Encapsulated quantum dots in porous particles

• US 10,030,851 B2
• Filed: 03/19/2014
• Issued: 07/24/2018
• Est. Priority Date: 03/20/2013
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Inventors: Koole, Roelof, Bohmer, Marcel Rene, Kriege, Jan Cornelis, Verhoeckx, Godefridus Johannes, Offermans, Paulus Hubertus Gerardus, Baesjou, Patrick John, Keur, Wilhelmus Cornelis, Cillessen, Johannes Franciscus Maria, Verstegen, Emile Johannes Karel, De Laat, Antonius Wilhelmus Maria
• Primary Examiner(s): Leong, Nathan T
• Application Number:
  US14/763,886
• Publication Number:
  US 20160084476A1
• Time in Patent Office: 1,588 Days
• Field of Search: None
• CPC Class Codes: B05D 1/18 performed by dipping
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/08 containing inorganic luminescent materials
• CPC Class Codes: C23C 16/403 of aluminium, magnesium or beryllium
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 7/30 the coatings comprising photoluminescent substances
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

The invention provides a process for the production of a (particulate) luminescent material comprising particles, especially substantially spherical particles, having a porous inorganic material core with pores, especially macro pores, which are at least partly filled with a polymeric material with luminescent quantum dots embedded therein, wherein the process comprises (i) impregnating the particles of a particulate porous inorganic material with pores with a first liquid (“ink”) comprising the luminescent quantum dots and a curable or polymerizable precursor of the polymeric material, to provide pores that are at least partly filled with said luminescent quantum dots and curable or polymerizable precursor; and (ii) curing or polymerizing the curable or polymerizable precursor within pores of the porous material, as well as a product obtainable thereby.

Claims

1. A process for the production of a luminescent material, the luminescent material comprising particles having a porous inorganic material core with pores which are at least partly filled with a polymeric material with luminescent quantum dots embedded therein, the process comprising:

impregnating the particles of the particulate porous inorganic material with a first liquid comprising the luminescent quantum dots and a curable or polymerizable precursor of the polymeric material, to provide pores that are at least partly filled with said luminescent quantum dots and curable or polymerizable precursor; and

curing or polymerizing the curable or polymerizable precursor within pores of the porous material.

2. The process according to claim 1, wherein before curing or polymerizing but after impregnating the particles, the impregnated particles and first liquid are separated.

3. The process according to claim 1, wherein the pores of the porous inorganic material are hydrophobized.

4. The process according to claim 1, wherein the particles have particle sizes in the range of 1-500 μ

m.

5. The process according to claim 1, wherein the process further comprises applying an encapsulation to the particles obtained after curing or polymerizing.

6. The process according to claim 5, wherein the process further comprises providing the encapsulation by at least partly coating the particles with an inorganic coating selected from the group consisting of a silicon containing oxide, an aluminum containing oxide, a zirconium containing oxide, a glass, a titanium containing oxide, a hafnium containing oxide and an yttrium containing oxide.

7. The process according to claim 5, wherein the process further comprises providing the encapsulation by multi-layer coating the particles, wherein the thus obtained multi-layer coating comprises an organic polymer coating and an inorganic coating, or at least two coatings selected from the group consisting of a silicon containing oxide, an aluminum containing oxide, a zirconium containing oxide, a glass, a titanium containing oxide, a hafnium containing oxide and an yttrium containing oxide.

8. The process according to claim 5, wherein the process further comprises providing the encapsulation by at least partly coating the particles by atomic layer deposition.

9. The process according to claim 5, wherein the process further comprises one or more of providing the encapsulation by embedding the particles in a light transmissive solid matrix, or providing the encapsulation by at least partly coating the particles and subsequently embedding the particles in a light transmissive solid matrix.

10. The process according to claim 1, wherein the porous inorganic material comprises porous silica.

11. The process according to claim 1, wherein the porous inorganic material comprises porous alumina.

12. The process according to claim 1, wherein the porous inorganic material comprises porous glass.

13. The process according to claim 1, wherein the porous inorganic material comprises porous zirconia.

14. The process according to claim 1, wherein the porous inorganic material comprises porous titania.

15. The process according to claim 1, wherein the pores have mean pore sizes in the range of 0.1-10 μ

m.

16. The process according to claim 1, wherein the precursor comprises a curable acrylate.

17. The process according to claim 1, wherein the precursor comprises silicone.