Divalent europium-activated barium fluorohalide phosphor

Claim 2

A divalent europium activated barium fluorohalide phosphor having the formula (I): in which X is at least one halogen selected from the group consisting of Cl, Br and I; A is at least one fired product of a hexafluoro compound selected from the group consisting of monovalent and divalent metal salts of hexafluoro silicic acid, hexafluoro titanic acid and hexafluoro zirconic acid; and x and y are numbers satisfying the conditions of 10 -6 ≦ x ≦ 0.1 and 0 < y ≦ 0.1, respectively.

Claim 3

The phosphor as claimed in Claim 1, in which x and y are numbers satisfying the conditions of 10 -4 ≦ x ≦ 10 and 10 -5 ≦ y ≦ 10 -2 , respectively.

Claim 4

The phosphor as claimed in Claim 1, in which the metal constituting the said monovalent or divalent metal salt is at least one metal selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Zn and Mn.

Claim 5

The phosphor as claimed in Claim 1, in which A in the formula (I) is at least one fired product of a metal salt having the formula (II) in which a is 2 or 1; M is an alkali metal selected from the group consisting of Li, Na, K, Rb and Cs, in the case of a= 2 ; and M is a divalent metal selected from the group consisting of Mg, Ca, Sr, Ba, Zn and Mn, in the case of a=l.

Claim 6

The phosphor as claimed in Claim 4, in'which a in the formula (II) is 2 and M is an alkali metal selected from the group consisting of Li, Na, K, Rb and Cs.

Claim 7

The phosphor as claimed in Claim 1, in which A in the formula (I) is at least one fired product of a metal salt having the formula (III): in which Q is Z r or Ti; and M is an alkali metal selected from the group consisting of Li, Na, K, Rb and Cs.

Claim 8

A process for the preparation of a divalent europium activated barium fluorohalide phosphor having. the formula (I): in which X is at least one halogen selected from the group consisting of Cl, Br and I; A is at least one fired product of a hexafluoro compound selected from the group consisting of monovalent and divalent metal salts of hexafluoro silicic acid, hexafluoro titanic acid and hexafluoro zirconic acid; and x and y are numbers satisfying the conditions of 10 -6 ≦ x ≦ 0.1 and 0 <y≦0.1, respectively, which comprises; mixing raw materials for the preparation of a phosphor in a stoichiometric ratio corresponding to the formula (IV): in which X and y have the same meanings as defined above; adding to the resulting mixture at least one hexafluoro compound selected from the group consisting of monovalent and divalent metal salts of hexafluoro silicic acid, hexafluoro titanic acid and hexafluoro zirconic acid, in the amount of x mol for 1 gram atom of barium contained in the mixture; and firing the so obtained mixture.

Claim 9

A process for the preparation of a divalent europium activated barium fluorohalide phosphor having. the formula (I): in which X is at least one halogen selected from the group consisting of Cl, Br and I; A is at least one fired product of a hexafluoro compound selected from the group consisting of monovalent and divalent metal salts of hexafluoro silicic acid, hexafluoro titanic acid and hexafluoro zirconic acid; and x and y are numbers satisfying the conditions of 10 -6 ≦ x ≦ 0.1 and 0 <y≦0.1, respectively, which comprises; mixing raw materials for the preparation of a phosphor in a stoichiometric ratio corresponding to the formula (IV): in which X and y have the same meanings as defined above; adding to the resulting mixture at least one hexafluoro compound selected from the group consisting of monovalent and divalent metal salts of hexafluoro silicic acid, hexafluoro titanic acid and hexafluoro zirconic acid, in the amount of x mol for 1 gram atom of barium contained in the mixture; and firing the so obtained mixture.