Ex Parte Chang

Board of Patent Appeals and Interferences

Jan 30, 2003

08816466 (B.P.A.I. Jan. 30, 2003)

1
The opinion in support of the decision being entered today was
not written for publication and is not binding precedent of the
Board.
Paper No. 57
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte MAIN CHANG
__________
Appeal No. 2002-0972
Application 08/816,466
___________
ON BRIEF
___________
Before OWENS, WALTZ and LIEBERMAN, Administrative Patent Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
This appeal is from the final rejection of claims 1-4, 6-9,
12-14 and 56. Claims 46-50, which are all of the other claims
remaining in the application, stand withdrawn from consideration
by the examiner as being directed toward a nonelected invention.
Appeal No. 2002-0972
Application 08/816,466

2
THE INVENTION
The appellant claims a method for making a supported
metallocene catalyst system. Claim 1 is illustrative:
1. A method for forming a supported catalyst system
comprising the steps of:
(a) introducing a porous inorganic carrier to a vessel
having a starting pressure,
(b) depressurizing the vessel,
(c) introducing into the vessel a solution comprising a
metallocene catalyst component and an activator while maintaining
the depressurized pressure from step (b)
(d) pressurizing the vessel, and
(e) recovering the supported catalyst system,
steps (a) and (b) are performed before step (c).
THE REFERENCES
Uvarov et al. (Uvarov) 4,246,134 Jan. 20, 1981
Nowlin et al. (Nowlin) 5,332,706 Jul. 26, 1994
THE REJECTION
Claims 1-4, 6-9, 12-14 and 56 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over the combined teachings of Nowlin
and Uvarov.
OPINION
We reverse the aforementioned rejection. We need to address
only the sole independent claim, i.e., claim 1.
Appeal No. 2002-0972
Application 08/816,466

1 Uvarov defines “macroporous copolymer” as “a two-phase system, therein
the polymeric compound is pierced with communicating cavities (pores) capable
of being filled with an external medium upon submersion thereinto” (col. 1,
line 66 - col. 2, line 2).
3
Nowlin discloses a method for forming a supported catalyst
system by contacting a solid, particulate porous carrier, which
preferably is inorganic and most preferably is silica, with a
solution comprising methylalumoxane (the appellant’s activator)
and preferably also comprising a metallocene (col. 3, lines 12-13
and 26-29; col. 6, lines 50-51; col. 7, line 7; col. 8, lines 14-
16). Nowlin does not disclose the appellant’s depressurizing and
pressurizing steps.
Uvarov discloses a supported catalyst system consisting of
1) a catalyst which is a compound of a transition metal of
groups IV-V, preferably titanium or vanadium, advantageously in
the form of chlorides thereof, deposited onto a polymeric carrier
comprising a macroporous copolymer of vinyl and divinyl monomers
having a specific surface area of 30 to 700 m2/g, and 2) an
organoaluminum co-catalyst (col. 1, lines 57-65; col. 2,
lines 40-42).1
Appeal No. 2002-0972
Application 08/816,466

4
Regarding the preparation of the catalyst system, Uvarov
teaches (col. 3, lines 8-23):
To obtain a catalyst based on titanium chloride,
the carrier is treated with titanium chloride or a
solution thereof in vacuum or in the atmosphere of an
inert gas at a temperature within the range of from
-70º to +180ºC.
It is possible to prepare a catalyst based on
titanium chloride by way of treatment of the carrier in
succession or in combination with titanium chloride and
an organo-aluminum compound (or with solutions thereof)
in vacuum or in the atmosphere of an inert gas at a
temperature within the range of from -70º to +180ºC.
The resulting catalyst is dried in vacuum at a
temperature of 80º to 180ºC.
To prepare a catalyst based on vanadium chloride,
the carrier is treated with vapors or solutions of
vanadium chloride and dried in vacuum.
The examiner argues that one of ordinary skill in the art
would have recognized that when Uvarov drys his catalyst by
heating it under vacuum in a flask (example 1), the pressure in
the flask increases and, consequently, the solution flows to a
region of lower pressure, namely, the catalyst pores (answer,
pages 5-6). Therefore, the examiner argues, if Uvarov’s process
were applied to Nowlin’s catalyst, the appellant’s claimed
invention would result (answer, page 5). Motivation for
combining the teachings of these references, the examiner argues,
Appeal No. 2002-0972
Application 08/816,466

2 The examiner further argues that there would be an expected benefit of
the catalyst not fouling the reactor (answer, page 5), but this is a benefit
of Nowlin’s catalyst (abstract) even if Uvarov’s teaching is not combined with
that of Nowlin.
3 The examiner argues that “[t]he present invention is in essence quite
simple. An increase in the gas pressure above a solution is used to drive
that solution into a porous material that is immersed in the solution”
(answer, page 6). The examiner alternatively should consider viewing the
function of the appellant’s vacuum as being to suck air out of the catalyst
pores so that this air does not impede the passage of the solution into the
pores.
5
would have been to obtain a highly useful method for making a
supported olefin polymerization catalyst (answer, pages 5-6).2
The examiner has not established that Uvarov does not adjust
the vacuum during the heating step such that the pressure remains
constant. Even if there is no pressure adjustment, the examiner
has not established that there is a region of higher pressure and
lower pressure in Uvarov’s flask. It reasonably appears that
both the catalyst and the solution within the flask are at the
same pressure.3
Thus, the examiner has not established that one of ordinary
skill in the art would have considered Uvarov’s vacuum to be
anything more than an alternative to Uvarov’s inert gas
atmosphere, i.e., another way of providing a nonreactive
atmosphere. The examiner has not established that such an
atmosphere would have been desired by one of ordinary skill in
Appeal No. 2002-0972
Application 08/816,466

6
the art when making Nowlin’s catalyst system wherein the catalyst
is a metallocene rather than Uvarov’s group IV-V transition
metal.
For the above reasons we conclude that the examiner has not
carried the burden of establishing a prima facie case of
obviousness of the appellant’s claimed invention.
DECISION
The rejection of claims 1-4, 6-9, 12-14 and 56 under
35 U.S.C. § 103 as being unpatentable over the combined teachings
of Nowlin and Uvarov is reversed.
REVERSED
)
TERRY J. OWENS )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
THOMAS A. WALTZ )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
PAUL LIEBERMAN )
Administrative Patent Judge )
Appeal No. 2002-0972
Application 08/816,466

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