Appeal No. 95-2011
Application No. 07/959,011
Although Ting does not state that the final
polymer is a core-shell polymer, Ting uses a two-
stage graft polymerization technique which would
presumably lead to core-shell polymers. In this
connection, Appellants have already acknowledged it
is known that multi-stage graft polymerization
yields core-shell polymers. See page 2, lines 1-11,
of the specification. Ting uses multi-stage graft
polymerization. Graft polymers are those where
poly-(B) are grafted onto the backbone of poly-(A):
AAAAAAAAAAAAAAAAAAAA
* * *
B B B
B B B
B B B.
As such, it would appear that Ting’s second stage
polymer would also form a sheath around the first
stage polymer. . . . In the instant case,
Appellants have not met their burden of clearly
showing that Ting’s polymer would not be a core-
shell polymer. [Underlining ours.]
We disagree. The portion of appellants’ specification
relied upon by the examiner states (p. 2, lines 1-11):
The term core-shell structure has become well-
understood in the art as defining a layered
particulate composition having a polymeric center or
core surrounded by a shell or overcoat formed of a
second polymeric material. Methods for the
preparation of such core-shell particulate
compositions are well known in the art and include a
variety of layered particulate materials having a
core and one or more shell layers. For example,
U.S. Pat. No. 3,661,994 discloses graft polymers
formed by a sequential polymerization process,
wherein a rigid, polymeric seed or core is
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