Ex Parte Guerra

Board of Patent Appeals and Interferences

Sep 8, 2006

10322254 (B.P.A.I. Sep. 8, 2006)

The opinion in support of the decision being
entered today was not written for publication
and is not binding precedent of the Board.

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UNITED STATES PATENT AND TRADEMARK OFFICE

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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES

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Ex parte MIGUEL A. GUERRA

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Appeal No. 2006-1161
Application No. 10/322,254
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ON BRIEF
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Before MILLS, GREEN and LINCK, Administrative Patent Judges.

LINCK, Administrative Patent Judge.

DECISION ON APPEAL

This is a decision on appeal under 35 U.S.C. § 134 from the final rejection of
claims 1-19, all of the pending claims in Application No. 10/322,254 (hereafter the “ ‘254
application”),1 under 35 U.S.C. § 103(a).
There are two independent claims in the ‘254 application, claims 1 and 11. They
are representative and read as follows:

1 The present application was filed on December 17, 2002 and is assigned to the 3M Company.
Appeal No. 2006-1161
Application No. 10/322,254

1. A continuous or repeated–batch process for preparation of a compound
according to formula (I):

X-Rf-CF2-O-CF(CF3)COF (I)

wherein X- is FOC- or FSO2- and wherein -Rf- is a linear, branched or cyclic
fluoroalkene group containing 1-20 carbon atoms which is highly fluorinated and
which may incorporate ether and tertiary amine groups, comprising the steps of:

a) providing a mixture of:

X-Rf-COF (II)

wherein X- and -Rf- are as defined for formula (I), a fluoride salt, and
a polar solvent;

b) adding hexfluoropropylene oxide (HFPO) in an amount such that
X-Rf-COF remains in molar excess of HFPO by at least 10% and
reacting X-Rf-COF with HFPO;

c) separating unreacted X-Rf-COF from a mixture of addition products of
hexafluoropropylene oxide (HFPO) and X-Rf-COF;

d) repeating step a) using unreacted X-Rf-COF separated in step c).

11. A method of reacting hexafluoropropylene oxide (HFPO) with a
perfluoroacyl fluorides according to the formula:

X-Rf-COF (II)

wherein X is FOC- or FSO2- and wherein -Rf- is a linear, branched or cyclic
fluoroalkene group containing 1-20 carbon atoms which is highly fluorinated and
which may incorporate ether and tertiary amine groups,

to form a mixture of addition products comprising the monoaddition
product according to the formula:

X-Rf-CF2-O-CF(CF3)COF (I)

wherein the molar amount of said monoaddition product is 90% or greater
of the combined molar amount of said monoaddition product and a biaddition
product according to the formula:

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Application No. 10/322,254

X-Rf-CF2-O-CF(CF3)CF2-O-CF(CF3)COF (III)

in said mixture of addition products.

The following references were cited and relied upon by the Examiner:
U.S. Patent No. 4,613,467 (issued Sept. 23, 1986 to Kimoto et al.) (hereafter “Kimoto”);

Lewis Sr., R.J., HAWLEY’S CONDENSED CHEMICAL DICTIONARY 995 (12th ed. 1993)
(hereafter “Lewis”).

Claims 1-19 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over
Kimoto in view of Lewis. Answer at 2.
We affirm.
BACKGROUND
Reactions of hexafluoropropylene oxide (HFPO) with
perfluoroacyl fluorides that result in a mixture of reaction products,
differing in the number of incorporated HFPO units, are known. In the
practice of these reactions, careful fractionation of the product mixture
may be required to remove undesirable byproducts, such as products
incorporating more than one HFPO unit. [Specification at 1.]

In this case, the perfluoroacyl fluoride is in molar excess of the HFPO by at least
10%, with the object of obtaining selectivity for the monoaddition product over the
biaddition product of 90% or greater. Specification at 1-2. The product is separated from
the unreacted perfluoroacyl fluoride, and this unreacted starting material is recycled by
again reacting it with HFPO. Id.
DISCUSSION
Concerning the application of § 103(a), the Supreme Court has articulated three
factors that are relevant to an obviousness determination: (1) the scope and content of the
prior art; (2) the differences between the prior art and claims at issue; and (3) the level of
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Application No. 10/322,254

ordinary skill in the pertinent art. Graham v. John Deere Co., 383 U.S. 1, 17 (1966).
See also Answer at 3. Thus, Graham instructs us to consider these three factors prior to
turning to the ultimate legal conclusion.
The Scope and Content of the Prior Art
The primary reference relied upon by the Examiner is Kimoto. Kimoto is directed
to a fluorinated copolymer “useful as a starting material for production of a cation
exchange membrane or a fluorinated cation exchange resin . . . and also to a process for
preparing the same.” Col. 1, lines 10-15. The copolymer is prepared by polymerizing a
fluorinated olefin with a sulfur-containing fluorinated vinylether. In turn, the fluorinated
vinylether can be prepared from a fluorinated acid fluoride. See, e.g., col. 11, line 67-
col. 12, line 29. Thus, one object of this invention “is to provide a novel fluorinated acid
fluoride represented by the formula:
FSO2( CF2)n+1 (OC(CF3)FCF2)pOC(CF3)FCOF [A]
wherein n is an integer of 2 to 4, and p is an integer of 0 to 50.”
Col. 10, lines 46-54. The fluorinated acid fluoride represented by formula A overlaps
with formula I in claim 1 of the ‘254 application. Thus, there is no question formula A
includes the monoaddition product of the presently claimed process when p is 0.
The Kimoto reference further teaches that the
applicable molar ratio of hexapropylene oxide to FSO2( CF2)nCOF is
from about 1/20 to about 100/1. When the compound [A] has a low p
value, for example, when p is 0 or 1, the relative proportion of
FSO2(CF2)nCOF is increased, and lower pressure and higher
temperature are preferred to be selected. . . .
. . . .
[A] cation exchange membrane prepared from a copolymer of
said fluorinated vinyl ether compound and tetrafluorethylene may
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Application No. 10/322,254

desirably have an ion-exchange capacity as large as possible. From this
standpoint, said fluorinated vinyl ether compound may preferably have
a molecular weight as small as possible. Accordingly, it is preferred
that the value of p may be 0 or 1, most preferably 0. [Col. 11, line 50-
col. 12, line 17.]

Examples 2 and 4 of Kimoto are relied upon by the Examiner to show that
Kimoto obtains both a monoaddition and a biaddition product and further that the product
is separated from remaining starting materials. Final Office Action at 4; Answer at 6-7.
In Example 2, FSO2(CF2)2COF was reacted with a slight excess HFPO. Col. 29,
lines 30-39. The reaction mixture separated into two layers, and the lower layer
was distilled to yield a fraction boiling at 45˚C, i.e., the monoaddition product
FSO2(CF2)3OC(CF3)FCOF. Id., lines 39-58. The yield was 225 g (0.57 mol, or 57%
based on the limiting reactant FSO2(CF2)2COF2). Example 4 used a greater molar excess
of HFPO and yielded more of the biaddition product than the monoaddition product. Col.
30, lines 38-56. Thus, these two examples considered together support Kimoto’s
statements regarding the impact of changing the proportion of HFPO to FSO2(CF2)nCOF.
See col. 11, lines 50-66.
Lewis (the dictionary reference) is relied upon to show what one of ordinary skill
in the art would have known at the time the invention was made, i.e., that recycling is
useful to obtain “a more efficient conversion of unreacted components or to reuse
auxiliary materials that remain unchanged during processing.” Lewis at 995. See also
Answer at 4-5.

2 Appellant’s calculation yielded 52%. Brief at 8. The difference in these calculations does not impact our
analysis.
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The Level of Skill in the Art
The level of skill in the art is not challenged and is reflected in the references
cited in the case and the Examiner’s statements regarding the general knowledge in the
art. See Answer passim.
The Differences Between the Prior Art and The Claims At Issue
The following limitations in claim 1 are not expressly disclosed in Kimoto or
Lewis:
1) “separating unreacted X-Rf-COF from a mixture of addition products of
hexafluoropropylene oxide (HFPO) and X-Rf-COF” (step c);
2) repeating step a) using unreacted X-Rf-COF separated in step c) (step d); and
3) maintaining X-Rf-COF reactant in molar excess of HFPO by at least 10% during
the reaction (step b).
The following additional limitations in claims 2-5 and 11-19 are not
expressly disclosed in Kimoto or Lewis:
1) Each of claims 2-5 and 11-19 additionally require that the selectivity for the
monoaddition product be 90% or greater; and
2) Claims 4, 5, 13 and 14 each add the limitation that the molar yield of the
monoaddition product (based on HFPO) be 75% or greater.
The § 103(a) Determination In View Of These Graham Findings
In view of the differences between the pending claims and the prior art, the teachings
and/or suggestions in the two cited references and the general knowledge in the art, the
Examiner found that one of ordinary skill in the art would have been motivated to:
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Application No. 10/322,254

(1) perform steps c) and d) of claim 1;
(2) maintain X-Rf-COF reactant in molar excess of HFPO by at least 10%
during the reaction; and
(3) obtain the selectivity and molar ratios claimed in claims 2-5 and 11-19.
Final Office Action at 4-5; Answer at 5-7. Based on these findings, the
Examiner concluded that the claims are unpatentable under 35 U.S.C. § 103(a).
Thus, the issue before us is whether the evidence of record supports the
Examiner’s prima facie case of obviousness.
Step c) requires “separating unreacted X-Rf-COF from a mixture of addition
products of hexafluoropropylene oxide (HFPO) and X-Rf-COF.” See claim 1. With
respect to this limitation, it is the Examiner’s position that step c) is “inherently taught by
Kimoto.” Answer at 4. Appellant responds: “Since Kimoto exemplifies the use of a
molar excess of HFPO, unreacted X-Rf-COF is not expected, and thus Kimoto cannot
anticipate the step of ‘separating unreacted X-Rf-COF.’ Kimoto is in fact silent as to the
fate of any unreacted X-Rf-COF in Examples 2 or 4, or as to whether any exists or is
expected.” Brief at 9.
The Examiner responds to Appellant’s argument as follows:
First, the X-Rf-COF does not need to be in excess in order [to] have a
portion of it remain unreacted. Second . . . , many chemical reactions
do not obtain 100% conversion of their chemical reactants. Thus, the
products usually contain some unreacted starting material. In Example
2 of Kimoto, the reaction mixture is disclosed as separating into two
layers and then subjecting the lower to distillation, a well known
purification technique, thus isolating the desired product. Although,
Kimoto does not explicitly teach that the unreacted starting materials,
i.e., the HFPO and FSO2(CF2)nCOF, are present in the upper layer
and/or fraction(s)separated from the lower layer, the ordinary skilled
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artisan would reasonably believe that the unreacted starting materials
are contained in at least one of the upper layer and/or fraction(s) which
were separated from the desired product. [Answer at 6-7.]

Kimoto clearly discloses separating reactants from the addition product, a very
routine step performed by those of ordinary skill in the art conducting synthetic reactions.
And we agree with the Examiner that unreacted FSO2(CF2)nCOF is undoubtedly
inherently present “in at least one of the upper layer and/or fraction(s) which were
separated from the desired product,” particularly given that yield of the product is
substantially less than 100%. See the discussion of Example 2 supra at 5.
In any case, Kimoto teaches separation of unreacted starting material(s) from the
final product. See col. 29, lines 39-52; col. 30, lines 41-53. These teachings clearly
suggest what Appellant has claimed in step c) regardless of whether the disclosed
separations yield unreacted HFPO, FSO2(CF2)nCOF or both. The skilled artisan seeking
to reap the benefits of recycling described in Lewis (and well understood in the art)
would have known how to and would have been motivated to separate any
FSO2(CF2)nCOF in order to conduct step d).
Step d) requires “repeating step a) using unreacted X-Rf-COF separated in step
c).” See claim 1. With respect to this limitation, the Examiner acknowledges that it is
not taught by Kimoto. Answer at 5. To bridge this difference, she relies on Lewis for the
“general teaching regarding recycling,” stating that it “gives reasons why one would want
to recycle unreacted starting materials.” Id. According to the Examiner, “the teaching of
Lewis is applicable to the process taught by Kimoto, which inherently contains unreacted
starting materials.” Id.
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We agree with the Examiner that, once reactants have been separated from
product, one of ordinary skill in the art would have been motivated to recycle the starting
materials “for the purpose of more efficient conversion of unreacted components.” Lewis
at 995. Appellants do not argue to the contrary, but rather state “step d) first requires step
c), which . . . Kimoto cannot anticipate. As a result, it makes no sense to proceed with
step d) and there can be no rationale to combine Kimoto with the Dictionary reference.”
Brief at 9. Given that step c) is either inherently disclosed in or suggested by Kimoto, a
skilled artisan would have been motivated to proceed with step d), as the Examiner
found. See Answer at 5.
Claim 1 also requires “adding hexfluoropropylene oxide (HFPO) in an amount
such that X-Rf-COF remains in molar excess of HFPO by at least 10%.” Appellants
argue that “Kimoto fails to anticipate and teaches away from” this claim limitation. Brief
at 8.
The Examiner responds:
Kimoto et al. do suggest using the X-Rf-COF in molar excess of HFPO
by at least 10% (see column 11, lines 50-52 wherein it is taught that
one can use a molar ratio of HFPO to FSO2(CF2)nCOF from about 1/20
to about 100/1). Thus, at the ratios ranging from 10:1 up to 20:1
[FSO2(CF2)nCOF:HFPO], Kimoto teaches using the FSO2(CF2)nCOF in
a molar excess of at least 10% relative to the HFPO. Kimoto further
goes on to teach that when the compound having the structure disclosed
in column 11, lines 53-58 has a low p value, for example when p is 0 or
1, the relative proportion of FSO2(CF2)nCOF is increased. Thus,
implying that if one wants to obtain the monoaddition product, i.e., p
equal to zero, then one should use higher amounts of the
FSO2(CF2)nCOF reactant relative to the HFPO reactant. [Answer at 5.]

Appellant does not dispute that the claimed “at least 10% molar excess” language
falls within Kimoto’s disclosed range of reactants, i.e., the “applicable molar ratio of
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hexapropylene oxide to FSO2( CF2)nCOF is from about 1/20 to about 100/1.” Col. 11,
lines 50-52. Instead Appellant argues “such a broad range fails to teach the range
claimed in the present invention with sufficient specificity to anticipate.” Brief at 9.
We agree that the disclosed range is broad. However, additional teachings in
Kimoto would point a skilled artisan toward the claimed invention. The skilled artisan
would have been motivated to make the monoaddition product, as Kimoto teaches the
value of p is “most preferably 0,” at least when making starting product for cation
exchange membranes. Col. 12, lines 9-17. And, when seeking the monoaddition product
(when p is zero), “the relative proportion of FSO2(CF2)nCOF should be increased.” Col.
11, lines 52-60. Thus, one of ordinary skill in the art seeking a high yield of the
monoaddition product would have been motivated to increase the relative proportion of
FSO2(CF2)nCOF used in Example 2 to optimize the 57% yield obtained in that example.
The 10% excess language of the claims falls within a disclosed range in Kimoto,
and there is sufficient teachings in Kimoto to direct the skilled artisan to use
FSO2(CF2)nCOF in excess, if the monoaddition product is sought. Given the direction
provided by Kimoto, only routine experimentation would be required to make the
claimed invention.
The Federal Circuit has addressed the situation in which a claimed range is
identified from routine experimentation:
“[I]t is not inventive to discover the optimum or workable ranges by
routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ
233, 235 (CCPA 1955). Only if the “results of optimizing a variable”
are “unexpectedly good” can a patent be obtained for the claimed
critical range. In re Antonie, 559 F.2d 618, 620, 195 USPQ 6, 8
(CCPA 1977); see also In re Dillon, 919 F.2d 688, 692, USPQ2d 1897,
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1901 (Fed. Cir. 1990) (in banc). [In re Geisler, 116 F.3d 1465, 1470,
43 USPQ2d 1362, 1365 (Fed. Cir. 1997).]

In this case, there is no evidence of unexpected results. Optimizing the yield of
monoaddition product would be achieved, just as expected, when following the
suggestion/teaching in Kimoto. Further this is not an “obvious to try” situation, given
the prior art expressly teaches what parameters to vary and how to vary them to obtain
the desired product. See In re O’Farrell, 853 F.2d 894, 903, 7 USPQ2d 1673, 1681 (Fed.
Cir. 1988), quoted in Merck & Co. v. Biocraft Labs, 874 F.2d 804, 807, 10 USPQ2d
1843, 1845 (Fed. Cir. 1989).
Appellants argue “the reference teaches away from the present invention by
demonstrating Examples which are qualitatively opposite the present invention.” Brief at
9 (emphasis in original). We disagree. “[A]ll of the disclosures in a reference . . . ‘must
be evaluated for what they fairly teach one of ordinary skill in the art.’” In re Inland
Steel Co., 265 F.3d 1354, 1361, 60 USPQ2d 1396, 1401 (Fed. Cir. 2001) (quoting In re
Boe, 355 F.2d 961, 965, 148 USPQ 507, 510 (CCPA 1966)). See also In re Mills, 470
F.2d 649, 651-52, 176 USPQ 196, 198 (CCPA 1972). Thus, the working examples must
be considered in light of Kimoto’s teachings as a whole, and the teachings as a whole do
not teach away from the present invention. See col. 11, line 50-col. 12, line 17 (quoted
supra at 4-5).
In any case, in Example 2 Kimoto obtains the sought-after monoaddition product
when a slight excess of HFPO is used. See col. 29, lines 43-58. The fact that the yield is
somewhat less than optimal does not mean the example teaches away from the claimed
invention. Kimoto teaches the skilled artisan how to obtain a greater yield of
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monoaddition product, i.e., by increasing the ratio of the perfluoro starting material to
HFPO. See col. 11, lines 50-66.
Turning to the additional limitations in claims 2-5 and 11-19, we agree with the
Appellant that “Kimoto fails to disclose a process” resulting in the selectivity and molar
ratios claimed in claims 2-5 and 11-19. See Brief at 8. However, the issue before us is
not anticipation but rather obviousness under § 103(a). As previously determined,
Kimoto would have motivated the skilled artisan to optimize the yield of the
monoaddition product. See the discussion supra at 9-12. See also Answer at 3-4; Final
Office Action at 3-4. The claimed selectivity and molar ratios are merely the result of
such optimization. Again, optimization of a previously disclosed range, resulting in such
claimed selectivity and molar ratios does not warrant the grant of patent, absent some
evidence that the results are “unexpectedly good.” We find no such results in the record.
Thus, we affirm the Examiner’s rejection of all the pending claim as prima facie obvious
over Kimoto in view of Lewis.
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No time period for taking any subsequent action in connection with this appeal
may be extended under 37 CFR § 1.136(a)(1)(iv) (2004).
AFFIRMED

DEMETRA J. MILLS )
Administrative Patent Judge )
)
)
)
)
) BOARD OF PATENT
LORA M. GREEN ) APPEALS AND
Administrative Patent Judge ) INTERFERENCES
)
)
)
)
NANCY J. LINCK )
Administrative Patent Judge )
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Office of Intellectual Property Counsel
3M Innovative Properties Co.
P.O. Box 33427
St. Paul, MN 55133-3427

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