Appeal 2006-2186
Application 09/991,640
of ordinary skill in the art would not have been able to obtain silica with a
DBP number of 380%. Id.
We cannot agree that Appellants have satisfied their burden.
As a first matter, we are not convinced that Reference Example 1 of
Appellants’ specification reproduces the process of Example 1 closely
enough to show that the DBP number of 380% reported in Nauroth’s
Example 1 was incorrect. We are cognizant of the fact that Appellants’
Reference Example 1 states that the precipitation of silica was conducted as
described in Example 1 of EP 0 078 909, a document which Appellents
confirmed at the hearing2 is equivalent in disclosure to Nauroth.3 However,
in the details, Reference Example 1 differs from the Example 1 of Nauroth.
For instance, Appellants’ Reference Example 1 reports the solids content of
the precipitation suspension as 47 g/l while that of Nauroth is 46 g/l.
Nauroth seems to indicate that establishing a silica concentration of 46 g/l is
important for obtaining the DBP number and other properties (see Nauroth,
col. 3, ll. 6-35). We also note that there are differences in the speeds at
which the water glass and sulfuric acid were added to the precipitation
vessel. For water glass the difference could be attributed to rounding (9.8
versus 10 m3/h), but the difference for sulfuric acid cannot be so attributed
(0.98 versus 0.9 m3/h). Because there are differences between Example 1 of
Nauroth and Reference Example 1 of the specification, the evidence is
insufficient to show that the DBP value of 380% reported in Nauroth was
not, in fact, obtained or would have been unobtainable by one of ordinary
skill in this art.
2 Hearing of September 14, 2006.
3 Nauroth and EP 0 078 909 both list DE 3144299 as a priority document.
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