Appeal No. 2003-1926 Page 4
Application No. 09/095,842
(2) A statement to the effect that “[u]sually the particle size of a latex tends to increase
together with a polymer concentration, and when the fluorine-containing surfactant is used solely
and if its amount is not more than 1 % by weight, there cannot be obtained a particle size of not
more than 200 nm if the solid content is assumed to be 30 to 50 % by weight.” (specification,
p. 3, ll. 4-10 in both the instant application and the parent application).
Appellants also looked to the data resulting from Comparative Examples 4 and 5 for
support for their statement of what was general knowledge in the prior art. According to
Appellants, those examples show that when the amount of perfluoro (octanoic acid) (PFOA), i.e.,
fluorine-containing surfactant, increases from 0.1 to 2.0 %, the average particle size decreases
from 320.1 nm to 196.3 nm, though the polymer (solid) content is not changed much (from
34.6% to 31.5%). What we conclude from the evidence as a whole is that, according to the
general knowledge in the prior art, one would need to employ more than 1 % by weight of the
fluorine-containing surfactant to obtain particle sizes at or below 200 nm in a 30-50 % by weight
solids content VdF dispersion.
Against the above backdrop, the specification further describes Appellants’ contribution
to the art as the reduction of fluorine-containing surfactant to levels of less than 1 wt. % through
the addition of a non-ionic, non-fluorine-containing surfactant. This is the only method disclosed
by Appellants for obtaining the 30-50 wt. % solids content and 200 nm or less particle size at the
claimed low levels of fluorine-containing surfactant (specification, p. 4, ll. 13-21; p. 6, ll. 17-37).
The data of the Examples and Comparative Examples illustrate that the claimed combination of
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