Luminescent material particles comprising a coating and lighting unit comprising such luminescent material

Patent metadata

Field	Value
Publication number	US-9334442-B2
Application number	US-201214127812-A
Country	US
Kind code	B2
Filing date	Jun 25, 2012
Priority date	Jun 29, 2011
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

The invention provides a a luminescent material comprising particles of UV-luminescent material having a coating, wherein the coating (a “multi-layer coating”) comprises a first coating layer and a second coating layer, wherein the first coating layer is between the luminescent material and the second coating layer, and wherein in a specific embodiment the second coating layer comprises an alkaline earth oxide, especially MgO. Further, the invention provides a lighting unit comprising such luminescent material.

First claim

The invention claimed is:

1. A luminescent material comprising:
a plurality of particles of an UV-luminescent material, the UV-luminescent material having a core of the UV-luminescent material, and a coating,
wherein the coating comprises a first coating layer and a second coating layer,
wherein the first coating layer is between the core and the second coating layer,
wherein the second coating layer comprises one or more alkaline earth oxides selected from the group consisting of: (Mg,Ca)O, (Ca,Sr) 3 Al 2 O 6 , (Mg,Ca,Sr)Al 2 O 4 , (Ca,Sr) 4 Al 14 O 25 , (Ca,Sr)Al 4 O 7 , (Ca,Sr)Al 12 O 19 , LaMgAl 11 O 19 , (Ba,Sr)MgAl 10 O 17 , and (Ba,Sr)Mg 3 Al 14 O 25 , and
wherein the second coating layer has extending structures.

2. The luminescent material according to claim 1 , wherein the second coating layer comprises an alkaline earth oxide having the formula:
(Mg x Ca 1-x )O,
wherein x=0.0-1.0.

3. The luminescent material according to claim 1 , wherein the second coating layer comprises MgO.

4. The luminescent material according to claim 1 , wherein the first coating layer comprises one or more materials selected from the group consisting of: Al 2 O 3 (α, γ, θ, δ-phase), Ln 2 O 3 (Ln=La, Y, Lu, or a combination thereof), LnPO 4 (Ln=La, Y, Lu, or a combination thereof), SiO 2 , Al 2 SiO 5 , Mg 2 SiO 4 , (Ca,Sr,Ba)-polyphosphate, (Mg,Ca) 2 P 2 O 7 , and ZrO 2 .

5. The luminescent material according to claim 1 , wherein the first coating layer comprises Al 2 O 3 .

6. The luminescent material according to claim 1 , wherein the UV-luminescent material comprises a luminescent material excitable by UV light of a dielectric barrier noble gas excimer discharge.

7. The luminescent material according to claim 1 , wherein the UV-luminescent material comprises one or more luminescent materials selected from the group consisting of:
K(Y 1-x Lu x ) 3 F 10 :A (A=Ce, Pr, Nd, Gd, Bi, or a combination thereof),
(Y 1-x-y La x Lu y )F 3 :A (A=Ce, Pr, Nd, Gd, or a combination thereof),
(Y 1-x-y La x Lu y )PO 4 :A (A=Ce, Pr, Nd, Gd, Bi, or a combination thereof),
(Y 1-x-y La x Lu y )BO 3 :A (A=Ce, Pr, Nd, Gd, Bi, or a combination thereof),
(Ca 1-x Sr x )Li 2 SiO 4 :PrNa,
(Ca 1-x Sr x )Li 2 SiO 4 :CeNa,
(Y 1-x-y Lu x La y )AlO 3 :A (A=Pr, Gd, or a combination thereof),
LaMgAl 11 O 19 :A (A=Ce, Pr, Nd, Gd, Bi, or a combination thereof),
(Ba,Sr) 2 SiO 4 :Pr,Na,
(Ca 1-x Sr x )Al 12 O 19 :PrNa,
(Ca 1-x Sr x ) 4 Al 24 O 25 :PrNa,
(Y 1-x-y La x Lu y ) 2 SiO 5 :A (A=Ce, Pr, Gd, Nd, Bi, or a combination thereof),
(Y 1-x-y La x L y ) 2 Si 2 O 7 :A (A=Ce, Pr, Nd, Gd, Bi, or a combination thereof),
(Y 1-x Lu x ) 3 Al 5-a Ga a O 12 :A (A=Pr, Gd, Bi, or a combination thereof),
(Ba 1-x Sr x )MgAl 10 O 17 :CeNa,
Sr 2 MgSi 2 O 7 :Pb,
Sr 2 MgSi 2 O 7 :PrNa,
BaSi 2 O 5 :Pb,
LaB 3 O 6 :A (A=Pr, Gd, Bi, or a combination thereof),
SrAl 12 O 19 :CeNa, GdMgB 5 O 10 :A (A=Ce, Pr, or a combination thereof),
CaF 2 :CeNa, LaCl 3 :A (A=Ce, Pr, Gd, or a combination thereof),
SrCl 2 :CeNa, and
SrB 4 O 7 :Eu,
wherein x, y and A are each independently selected, and x=0.0-1.0, y=0.0-1.0, and x+y≦1.

8. The luminescent material according to claim 1 , wherein the UV-luminescent material comprises YPO 4 :Bi 3+ .

9. The luminescent material according to claim 1 , having a coating thickness of the multi-layer coating in the range of 2-800 nm.

10. A lighting unit comprising a light source configured to generate UV light and the luminescent material according to claim 1 .

11. The lighting unit according to claim 10 , wherein the lighting unit comprises a dielectric barrier noble gas excimer discharge lamp as light source.

12. The luminescent material according to claim 3 , wherein the second coating layer exhibits a flake-like structure.

13. The luminescent material according to claim 1 , wherein the first coating layer comprises one or more materials selected from the group consisting of Al 2 O 3 (α, γ, θ, δ-phase), Ln 2 O 3 (Ln=La, Y, Lu, or a combination thereof), LnPO 4 (Ln=La, Y, Lu, or a combination thereof), SiO 2 , Al 2 SiO 5 , Mg 2 SiO 4 , (Ca,Sr,Ba)-polyphosphate, (Mg,Ca) 2 P 2 O 7 , or ZrO 2 , and wherein the alkaline earth oxide comprise (Mg x Ca 1-x )O, with x=0.0-1.0.

Assignees

• Greuel Georg
• Juestel Thomas
• Kuc Jagoda Magdalena
• Koninkl Philips Nv

Inventors

• Greuel Georg
• Juestel Thomas
• Kuc Jagoda Magdalena

Classifications

• C09K11/772

  with alkali or alkaline earth metals · CPC title

• C09K11/778

  Borates · CPC title

• C09K11/7713

  Sulfates · CPC title

• C09K11/7701

  Chalogenides · CPC title

• C09K11/7741

  Sulfates · CPC title