Appeal No. 1997-2384 Page 5
Application No. 08/430,083
Coogan discloses a composition comprising an aqueous
dispersion of polyurethane that may be used as a coating
material. The composition is a product of the reaction of:4
(a) a water-dispersible isocyanate-terminated
polyurethane prepolymer having an NCO content of 2.1
to 10% percent by weight,
(b) an organic polyisocyanate having an average
isocyanate functionality of 2.1 to 4.0, and
(c) an active hydrogen-containing chain extender.
The prepolymer reactant of Coogan is disclosed as being
made from an organic diisocyanate, a polyol having a specified
molecular weight range and a specified compound having a
hydrophillic center (column 2, lines 12-19). Coogan (column
2, lines 31-35) further teaches that mixtures of
polyisocyanates may be used and a variety of modified
polyisocyanates that have “... urethane, allophanate, urea,
biuret, carbodimide, uretonimine or isocyanurate residues”
introduced therein are useful in making the prepolymer.
The examiner takes the position that Coogan does not
disclose the incorporation of uretdione moieties (dimer) in
the polyurethane prepolymer used to form the composition that
is employed by appellants and hence does not disclose the
4Coogan, column 2, lines 6-11.
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