Appeal no. 97-1293
Application no. 08/281,812
green body, and sintering the handleable green body to form the sintered titanium diboride
body. Claim 1 further limits the method as follows. The preceramic organosilicon polymer
is at least 10 % by weight of the uniform mixture and must provide a char containing silicon
and carbon in which carbon is present in at least a stoichiometric amount based on the
silicon content. The sintering occurs in an inert atmosphere at a temperature greater than
2000EC. Finally, the sintered titanium diboride body also must have a density greater than
3
about 4.0 g/cm .
2. The prior art
The examiner relied upon two references, Lukacs and Yajima, as evidence of
obviousness. Both references are discussed below.
A. Lukacs (US 5,190,709).
With respect to the claimed invention, the reference teaches:
A method of preparing a sintered ceramic comprising the steps of
mixing ceramic powder and preceramic organosilicon polymer
to form a uniform mixture, shaping the uniform mixture to
obtain a handleable green body, and sintering the handleable
green body in an inert atmosphere (e.g., nitrogen) to form the
sintered material (col. 3, line 1, through col. 6, line 25).
“Any ceramic powder” (col. 4, lines 61 and 62).
Amounts of more than 10 wt% preceramic organosilicon polymer
(Examples 1-5).
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