Appeal No. 1996-2769
Application 08/270,089
b) precipitating rare earth hydroxycarbonate particles from said solution, said
particles having a spherical shape and particle size of less than one micron;
c) collecting the rare earth hydroxycarbonate particles;
d) heating the hydroxycarbonate particles in an oxygen-containing atmosphere at a
temperature in the range of about 700 to about 1000EC to form the corresponding rare
earth oxide compound while maintaining the particle size and spherical shape of the
hydroxycarbonate particles; and
e) heating the rare earth oxide particles in a flux composition of sulfur and one or
more salts selected from the group consisting of alkali metal sulfates, phosphates and
carbonates in the absence of oxygen at a temperature of no more than about 900E C to
convert the oxide to the corresponding oxysulfide compound without changing the shape or
the particle size of the particles.
The references relied upon by the examiner are:
Royce et al. (Royce) 3,502,590 Mar. 24, 1970
Hewes 3,541,022 Nov. 17, 1970
Matijevic 5,015,452 May 14, 1991
3+
Kanehisa et al. (Kanehisa), “Formation Process of Y O S:Eu in a Preparation with Flux,”
2 2
J. Electrochem. Soc. Solid-Sci. and Technology, Vol. 132, No. 8, pp. 2023-27 (Aug.
1985).
Beverloo et al. (Beverloo), “Inorganic Phosphors and New Luminescent Labels for
Immunocytochemistry and Time-Resolved Microscopy,” Cytometry, Vol. 11, pp. 784-92
(1990).
Claims 1 through 7 and 9 through 17 stand rejected under 35 U.S.C. § 103 as
being unpatentable over Royce in view of Hewes, Matijevic, Kanehisa and Beverloo.
We reverse.
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