sr b Ba c ) 1−x F 2+x−2y O y
wherein RE represents a three-valent rare-earth element, 0.005≦x≦0.20, and 0≦y≦0.2, a+b+c=1, with the proviso at least two of a, b, and c are not equal to zero; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths.
13. The process of claim 12 wherein at least one pair of the plurality of peaks exhibits an intensity ratio with respect to one another that differs by at least 5% from the corresponding peak intensity ratio of the corresponding reference process.
14. The process of claim 12 wherein RE is Eu +3 , Tb +3 or Er +3 .
15. The process of claim 12 wherein c=0.
16. The process of claim 12 wherein 0.01≦x≦0.10.
17. The process of claim 13 wherein the intensity ratios differ by at least 10%.
18. The process of claim 13 wherein the carrier matrix comprises a liquid.
19. The process of claim 18 wherein the liquid is water.
20. The process of claim 13 wherein the carrier matrix comprises a polymer.
21. The process of claim 18 wherein the polymer is dissolved in the liquid.
22. The process of claim 20 wherein the polymer is ethyl cellulose.
23. The process of claim 12 wherein the contacting is effected by printing.
24. The process of claim 23 wherein the printing is selected from screen printing or ink jet printing.
25. An article having a surface, the surface having disposed upon it a coating comprising a particulate luminescent composition dispersed therein, the particulate luminescent composition comprising a rare-earth-doped solid-state solution of alkaline earth fluorides represented by the chemical formula
RE x (Ca a Sr b Ba c ) 1−x F 2+x−2y O y
wherein RE represents a three-valent rare-earth element, 0.005≦x≦0.20, and 0≦y≦0.2, a+b+c=1, with the proviso at least two of a, b, and c are not equal to zero; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths.
26. The article of claim 25 wherein at least one pair of the plurality of peaks exhibits an intensity ratio with respect to one another that differs by at least 5% from the corresponding peak intensity ratio of the corresponding reference composition.
27. The article of claim 25 wherein the coating composition further comprises a polymer.
28. The article of claim 25 wherein RE is Eu +3 , Tb +3 or Er +3 .
29. The article of claim 25 wherein c=0.
30. The article of 25 wherein 0.01≦x≦0.10.
31. The article of claim 26 wherein the intensity ratios differ by at least 10%.
32. The article of claim 27 wherein the polymer is ethyl cellulose.