Appeal No. 2001-0773
Application No. 09/200,421
(ii) sintering said green body at a temperature ranging from
about 1400°C to about 1700°C for a time period ranging from about
8 hours to about 12 hours.
In the rejection of the appealed claims, the examiner relies
upon the following references:
Heytmeijer et al. (Heytmeijer) 4,396,595 Aug. 02, 1983
Rhodes et al. (Rhodes) 4,762,655 Aug. 09, 1988
Takahashi et al. (Takahashi) 5,382,556 Jan. 17, 1995
Bennison et al. (Bennison) 5,411,583 May 02, 1995
Rzywucki PL 145,579 Sep. 30, 1989
(Polish Patent Specification)
Morita et al. (JP '946) 5-217946 Aug. 27, 1993
(Japanese Patent Application)
Appellants' claimed invention is directed to a poly-
crystalline alumina ceramic body which surface area comprises
less than 0.1% of unsintered particles. The ceramic body is
formed by sintering a green body comprising alumina and a binder,
such as magnesium oxide, at specific conditions of temperature
and time of 1400°-1700°C and 8-12 hours, respectively. The
ceramic body is said to be resistant to fluorine plasma.
According to appellants' specification, "[a] green body which is
to be sintered to produce a polycrystalline alumina ceramic
material according to the invention can be formed from an alumina
powder having any desired composition" (page 5, third paragraph).
As for appellants' advancement in the art, the specification
relates the following:
-2-
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