Ex Parte Barsa et al

Board of Patent Appeals and Interferences

Sep 15, 2011

12077252 (B.P.A.I. Sep. 15, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte EDWARD A. BARSA and
BETH M. STEINMETZ
__________

Appeal 2011-006962
Application 12/077,252
Technology Center 1600
__________

Before DONALD E. ADAMS, ERIC GRIMES, and FRANCISCO C.
PRATS, Administrative Patent Judges.

GRIMES, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a process
for producing glycerol di-tert-butyl ether. The Examiner has rejected the
claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.
STATEMENT OF THE CASE
The Specification discloses that di-tert-butyl ethers of glycerol are
useful as additives to diesel fuel (Spec. 1: 22-32). The Specification
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discloses methods of making “a di-tert-butyl ether product mixture
containing less than 5 wt. % of isobutylene oligomers” (id. at 3: 31-33).
Claims 1-9 are on appeal. Claims 1 and 7, the only independent
claims, read as follows:
1. A process which comprises reacting glycerol and isobutylene in the
presence of a β-zeolite having a silicon to aluminum ratio greater than 150 to
give a product mixture comprising a glycerol di-tert-butyl ether.

7. A process which comprises reacting glycerol and isobutylene in the
presence of a β-zeolite and added tert-butyl alcohol to give a product
mixture comprising a glycerol di-tert-butyl ether.

Issues
The Examiner has rejected claims 1-91 under 35 U.S.C. § 103(a) as
being obvious in view of Karinen,2 Klepáčová,3 Dewattines,4 and Cannan5
(Answer 46). The Examiner finds that Karinen discloses “a process for
preparing glycerol ethers comprising reacting glycerol, isobutylene, and
TBA [tert-butyl alcohol] in the presence of an acidic ion exchange resin

1 The Examiner’s statement of the rejection only refers to claims 1-8
(Answer 4) but claims 1-9 are pending and rejected (id. at 2). Therefore, we
understand the rejection to apply to all of claims 1-9, which is how
Appellants understood and addressed the rejection (Appeal Br. 2).
2 R. S. Karinen et al., New biocomponents from glycerol, 306 APPLIED
CATALYSIS A: GENERAL 128-133 (2006)
3 K. Klepáčová et al. Etherification of Glycerol with tert-Butyl Alcohol
Catalysed by lon-Exchange Resins” 60 CHEM. PAP. 224-230 (2006)
4 Dewattines, EP 0649829, 1999
5 Cannan, US 5,139,759, Aug. 18, 1992
6 The Examiner’s statement of the rejection also recites “Applicants
admission” (Answer 4), but the Examiner does not specify what admission is
being referred to.
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catalyst.… It is taught that TBA prevents the oligomerization reaction of
isobutene and thereby improves the selectivity towards ethers.” (Answer 4.)
The Examiner finds that “zeolites are also taught [by Karinen] to be
suitable” catalysts and that Klepáčová discloses the “use of large-porous
zeolites in place of acidic ion exchange resins” (id.).
The Examiner finds that Dewattines discloses that using “zeolites
having Si/Al atomic ratios of greater than 5, such as β-zeolite, … results in
producing tertiary alkyl glycerol ethers in good yield, limiting the
undesirable by-products, such as isobutene oligomers” (id. at 4-5). The
Examiner concludes that the claimed invention would have been obvious
“because all the claimed elements were known in the prior art and one
skilled in the art could have combined the elements … with no change in
their respective functions” (id. at 5).
Appellants contend that it would not have been obvious to combine
Karinen’s tert-butyl alcohol with Dewattines’ β-zeolite catalyzed process
(Appeal Br. 5). Appellants also argue that they have presented evidence of
unexpected results that overcomes any prima facie case of obviousness (id.
at 6-7).
The issues presented are: Does the evidence of record support the
Examiner’s conclusion that the cited references would have made obvious
the methods of claims 1 and 7? and, if so,
Have Appellants provided evidence of unexpected results that
outweighs the evidence supporting the prima facie case of obviousness?
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Findings of Fact
1. Dewattines discloses a process in which “glycerol reacts with
isobutylene in the presence of [a] zeolite beta” catalyst to produce glycerol
di-tert-butyl ether (Dewattines 2).
2. Dewattines discloses that its process uses a zeolite beta (i.e., β-
zeolite) catalyst with a Si/Al atomic ratio of greater than 5 (id. at 1).
3. Dewattines discloses that its process “limit[s] the undesirable by-
products such as oligomers of olefine for example” (id.).
4. Appellants have acknowledged that Cannan describes a method of
making β-zeolites having a Si/Al ratio as high as 221, and that β-zeolites
having Si/Al ratios greater than 150 are commercially available (Appeal Br.
3).
5. Karinen discloses the “[e]therification of glycerol with isobutene in
liquid phase with [an] acidic ion exchange resin catalyst” (Karinen,
abstract).
6. Karinen discloses that the reaction produced mono-tert-butyl
ethers, di-tert-butyl ethers, and tri-tert-butyl ether (id. at 131, Fig. 4).
7. Karinen discloses that “[i]n some experiments, tert-butyl alcohol
(TBA) was added to the reaction mixture in order to prevent the
oligomerisation reaction of isobutene and thereby improve the selectivity
towards ethers” (id. at 132, left col.).
8. Karinen discloses that TBA “had a clear effect on the selectivity
and the hydrocarbon distribution” (id.).
9. Klepáčová discloses that the
[e]therification (O-alkylation) of glycerol is [an] acid catalysed
reaction with formation of mono-, di-, and tri-tert-butyl
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glycerol ethers.… Catalysts can be homogeneous … but more
preferred are eco-friendly heterogeneous catalysts (very acid
ion-exchange resins). Large-porous zeolites can also be used.
(Klepáčová, 225, right col.)
10. The Specification discloses that a reaction containing a β-zeolite
catalyst with a Si/Al molar ratio of 300, and no TBA, yielded 78.6%
glycerol di-tert butyl ether and 14.14% (12.7% + 1.44%) isobutylene
oligomers (Spec. 10, Table 1, Example 1).
11. The Specification discloses that a reaction containing a β-zeolite
catalyst with a Si/Al molar ratio of 150, and no TBA, yielded 72.4%
glycerol di-tert butyl ether and 24.89% (21.0% + 3.89%) isobutylene
oligomers (Spec. 10, Table 1, Example C4).
Principles of Law
“Obviousness does not require absolute predictability of success…
For obviousness under § 103, all that is required is a reasonable expectation
of success.” In re O’Farrell, 853 F.2d 894, 903-04 (Fed. Cir. 1988).
“It is well established that the objective evidence of nonobviousness
must be commensurate in scope with the claims.” In re Lindner, 457 F.2d
506, 508 (CCPA 1972).
“If an applicant demonstrates that an embodiment has an unexpected
result and provides an adequate basis to support the conclusion that other
embodiments falling within the claim will behave in the same manner, this
will generally establish that the evidence is commensurate with [the] scope
of the claims.” In re Kao, 639 F.3d 1057, 1068 (Fed. Cir. 2011).
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Analysis
Claim 1 is directed to a process of making a glycerol di-tert-butyl
ether by reacting glycerol and isobutylene in the presence of a β-zeolite
catalyst having a Si/Al ratio greater than 150. Claim 7 is directed to a
similar process but does not require the β-zeolite catalyst to have any
specific Si/Al ratio and includes tert-butyl alcohol in the reaction.
Dewattines discloses a process in which glycerol reacts with
isobutylene in the presence of a β-zeolite catalyst having a Si/Al ratio greater
than 5 to produce glycerol di-tert-butyl ether. Appellants have conceded that
Cannan discloses β-zeolites having a Si/Al ratio as high as 221, and that β-
zeolites with Si/Al ratios greater than 150 are commercially available. We
agree with the Examiner that it would have been obvious to use the high
Si/Al β-zeolites taught by Cannan, and commercially available, in
Dewattines’ process because Dewattines discloses that β-zeolites with a
Si/Al ratio greater than 5 are suitable in its process.
With regard to claim 7, Karinen discloses that adding tert-butyl
alcohol to the reaction of glycerol with isobutene, with an acidic ion
exchange resin catalyst, to produce di-tert-butyl ether inhibited the
oligomerization of isobutene and improved the selectivity towards ethers. In
view of this disclosure, it would have been obvious to add tert-butyl alcohol
to Dewattines’ β-zeolite catalyzed reaction in order to obtain the benefits
disclosed by Karinen.
Appellants argue that one of ordinary skill in the art would not have
reasonably expected that tert-butyl alcohol would be beneficial in
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Dewattines’ reaction because Karinen and Dewattines used different
catalysts and “the catalyst art is inherently unpredictable” (Appeal Br. 5).
This argument is not persuasive. Klepáčová discloses that the
etherification of glycerol is an acid catalyzed reaction that may be catalyzed
with either acidic ion-exchange resins or large-porous zeolites. Thus,
because Dewattines and Karinen disclose acid-catalyzed reactions of the
same reactants, one of ordinary skill in the art would have reasonably
expected that Karinen’s tert butyl alcohol would also have beneficial effects
in Dewattines’ reaction, regardless of the presence of a different catalyst. In
accordance with In re O’Farrell, obviousness requires only a reasonable
expectation of success, not absolute predictability.
Appellants also argue that they have overcome any prima facie case of
obviousness by providing evidence of unexpected results (Appeal Br. 5-7).
With regard to claim 1, Appellants argue that they have
surprisingly found that the amounts of isobutylene oligomers
could be reduced to relatively low levels while coincidentally
achieving high selectivities (69-79%) to di-tert-butyl ethers. In
particular, Appellants’ Table 1 shows that β-zeolite catalysts
generally provide a high proportion of glycerol di-tert-butyl
ethers, and the amount of isobutylene oligomers is reduced
significantly by selecting a β-zeolite having a Si/Al molar ratio
greater than 150.
(Id. at 5.)
With regard to claim 7, Appellants argue that they have “surprisingly
found that adding tert-butyl alcohol into the reaction of glycerol and
isobutylene catalyzed by β-zeolite dramatically reduces the amount of
isobutylene oligomers formed” (id. at 6).
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These arguments are not persuasive. Evidence of nonobviousness
must be commensurate in scope with the claims; i.e., it must “provide[ ] an
adequate basis to support the conclusion that other embodiments falling
within the claim will behave in the same manner” as the tested embodiment.
See In re Kao, 639 F.3d at 1068. Here, the Specification discloses that a
β-zeolite catalyst with a Si/Al molar ratio of 300 results in an increased
proportion of di-tert butyl ether (over mono- or tri-tert butyl ether) and lower
amounts of isobutylene oligomers, compared to a β-zeolite catalyst with a
Si/Al molar ratio of 150. However, the Specification does not provide a
reasonable basis for concluding that the full range of ratios encompassed by
the claims – including, for example, a β-zeolite catalyst with a Si/Al molar
ratio of 160 – would show similar results to those obtained with a β-zeolite
catalyst with a Si/Al molar ratio of 300. Thus, the evidence of unexpected
results is not commensurate in scope with the claim.
With respect to Appellants’ argument that the method of claim 7
provides unexpected results, we agree with the Examiner “Karinen et al.
recognize that the use of TBA prevents the oligomerization reaction of
isobutene and thereby improves the selectivity towards ethers. Thus, the
results obtained by Appellants are not unexpected.” (Answer 7-8.)
Although Karinen’s results were obtained using a different catalyst than
used in the claimed invention, Appellants have provided no evidence to
show that those skilled in the art would have expected the effect of TBA to
differ depending on the identity of the catalyst.

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Conclusion of Law
The evidence of record supports the Examiner’s conclusion that the
cited references would have made obvious the methods of claims 1 and 7.
Appellants have not provided evidence of unexpected results that outweighs
the evidence supporting the prima facie case of obviousness.
SUMMARY
We affirm the rejection of independent claims 1 and 7 under 35
U.S.C. § 103(a). Claims 2-6, 8, and 9 were not argued separately and
therefore fall with the independent claims. 37 C.F.R. § 41.37(c)(1)(vii).
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED

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