Ex Parte Bockholt et al

Board of Patent Appeals and Interferences

May 27, 2010

11572536 (B.P.A.I. May. 27, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte ANDREAS BOCKHOLT and LEONHARD BRADER
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Appeal 2010-002742
Application 11/572,536
Technology Center 1600
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Decided: May 27, 2010
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Before DONALD E. ADAMS, LORA M. GREEN, and
JEFFREY N. FREDMAN, Administrative Patent Judges.

GREEN, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from the
Examiner’s rejection of claims 8-22. We have jurisdiction under 35 U.S.C.
§ 6(b).

Appeal 2010-002742
Application 11/572,536

STATEMENT OF THE CASE
Claim 8 is the only independent claim on appeal, and reads as follows:

8. A process for preparing phosphonatosilanes of the formula (II)

R1n(X)3-n-Si-R3-PO(OR4)(OR5) (II)

comprising reacting halogenated silanes of the formula (III)

R1n(X)3-n-Si-R3-Hal (III)

with phosphites of the formula (IV)

P(OR4)(OR5)(OR6) (IV)

in a reaction vessel,
where
R1 is an optionally halogen-substituted hydrocarbon radical having 1-20
carbon atoms or hydrogen,
X is a hydrolyzable group or OH,
R3 is an optionally halogen-substituted alkylene radical having 1-10
carbon atoms,
R4, R5 and R6 are each optionally halogen-substituted hydrocarbon radicals
having 1-20 carbon atoms,
Hal is a halogen atom and
n is 0, 1, 2 or 3,
in which a portion of the reaction mixture is withdrawn continuously
or repeatedly during the reaction, separating the product formed from the
reactants by applying the reaction mixture to a thin-film evaporator,
separating a bottoms high boiler fraction containing product, and recycling
distillate to the reaction vessel.

We reverse.

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ISSUES
Does the preponderance of evidence of record support the Examiner’s
conclusion that the combination of Gallagher, Silverman, and Benghiat
renders the method of claim 8 prima facie obvious?
If yes, have Appellants presented evidence of unexpected results, that
when weighed when the evidence of obviousness, sufficient to demonstrate
the unobviousness of the claimed method?

FINDINGS OF FACT
FF1 The Examiner rejects claims 8-22 under 35 U.S.C. § 103(a) as being
rendered obvious by the combination of Gallagher,1 Silverman,2 and
Benghiat.3 (Ans. 3.)
FF2 We adopt the Examiner’s findings as to the prima facie obviousness
rejection as our own. (See id. at 3-5.)
FF3 Example 3 is drawn to preparation of diethylphosphonatomethyl-
trimethoxysilane. (Spec. 6.) The reaction is performed at 100ºC, and the
volume of the reaction mixture is kept constant by addition of reaction
mixture. (Id.) According to the Specification:
The yield of diethylphosphonatomethyltrimethoxysilane is 100
ml/h. The product is obtained in a purity of 96% (by GC). The
reactants form the main impurities; by-products are found only
in traces.

1 Skip Gallagher, Synthesis and Characterization of Phosphonate-
Containing Polysiloxanes, 41 J. POLYMER SCIENCE 48-59 (2003).
2 Richard B. Silverman, THE ORGANIC CHEMISTRY OF DRUG DESIGN AND
DRUG ACTION 15-22 (Academic Press, Inc., 1992).
3 Benghiat, US 3,700,760, issued Oct. 24, 1972.
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Application 11/572,536

(Id.)
FF4 The Specification lists the last example as a “Noninventive
Comparative Example: Preparation of diethylphosphonatomethyl-
trimethoxysilane.” (Id. at 7.)
FF5 The reaction is again performed at 100ºC, and the Specification
teaches that “132.1 g of diethylphosphonatomethyltrimethoxysilane are
obtained in a purity of 94%.” (Id.)
FF6 Gallagher reports the following reaction conditions for the synthesis
of the disclosed phosphanatosilanes:

(Gallagher 54.)

PRINCIPLES OF LAW
The burden of demonstrating unexpected results rests on the party
asserting them, and “it is not enough to show that results are obtained which
differ from those obtained in the prior art; that difference must be shown to
be an unexpected difference.” In re Klosak, 455 F.2d 1077, 1080 (CCPA
1972).
When a patent applicant puts forth rebuttal evidence, the Board
must consider that evidence. See In re Soni, 54 F.3d 746, 750
(Fed. Cir. 1995) (stating that “all evidence of nonobviousness
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Application 11/572,536

must be considered when assessing patentability”); In re
Sernaker, 702 F.2d 989, 996 (Fed. Cir. 1983) (“If, however, a
patent applicant presents evidence relating to these secondary
considerations, the board must always consider such evidence
in connection with the determination of obviousness.”).

In re Sullivan, 498 F.3d 1345, 1351 (Fed. Cir. 2007).

ANALYSIS
As to the prima facie case of obviousness, Appellants argue that based
on the low yields, high reaction temperatures, and long reaction times of
Gallagher, the ordinary artisan would not be motivated to adapt it to a
continuous process. (App. Br. 4.) But as acknowledged by Appellants (id.
at 6), converting a batch process to a continuous process is not ordinarily
inventive, and the ordinary artisan would understand the weighing of
different considerations, such as long reaction time versus the desirability of
the product.
Appellants argue further that Silverman in not relevant at all, as it
relates to isosterism as applied to pharmacological compounds, and methyl
and hydroxyl, while being isosteres, are not equivalent in chemical reactions.
(Id. at 8.) The Examiner relied on Silverman for its teaching that methyl and
hydroxyl groups are isosteres and thus have similar chemical, physical, and
biological properties (Ans. 4.), and the methyl group off of the silicon atom
of Gallagher is not being modified in the reaction of Gallagher.
Appellants assert further that Benghiat is not analogous art, as it “is
not directed to the production of phosphonatosilanes, but to highly
halogenated alkylphosphite esters.” (App. Br. 8.) The Examiner relied on
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Benghiat for its teaching of a continuous process, wherein a portion of the
reaction mixture is recycled continuously after purification. (Ans. 4.) The
analysis under 35 U.S.C. § 103, however, “need not seek out precise
teachings directed to the specific subject matter of the challenged claim, for
a court can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ.” KSR Int'l Co. v. Teleflex Inc., 550
U.S. 398, 418 (2007); see also id. at 421 (“A person of ordinary skill is also
a person of ordinary creativity, not an automaton.”). Thus, the ordinary
artisan would have understood that the continuous process of Benghiat could
be used for other reactions, and not just in the production of highly
halogenated alkylphosphite esters.
We therefore conclude that the Examiner has set forth a prima facie
case of obviousness, and thus turn to Appellants’ showing of unexpected
results. (App. Br. 4-6; see also Reply Br. 5-6.) According to Appellants, the
claimed process and the process of Gallagher have been compared as seen
from Example 3 and the “non-inventive Comparative Example.” (Id. at 4-
5.) Scaling the reaction due to the different starting amounts or reactants
(4.0 mol in the inventive example, and 0.6 mol in the comparative example);
Appellants present the following Table:

(Id. at 5.)
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Application 11/572,536

Based on the Table, Appellants argue:
As can be seen, with both reactions conducted at the
same temperature, and now comparing the same initial quantity
of reactants (4.0 mol of each reactant) the continuous process
produced a 570% improvement over the batch process. Over
50 hours, the continuous process would have yielded 5 Kg of
product, while the batch reaction would have yielded only
132.lg. Moreover, the yield of the continuous process is very
high, above 90%, which is evident from the fact that the volume
in the reactor is made up by addition of reactants in the same
volume as product obtained while the yield of the comparative
example, even after 50 hours, is only 76%.

(Id.)
The Examiner concludes that data does not demonstrate unexpected
results for several reasons. (Ans. 6-7.) First, the Examiner notes that the
data are presented at a yield rate (g/h), but that the noninventive batch
reaction was run for 50 hours without determining yield at an intermediate
point. (Id. at 6.) The Examiner asserts “[i]f the batch process had run to
completion within, e.g. 4 hours, using 50 hours in calculating the reaction
rate would be misleading, as the actual rate would be much greater.” (Id.)
The reactions of Gallagher were run at a minimum of 4 days, with a
minimum temperature of 180 ºC. (See, e.g., FF6.) Thus, in view of the
teachings of Gallagher, the ordinary artisan would not have expected the
comparative noninventive batch example presented in the Specification,
which was run at 100 ºC, to have run to completion in 50 hours.
The Examiner further notes that in the inventive example, the volume
of the reaction mixture is kept constant by adding additional reaction
mixture, wherein no additional reaction mixture was added to the batch
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Application 11/572,536

reaction. (Ans. 6.) The Examiner has not presented evidence or argument,
however, as to why the ordinary artisan would have expected a 570%
improvement over the batch process even with the addition of additional
reaction mixture, because, as discussed above, the ordinary artisan would
have expected a slow reaction rate based on the teachings of Gallagher.
Thus, we conclude that the preponderance of evidence of record
supports Appellants’ position that the conversion of the batch reaction of
Gallagher to the claimed continuous reaction provides yields that would
have been unexpected in view of the teachings of Gallagher.

CONCLUSIONS OF LAW
We conclude that the preponderance of evidence of record supports
the Examiner’s conclusion that the combination of Gallagher, Silverman,
and Benghiat renders the method of claim 8 prima facie obvious. However,
Appellants have presented evidence of unexpected results, that when
weighed when the evidence of obviousness, are sufficient to demonstrate the
unobviousness of the claimed method.
We thus reverse the rejection of claims 8-22 under 35 U.S.C. § 103(a)
as being rendered obvious by the combination of Gallagher, Silverman, and
Benghiat.

REVERSED

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