Coatable compositions, coatings prepared therefrom, 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 alkaline earth fluoride represented by the formula RE x A 1−x F 2+x−2y O y wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002≦x≦0.20, and 0≦y≦x; 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 alkaline earth fluoride represented by the formula
RE x A 1−x F 2+x−2y O y
wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002≦x≦0.20, and 0≦y≦x; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths, wherein at least one pair of the intensity peaks at different wavelengths in the luminescence spectrum of the particulate luminescent compound exhibits a peak intensity ratio that is at least 5% greater than the corresponding peak intensity ratio of a corresponding first reference composition, and that is also at least 5% less than the corresponding peak intensity ratio of a corresponding second reference composition wherein the first corresponding reference composition has not been exposed to a temperature above 100° C. and the second corresponding reference composition has been subject to heating to 900° C. for 6 hours.
2. The composition of claim 1 wherein RE is selected from Eu +3 , Tb +3 or Er +3 .
3. The composition of claim 1 wherein A is selected from Sr +2 , Ca +2 , or Ba +2 .
4. The composition of claim 1 wherein 0.01≦x≦0.10.
5. The composition of claim 1 wherein the intensity ratios differ by at least 10%.
6. The composition of claim 1 wherein the carrier matrix comprises a liquid.
7. The composition of claim 6 wherein the liquid is water.
8. The composition of claim 1 wherein the carrier matrix comprises a polymer.
9. The composition of claim 8 wherein the polymer is dissolved in the liquid.
10. The composition of claim 8 wherein the polymer is ethyl cellulose.
11. 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 alkaline earth fluoride represented by the formula
RE x A 1−x F 2+x−2y O y
wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002≦x≦0.20, and 0≦y≦x; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths, wherein at least one pair of the intensity peaks at different wavelengths in the luminescence spectrum of the particulate luminescent compound exhibits a peak intensity ratio that is at least 5% greater than the corresponding peak intensity ratio of a corresponding first reference composition, and that is also at least 5% less than the corresponding peak intensity ratio of a corresponding second reference composition wherein the first corresponding reference composition has not been exposed to a temperature above 100° C. and the second corresponding reference composition has been subject to heating to 900° C. for 6 hours.
12. The process of claim 11 wherein RE is selected from Eu +3 , Tb +3 or Er +3 .
13. The process of claim 11 wherein A is selected from Sr +2 , Ca +2 , or Ba +2 .
14. The process of claim 11 wherein 0.01≦x≦0.10.
15. The process of claim 11 wherein the intensity ratios differ by at least 10%.
16. The process of claim 11 wherein the carrier matrix comprises a liquid.
17. The process of claim 16 wherein the liquid is water.
18. The process of claim 11 wherein the carrier matrix comprises a polymer.
19. The process of claim 18 wherein the polymer is dissolved in the liquid.
20. The process of claim 18 wherein the polymer is ethyl cellulose.
21. The process of claim 11 wherein the contacting is effected by printing.
22. The process of claim 21 wherein the printing is screen printing.
23. The process of claim 21 wherein the printing is ink jet printing.
24. 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 alkaline earth fluoride represented by the formula
RE x A 1−x F 2+x−2y O y
wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002≦x≦0.20, and 0≦y≦x; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths, wherein at least one pair of the intensity peaks at different wavelengths in the luminescence spectrum of the particulate luminescent compound exhibits a peak intensity ratio that is at least 5% greater than the corresponding peak intensity ratio of a corresponding first reference composition, and that is also at least 5% less than the corresponding peak intensity ratio of a corresponding second reference composition wherein the first corresponding reference composition has not been exposed to a temperature above 100° C. and the second corresponding reference composition has been subject to heating to 900° C. for 6 hours.
25. The article of claim 24 wherein the coating composition comprises a polymer.
26. The article of claim 24 wherein RE is selected from Eu +3 , Tb +3 or Er +3 .
27. The article of claim 24 wherein A is selected from Sr +2 , Ca +2 , or Ba +2 .
28. The article of claim 24 wherein 0.01≦x≦0.10.
29. The article of claim 24 wherein the intensity ratios differ by at least 10%.
30. The article of claim 25 wherein the polymer is ethyl cellulose.