Appeal No. 1998-3182
Application No. 08/459,526
Furthermore, while Example 13 of Tsutsui, cited by the
examiner, prepares the catalyst by prepolymerizing a suspension
of a silica support, an alumoxane and an unbridged metallocene,
and incorporates the bridged metallocene after prepolymerizing,
we find that one of ordinary skill in the art would have
understood Tsutsui as teaching that the support, alumoxane,
unbridged metallocene and bridged metallocene can be combined
prior to prepolymerization. It is well settled that a reference
is not limited to its examples or preferred embodiments and, in
addition to the disclosure at column 5 cited above, Tsutsui
discloses that the bridged metallocene may be supported on the
carrier before prepolymerization (see column 16, lines 4 et seq.)
Also, we point out that Tsutsui expressly discloses that before
prepolymerization, the support (carrier), unbridged metallocene
and bridged metallocene may be presupported on a carrier, “or
these catalyst components may only be arbitrarily contacted
and mixed” (column 20, lines 38-42). (See also column 20, lines
29-37). Hence, appellants’ arguments to the contrary notwith-
standing, we are satisfied that Tsutsui fairly discloses the
presently claimed catalyst system which, necessarily, would be
effective in preparing a polyolefin having a bimodal molecular
5
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