Silicon Nitride Powder for Siliconnitride Phosphor, CaAlSiN3 Phosphor Using Same, Sr2Si5N8 Phosphor Using Same, (Sr, Ca)AlSiN3 Phosphor Using Same, La3Si6N11Phosphor Using Same, and Methods for Producing the Phosphors

• US 20130140490A1
• Filed: 07/29/2011
• Published: 06/06/2013
• Est. Priority Date: 08/04/2010
• Status: Active Grant

• Current Assignee: UBE Industries Limited
• Original Assignee: UBE Industries Limited
• Inventors: Fujinaga, Masataka, Sakai, Takuma, Ueda, Takayuki, Jida, Shinsuke
• Granted Patent: US 9,023,240 B2
• Time in Patent Office: Days
• 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 silicon nitride powder for siliconitride phosphors with higher luminance, which can be used for a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), a light emitting diode (LED), and the like; a CaAlSiN₃ phosphor, an Sr₂Si₅N₈ phosphor, an (Sr, Ca)AlSiN₃ phosphor and an La₃Si₆N₁₁ phosphor, each using the silicon nitride powder; and methods for producing the phosphors. The present invention relates to a silicon nitride powder for siliconitride phosphors, which is characterized by being a crystalline silicon nitride powder that is used as a starting material for producing a siliconitride phosphor that includes silicon element and nitrogen element but does not contain oxygen element as a constitutent element, and which is characterized by having an oxygen content of 0.2% by weight to 0.9% by weight; a CaAlSiN₃ phosphor, an Sr₂Si₅N₈ phosphor, an (Sr, Ca)AlSiN₃ phosphor and an La₃Si₆N₁₁ phosphor, each using the silicon nitride powder; and methods for producing the phosphors.

Claims

1-12. -12. (canceled)

13. A crystalline silicon nitride powder for siliconitride phosphors, which 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.

14. The silicon nitride powder for the siliconitride phosphors according to claim 13, wherein the silicon nitride powder has an average particle diameter of 1.0 μ

m to 12 μ

m.

15. The silicon nitride powder for the siliconitride phosphors according to claim 13, wherein the silicon nitride powder has a specific surface area of 0.2 m²/g to 4.0 m²/g.

16. The silicon nitride powder for the siliconitride phosphors according to claim 13, wherein the siliconitride phosphor is a CaAlSiN₃ phosphor, a Sr₂Si₅N₈ phosphor, a (Sr, Ca)AlSiN₃ phosphor, or a La₃Si₆N₁₁ phosphor.

17. A method for producing a CaAlSiN₃ phosphor by using the silicon nitride powder for the siliconitride phosphors according to claim 13, 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.

18. A CaAlSiN₃ phosphor using the silicon nitride powder for the siliconitride phosphors according to claim 13, which is represented by the general formula of (Eu_xCa_1-x) AlSiN₃ (with the proviso that, 0<

x<

0.1), and is obtained by calcining a mixture powder including the silicon nitride powder for the siliconitride phosphors, a Ca₃N₂ powder, an AlN powder, and an EuN powder at 1400 to 2000°

C. under a nitrogen-containing inert gas atmosphere.

19. A method for producing a Sr₂Si₅N₈ phosphor by using the silicon nitride powder for the siliconitride phosphors according to claim 13, 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.

20. A Sr₂Si₅N₈ phosphor using the silicon nitride powder for the siliconitride phosphors according to claim 13, which is represented by the general formula of (Eu_xSr_1-x)₂Si₅N₈ (with the proviso that, 0.01<

x<

0.2), and is obtained by calcining a mixture powder including the silicon nitride powder for the siliconitride phosphors, a strontium nitride powder and an europium nitride powder at 1400 to 2000°

C. under a nitrogen-containing inert gas atmosphere.

21. A method for producing a (Sr, Ca)AlSiN₃ phosphor by using the silicon nitride powder for the siliconitride phosphors according to claim 13, 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.

22. A (Sr, Ca)AlSiN₃ phosphor using the silicon nitride powder for the siliconitride phosphors according to claim 13, which is represented by the general formula of (Eu_xSr_yCa_y)AlSiN₃ (with the proviso that, x+y+z=1, 0.002≦

x≦

0.03, and 0.1≦

y≦

0.8), and is obtained by calcining a mixture powder including the silicon nitride powder for the siliconitride phosphors, a Sr₃N₂ powder, a Ca₃N₂ powder, an EuN powder, and an AlN powder at 1400 to 2000°

C. under a nitrogen-containing inert gas atmosphere.

23. A method for producing a La₃Si₆N₁₁ phosphor by using the silicon nitride powder for the siliconitride phosphors according to claim 13, 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.

24. A La₃Si₆N₁₁ phosphor using the silicon nitride powder for the siliconitride phosphors according to claim 13, which is represented by the general formula of (Ce_xLa_1-xSi₆N₁₁ (with the proviso that, 0.001<

x<

1.0), and is obtained by calcining a mixture powder including the silicon nitride powder for the siliconitride phosphors, a LaN powder and a CeN powder at 1400 to 2000°

C. under a nitrogen-containing inert gas atmosphere.