The claims
1. The application on appeal contains claims 1-5.
2. According to applicant (Appeal Brief, page 4),
dependent claims 2-5 stand or fall with independent claim 1.
3. Claim 1 reads (matter in [brackets] added):
A process for purification of diaryl carbonates, which
comprises:
[1] providing a crude solution of diaryl carbonate in
admixture with contaminant by-products of a diaryl carbonate
preparation;
[2] cooling the solution to a temperature of about
1-2°C below the nucleation temperature of the diaryl
carbonate whereby nucleation occurs;
[3] subsequently further cooling the solution
containing nucleated diaryl carbonate at a controlled rate,
between about 0.01 to 1.0°C per minute whereby crystals of the
diaryl carbonate form in a residue of cooled solution;
[4] separating the residue of cooled solution from the
formed crystals of the diaryl carbonate;
[5] heating the separated crystals at a controlled
rate to their melt temperature, incrementally;
[6] separating sweat exuding from the heated crystals
in each increment; and
[7] collecting the melted crystals to obtain high
purity diaryl carbonate.
The rejection
4. The examiner has rejected claims 1-5 as being
unpatentable under 35 U.S.C. § 103(a) over Shafer, U.S. Patent
5,239,106 (1993).
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