Ex Parte Cook et al

Board of Patent Appeals and Interferences

Mar 2, 2010

11732236 (B.P.A.I. Mar. 2, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte STEVEN LEROY COOK,
PHILLIP WAYNE TURNER, and VICKIE HAYGOOD OSBORNE
__________

Appeal 2009-013205
Application 11/732,236
Technology Center 1600
__________

Decided: March 3, 2010
__________

Before LORA M. GREEN, FRANCISCO C. PRATS,
JEFFREY N. FREDMAN, Administrative Patent Judges.

FREDMAN, Administrative Patent Judge.

DECISION ON APPEAL

This is an appeal under 35 U.S.C. § 134 involving claims to a process
for preparing di-n-butyl terephthalate. We have jurisdiction under 35 U.S.C.
§ 6(b). We reverse.

Appeal 2009-013205
Application 11/732,236

2
Statement of the Case
Background
“Terephthalic acid di-esters, such as Di-n-butyl terephthalate, also
known as DBT, can be used as plasticizers in a variety of polymeric
materials such as polyvinyl chloride” (Spec. 1, ll. 14-16). The Specification
teaches that “titanate catalyst cannot be used directly to produce di-n-butyl
terephthalate” (Spec. 1, ll. 23-24).
According to the Specification, incorporation of “excess strong acids,
such as methane sulfonic acid and sulfuric acid, in combination with a
fractionating column overcome this problem” (Spec. 1, ll. 25-27).
The Claims
Claims 1-3 are on appeal. Claim 1 is representative and reads as
follows:
1. A process for the preparation of di-n-butyl
terephthalate, comprising:
contacting terephthalic acid with butanol in the
presence of a catalyst in a reactor, and
removing water via a fractionation column fitted to
the reactor,
wherein the total pressure is maintained at about
atmospheric pressure,
the temperature is maintained at about 110° to 220°C,
catalyst is selected from the group consisting of
methane sulfonic acid, sulfuric acid, methane disulfonic
acid, butane sulfonic acid, perfluorobutane sulfonic acid,
and mixtures thereof, and
the catalyst is present in amount of from about 3% to
about 15 % by weight.

Appeal 2009-013205
Application 11/732,236

3
The prior art
The Examiner relies on the following prior art references to show
unpatentability:
Graves US 1,944,887 Jan. 30, 1934
Dijk et al. US 2,802,861 Aug. 13, 1957
Tatsuoka et al. JP 60-4151 Jan. 10, 1985

The issue
The Examiner rejected claims 1-3 under 35 U.S.C. § 103(a) as
obvious over Tatsuoka, Dijk, and Graves (Ans. 3-4).
The Examiner finds that Tatsuoka “teaches the production of
terephthalic acid diester from the reaction of TPA with an alcohol under
atmospheric pressure and temperature of greater than or equal to 110°C”
(Ans. 3). The Examiner finds that Tatsuoka teaches “removal of water via
distillation” and the use of a titanium catalyst (Ans. 3). The Examiner finds
that Tatsuoka does not teach “a reactor fitted with a fractionation column to
remove water and the different stages thereto and therewith; (b) and the
claimed catalysts” (Ans. 3). The Examiner concludes that it would have
been obvious that “[a] fractionation column incorporated with the
esterification reactor would result to removal of water and would be an
obvious design choice” (Ans. 3).
The Examiner finds that Graves teaches that “sulfuric acid and/or
sulfonic acid have been used as esterification catalysts” (Ans. 4). The
Examiner concludes that the “claim would have been obvious because the
substitution of one known element for another, as in the use of sulfonic acid
as esterification catalyst instead of dimethyl tin oxide, would have yielded
Appeal 2009-013205
Application 11/732,236

4
predictable results to one of ordinary skill in the art at the time of the
invention” (Ans. 4).
Appellants argue that “the prior art fails to teach the limitations: a)
removing water via a fractionation column fitted to the reactor and b)
maintaining the total pressure at about atmospheric pressure as recited in
independent claim 1” (App. Br. 3).
In view of these conflicting positions, we frame the obviousness issue
before us as follows:
Have Appellants demonstrated that the Examiner erred in finding it
obvious to modify Tatsuoka’s method so that “the total pressure is
maintained at about atmospheric pressure” as required by Claim 1?
Findings of Fact (FF)
1. Tatsuoka teaches “a method for the efficient production of
terephthalic acid diesters of higher alcohols” (Tatsuoka trans. 3).
2. Tatsuoka teaches that “terephthalic acid . . . 2-ethylhexanol . . .
and 0.2 ml of tetraisopropyl titanate . . . were introduced to an autoclave . . .
equipped with a condensor . . . such that only the 2-ethylhexanol of the
condensed liquid could be refluxed to the reaction system. . . . The pressure
of the reaction system at 220°C was 3.5 kg/cm2” (Tatsuoka trans. 5-6).
3. Tatsuoka teaches in Working Example 3 that n-butanol was
“used in place of the 2-ethylhexanol in Working Example 1 . . . and the
conversion rate was 87%” (Tatsuoka trans. 8).
4. Tatsuoka teaches that “[t]oo high a pressure is a disadvantage
because it will be difficult to distill off the water. Consequently, if pressure
is increased as appropriate for the reaction temperature, the water that is
Appeal 2009-013205
Application 11/732,236

5
produced as a result of esterification will be thoroughly removed and the
reaction will proceed quickly” (Tatsuoka trans. 5).
5. Tatsuoka teaches that “[p]ressure is adjusted using an inert gas
such as nitrogen, and the reaction is within a range of 120 to 270°C”
(Tatsuoka trans. 4).
6. Tatsuoka teaches “[i]t is essential that the method of the present
invention be performed under increased pressure while stirring the
terephthalic acid and alcohol . . . and it is essential that it be performed at a
temperature that is m at least the boiling point of the alcohol at normal
pressure but is less than the boiling point of the alcohol under increased
pressure” (Tatsuoka trans. 4).
7. The Examiner finds that “in example 1 [of Tatsuoka], a
pressure of 1.0 Kg/cm2, which is equivalent to 0.968 atmosphere, which is
about the atmospheric pressure” (Ans. 5).
8. The Examiner finds that fractionation columns were known in
the prior art and represented a design choice for removal of water (See Ans.
3).
9. Graves teaches “esterification catalysts such as sulfuric acid,
chlorsulfonic acid, and benzene sulfonic acids may be added to the reaction
mixture in small quantities to accelerate the esterification reaction” (Graves
2, ll. 106-111).

Principles of Law
The question of obviousness is resolved on the basis of underlying
factual determinations including: (1) the scope and content of the prior art;
Appeal 2009-013205
Application 11/732,236

6
(2) the level of ordinary skill in the art; (3) the differences between the
claimed invention and the prior art; and (4) secondary considerations of
nonobviousness, if any. Graham v. John Deere Co., 383 U.S. 1, 17 (1966).
The Supreme Court has emphasized that “the [obviousness] analysis 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 v.
Teleflex Inc., 550 U.S. 398, 418 (2007).
“[R]ejections 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.” KSR at 417-18, quoting In re Kahn, 441 F.3d 977, 988 (Fed.
Cir. 2006). The Examiner has the initial burden of establishing a prima facie
case obviousness under 35 U.S.C. § 103. In re Oetiker, 977 F.2d 1443, 1445
(Fed. Cir. 1992) (“[T]he examiner bears the initial burden, on review of the
prior art or on any other ground, of presenting a prima facie case of
unpatentability.”).
“A reference may be said to teach away when a person of ordinary
skill, upon reading the reference, would be discouraged from following the
path set out in the reference, or would be led in a direction divergent from
the path that was taken by the applicant. The degree of teaching away will of
course depend on the particular facts; in general, a reference will teach away
if it suggests that the line of development flowing from the reference's
disclosure is unlikely to be productive of the result sought by the applicant.”
In re Gurley, 27 F.3d 551, 553, 31 USPQ2d 1130, 1131 (Fed. Cir. 1994).
Appeal 2009-013205
Application 11/732,236

7
Analysis
Tatsuoka teaches a process for the preparation of terephthalate
comprising contacting terephthalic acid with butanol (FF 1, 3). In the first
working example, Tatsuoka teaches the use of a condensor which refluxes
only the 2-ethylhexanol back to the reaction system, thereby inherently
removing water vapor from the reaction, but at a pressure that reached 3
times atmospheric pressure (FF 2). Tatsuoka explains this removal, noting
that “[t]oo high a pressure is a disadvantage because it will be difficult to
distill off the water. Consequently, if pressure is increased as appropriate for
the reaction temperature, the water that is produced as a result of
esterification will be thoroughly removed and the reaction will proceed
quickly” (Tatsuoka trans. 5; FF 4). Tatsuoka exemplifies a reaction pressure
which begins approximately atmospheric (FF 6-7).
However, while the Examiner argues that Tatsuoka “expressly
mentions that the pressure is a variable factor” (Ans. 5), the Examiner does
not identify any teaching of “maintaining” the “total pressure at atmospheric
pressure.” We are not persuaded by the Examiner’s interpretation of the
phrase “the total pressure is maintained at about atmospheric pressure” as
only requiring atmospheric pressure at one point during the reaction. The
use of the word “maintained” clearly requires that the reaction pressure is
kept at atmospheric for the duration of the reaction. This is consistent with
the Specification, which contrasts reactions maintained at atmospheric
pressure from pressurized reaction systems (see Spec. 3, ll. 26-31).
We also agree with Appellants that Tatsuoka “arguably teaches away
from, maintaining a reaction pressure at about atmospheric pressure” (App.
Appeal 2009-013205
Application 11/732,236

8
Br. 4). As Appellants point out, Tatsuoka teaches that “[i]t is essential that
the method of the present invention be performed under increased pressure
while stirring the terephthalic acid and alcohol” (Tatsuoka trans. 4; FF 6).
Consistent with Gurley, this teaching directly leads away from the claimed
method, which requires that the reaction is performed under atmospheric,
and not increased pressures that were “essential” to Tatsuoka.

Conclusion of Law
Appellants have demonstrated that the Examiner erred in finding it
obvious to modify Tatsuoka’s method so that “the total pressure is
maintained at about atmospheric pressure” as required by Claim 1.

SUMMARY
In summary, we reverse the rejection of claims 1-3 under 35 U.S.C. §
103(a) over Tatsuoka, Dijk, and Graves.

REVERSED

dm

BRETT L. NELSON
EASTMAN CHEMICAL COMPANY
100 NORTH EASTMAN ROAD
KINGSPORT, TN 37660-5075