Ex Parte Sanders et al

Patent Trial and Appeal Board

Sep 6, 2013

12855073 (P.T.A.B. Sep. 6, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte JOSEF SANDERS, HANNO BRUMMER, JORG LAUE,
BERND SOJKA, MARCUS EICHMANN, and VERENA HAVERKAMP
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Appeal 2012-003271
Application 12/855,073
Technology Center 1600
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Before FRANCISCO C. PRATS, MELANIE L. McCOLLUM, and
ERICA A. FRANKLIN, Administrative Patent Judges.

FRANKLIN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal1 under 35 U.S.C. § 134(a) involving claims to a
process for producing an isocyanate comprising phosgenating an amine in
the gas phase using a heat exchanger. The Patent Examiner rejected the
claims as obvious. A related appeal, Appeal No. 2009-011767, was decided
on June 14, 2010. We have jurisdiction under 35 U.S.C. § 6(b). We reverse.

1 Appellants identify Bayer MaterialScience AG as the real party in interest.
(App. Br. 1.)
Appeal 2012-003271
Application 12/855,073

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STATEMENT OF THE CASE
Claims 1-14 are on appeal. Claim 1 is representative and reads as
follows:
1. A process for producing an isocyanate comprising phosgenating an
amine in the gas phase in which at least one heat exchanger having
a. a heat transfer area per unit volume for the amine side of at
least 1,000 m2/m3 and
b. channels with a hydraulic diameter of from 1,000 to 10,000 μm
for the flow of the amine
is used for liquid heating, vaporization and/or gas superheating of the
amine.

The Examiner rejected claims 1-14 under 35 U.S.C. § 103(a) as
unpatentable over Frosch,2 Kupper,3 Jahn `879,4 and Jahn `749.5

OBVIOUSNESS
The Examiner found that Frosch taught a process for phosgenation of
amines in the gas phase. (Ans. 4.) However, the Examiner found that
Frosch did not teach the use of a heat exchanger in its process. (Id. at 5.)
The Examiner found that Kupper taught a process for removing
volatile compounds from mixtures of substances using a micro-evaporator
displaying channels for carrying the mixture of substances having a

2 US Patent No. 4,847,408 issued to Hans-Georg Frosch et al., Jul. 11, 1989.
3 Patent Application Publication No. US 2005/0022940 A1 by Kurt-Manfred
Kupper et al., published Feb. 3, 2005.
4 Patent Application Publication No. US 2003/0103879 A1 by Peter Jahn et
al., published Jun. 5, 2003.
5 Patent Application Publication No. EP 1486749 A2 by Peter Jähn et al.,
published Dec. 15, 2004.

Appeal 2012-003271
Application 12/855,073

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hydraulic diameter of 5 to 1000 μm and an evaporator surface area of at least
103 m2/m3. (Id.)
According to the Examiner, it would have been obvious to a person of
ordinary skill in the art at the time the invention was made to have combined
the teachings of the references. (Id.) The Examiner reasoned that “[o]ne
would have been motivated to do this because Frosch et al teach[es] a
process for the phosgenation of amines in the gas phase [and] Kupper et al
teach[es] micro-evaporator, which has a layered structure, and consisting of
thin metal plates, each plate displaying a large number of parallel channels
….” (Id.) Therefore, the Examiner found that “one would combine the
teachings of [the] references in order to provide a better integrated process
for the preparation of isocyanates.” (Id. at 6.)
Appellants contend, among other things, that the “skilled artisan
would not ... consider it obvious to combine the teachings of Frosch et al and
Kupper et al in the manner proposed by Examiner.” (App. Br. 7.)
Specifically, Appellants assert that “Kupper et al teaches that the output of
the micro-evaporator disclosed therein is a two-phase gas/liquid mixture –
not a gas that could be used as a reactant in gas phase reaction.” (Id.)
According to Appellants, “[o]ne skilled in the art seeking to develop an
improved gas phase phosgenation process would clearly not consider the
gas-liquid mixture produced by Kupper et al suitable for use in a gas phase
phosgenation process.” (Id.)
In response, the Examiner states that Kupper taught that “using
evaporators or traditional heat exchangers are problematic because they have
large film thicknesses.” (Ans. 8.) Therefore, the Examiner concluded that
“it would have been obvious for those in the art to look to Kupper to solve
Appeal 2012-003271
Application 12/855,073

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the problems of traditional heat exchangers to control the reaction heat of the
gas phase phosgenation reaction taught in Frosch et al.” (Id.) According to
the Examiner, “all the claimed elements were known in the prior art and one
skilled person in the art could have combined the elements as claimed by
known methods with no change in their respective functions, and the
combination would have yielded predictable results ….” (Id.)
After considering the evidence and the arguments, we find that
Appellants have the better position. In particular, what is missing from the
rejection is a finding, supported by the evidence of record, as shown by
some objective teaching in the prior art or by knowledge generally available
to one of ordinary skill in the art, that a person of ordinary skill in the art
would have used a traditional heat exchanger in the process of Frosch, see In
re Fine, 837 F.2d 1071, 1074 (Fed. Cir. 1988), so as to motivate the artisan
to look to Kupper for an improved heat exchanger.
Moreover, what is also missing from the Examiner’s Answer is an
explanation of how using Kupper’s micro-evaporator, which is expressly
used to remove volatile compounds from a liquid mixture (see Kupper
[0017]), would be “suitable for use in a gas phase phosgenation process” as
described in Frosch. (See App. Br. 7.)
Accordingly, we reverse the obviousness rejection.
REVERSED

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