Ex parte Schlund et al.

Board of Patent Appeals and Interferences

Aug 18, 1998

07894128 (B.P.A.I. Aug. 18, 1998)

Application for patent filed June 4, 1992.
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today
(1) was not written for publication in a law journal and
(2) is not binding precedent of the Board.
Paper No. 14
UNITED STATES PATENT AND TRADEMARK OFFICE
________________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
________________
Ex parte RUEGER SCHLUND and BERNHARD RIEGER
________________
Appeal No. 95-1959
Application 07/894,1281
________________
ON BRIEF
________________
Before KIMLIN, METZ and WEIFFENBACH, Administrative Patent
Judges.
METZ, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 from the
examiner's refusal to allow claims 1 through 3 and 6 through
8, all the claims remaining in this application.
Appeal No. 95-1959
Application 07/894,128
2
THE INVENTION
Appellants' claimed invention is directed to
catalyst systems (claims 1 through 3, 6 and 7) and to a
process for preparing a catalyst system (claim 8). The
catalyst system comprises a Group IV or Group V metal complex
and an oligomeric alumoxane compound applied to a finely
divided polypropylene support. Useful metals include
titanium, zirconium, hafnium, vanadium, niobium and tantalum.
The method of preparing the catalyst system comprises mixing
the metal complex and the alumoxan oligomer to form a mixture
and thereafter applying the resulting mixture to finely
divided polypropylene. The catalyst system is useful for the
polymerization of C -C 1-alkenes.2 10
Claim 1 is adequately representative of the appealed
subject matter and is reproduced below for a more facile
understanding of appellants' invention.
1. A catalyst system suitable for the polymerization
of C -C -alk-1-enes comprising, as active2 10
ingredients, a complex compound of metals in Sub-
groups IV and V of the Periodic Table and an
oligomeric alumoxan (sic) compound and obtained by a
procedure in which metals in Sub-groups IV and V of
the Periodic table are mixed with the oligomeric
alumoxan (sic) compound and the resulting mixture is
then applied to finely divided polypropylene.
Appeal No. 95-1959
Application 07/894,128
All reference to Takahashi in this opinion is a2
reference to the complete English language translation of the
Japanese document, a copy of which was furnished to appellants
by the examiner in his first Office action.
3
The references of record which are being relied on
by the examiner as evidence of nonobviousness are:
Maemoto et al. (Maemoto) 4,098,979 July 4, 1978
Welborn, Jr. (Welborn) 4,897,455 January 30, 1990
Winter et al. (Winter) 5,081,322 January 14, 1992
Takahashi, Japanese Kokai No. 63-92621, published April 23,
19882
The appealed claims stand rejected as being
unpatentable under 35 U.S.C. § 103 from the disclosure of
Welborn, considered with Takahashi, Maemoto and Winter. We
affirm.
THE REFERENCES
Maemoto discloses a method for the preparation of
easily pourable polyolefin granules by polymerizing an olefin
in the presence of a catalyst system having a main catalyst
component supported on a spheroidal particle of a high
molecular weight used as a carrier and an organometallic
compound (column 1, lines 7 through 14). The high molecular
weight compounds used as a carrier include polyethylene,
polypropylene and polybutylene (column 2, lines 28 through
Appeal No. 95-1959
Application 07/894,128
4
36). The main requirement for the substance used as a carrier
is that it is insoluble or sparingly soluble in the
polymerization medium and will not strongly inactivate the
catalyst component (column 2, lines 36 through 41). Particle
size for the carrier ranges from 1 to 1,000 microns (column 2,
lines 41 through 43). The main catalyst component to be
supported must remain insoluble in the polymerization medium
during polymerization and may comprise the well known catalyst
system for polymerizing olefins comprising a compound of
Groups IV through VI of the Periodic Table and an
organometallic compound of a metal of Groups I to III (column
2, lines 54 through 64). The proportion of main catalyst
component supported on the carrier is 50% by weight or less,
preferably 0.5 to 30 % by weight or less (column 3, lines 26
through 30). The particle size of the polyolefin formed in
the polymerization reaction may be controlled by controlling
the particle size of the carrier (column 3, lines 65 through
68). Olefins which may be prepared by polymerization with the
catalyst system include polypropylene (column 4, lines 20
through 23). Useful organometallic compounds include aluminum
compounds represented by the formula R AlX wherein "R" is an 3-n
hydrocarbon of from 1 to 8 carbon atoms, "X" is halogen,
Appeal No. 95-1959
Application 07/894,128
5
alkoxy or hydrogen and "n" is a positive number of 3 or less
(column 4, lines 25 through 35).
Welborn discloses a new, improved catalyst useful
for polymerization of olefins. The catalyst is a
heterogeneous transition metal containing supported catalysts
which may be used without the use of a cocatalyst (column 1,
lines 8 through 20). Specifically, a new metallocene/alumoxane
catalyst is provided for olefin polymerization useful for the
polymerization of polyethylenes and copolymers of alphaolefins
having from 3 up to 18 or more carbon atoms (column 2, lines
32 through 38). In one embodiment, the catalyst comprises the
reaction product of at least one metallocene and an alumoxane
in the presence of a support material thereby providing a
supported metallocene/ alumoxane reaction product as the
catalyst (column 2, lines 39 through 44). The metallocenes
are organometallic coordination compounds which are
cyclopentadienyl derivatives of a Group 4b, 5b or 6b metal of
the Periodic Table and include metallocenes of titanium,
zirconium, hafnium and vanadium. The alumoxanes are the
reaction products of aluminum trialkyl with water. Useful
supports include any of the solid, particularly porous
supports such as talc, inorganic oxides and resinous supports
Appeal No. 95-1959
Application 07/894,128
6
such as polyolefins (column 3, lines 41 through 45). Finely
divided polyethylene makes a useful support (column 3, lines
52 through 55). The supported catalyst is prepared by simply
mixing the reactants in a suitable solvent to the support
material slurry (column 5, lines 8 through 11). The amount of
catalyst used may vary over a wide range and the ratios
suitable for use are significantly less than that which is
necessary in a homogeneous system (column 5, lines 41 through
56). The particle size of the support effects the particle
size of the product obtained. A particle size of from 30 to
600 microns is suitable (column 8, lines 25 through 40).
Winter discloses a catalyst for copolymerizing
propylene with other olefins (column 1, lines 56 through 58).
The catalyst comprises a metallocene and an alumoxane (column
2, line 23 through column 3, line 40). The metallocene may be
preactivated by reaction with an alumoxane before the
polymerization (column 7, lines 33 through 52).
Takahashi discloses a method for the preparation of
an ethylene copolymer by the gas phase copolymerization of
ethylene and an alpha-olefin of from 3 to 10 carbon atoms in
the presence of a catalyst comprising a transition metal
complex of cyclopentadiene and alumoxane supported on a
Appeal No. 95-1959
Application 07/894,128
7
granular polyethylene support having a density of from 0.80 to
0.935 g/cm Page 4, lines 1 through 13).3
OPINION
There is no dispute between the examiner and
appellants concerning what the prior art relied on to reject
the claims discloses. Thus, the only issue before us concerns
the meaning which would have been given to the respective
disclosures by the hypothetical person of ordinary skill in
the art at the time appellants' invention was made. Thus,
appellants urge that no prima facie case of obviousness is
engendered by the prior art on which the examiner relies.
Alternatively, appellants urge that assuming a prima facie
case of obviousness is made out then appellants have overcome
the prima facie case by the presentation of objective evidence
of nonobviousness in the nature of the two declarations filed
pursuant to 37 C.F.R. § 1.132 by Reuger Schlund, one of the
herein named inventors.
After a careful consideration of the entire record
before us, including all the evidence of record and the stated
positions of both the appellants and the examiner, we agree
with the examiner's conclusion that the claimed subject matter
Appeal No. 95-1959
Application 07/894,128
8
would have been prima facie obvious to a person of ordinary
skill in the art at the time appellants' invention was made.
Moreover, upon reconsidering the prima facie case anew in
light of all the evidence, including appellants' rebuttal
evidence, we also agree with the examiner that the rebuttal
evidence is inadequate to overcome the prima facie case of
obviousness.
As we stated above, appellants have not argued that
the prior art of record fails to disclose the active catalyst
ingredients of the claims. That is, we find the combination
of a "complex compound of metals in Sub-groups IV and V of the
Periodic Table and an oligomeric alumoxan (sic) compound" to
be notoriously well-known catalysts for the polymerization and
copolymerization of olefins. Indeed, appellants have conceded
as much at page 3 of their main brief in their discussion of
what Welborn does and does not disclose and, again, at pages 6
and 7 in discussing the metal complexes applied to the
substrate. Thus, the narrow question before us is whether or
not it can be fairly said that the prior art relied on teaches
or suggests using the well-known prior art catalysts on a
support comprising "finely divided polypropylene". We find
Appeal No. 95-1959
Application 07/894,128
9
that the art relied on strongly suggests the use of
polyolefins in general and polypropylene in particular.
We agree with the examiner's conclusion that
Welborn's teaching that "finely divided olefins such as finely
divided polyethylene" as a support for a complex of a
metallocene and alumoxane is a strong suggestion that
polyolefins, in general, and lower polyolefins, specifically,
would have been expected to be useful supports for catalysts
as claimed. Considered with the fact that Maemoto discloses
that high molecular weight polypropylene is one of many useful
solid materials which serve as a useful support for catalysts
for polymerization of olefins, including polypropylene, we
find that a prima facie case of obviousness is raised by the
references on which the examiner relies. Appellants' brief is
totally silent with respect to the disclosure of Maemoto
except for the terse recognition by appellants at page 3 of
their main brief that Maemoto teaches both polyethylene and
polypropylene have been used as supports for Ziegler-type
catalysts useful in polymerizing olefins.
We find ample motivation to use a supported catalyst
solely from the well-known benefits that a heterogeneous
catalyst is known to engender. Specifically, these benefits
Appeal No. 95-1959
Application 07/894,128
10
would at least include ease of separation from the reaction
mixture, simplicity of catalyst recovery and easier
regeneration. Moreover, Welborn and Maemoto's respective
disclosures that the particle size of the product obtained may
be controlled by selection of the particle size of the support
for the catalyst serves as additional motivation to use
"finely divided" polyolefin supports and, specifically, the
polypropylene support disclosed by Maemoto.
In our view, appellants have failed to consider what
the prior art relied on by the examiner would have fairly
suggested to the routineer in the art at the time their
invention was made. Rather, appellants have chosen to focus
on the individual references separately for what the
references disclose individually. Such analysis is improper
where, as here, the rejection is founded on a combination of
references.
We have not overlooked appellants' reliance on In re
Baird, 16 F.3d 380, 29 USPQ2d 1550 (Fed. Cir. 1994) for the
proposition that the broad disclosure of polyolefins as
supports in Welborn without exemplification of polypropylene
as a support does not suggest the claimed invention or support
a prima facie case of obviousness. We simply consider Baird
Appeal No. 95-1959
Application 07/894,128
11
to lack relevance to the facts in this case. That is, while
Welborn does not specifically disclose polypropylene, Maemoto
does and appellants have simply failed to address the
relevance of the combination of references on which the
examiner has relied to reject the claims. To extend Baird
beyond the specific facts of that case and apply the rule of
that case here is simply unwarranted.
Having concluded that the examiner has made out a
prima facie case of obviousness with respect to the appealed
subject matter, it is necessary for us to consider appellants'
rebuttal evidence, if any, and to reconsider the prima facie
case in light of all the evidence. In re Piasecki, 745 F.2d
1468, 223 USPQ 785 (Fed. Cir. 1984). Appellants' rebuttal
evidence constitutes the declarations of one the named
inventors, Rueger Schlund. For reasons set forth below, we
find appellants' evidence to be inadequate to rebut the prima
facie case of obviousness.
In his first declaration, Schlund states at page 1,
that he is addressing the examiner's conclusion that the
claims are "either anticipated by Takahashi (6392631-4/88) or
obvious over Takahashi in view of Welborn." Nonetheless, the
Appeal No. 95-1959
Application 07/894,128
12
rejection with which declarant was faced under 35 U.S.C. § 103
was over Welborn in view of Takahashi, Sinn et al. Maemoto and
Winter. Inexplicably, declarant fails to address the rejection
made by the examiner or acknowledge that Maemoto fairly
suggests "finely divided" polypropylene as a carrier for
catalysts as claimed. At page 2, declarant states that he
has:
carried out a Comparative Experiment, in which,
under otherwise identical conditions, Example 3 of
the instant application has been repeated with the
exception that I replaced polypropylene grit by
polyethylene grit.
The examiner objected to the declaration on various grounds,
including the failure to adequately identify the nature of the
"polyethylene grit." Accordingly, a second declaration was
proffered in which the declarant specifically attempted to
address the examiner's objections to the first declaration.
In the second declaration, after restating the
rejections and issues to which his second declaration is
addressed, Dr. Schlund states that the polyethylene grit used
in the previous declaration had a particular particle size and
a particular average particle size distribution. In the
paragraph bridging page 1 and 2 of the second declaration,
declarant states:
Appeal No. 95-1959
Application 07/894,128
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The average particle size distribution of the
polyethylene grit used corresponds to the average
particle size distribution of the polypropylene grit
used in Example 3 of the instant application.
No density or molecular weight for the polyethylene grit is
set forth in either declaration.
As a starting point in our analysis of the
declarations, we turn to Example 3 at page 9 of the instant
application. In Part A. of Example 3, captioned "Preliminary
Activation" it is recited that, "[i]n a manner similar to that
described in Example 1" particular components were mixed to
obtain a solution containing aluminum and zirconium in an
atomic ratio of 400:1. In Part B. of Example 3, captioned
"Application to Substrate", it is recited that "[i]n a manner
similar to that described in Example 1" the same polypropylene
grits from Example 1 were combined with the solution in the
activation step. The polypropylene grits in Example 1 have an
average particle size distribution of from 0.25mm to 0.5mm.
No description of the density or the molecular weight for the
polypropylene grit is set forth in either the declaration or
in Example 3 of the instant specification. In part C. of
Example 3 of the specification, captioned "Polymerization", it
is recited that "[i]n a manner similar to that described in
Appeal No. 95-1959
Application 07/894,128
14
Example 2" the supported catalyst from step B., in a
suspension of methylalumoxane and heptane, was used to
polymerize propylene in the gas phase.
By describing the comparative example in the
declaration in narrative terms rather than by explicitly
describing what reactants were used, what amounts or
proportions of reactants were used and what reaction
conditions were used, declarant has rendered it difficult for
us to ascertain exactly what the experiment entailed and what
was being compared. Further, by referencing examples in the
specification in the declaration, which examples themselves
are described as "similar" to other examples which are also
described as "similar" to other procedures, declarant has
injected further uncertainty in determining exactly what was
compared.
Additionally, as noted by the examiner, the scope of
appellants' claim 1 is considerable. No particular metal
complex or alumoxane is claimed nor is any particular
polypropylene, other than it is "finely divided." We agree
with the examiner's conclusion that, in light of the
particular and admitted relevance of the prior art, and in
light of the narrow issue before us, the welter of undefined
Appeal No. 95-1959
Application 07/894,128
15
variables in the proffered showing makes it impossible to
attribute the results in the declaration to the nature of the
carrier or support. Indeed, we question whether by reference
to Example 3 in the specification in the declarations and the
reference in Example 3 to procedures "similar" to procedures
in other examples, the declaration adequately defines what was
the nature of the experiment conducted by declarant.
It is also apparent that in making the above-noted
declarations, the declarant either ignored or overlooked the
rejections of record and the teachings of certain of the
references relied on to reject the claims as in, for example,
Maemoto where polypropylene of a particle size which would be
considered "finely divided" is taught as a carrier for
catalysts as claimed. Further, it is unclear whether
declarant observed the caution in Maemoto that the carrier
material must be insoluble or sparingly soluble in the
polymerization medium. This is the very point we believe the
examiner is attempting to make in the paragraph bridging pages
6 and 7 of his Answer and which appellants chose not to
address in their reply brief. Thus, we are also unable to
determine the basis for declarant's conclusion on page 2 of
the first declaration that reactor fouling was due to
Appeal No. 95-1959
Application 07/894,128
16
replacement of polypropylene grit with polyethylene grit.
We have not overlooked appellants' entreaty that we
separately consider the patentability of claim 6, said to be
commensurate in scope with appellants' evidence of
nonobviousness, in light of the declarations. Nevertheless,
claim 6 does not further define the support or carrier recited
in claim 1 but only limits the catalysts in Claim 1 to
catalysts prepared from particular metals and unsaturated
cyclic hydrocarbons. In light of the admission by appellants
that it is the support or carrier which yields their
unexpected or surprising results we do not understand
appellants' naked conclusion at page 7 of their main brief
that claim 6 "must stand as separately patentable." Suffice
it to say appellants have not explained the basis for their
conclusion.
Based on all the above, we agree with the examiner's
explicit and implicit conclusions that the declarations set
forth inadequate details for us determine if a truly
comparable comparison has been made. Moreover, the examiner
has made certain factual findings in his Answer at pages 5, 6
and 7 which findings appellants had an opportunity to rebut in
their reply brief but which they chose not even to address.
Appeal No. 95-1959
Application 07/894,128
17
Specifically, the examiner found that in light of the art
recognition that the support's characteristics affect the
characteristics of the polymers it is necessary to know the
exact nature of the support used in any comparative run.
Additionally, the examiner found that the skilled routineer
would have expected certain catalysts within the scope of
Claim 6 to produce atactic polypropylenes while other
catalysts also within the scope of Claim 6 would have been
expected to yield crystalline polypropylene. Appellants have
not rebutted or even challenged these findings by the
examiner. We, therefore, accept them as true.
Accordingly, the decision of the examiner is
AFFIRMED.
No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
1.136(a).
AFFIRMED
EDWARD C. KIMLIN )
Administrative Patent Judge )
)
)
)
Appeal No. 95-1959
Application 07/894,128
18
ANDREW H. METZ ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
CAMERON WEIFFENBACH )
Administrative Patent Judge
)
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