Granted Patent B2

US 9,546,318 · App. 14/267,449 · Granted Jan 17, 2017

Abstract

Claims (41)

1. A process for preparing a Mn 4+ doped phosphor of formula I,

A x [MF y ]:Mn +4    I

the process comprising contacting a mixture of a compound of formula A x [MF y ], a compound of formula AX, and a Mn +n source comprising a fluoromanganese compound, with a fluorine-containing oxidizing agent in gaseous form, at an elevated temperature, to form the Mn 4+ doped phosphor; wherein

A is Li, Na, K, Rb, Cs, 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;

X is F, Cl, Br, I, HF 2 , or a combination thereof;

x is 1, 2, or 3, and is equal to the absolute value of the charge of the [MF y ] ion;

y is 5, 6 or 7; and

n is 2, 3, or 4.

2. A process according to claim 1 , wherein the Mn 4+ doped phosphor is K 2 SiF 6 :Mn 4+ .

3. A process according to claim 1 , wherein the compound of formula A x [MF y ] is K 2 SiF 6 .

4. A process according to claim 1 , wherein the compound of formula AX is KF, KHF 2 , or a combination thereof.

5. A process according to claim 1 , wherein the Mn +n source is selected from K 2 MnF 6 , K 2 MnF 5 .H 2 O, KMnF 4 , K 2 MnF 4 , KMnF 3 , MnF 2 , MnF 3 , MnF 4 , and combinations thereof.

6. A process according to claim 1 , wherein the Mn +n source is K 2 MnF 6 , MnF 2 , MnF 3 , or a combination thereof.

7. A process according to claim 1 , wherein the fluorine-containing oxidizing agent is F 2 .

8. A process according to claim 1 , additionally comprising treating the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid, after contacting with the fluorine-containing oxidizing agent

A x [MF y ]   II.

9. A process for preparing a Mn 4+ doped phosphor, the process comprising contacting a mixture of a host compound of the phosphor, a compound of formula AX or EX 2 , and a Mn +n source comprising a fluoromanganese compound; with a fluorine-containing oxidizing agent in gaseous form, at an elevated temperature, to form the Mn 4+ doped phosphor;

wherein the host compound is selected from the group consisting of

(a) A 2 [MF 5 ], where M is selected from Al, Ga, In, and combinations thereof;

(b) A 3 [MF 6 ], where M is selected from Al, Ga, In, and combinations thereof;

(c) Zn 2 [MF 7 ], where M is selected from Al, Ga, In, and combinations thereof;

(d) A[In 2 F 7 ];

(e) A 2 [MF 6 ], where M is selected from Ge, Si, Sn, Ti, Zr, and combinations thereof;

(f) E[MF 6 ], where E is selected from Mg, Ca, Sr, Ba, Zn, and combinations thereof; and where M is selected from Ge, Si, Sn, Ti, Zr, and combinations thereof;

(g) Ba 0.65 Zr 0.35 F 2.70 ; and

(h) A 3 [ZrF 7 ]; and combinations thereof in solid solution;

A is Li, Na, K, Rb, Cs, or a combination thereof.

10. A process according to claim 9 , wherein the fluorine-containing oxidizing agent is F 2 .

11. A process for preparing a Mn 4+ doped phosphor of formula I,

A x [MF y ]:Mn +4    I

the process comprising contacting a mixture of a phosphor precursor and a flux compound selected from compounds of formula AX, EX 2 , MF 2 , or MF 3 , or a combination thereof, with a fluorine-containing oxidizing agent in gaseous form at an elevated temperature, to form the Mn 4+ doped phosphor;

wherein

A is Li, Na, K, Rb, Cs, or a combination thereof;

E is Mg, Ca, Sr, Ba, Zn, and combinations thereof;

M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof;

X is F, CI, Br, I, HF 2 ,or a combination thereof;

x is 1, 2, or 3, and is equal to the absolute value of the charge of the [MF y ] ion; and

y is 5, 6 or 7.

12. A process according to claim 11 , wherein the flux compound is of formula AX.

13. A process according to claim 12 , wherein the compound of formula AX is KF, KHF 2 , or a combination thereof.

Assignments (10)