Processes for preparing color stable manganese-doped complex fluoride phosphors

Patent metadata

Field	Value
Publication number	US-9388336-B2
Application number	US-201414568396-A
Country	US
Kind code	B2
Filing date	Dec 12, 2014
Priority date	Dec 13, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A process for preparing a color stable Mn 4+ doped complex fluoride phosphor of formula I includes

A x (M (1−m) , Mn m )F y   (I)

contacting a first aqueous HF solution comprising (1−m) parts of a compound of formula H x MF y , and a second aqueous HF solution comprising m*n parts of a compound of formula A x [MnF y ], with a third aqueous HF solution comprising (1−n) parts of the compound of formula A x [MnF y ] and a compound of formula A a X, to yield a precipitate comprising the color stable Mn 4+ doped complex fluoride phosphor;
wherein
A is Li, Na, K, Rb, Cs, NR 4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; X is an anion; a is the absolute value of the charge of the X anion; x is the absolute value of the charge of the [MF y ] ion; y is 5, 6 or 7; 0<m≦0.05; 0.1≦n≦1.

First claim

The invention claimed is:

1. A process for preparing a color stable Mn 4+ doped complex fluoride of formula I,
A x (M (1−m) , Mn m )F y   (I)

the process comprising contacting a first aqueous HF solution comprising (1−m) parts of a compound of formula H x MF y , and
a second aqueous HF solution comprising m*n parts of a compound of formula A x [MnF y ], with a third aqueous HF solution comprising (1−n) parts of the compound of formula A x [MnF y ] and a compound of formula A a X,
to yield a precipitate comprising the color stable Mn 4+ doped complex fluoride;
wherein
A is Li, Na, K, Rb, Cs, NR 4 or a combination thereof;
M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof;
R is H, lower alkyl, or a combination thereof;
X is an anion;
a is the absolute value of the charge of the X anion;
x is the absolute value of the charge of the [MF y ] ion;
y is 5, 6 or 7;
0<m≦0.05;
0.1≦n≦1.

2. A process according to claim 1 , wherein n ranges from 0.25 to 0.95.

3. A process according to claim 1 , wherein n ranges from 0.5 to 0.9.

4. A process according to claim 1 , wherein n ranges from 0.6 to 0.8.

5. A process according to claim 1 , wherein n is about 0.7.

6. A process according to claim 1 , wherein the Mn 4+ doped complex fluoride of formula I is K 2 (Si (1−m) , Mn m )F 6 .

7. A process according to claim 1 , wherein the salt of formula A a X is selected from KF, KHF 2 , and combinations thereof.

8. A process according to claim 1 , wherein the first and second aqueous HF solutions are added gradually to the third solution.

9. A process according to claim 1 , additionally comprising precipitating the compound of formula A x MnF y from a concentrated aqueous HF solution, and isolating the precipitate, prior to the contacting step.

10. An LED lighting apparatus comprising a complex fluoride prepared by the process of claim 1 .

11. An LED lighting apparatus comprising an LED chip; and a complex fluoride prepared by the process of claim 1 , disposed on a surface of the LED chip.

12. A process for preparing a color stable Mn 4+ , doped complex fluoride phosphor of formula K 2 (Si (1−m) , Mn m )F 6 ,the process comprising
contacting a first aqueous HF solution comprising (1−m) parts of a compound of formula H 2 SiF 6 ,and
a second aqueous HF solution comprising m*n parts of a compound of formula K 2 MnF 6 , with a third aqueous HF solution comprising (1−n) parts of the compound of formula K 2 MnF 6 and a compound selected from KF, KHF 2 , and combinations thereof;
to yield a precipitate comprising the color stable Mn 4+ , doped complex fluoride,
wherein
0<m≦0.08; and
0.1≦n≦1.

13. A process according to claim 1 , wherein n ranges from 0.6 to 0.8.

14. A process according to claim 1 , additionally comprising, prior to the gradual addition step, precipitating the compound of formula K 2 (Si (1−m) , Mn m )F 6 from a concentrate aqueous HF solution, and isolating the precipitate.

Assignees

• Gen Electric

Inventors

• Murphy James Edward
• Beers William Winder
• Lyons Robert Joseph
• Du Fangming

Classifications

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• C09K11/616 Primary

  with alkali or alkaline earth metals · CPC title

• Y02B20/00

  Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps · CPC title

• H10H20/8515

  not being in contact with the bodies · CPC title