Appeal No. 2006-2369 Page 11
Application No. 10/169,618
Sony ‘775 as being equivalent to the isocyanates used in Sony ‘649 for the same
purpose, we agree with the examiner that the isocyanate moiety recited in claim 9 would
have been obvious to one of ordinary skill at the time the invention was made.
Finally, we agree with the examiner that the references disclose urethane
derivatives with a degree of substitution (DS) between 0.01 and 2.0 alkyl carbamate
groups per glucosyl unit. Sony ‘649 teaches that the molar ratio of isocyanate
compound to hydroxyl groups in the polysaccharide is preferably 1:1 to 1:3. Paragraph
[0010]. The alkyl carbamate groups recited in claim 9 result from reacting an
isocyanate with a hydroxyl. We take official notice that each glucose residue in a
glucose-based polymer has three hydroxyl groups. Thus, Sony ‘649’s preferred ratio
corresponds to a carbamate:glucosyl unit ratio of 3:1 to 1:1, or a degree of substitution
between 1.0 and 3.0. Sony ‘649 therefore suggests DS values that overlap those in the
claims.
We also agree with the examiner that Sony ‘649 and Sony ‘775 render claim 14
obvious. Looking to the illustrative examples, as urged by the examiner, Example 1 in
Sony ‘649 prepares a polysaccharide urethane derivative by first immersing the
polysaccharide in dimethylformamide. Sony ‘649, at [0017]. The isocyanate compound
is then added dropwise to the polysaccharide-containing dimethylformamide solution.
Id., at [0018] (“Phenyl isocyanate . . . was dropped from the dropping funnel.”). The
polysaccharide urethane derivative produced by reacting the polysaccharide and
isocyanate is isolated by precipitation while stirring. Id., at [0020] (”After cooling
contents . . . to a room temperature, it was dropped into the methanol stirred violently
(gradually), and white powder-like settlings were obtained.”). The precipitated
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