Rare earth optical elements for LED lamp
View Patent ↗The present disclosure relates to optical elements and coatings comprising rare-earth element (REE) compounds for light wavelength attenuation of light emitting diode (LED) elements and lamps. More particularly, the present disclosure relates to LED elements and lamps comprising wavelength attenuating elements comprising REE compounds having at least a portion of non-crystalline, non-hydrate form, methods of preparing such elements, and LED elements, LED arrays, LED packages, optical elements, lamps and systems made with same.
1. A composition comprising a polymer matrix comprising at least one rare-earth element (REE) compound, at least an amount of the REE compound present in an amorphous or non-crystalline form, or present substantially without hydrate forms, the at least one REE compound has a melting point less than a decomposition temperature or a cure temperature of the polymer matrix.
2. The composition of claim 1 , further comprising a polymer matrix of one or more polysiloxanes, polycarbonates, poly(meth)acrylates, thermoplastics, thermoplastic elastomers, thermosets, or polyurethanes.
3. The composition of claim 1 , wherein the at least one REE compound comprises a REE selected from neodymium, didymium, dysprosium, erbium, holmium, praseodymium, and thulium.
4. The composition of claim 1 , wherein the at least one REE compound is a REE nitrate, phosphate, sulfate, halide, carbonate, alkoxide, or acetate.
5. The composition of claim 1 , wherein the at least one REE compound is a REE nitrate, phosphate, sulfate, halide, carbonate, alkoxide, or acetate with one or more waters of hydration removed.
6. The composition of claim 1 , further comprising one or more phosphors or diffusers.
7. The composition of claim 1 , wherein the at least one REE compound excludes REE oxides, REE silicates, REE aluminates, or crushed REE-doped glass particles.
8. The composition of claim 1 , the composition is integral with an LED encapsulant, an optical lens, a diffuser, or a reflector.
9. The composition of claim 1 , comprising a mixture of two or more REE compounds, at least an amount of one of the two or more REE compounds present in an amorphous, non-crystalline, or non-hydrate form within the polymer matrix; and at least an amount of one of the two or more REE compounds present in a crystalline form within the polymer matrix.
10. The composition of claim 9 , wherein at least an amount of one of the two or more REE compounds present in a crystalline form is a REE oxide, a REE silicate, a REE aluminate, or crushed REE-doped glass particles.
11. The composition of claim 1 , wherein the polymer matrix comprising the least one rare-earth element (REE) compound is disposed on or integral with a substrate.
12. The composition of claim 11 , wherein the substrate is an LED chip, an LED array, a portion of an LED package, an LED encapsulant, an optical lens, a diffuser, or a reflector.
13. The composition of claim 1 , wherein the composition is at least partially non-transparent to light between about 350 nm to about 850 nm.
14. The composition of claim 13 , wherein the composition is at least partially non-transparent to light between the wavelengths of 520 nm and 605 nm.
15. The composition of claim 13 , wherein the composition is at least partially non-transparent to light between the wavelengths of 565 nm and 600 nm.
16. The composition of claim 13 , wherein the composition is at least partially non-transparent to light between the wavelengths of 570 nm and 595 nm.
17. A method of preparing a composition, the method comprising:
combining at least one REE compound with a polymer matrix or one or more polymer matrix precursors, the at least one REE compound having a crystalline form or a hydrate form; and
heating the combination of the at least one REE compound and the polymer matrix or the at least one of the one or more polymer matrix precursors above a thermal transition temperature of the at least one REE compound;
and
obtaining the composition as defined in claim 1 .
18. The method of claim 17 , wherein the thermal transition temperature of the at least one REE compound is at least partial melting of the crystalline form.
19. The method of claim 17 , wherein the thermal transition temperature of the at least one REE compound is at least partial dehydration of the hydrate form.
20. The method of claim 17 , wherein the one or more polymer matrix precursors are substantially organic solvent-free.
21. The method of claim 17 , wherein the at least one REE compound is a REE nitrate, phosphate, sulfate, halide, carbonate, alkoxide, or acetate.
22. The method of claim 17 , wherein the heating step is performed under vacuum.
23. The method of claim 17 , wherein the composition is integral with a visible light transparent lens.
24. The method of claim 17 , further comprising contacting an LED, an LED array, a phosphor-coated LED, or reflector, diffuser, or enclosure with the combined at least one REE compound with the polymer matrix or the polymer matrix precursor before or after heating.
25. The method of claim 17 , wherein the one or more polymer matrix precursors comprises one or more curable oligomeric or polymeric polysilicones, polysiloxanes, or polyurethanes, or, the polymer matrix comprises one or more thermoplastics, thermoplastic elastomers, or thermosets.
26. The method of claim 25 , wherein the composition comprises one or more curable oligomeric siloxanes having alkenyl-containing functional groups and/or silicon hydride functional groups.
27. The method of claim 25 , wherein the composition further comprising a viscosity stabilizer in an amount sufficient to inhibit curing.
28. The method of claim 25 , wherein the composition comprises a curable thermoplastic polymer or thermoplastic elastomer having a durometer sufficient for forming an optical element when cured.