Li-containing α-sialon-based phosphor, production process thereof, lighting device and image display device

Patent metadata

Field	Value
Publication number	US-9464226-B2
Application number	US-201414217816-A
Country	US
Kind code	B2
Filing date	Mar 18, 2014
Priority date	Aug 13, 2008
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

An Li-containing α-sialon-based phosphor represented by the formula (1): Li x Eu y Si 12−(m+n) Al (m+n) O n+δ N 16−n−δ (wherein assuming that average valence of Eu is a, x+ya+δ=m; 0.45≦x<1.2, 0.001≦y≦0.2, 0.9≦m≦2.5, 0.5≦n≦2.4, and δ>0).

First claim

The invention claimed is:

1. A process of producing an Li-containing α-sialon-based phosphor represented by formula (1):
Li x Eu y Si 12−(m+n) Al (m+n) O n+δ N 16−n−δ   (1)

wherein, assuming that average valence of Eu is a, x+ya+δ=m; 0.45≦x<1.2, 0.001≦y≦0.2, 0.9≦m≦2.5, 0.5≦n≦2.4, and δ>0;
the process comprising:
i) weighing and mixing
a) a silicon nitride powder and/or a nitride-containing silane compound,
b) an aluminum source containing at least aluminum nitride,
c) a nitride, oxynitride or oxide of Eu or a precursor substance capable of becoming an oxide of Eu by pyrolysis, and
d) a nitride, oxynitride or oxide of Li or a precursor substance capable of becoming an oxide of Li by pyrolysis, in such amounts to produce a composition of the Li-containing α-sialon-based phosphor represented by formula (1) provided that lithium is contained in an amount in excess over a theoretical amount of Li in the Li-containing α-sialon-based phosphor represented by formula (1) by 0.1 to 1.25 mole per 1 mole of the Li-containing α-sialon-based phosphor, and
ii) firing a mixture obtained by said mixing at 1,500 to 1,800° C. in a nitrogen-containing inert gas atmosphere under atmospheric pressure, to obtain the Li-containing α-sialon-based phosphor represented by formula (1).

2. The process of claim 1 , wherein the Li-containing α-sialon-based phosphor after said firing is subjected to acid washing.

3. The process of claim 1 , wherein a powder of the Li-containing α-sialon-based phosphor is produced in which an average aspect ratio of primary particles as measured by image analysis of a scanning electron micrograph is 2 or less and average particle diameter D particle of the primary particles is 1 to 3.0 μm.

4. The A process of producing an Li-containing α-sialon-based phosphor represented by formula (1):
Li x Eu y Si 12−(m+n) Al (m+n) O n+δ N 16−n−δ   (1)

wherein, assuming that average valence of Eu is a, x+ya+δ=m; 0.45≦x<1.2, ≦0.001≦y≦0.2, 0.9≦m≦2.5, 0.5≦n≦2.4, and δ>0;
the process comprising:
i) weighing and mixing
a) an amorphous silicon nitride powder and/or a nitride-containing silane compound,
b) an aluminum source containing at least aluminum nitride,
c) a nitride, oxynitride or oxide of Eu or a precursor substance capable of becoming an oxide of Eu by pyrolysis, and
d) a nitride, oxynitride or oxide of Li or a precursor substance capable of becoming an oxide of Li by pyrolysis, in such amounts to produce a composition of the Li-containing α-sialon-based phosphor represented by formula (1) provided that lithium is contained in an amount in excess over a theoretical amount of Li in the Li-containing α-sialon-based phosphor represented by formula (1) by 0.1 to 1.25 mole per 1 mole of the Li-containing α-sialon-based phosphor, and
ii) firing a mixture obtained by said mixing at 1,500 to 1,800° C. in a nitrogen-containing inert gas atmosphere under atmospheric pressure to obtain a powder of the Li-containing α-sialon-based phosphor in which an aspect ratio of primary particles as measured by image analysis of a scanning electron microscope is 3 or less and a length of short axis of the primary particles is more than 3 μm.

5. The process of claim 4 , wherein the Li-containing α-sialon-based phosphor after said firing is subjected to acid washing.

Assignees

• Ube Industries

Inventors

• Sakata Shin-chi
• Oda Hiroshi
• Sakai Takuma

Classifications

• C09K11/7728 Primary

  containing europium · CPC title

• C09K11/0883

  Arsenides; Nitrides; Phosphides · CPC title

• C09K11/77348

  Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides · CPC title

• H10H20/8512

  Wavelength conversion materials · CPC title

• H10H20/80 Primary

  Constructional details · CPC title