Silicon nitride powder for siliconnitride phosphor, CaAlSiN;phosphor using same, Sr;Si;N;phosphor using same, (Sr, Ca)AlSiN;phosphor using same, La;Si;N;Phosphor using same, and methods for producing the phosphors

• US 9,023,240 B2
• Filed: 07/29/2011
• Issued: 05/05/2015
• Est. Priority Date: 08/04/2010
• Status: Active Grant

• Current Assignee: UBE Industries Limited
• Original Assignee: UBE Industries Limited
• Inventors: Fujinaga, Masataka, Ueda, Takayuki, Sakai, Takuma, Jida, Shinsuke
• Primary Examiner(s): Koslow, Carol M
• Assistant Examiner(s): EDMONDSON, LYNNE RENEE
• Application Number:
  US13/813,596
• Publication Number:
  US 20130140490A1
• Time in Patent Office: 1,376 Days
• Field of Search: 252/301.4 F, 252/301.4 R, 252/301.6 F, 428/325, 428/402, 428/698, 428/704
• US Class Current: 252/301.4F
• CPC Class Codes: C01B 21/0602 with two or more other elements chosen from metals, silicon or boron
• CPC Class Codes: C01B 21/068 with silicon
• CPC Class Codes: C01P 2002/54 one element only
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/77747 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

Provided are a crystalline silicon nitride powder for a siliconitride phosphors, which is used as a starting material for producing a siliconitride phosphor containing a silicon element and a nitrogen element but no oxygen element as a constitutent element, an oxygen content of the silicon nitride phosphor being 0.2-0.8 wt %; a CaAlSiN₃ phosphor, an Sr₂Si₅N₈ phosphor, an (Sr, Ca)AlSiN₃ phosphor and an La₃Si₆N₁₁ phosphor, each using the silicon nitride powder; and a method for producing the phosphors.

Claims

1. A crystalline silicon nitride powder for siliconitride phosphors, which consists of an α

-type crystalline silicon nitride powder and is used as a raw material for producing a siliconitride phosphor comprising a silicon element and a nitrogen element but no oxygen element as a constituent element, an oxygen content of said silicon nitride powder being 0.2% by weight to 0.8% by weight, wherein the silicon nitride powder has an average particle diameter of 3 μ

m to 12 μ

m, a specific surface area of 0.2 to 1.0 m²/g.

6. The crystalline silicon nitride powder for siliconitride phosphors according to claim 1, which is produced by a method comprising calcining an amorphous silicon nitride powder.

2. A method for producing a CaAlSiN₃ phosphor by using as a raw material a crystalline silicon nitride powder for the siliconitride phosphors comprising a silicon element and a nitrogen element but no oxygen element as a constituent element, an oxygen content of said silicon nitride powder being 0.2 by weight to 0.8% by weight, wherein the silicon nitride powder has an average particle diameter of 1.0 to 12 μ

m, and a specific surface area of 0.2 or more and less than 3.0 m²/g, the method comprising;

mixing the silicon nitride powder for the siliconitride phosphors, a material as an aluminum source, a material as a calcium source, and a material as an europium source to have the general formula of (Eu_xCa_1-x)AlSiN₃ (with the proviso that, 0<

x<

0.1); and

calcining the mixture at 1400 to 2000°

C. under a nitrogen atmosphere of 0.05 MPa to 100 MPa.

3. A method for producing a Sr₂Si₅N₅ phosphor by using as a raw material a crystalline silicon nitride powder for the siliconitride phosphors comprising a silicon element and a nitrogen element but no oxygen element as a constituent element, an oxygen content of said silicon nitride powder being 0.2 by weight to 0.8% by weight, wherein the silicon nitride powder has an average particle diameter of 1.0 to 12 μ

m, and a specific surface area of 0.2 or more and less than 3.0 m²/g, the method comprising;

mixing the silicon nitride powder for the siliconitride phosphors, a material as a strontium source, and a material as an europium source to have the general formula of (Eu_xSr_1-x)₂Si₅N₈ (with the proviso that, 0.01<

x<

0.2); and

calcining the mixture at 1400 to 2000°

C. under a nitrogen atmosphere of 0.05 MPa to 100 MPa.

4. A method for producing a (Sr, Ca)AlSiN₃ phosphor by using as a raw material a crystalline silicon nitride powder for the siliconitride phosphors comprising a silicon element and a nitrogen element but no oxygen element as a constituent element, an oxygen content of said silicon nitride powder being 0.2 by weight to 0.8% by weight, wherein the silicon nitride powder has an average particle diameter of 1.0 to 12 μ

m, and a specific surface area of 0.2 or more and less than 3.0 m²/g, the method comprising;

mixing the silicon nitride powder for the siliconitride phosphors, a material as a strontium source, a material as a calcium source, a material as an europium source, and a material as an aluminum source to have the general formula of (Eu_xSr_yCa_z)AlSiN₃ (with the proviso that, x+y+z=1, 0.002≦

x≦

0.03, and 0.1≦

y≦

0.8); and

calcining the mixture at 1400 to 2000°

C. under a nitrogen atmosphere of 0.05 MPa to 100 MPa.

5. A method for producing a La₃Si₆N₁₁ phosphor by using as a raw material a crystalline silicon nitride powder for the siliconitride phosphors comprising a silicon element and a nitrogen element but no oxygen element as a constituent element, an oxygen content of said silicon nitride powder being 0.2 by weight to 0.8% by weight, wherein the silicon nitride powder has an average particle diameter of 1.0 to 12 μ

m, and a specific surface area of 0.2 or more and less than 3.0 m²/g, the method comprising;

mixing the silicon nitride powder for the siliconitride phosphors, a material as a lanthanum source, and a material as a cerium source to have the general formula of (Ce_xLa_1-x)₃Si₆N₁₁ (with the proviso that, 0.001<

x<

1.0); and

calcining the mixture at 1400 to 2000°

C. under a nitrogen atmosphere of 0.05 MPa to 100 MPa.