Title:
EUROPIUM-ACTIVATED YTTRIUM OXIDE AND PROCESS FOR PRODUCING THE SAME
Document Type and Number:
WIPO Patent Application WO/2008/018582
Kind Code:
A1
Abstract:
This invention provides a europium-activated yttrium oxide which has a median
diameter of 2 to 8 μm as measured by a laser diffraction/scattering method
and a (δ2θ)cosθ of 0.083 degree at the largest as calculated
from a diffraction peak from a 440 face measured by an X-ray diffraction method
wherein θ represents a diffraction angle; and δ2θ represents
a half value width (degree) of a diffraction peak. This europium-activated
yttrium oxide may be produced by mixing a europium-containing yttrium compound
and a flux together in a water system to prepare a slurry, spray drying the slurry
to prepare spherical secondary particles, and then firing the secondary particles
so that the median diameter after the firing is 0.65 to 0.75 time that of the median
diameter before the firing to bring the median diameter after the firing to 2 to
8 μm. The europium-activated yttrium oxide is a red fluorescent substance
suitable for electron beam excitation light emitting elements, for example,
in electric field emission displays (FEDs).
Inventors:
SUITA, Tokuo (ISHIHARA SANGYO KAISHA LTD., 3-1, Nishishibukawa 2-chome, Kusatsu-sh, Shiga 25, 5250025, JP)
Application Number:
JP2007/065702
Publication Date:
February 14, 2008
Filing Date:
August 10, 2007
Export Citation:
Assignee:
ISHIHARA SANGYO KAISHA, LTD. (3-15, Edobori 1-chome Nishi-ku, Osaka-sh, Osaka 02, 5500002, JP)
石原産業株式会社 (〒02 大阪府大阪市西区江戸堀１丁目３番１５号 Osaka, 5500002, JP)
石原産業株式会社 (〒02 大阪府大阪市西区江戸堀１丁目３番１５号 Osaka, 5500002, JP)
International Classes:
C09K11/78; C09K11/08; H01J29/20; C09K11/77; C09K11/08; H01J29/20
Attorney, Agent or Firm:
ASAMURA, Kiyoshi et al. (Room 331, New Ohtemachi Bldg.2-1, Ohtemachi 2-chome,Chiyoda-k, Tokyo 04, 1000004, JP)