Complex fluoride phosphor and method for producing same

Patent metadata

Field	Value
Publication number	US-10294418-B2
Application number	US-201515115326-A
Country	US
Kind code	B2
Filing date	Jan 15, 2015
Priority date	Jan 30, 2014
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

Provided is a method for producing a phosphor having a chemical composition represented by formula (I), A2MF6:Mn (I) (A is one type or more of an alkali metal selected from Li, Na, K, Rb, and Cs, and includes at least Na and/or K, and M is one type or more of a tetravalent element selected from Si, Ti, Zr, Hf, Ge, and Sn.), the method comprising preparing a first hydrofluoric acid solution containing M and a second hydrofluoric acid solution containing A as well as either dissolving a compound containing Mn in either the first hydrofluoric acid solution or the second hydrofluoric acid solution or preparing a separate solution in which the compound containing Mn is dissolved. When the solutions are mixed to precipitate the phosphor of the formula (I), the solutions are mixed so that the concentration of M is 0.1 to 0.5 mol/liter when all the solutions are mixed. According to the present invention, a complex fluoride phosphor having excellent luminescence properties can be produced stably with high yield.

First claim

The invention claimed is:

1. A method for producing a complex fluoride phosphor having a chemical composition of the formula (I):
A 2 MF 6 :Mn  (I)

wherein A is one or more alkali metal selected from the group consisting of lithium, sodium, potassium, rubidium and cesium, and includes at least sodium and/or potassium, and M is one or more tetravalent element selected from the group consisting of silicon, titanium, zirconium, hafnium, germanium and tin, the method comprising the steps of:
providing a first hydrofluoric acid solution which contains M and a second hydrofluoric acid solution which contains A,
dissolving a manganese-containing compound in either of the first hydrofluoric acid solution and the second hydrofluoric acid solution or separately preparing a solution in which a manganese-containing compound is dissolved, and
mixing together the solutions so as to precipitate the phosphor of formula (I) such that the concentration of M, when the solutions are completely mixed, is at least 0.1 mol/L and not more than 0.5 mol/L, wherein the amount of A when the solutions are completely mixed, expressed as a molar ratio with respect to the sum of M and manganese, is at least 2.8.

2. The production method of claim 1 , wherein a manganese-containing compound is dissolved in the M-containing first hydrofluoric acid solution, and the A-containing second hydrofluoric acid solution is added to the first solution.

3. The production method of claim 1 , wherein the amount of A when the solutions are completely mixed, expressed as a molar ratio with respect to the sum of M and manganese, is not more than 5.

4. The production method of claim 1 , wherein the proportion of hydrogen fluoride, when the solutions are completely mixed, is at least 20 wt % and not more than 60 wt % of the overall mixture.

5. The production method of claim 1 , wherein the phosphor of formula (I) has an emission intensity at 130° C. that is at least 90% of the emission intensity at 20° C.

Assignees

• Shinetsu Chemical Co

Inventors

• Kaneyoshi Masami
• Ishii Masatoshi

Classifications

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01G25/006

  Compounds containing zirconium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01G27/006

  Compounds containing hafnium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01P2002/54

  one element only · CPC title

• C09K11/617 Primary

  Silicates · CPC title