Ex Parte Schurzky et al

Board of Patent Appeals and Interferences

May 20, 2010

10492610 (B.P.A.I. May. 20, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte KENNETH G. SCHURZKY, ROBERT L. SANTANA,
FRED D. EHRMAN, and PRADEEP P. SHIRODKAR
____________

Appeal 2008-006242
Application 10/492,610
Technology Center 1700
____________

Decided: May 20, 2010
____________

Before JAMES T. MOORE, Vice Chief Administrative Patent Judge,
ALLEN R. MACDONALD, Vice Chief Administrative Patent Judge, and
PETER F. KRATZ, Administrative Patent Judge.

KRATZ, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from the
Examiner’s final rejection of claims 1-8, 11-20, 23-29, 32-38, and 41-74.
We have jurisdiction pursuant to 35 U.S.C. § 6(b).

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Appellants’ claimed invention is directed to an olefin polymerization
method using metallocene and non-metallocene catalysts wherein feed rates
of hydrogen and a selected monomer or comonomer provided to a reactor
are determined (Spec. p. 4, ll. 8-9, and p. 14, l. 25- p. 15, l. 2). In addition,
gas phase relative concentrations of hydrogen and the monomer/comonomer
in a recycle gas stream are assessed (Spec. 4, ll. 9-14). A leading indicator
function (L) is obtained comprising, for example, a ratio of the concentration
of hydrogen divided by the feed rate of hydrogen to the concentration of
monomer divided by the feed rate of monomer; then L, its inverse (L-1) or a
function of L, such as (L(t)) is compared to a target value or target function;
and at least one reactor parameter is adjusted in response to a deviation
between L or L-1 and the target value or L(t) or L-1 (t) and the target function
(Spec. p. 4, ll. 8-27, p. 12, ll. 16-21, and p. 13, ll. 21-30).
Appellants disclose that monitoring of such a leading indicator allows
for earlier diagnosis of reactor problems and adjustments of reaction
parameters in a relatively quicker manner as compared to employing
laboratory analysis of product samples (Spec., p. 4, ll. 14-19). Appellants
disclose and claim that the reaction parameter adjustment alters the relative
productivity of the catalysts (see, for example, claim 1 and Spec., p. 5, ll. 2-
4).
Claims 1, 14, and 44 are illustrative and reproduced below:

1. A method of olefin polymerization in a continuous reactor, the
method comprising:

(a) determining feed rates FH2 and FM of hydrogen and a selected
monomer
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or comonomer, respectively, provided to the reactor and gas phase
relative concentrations CH2 and CM of the hydrogen and the selected
monomer or comonomer, respectively, in a recycle gas stream of the
reactor to obtain a leading indicator function L defined by:

(b) comparing L or L-1 to a target value; and

(c) adjusting at least one reactor parameter in response to a deviation
between L or L-1 and the target value;

wherein the olefin polymerization is catalyzed by a catalyst system,
the catalyst system comprising a metallocene catalyst and a non-metallocene
catalyst; and wherein the step of adjusting at least one reactor parameter is
effective to alter the relative productivity of the catalysts.

14. A method of olefin polymerization in a fluidized bed reactor, the
method comprising:

(a) determining feed rates FH2 and FM of hydrogen and a selected
monomer or comonomer, respectively, provided to the reactor and gas
phase relative concentrations CH2 and CM of the hydrogen and the
selected monomer or comonomer, respectively, in a recycle gas
stream of the reactor to obtain a leading indicator function L defined
by:

wherein step (a) is repeated a plurality of times to obtain L as a
function of time, L(t);

(b) comparing L(t) or L-1(t) to a target function; and
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(c) adjusting at least one reactor parameter in response to a deviation
between L(t) or L-1(t) and the target function;

wherein the olefin polymerization is catalyzed by a catalyst system,
the catalyst system comprising a metallocene catalyst and a non-metallocene
catalyst; and wherein the step of adjusting at least one reactor parameter is
effective to alter the relative productivity of the catalysts.

44. A method of olefin polymerization in a continuous reactor, the
method comprising:

(a) determining feed rates FH2 and FM of hydrogen and a selected
monomer or comonomer, respectively, provided to the reactor and gas
phase relative concentrations CH2 and CM of the hydrogen and the
selected monomer or comonomer, respectively, in a recycle gas
stream of the reactor to obtain a leading indicator function L defined
by:

(b) comparing L or L-1 to a target value; and

(c) adjusting at least one reactor parameter in response to a deviation
between L or L-1 and the target value;

wherein the olefin polymerization is catalyzed by a catalyst system,
the catalyst system comprising a metallocene catalyst and a non-metallocene
catalyst; and wherein the metallocene and non-metallocene catalysts are
supported and are both present on the same support.

The Examiner relies on the following prior art reference as evidence
in rejecting the appealed claims:
Lue US 6,207,606 B1 Mar. 27, 2001

The Examiner presents the following ground of rejection:
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Claims 1-8, 11-20, 23-29, 32-38, and 41-74 stand rejected under 35
U.S.C. § 102(b) as being anticipated by or, in the alternative, under 35
U.S.C. § 103(a) as being obvious over Lue.1
No other grounds of rejection are maintained by the Examiner.
Consequently, our review is limited to the aforementioned
obviousness rejection, which has been contested by Appellants in the Appeal
Brief and Reply Brief.
The Examiner acknowledges that “the claimed L function is not
explicitly disclosed in Lue” (FOA 4).
However, the Examiner asserts that:
Regarding the claimed function L, since LUE et al.
clearly indicates that the hydrogen, monomer and comonomer
were controlled to maintain at fixed composition targets, the
examiner has a reasonable basis to believe that the claimed
function L is inherently possessed by the disclosure to LUE et
al.
Ans. 5.
The Examiner maintains that:
Regarding the claimed feature "the step of adjusting at
least one reactor parameter is effective to alter the relative
productivity of the catalysts", the examiner has a reasonable
basis [to believe] that this claimed feature is inherently
possessed in Lue et al. because a change or readjustment of the
gaseous feed streams of ethylene and hydrogen will affect the

1 The Examiner errs by listing the rejected claims as claims 8, 9, 11-13, 19-
21, 23-25, 29, 30, 32-34, and 38-43 (Ans. 4). The Final Office Action
(FOA) identifies the rejected claims as claims 1-8, 11-20, 23-29, 32-38, and
41-74, as do Appellants (FOA 3; App. Br. 2). This error is deemed
inadvertent and it is obviously resolvable as the Examiner acknowledges the
correctness of the status of the claims and grounds of rejection to be
reviewed on appeal as presented by Appellants in the Appeal Brief (Ans. 2;
see also App. Br. 2 and 10).
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metallocene and the non-metallocene catalyst in activity
differently or at a different degree.
Ans. 4-5.
In the alternative, the Examiner opines that:
Even assuming that the claimed L function is not inherent
to Lue et al., it would have been obvious to one of ordinary skill
in art to establish the L function as claimed, which is the ratio
of CH2/FH2 to CM/FM. Appellants must recognize that in a
controlled gas polymerization process where hydrogen gas is
used as molecular weight controlling agent, where the ratio of
the hydrogen feed to the monomer feed and the ratio of the
hydrogen concentration to the monomer concentration are
critical parameters for determining the final molecular weights
as well as the catalyst activities. Therefore, motivated by the
expectation of success and the ease of monitoring and
controlling a gas phase polymerization process, it would have
been obvious to one of ordinary skill in art to monitor or control
the polymerization of Lue et al. by through the adjustment of
hydrogen gas relative to the monomer in the system through the
determination of the ratio of CH2/FH2 to CM/FM, which results
[in] the L function as claimed.
Ans. 8.
Appellants, on the other hand, urge that:
The Examiner has failed to provide a reasonable basis to
support the determination of inherent disclosure. The function
L does not necessarily flow from the disclosure to Lue et al.
The method of using the relationships between flows and
concentrations of gas components in the way defined by the
function L are not facts known to one in skilled in the art, and
are not explicitly or inherently disclosed in Lue et al.
App. Br. 12.
Furthermore, Appellants maintain that:
the L function provides a method to determine the
relationships between the flows and concentrations of
hydrogen, monomer, and/or comonomer to assist in the control
the resin composition. Lue et al. fails to disclose a description
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or indication of the claimed relationship between the
concentration and flow ratios and how the relationship may be
used to predict changes in resin property. Lue et al. merely
states that the levels of hydrogen, ethylene, and comonomer can
[be] controlled to maintain fixed composition targets (Col. 18,
Lines 34-39) but does not teach an artisan how to.
App. Br. 12.
Also, Appellants contest the Examiner’s obviousness assertion by
arguing, inter alia, that:
The Examiner has failed to establish that one skilled in
the art would be led to employ the claimed relationship between
the flows and concentrations described by the leading indicator
function L in view of Lue et al. The Examiner simply asserts
that one of ordinary skill in the art would be motivated by the
expectation of success and ease of monitoring and controlling
the polymerization process, and that it would have been
obvious to adjust the hydrogen and monomer as represented by
the function L. (Office Communication dated 12/19/2006, page
4).
The mere disclosure in Lue et al. that hydrogen,
monomer and comonomer can be controlled to maintain at
fixed composition targets is not enough to motivate one to alter
Lue et al. to arrive at the presently claimed features. "The mere
fact that references can be combined or modified does not
render the resultant combination obvious unless the prior art
suggests the desirability of the combination.
App. Br. 12-13.
Thus, the principal issues before us are: (1) Has the Examiner
established that Lue inherently describes a polymerization process that
includes Appellants’ claimed function L and associated comparison and
adjusting steps that the claimed process reads on; and/or (2) Has the
Examiner established that it would have been obvious to one of ordinary
skill in the art to employ Appellants’ L function and the correspondingly
claimed comparing and adjustment steps in Lue based on the teachings of
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Lue and the Examiner’s rebuttal assertions of a reasonable expectation of
success, knowledge of the art and ease of monitoring and control of a
polymerizing process?
We answer both questions in the negative and we reverse the stated
anticipation and alternative obviousness rejections.
FINDINGS OF FACT
In addition to findings of fact set forth elsewhere in this Opinion, we
make the following factual determinations.
Lue is directed to a mixed catalyst and a method of making same, and
a process of using the catalyst in olefin polymerization (col. 1, ll. 5-15, col.
2, l. 65 – col. 4, l. 27). Lue discloses that the catalyst may comprise a mixed
metallocene-type bridged catalyst used together with a non-metallocene
catalyst (col. 3, ll. 48-60 and col. 10, ll. 53-61). Lue teaches that the catalyst
can be combined with a support (col. 10, ll. 62-67).
Lue discloses that a pre-polymerization step can be employed and can
take place in the presence of any molecular weight controlling agent, such as
hydrogen (col. 12, ll. 16-30).
Lue discloses the olefin polymerization reaction can employ ethylene
as a monomer and a comonomer such as hexene-1 (col. 14, ll. 23-31).
Lue teaches that the polymerization can be carried out using a typical
gas phase fluidized bed process wherein a gaseous stream including one or
more monomers is recycled back through the fluidized bed with monomer
added to replace polymerized monomer (col. 14, ll. 32-49).
Lue discloses that polymer produced by the process can have a range
of densities, narrow composition and molecular weight distributions, and be
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characterized by a range of melt indexes and melt index ratios (col. 15, l. 42-
col. 16, l. 31).
Lue furnishes examples wherein ethylene is polymerized in a
fluidized bed reactor and introduced with a co-monomer comprising
Hexene-1 and hydrogen into a recycle gas line of the reactor (col. 18, ll. 25-
35).
Lue (col. 18, ll. 35-42) explains that:
The individual flow rates of ethylene, hydrogen, and
comonomer were controlled to maintain fixed composition
targets. The ethylene concentration was controlled to maintain
a constant ethylene partial pressure. The hydrogen was
controlled to maintain a constant hydrogen to ethylene mole
ratio. The concentration of all of the gases were measured by
an on-line chromatograph to ensure relatively constant
composition in the recycle gas stream.

Lue presents reaction data for comparative Examples 1-5 and
Examples 6-9 in Tables 1 and 2 and product data in Table 3. Tables 1 and 2
include reaction information including hydrogen to ethylene concentration
ratio and hexene to ethylene concentration ratio values, ethylene and hexene
mole percent values, hydrogen (mole ppm.), hydrogen flow values (Table 2),
and other information for the examples.
Lue does not explicitly describe an olefin polymerization process that:
(1) employs a leading indicator or leading indicator function for calculating
a leading indicator (L) based on a ratio of ratios comprising a ratio of
hydrogen concentration in a recycle stream (CH2) to hydrogen flow into a
reactor (FH2) to a ratio of monomer concentration in the recycle stream (CM)
to monomer flow into the reactor (FM); that is, a ratio of CH2/FH2 to a ratio of
CM/FM; (2) comparing such a calculated L to a target value or comparing L,
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as a function of time (L(t)), to a target function; and/or (3) adjusting a
reaction parameter based on a deviation between such a calculated L and the
target value or based on a deviation between L(t) and the target function.

PRINCIPLES OF LAW
It is well settled that the burden of establishing a prima facie case of
non-patentability resides with the Examiner. See In re Piasecki, 745 F.2d
1468, 1472 (Fed. Cir. 1984); see also Ex Parte Frye, 94 USPQ2d 1072,
1075 (BPAI 2010) (Precedential).
An appellant may attempt to overcome an examiner’s rejection on
appeal to the Board by submitting arguments and/or evidence to show that
the examiner made an error in either (1) an underlying finding of fact upon
which the final conclusion was based, or (2) the reasoning used to reach the
legal conclusion. See Frye, 94 USPQ2d at 1075. The panel then reviews the
rejection for error based upon the issues identified by appellant, and in light
of the arguments and evidence produced thereon. See Oetiker, 977 F.2d
1443, 1445 (Fed. Cir. 1992); See also Frye, 94 USPQ2d at 1075.

ANALYSIS
Each of the independent claims (claims 1, 14, 26, 35, 44, 54, 63, and
69) on appeal is directed to a catalytic olefin polymerization method which
includes steps comprising:
1. Determining feed rates to a reactor and recycle gas stream
concentrations of hydrogen and a selected monomer and obtaining a leading
indicator function L as called for in the appealed claims;
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2. Comparing L or the inverse of L to a target value, or a function of L
(L(t)) to a target function; and
3. Adjusting at least one reactor parameter in response to a deviation
between L and a target value or in response to a deviation between L(t) and
the target function.

Anticipation Rejection
We agree with the Examiner that Lue teaches or suggests an olefin
polymerization process wherein individual flow rates of ethylene, hydrogen
and hexene (co-monomer) into the reactor are controlled to achieve a
constant or fixed composition target (Ans. 4-5; Lue, col. 18, ll. 34-42 and
Tables 1 and 2). However, as the Examiner has recognized, Lue does not
explicitly disclose the specified leading indictor employed in the process of
Appellants’ rejected independent claims 1, 14, 26, 35, 44, 54, 63, and 69
(FOA. 4).
Even though we agree with the Examiner that Lue provides a
teaching of controlling the individual flow rates of hydrogen and ethylene
during the polymerization of olefins and furnishes Examples that evince that
the feed rates of ethylene and hydrogen were determined (Ans. 5 and 7), the
Examiner bears the burden of presenting a sustainable rationale as to why
the claimed process, including a reactor parameter adjustment responsive to
a deviation between a target value and a leading indicator (L) obtained via a
comparison step as the involved claims require, and wherein L is based on a
formula as specified in the independent claims, would have been inherently
taught by Lue.
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At the outset, we note that the Examiner does not particularly address
any of the appealed claims individually in maintaining the anticipation
rejection. In this regard, a finding of anticipation requires the disclosure in a
single reference of every element of the claimed invention of each claim so
rejected, either explicitly or inherently. See In re Schreiber, 128 F.3d 1473,
1477 (Fed. Cir. 1997).
Here, the Examiner’s assertion about the L value having little weight
in assessing the patentability of the claims and the conclusively presented
assessment arguing that a fully encompassing disclosure is present in Lue
are off the mark and insufficient to make out a sustainable case with respect
to an inherent teaching of a process corresponding in all of the requirements
of any of the rejected independent claims by Lue (Ans. 4-7). As argued by
Appellants, Lue provides no disclosure pertaining to the claimed L function;
that is, a relationship between flow and concentrations of hydrogen and
flows and concentrations of monomer as specified in the claimed leading
indicator, which L value or function is compared with a target value or
function to detect a deviation, which deviation is used to prompt a parameter
adjustment, as variously called for in each of the rejected independent claims
(App. Br. 10-12; Reply Br. 2-4). Inherency may not be established by
probabilities or possibilities. The mere fact that a certain thing may result
from a given set of circumstances is not sufficient. In re Robertson, 169 F.3d
743, 745 (Fed. Cir. 1999).
Moreover, the Examiner’s rearrangement of the claimed L function
coupled with the Examiner’s assertion about a lack of limits for the
concentration and flow rates of hydrogen and monomer in the appealed
claims, as presented in rebuttal, is noted (Ans. 6). However, the Examiner
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does not reasonably articulate how this results in Lue providing an
anticipatory disclosure based on the rearranged formula and the breadth of
the concentration and feed rate variables employed in the claimed L
function. In this regard, the Examiner does not explain how Lue’s control of
individual flow rates to obtain a fixed composition target necessarily results
in a polymerization process wherein parameter adjustment is effected in
response to a deviation between L or a function of L, as claimed.
On this record, the Examiner has not carried the burden to establish
that Lue furnishes an anticipatory disclosure based on the advocated
inherency theory.

Obviousness Rejection
The Examiner has not reasonably articulated how Lue’s use of
hydrogen in the a pre-polymerization step or in the polymerization process
as a molecular weight controlling agent taken with the Examiner’s allegation
of the criticality of hydrogen feed to monomer feed ratio and hydrogen
concentration to monomer concentration ratio and the conclusive assertion
about a reasonable expectation of success and ease of monitoring and
controlling a polymerization process establishes the obviousness of
Appellants’ claimed process (Ans. 8).
Again, we agree that the Examiner has correctly determined that Lue
discloses controlling monomer and hydrogen flow rates individually so as to
achieve fixed composition targets (Ans. 5). However, the Examiner does
not persuasively articulate how Lue’s broadly disclosed individual control of
these feed rates for the purpose of maintaining fixed composition targets,
and/or Lue’s teaching of a constant hydrogen to ethylene mole ratio (col. 18,
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ll. 38-40), and/or Lue’s teaching about pre-polymerization use of hydrogen
(Ans. 7; Lue, col. 12, l. 26) would have directed an ordinarily skilled artisan
toward arrival at Appellants’ leading indicator formula and manner of
adjusting polymerization reactor parameters in response to deviations of a
calculated L from a target L value. The Examiner furnishes no other
evidence beyond the teachings of Lue in presenting the rejection to
substantiate why one of ordinary skill in the art would have provided for a
use of a leading indicator (L), as claimed here, a comparison step of L with a
target, and adjustment of a reaction parameter based on a deviation between
L and the target during the polymerization reaction of Lue.
As Appellants essentially argue, the Examiner’s attempt at finding
motivation for the necessary modifications to Lue’s process based on a
conclusive assertion of “expectation of success” is basically a non-starter by
itself (App. Br. 13-14). Furthermore, the Examiner’s assertion of the ease of
performing such control is incomplete in furnishing a rationale for the
necessary modification to Lue for arrival at the claimed subject matter and,
in any event, it is not substantiated with persuasive evidence (Ans. 8).
In sum, the Examiner has not presented a sustainable basis for the
obviousness rejection. In this regard, “rejections on obviousness grounds
cannot be sustained by mere conclusory statements; instead, there must be
some articulated reasoning with some rational underpinning to support the
legal conclusion of obviousness” being asserted. In re Kahn, 441 F.3d 977,
988 (Fed. Cir. 2006) (quoted with approval in KSR Int'l Co. v. Teleflex Inc.,
550 U.S. 398, 418 (2007)). After all, rejections based on § 103(a) must rest
on a factual basis with these facts being interpreted without impermissible
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hindsight reconstruction of the invention from the prior art. See In re
Warner, 379 F.2d 1011, 1017 (CCPA 1967).
On this record, we reverse the Examiner’s obviousness rejection of
the appealed claims.

CONCLUSION
The Examiner has not established that Lue inherently describes a
polymerization process that includes Appellants’ claimed function L and
associated comparison and adjusting steps that the claimed process reads on.
The Examiner has not established that it would have been obvious to
one of ordinary skill in the art to employ Appellants’ L function and the
corresponding comparing and adjustment steps in Lue, as variously required
by the appealed claims, based on the teachings of Lue and the Examiner’s
rebuttal assertions of a reasonable expectation of success, knowledge of the
art about hydrogen use in molecular weight control, and unsubstantiated
allegations regarding the ease of monitoring and control of a polymerizing
process.

ORDER
The Examiner’s decision to reject claims 1-8, 11-20, 23-29, 32-38,
and 41-74 under 35 U.S.C. § 102(b) as being anticipated by or, in the
alternative, under 35 U.S.C. § 103(a) as being obvious over Lue is reversed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 CFR § 1.136(a)(1).

REVERSED

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PL Initial:
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