Dexerials Corporation

Masaki Kanno

Tsuneo Kusunoki

Takamasa Izawa

Takahiro Igarashi

Hiraku Akiho

A red phosphor of high efficiency and a method for producing it are provided. A white light source and an illumination device that allow illumination with the pure white color using the red phosphor are also provided. In addition, a liquid crystal display device using the red phosphor and exhibiting good color reproducing performance is provided. The red phosphor contains an element A, europium (Eu), silicon (Si), carbon (C), oxygen (O) and nitrogen (N) in the ratios of the numbers of atoms of the following compositional formula (1):[Chemical Formula 1][AEu][SiC]ON&#x2003;&#x2003; compositional formula (1)where the element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba), and where m, x and n in the compositional formula (1) satisfy the relationships of 3&#x3c;m&#x3c;5, 0&#x3c;x&#x3c;1, 0&#x3c;y&#x3c;2 and 0&#x3c;n&#x3c;10 (FIG.A).

Red phosphor, method for producing red phosphor, white light source, illuminating device, and liquid crystal display device

Provided is a process for producing a red phosphor, said process achieving enhanced productivity. Also provided are: a red phosphor having excellent luminescence characteristics; and a white light source, a lighting system, and a liquid crystal display device, using the red phosphor. This process comprises: mixing an A-containing compound, a nitrogen-free europium source, a silicon-containing compound, an aluminum-containing compound and a carbon-containing reducing agent so as to form a mixture wherein the atomic ratio among A, europium (Eu), silicon (Si), aluminum (Al) and carbon (C) is a value represented by compositional formula (1); firing the mixture; and pulverizing the fired mixture. (Am&#x2212;xEux)Aly(Si1&#x2212;zCz)90 nN[12+y&#x2212;2(n&#x2212;m)/3] (1) [wherein A is at least one element selected from among magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba), and m, x, z and n satisfy the relationships: 3.

Method for manufacturing red phosphor

A process for producing a coated phosphor, namely a phosphor coated with a coating material, which includes a mixing step of mixing a phosphor with a coating material in a solvent to form a mixed fluid and a separation step of separating the mixed fluid into a solid phase and a liquid phase, wherein the phosphor comprises barium (Ba), strontium (Sr), europium (Eu), silicon (Si) and oxygen (O) at an atomic ratio represented by compositional formula (1), and the mass ratio of the phosphor to the coating material is 40:260 to 200:260, [(Ba1-ySry)1-xEux]aSibOc (1) [wherein a, b, c, x and y satisfy the relationships: 2.7&#x3c;a&#x3c;3.3, 0.9&#x3c;b&#x3c;1.1, 4.5&#x3c;c&#x3c;5.5, 0&#x3c;x&#x3c;0.09 and 0.25&#x3c;y&#x3c;0.75].

Method for manufacturing coated phosphor, and coated phosphor

A red phosphor of high efficiency and a method for producing it are provided. A white light source and an illumination device that allow illumination with the pure white color using the red phosphor are also provided. In addition, a liquid crystal display device using the red phosphor and exhibiting good color reproducing performance is provided. The red phosphor contains an element A, europium (Eu), silicon (Si), carbon (C), oxygen (O) and nitrogen (N) in the ratios of the numbers of atoms of the following compositional formula (1):[Chemical Formula 1][AEu][SiC]ON&#x2003;&#x2003;compositional formula (1)where the element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba), and where m, x and n in the compositional formula (1) satisfy the relationships of 3&#x3c;m&#x3c;5, 0&#x3c;x&#x3c;1, 0&#x3c;y&#x3c;2 and 0&#x3c;n&#x3c;10 (FIG.A).

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Tochigi, Japan

Masaki Kanno