Appeal 2007-1386
Application 10/439,922
free diisocyanate (LF) prepolymers with polyols containing pendent
carboxyl, sulfonic, or polyoxyethylene moieties, it is possible to make
dispersions which are free of organic solvents. Claim 5 is illustrative of the
invention and is reproduced below:
5. A stable aqueous polyurethane dispersion prepared by a process
comprising subjecting a low free-diisocyanate polyurethane prepolymer
modified by the addition of pendent anionic, cationic, or nonionic moieties
to high shear mixing in the presence of a reaction retarder and water to form
a dispersion of said prepolymer, then extending said prepolymer to yield
said stable aqueous polyurethane dispersion.
The Examiner relies on the following prior art references to show
unpatentability:
Dieterich US 4,276,044 Jun. 30, 1981
Lorenz US 4,528,323 Jul. 9, 1985
The Examiner made the following rejection:
Claims 2, 4-8, and 14-27 under 35 U.S.C. § 103 as unpatentable over
Lorenz in view of Dieterich.
ISSUE
Based on the contentions of the Examiner and the Appellants, the
issue before us is: Has the Examiner made accurate and sufficient factual
findings such that it is reasonable to conclude that one of ordinary skill in
the art would have been motivated to combine the teachings of the
references in the manner claimed? For the reasons discussed below, we
answer this question in the affirmative.
RELEVANT FINDINGS OF FACT
1) Lorenz discloses a “process for the preparation of aqueous
dispersions of polyurethanes containing chemically fixed carboxylate
2
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