Appeal 2007-1897
Application 10/044,846
are repeated “n” times. Since “n” is an integer ranging from 1 to 100, there
is at least one (1) O-alkylene unit inside the brackets” (id. at 2-3). Thus,
“there are always present in the backbone at least two (2) O-alkylene units”
(id. at 3).
According to the Specification, the cross-linked polysaccharide of
formula 2 is obtained by a “process comprising the step of contacting a
polysaccharide (e.g. a starch) with at least one cross-linking agent selected
[from] the group consisting of activated polyalkylene glycols of formula 2a
so as to obtain said cross-linked polysaccharide (e.g. cross-linked starch)
wherein each Alkylene is as defined above” and “each X group is a group
able to react with an alcohol hydroxyl group of said polysaccharide . . . so as
to provide an ether oxygen atom link” (Spec. 8: 15 to 9: 8). The activated
cross-linking agents of formula 2a may be halogenated, mesylated,
tosylated, or triflated polyalkylene glycols. Thus, “[e]ach X may for
example be selected from the group consisting of halogen (e.g. Cl, Br, I),
-O-Ms, -O-Ts, and –O-Tf, wherein Ms is CH3SO2-, Ts is p-CH3C6H4SO2-
and Tf is CF3SO2-” (id. at 9: 14-17, and 10: 20). “Preferred cross-linking
agents are 1,5-dichloro-3-oxopentane, 1,8-dichloro-3,6-dioxooctane, 1,11-
dich[l]oro-3,6,9-trioxoundecane” (id. at 11: 7-8), etc.
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Last modified: September 9, 2013