Appeal No. 2002-2266 Page 9
Application No. 09/366,477
The Rejection of Claims 4, 5, and 20 over Abichandani, Chang and Dwyer
Claims 4, 5, and 20 stand further rejected as obvious over Abichandani and Chang and
further in view of Dwyer. These claims require that the catalyst for each stage have a particular
crystal size. Claim 4 requires a crystal size of at least 0.5 microns in each stage. Claims 5 and 20
require that the crystals have a major dimension of at least about 1 micron in each stage.
Appellants argue that the ethylbenzene conversion reactions disclosed in Dwyer at
column 7, lines 18-27 are different than that claimed (Brief at p. 10). We agree with the
Examiner’s determination that the selection of the crystal size would have been within the
ordinary skill in the art (Final Rejection at p. 3-4; Answer at pp. 4-5).
For toluene disproportionation, Chang specifies that the crystal size is preferably greater
than 0.1 micron (col. 12, ll. 34-35). Dwyer indicates a size of at least 1 micron for a ZSM-5 type
catalyst useful for toluene disproportionation (col. 6, ll. 44-48). Therefore, the crystal sizes for
toluene disproportionation discussed in the prior art encompass those of the claims (claim 4: at
least 0.5 microns; claims 5 and 20: at least about 1 micron).
For ethylbenzene conversion, Abichandani specifies a crystal size of between about 0.1
and 1 microns (col. 4, ll. 35-36). This range overlaps or abuts the claimed ranges (claim 4: at
least 0.5 micron; claims 5 and 20: at least about 1 micron).
Where, as here, the ranges are encompassed by the prior art, overlap or abut, a prima
facie case of obviousness is established. See In re Peterson, 315 F.3d 1325, 1329, 65 USPQ2d
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