Appeal No. 2007-3827
Application 08/713,905
ether polyisocyanate could not be obtained,” in view of which “one skilled
in the art, such as Dr. Stutz, would have expected to encounter this problem
in phosgenation of ether amines, particularly in a gas phase phosgenation
process” as stated in the declaration
(Reply Br. 3). Appellants point out Lehmann teaches “it is known
that diamines containing ether groups ‘upon phosgenation yield mainly ether
cleavage products’” (id., citing Lehmann, col. 1, ll. 16-18). Appellants thus
maintains Biskup “teaches gas phase phosgenation of aromatic amines
which ‘may’ contain ether groups but does not teach or suggest that those
ether groups ‘survive’ phosgenation to such a degree that a high yield of
ether (poly)isocyanates having a hydrolyzable chlorine content of 48 ppm or
less is obtained” (id., original emphasis omitted).
The issues in this appeal are whether the Examiner has established a
prima facie case of obviousness over the applied references and whether
Appellants’ arguments based on the evidence in the Stutz Declaration are
sufficient to rebut the prima facie case.
We find that Lehman acknowledges “[f]or example, diamines
obtained by the addition of acrylonitrile to bifunctional alcohols with
subsequent hydrogenation upon phosgenation yield mostly cleavage
products with an accompanying minute amount of diisocyanate formed; see
in this regard Annalen der Chemie, vol. 562, page 87 (1949)” (id. col. 1,
ll. 15-28; emphasis supplied). Lehman would have disclosed to one of
ordinary skill in this art that, contrary to the teachings of the prior art which
would expect ether cleavage products to be formed during the phosgenation
of ether (poly)amines to the corresponding isocyanate in low yield, the
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