Ex Parte Garcia-Alonso et al

Patent Trial and Appeal Board

Mar 30, 2016

13585235 (P.T.A.B. Mar. 30, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/585,235 08/14/2012
22045 7590 04/01/2016
BROOKS KUSHMAN P,C
1000 TOWN CENTER
TWENTY-SECOND FLOOR
SOUTHFIELD, MI 48075
FIRST NAMED INVENTOR
Nuria Garcia-Alonso
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
W AS0881PUSA1 8584
EXAMINER
NGUYEN, NGOC YEN M
ART UNIT PAPER NUMBER
1734
NOTIFICATION DATE DELIVERY MODE
04/01/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
docketing@brookskushman.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte NURIA GARCIA-ALONSO, CHRISTOPH RUEDINGER,
and HANS-JURGEN EBERLE 1
Appeal2014-006052
Application 13/585,235
Technology Center 1700
Before CHUNG K. PAK, MICHAEL P. COLAIANNI, and
N. WHITNEY WILSON, Administrative Patent Judges.
COLAIANNI, Administrative Patent Judge.
DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134 the final rejection of claims
1-16, 18 and 19. We have jurisdiction over the appeal pursuant to 35 U.S.C.
§ 6(b ).
We AFFIRM.
1 Appellants state that the real party in interest is "Wacker Chemie AG" in
its Appeal Brief filed October 30, 2013 ("App. Br.) 1.
Appeal2014-006052
Application 13/585,235
Appellants' invention relates to a process for preparing trichlorosilane
by means of thermal hydrogenation of silicon tetrachloride. (Specification
("Spec.") 1:14-15; claim 1).
Claim 1 is illustrative:
1. A process for producing trichlorosilane by reaction of
tetrachlorosilane with hydrogen, comprising reacting a
tetrachlorosilane-containing reactant gas and a hydrogen-containing
reactant gas in a reactor at a reaction temperature of from 700°C to
l 500°C to form a trichlorosilane-containing product gas mixture, and
cooling the product mixture by means of a heat exchanger constructed
of a material selected from the group consisting of silicon carbide,
silicon nitride, quartz glass, graphite, silicon carbide coated graphite
and combinations thereof, wherein passages in the heat exchanger
have a hydraulic diameter> 5mm, the heat exchanger has a ratio of
heat exchange surface to volume of> 400-1 and a heat transfer
coefficient of> 300 watts /m2K, and cooling the product gas mixture
to a temperature T cooling over a heat exchanger residence time of the
product gas mixture in the heat exchanger 1"[ ms], where
r ~A ·e B·Tcooling (Equation 1)
1000
where A= 4000, 6 :SB :S 50, and 100°C :S Tcooling :S 900°C, wherein
the product gas mixture is cooled by reactant gases in the heat
exchanger to a temperature lower than the reaction temperature and at
most 700°C in less than 50 ms, and the reactant gases are heated
thereby. App. Br., Claims App'x 1-3 (emphasis added.)
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Appeal2014-006052
Application 13/585,235
Appellants appeal the following rejection:
Claims 1-16, 18 and 19 have been rejected under 35 U.S.C. § 103(a) as
unpatentable over Weigert (U.S. 4,217,334 to Weigert et al. issued August
12, 1980) in view of Hamster (U.S. 4,536,642 to Hamster et al. issued
August 20, 1985) and Shah ("Fundamentals of Heat Exchanger Design,"
(2003), pp. 1-20 and 78-96) (Final Action dated June 5, 2013 ("Final Act.")
3-6; Examiner's Answer dated February 12, 2014 ("Ans.") pages 2-6).
Appellants argue separately claims 1, 14 and 15 (App. Br. 22 and 23).
Any claims not argued separately will stand or fall with our analysis
regarding claim 1.
FINDINGS OF FACT & ANALYSIS
CLAIM 1
The Examiner finds that Weigert teaches a process that produces
trichlorosilane by reacting tetrachlorosilane with hydrogen as recited in
claim 1 except for the step of using the energy of the product gas removed
via a heat exchanger to heat the reactant gases and for specific design
limitations of the heat exchanger (Final Act. 3-5). The Examiner finds that
Hamster teaches a device containing a heat exchanger used in processes,
such as forming trichlorosilane from tetrachlorosilane and hydrogen (Final
Act. 6). The Examiner further finds that Hamster teaches that reactant gases
can be preheated in the heat exchanger by reaction gases while still hot
(Final Act. 6). The Examiner concludes that it would have been obvious to
one skilled in the art to use Hamster's heat exchanger in Weigert's process
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Application 13/585,235
because it can minimize energy losses and ensures uniform temperature
(Final Act. 6).
As to properties and design characteristics of the heat exchanger, the
Examiner finds that Shah teaches that it is conventional to modify the
mechanical/thermal design, particularly, the hydraulic diameter, of a heat
exchanger in accordance with process specifications (Final Act. 6). The
Examiner concludes that it would have been obvious to design Weigert' s
heat exchanger including the materials; hydraulic diameter; ratio of heat
exchange surface to volume; and heat transfer coefficient as taught by Shah
to cool effectively the product gas in Weigert's process (Final Act. 6).
Appellants contend that Weigert discloses using a heat exchanger only
in small/laboratory scale processes, and that Weigert discourages using heat
exchangers in large-scale applications where it teaches only rapid quenching
of reactor product gases in industrial practice (App. Br. 12-16; Declaration, 2
5-6). Appellants contend that Weigert's heat exchanger is not a gas/gas heat
exchanger employing reactant gases as the cooling medium but that it wastes
product gas and thereby does not have the economic benefits provided by
the claimed heat exchanger (App. Br. 13, 17, 20-22; Declaration, 12-13).
Appellants further contend that Hamster's reactor is integrated entirely
within the reactor shell and depicts the product gas mixture in its examples
as cooled while reactant gases are heated (App. Br. 17-19). Appellants
further contend that Shah is "merely a general treatise" that provides
theoretical and practical information on designing and constructing
2 Declaration by Dr. Rudinger (an inventor) (hereinafter "Rudinger
Declaration") filed September 14, 2012 that has been attached to Appellants'
Appeal Brief.
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Application 13/585,235
numerous types of heat exchangers and does not suggest, for example, the
hydraulic diameter specified in claim 1 within a gas/gas heat exchanger
(App. Br. 19-22).
Appellants' primary argument concerns whether Weigert discloses
using its heat exchanger in industrial applications. As pointed out by the
Examiner, Weigert discloses at column 2, lines 32-42 wherein the heat
exchanger is used in "small reactor units", which the Examiner finds are not
laboratory scale units (Ans. 9-10). Appellants do not respond to this finding
in the Reply Brief. We agree with the Examiner that the present claims are
not limited to an "industrial process"; the claims do not recite that the
process is an industrial process or provide any recitation of volume/amount
of trichlorosilane produced (Ans. 11 ). Thus, even if Weigert were limited to
laboratory-scale units, its teachings would be pertinent to the claims on
appeal.
With respect to Appellants' arguments that, even though Wiegert
discloses examples that use a heat exchanger, it suggests quenching the
product gases in large scale applications, the Examiner finds that
Weigert'sdisclosure is not limiting the use of a heat exchanger to small scale
processes but is instead teaching quenching product gases as a preferred
embodiment for large scale applications (Ans. 10, 12 and 13). We agree
with the Examiner that Weigert' s disclosure is merely a preferred
embodiment of the reference. Weigert's process is not limited to quenching
the product gas in industrial applications but also discloses using a heat
exchanger its processes for converting trichlorosilane from tetrachlorosilane
that fall within the meaning of the claims (Ans. 10).
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Appeal2014-006052
Application 13/585,235
We are unpersuaded by Appellants' arguments that the teachings of
Weigert and Hamster would not have been combined because Hamster's
integrated heat exchanger in the reactor shell does not preheat the reactant
gases with heat from the product gases which is contrary to Weigert's heat
exchanger where heat is transferred from the product to a cooler medium.
(Reply Br. 2-4 and 8) The Examiner finds that Hamster suggests using
product/reaction gases while still hot to preheat reactant gases in a heat
exchanger and that it would have been obvious to modify Weigert' s heat
exchanger to do so in view of Hamster's teachings (Ans. 10, 12-14;
Hamster, col. 3, 11. 7-14). In other words, the Examiner relies upon the
concept taught by Hamster of using the hot product gases to preheat cooler
reactant gases to modify Weigert' s heat exchanger to permit such
recuperation of the heat in the product gases, not the bodily incorporation of
Hamster's heat exchanger into Weigert's device and process.
As to Appellants' arguments that Shah "adds nothing" to the teachings
of Weigert and Hamster, we agree with the Examiner's that Shah teaches
that an ordinarily skilled artisan can tailor a heat exchanger to satisfy the
particular conditions or requirements of a given process (Ans. 15-17). Shah
teaches the variables that are used in designing heat exchangers include,
inter alia, the hydraulic diameter, residence time, heat exchanger surface
area, and heat transfer coefficient. (See e.g., Shah generally and 8-9, 84-85).
Accordingly, the ordinarily skilled artisan would have modified Weigert's
heat exchanger in the process as per the teachings of Shah and Hamster in
order to tailor the heat exchanger to the particulars of the tetrachlorosilane
conversion process and in so doing arrive at a heat exchanger having the
parameters recited in the claim. KSR Int'l. Co. v. Teleflex Inc., 550 U.S.
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Application 13/585,235
398, 417 (2007) ("[I]f a technique has been used to improve one device, and
a person of ordinary skill in the art would recognize that it would improve
similar devices in the same way, using the technique is obvious unless its
actual application is beyond his or her skill.").
We find that the preponderance of the evidence favors the Examiner's
conclusion of obviousness. We now consider Appellants' evidence of
secondary considerations.
Appellants argue that there has been a continual long felt need to
efficiently regenerate trichlorosilane from tetrachlorosilane exiting Siemens
reactors (conventional industrial reactors used in this process) in an
economical manner (App. Br. 3-11; Reply Brief entered April 14, 2014
("Reply Br.") 4-6). Appellants additionally argue that the heat exchanger
having a small hydraulic diameter is critical to the claimed process (App. Br.
21-22) and that comparative data submitted in the Rudinger Declaration
demonstrates unexpected results as evidence of the criticality for a heat
exchanger having a hydraulic diameter less than 6 mm as recited in present
claim 1 (App. Br. 19-20 and21-23; Declaration 14-15; Ans. 19).
We are not persuaded by Appellants' arguments and evidence of
secondary considerations based upon a "continual long felt need" to
efficiently regenerate trichlorosilane from tetrachlorosilane exiting reactors
used in industrial processes (Reply Br. 4-6). Appellants have not established
that the long-felt need had not been satisfied by another before Appellants'
claimed invention, and, moreover, that the claimed invention satisfies the
long felt need. Newell Companies v. Kenney Mfg. Co., 864 F.2d 757, 768
(Fed. Cir. 1988).
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Application 13/585,235
First, as discussed above, the present claims are not limited to an
industrial process as argued. Therefore, a showing that the prior art
achieved a more efficient production of trichlorosilane from
tetrachlorosilane at a small scale or even laboratory scale would suffice to
counter Appellants' evidence and argument of long felt need. Nevertheless,
the Examiner has shown that Example 3 in Weigert's process (using a heat
exchanger) is more productive in that it provides a greater yield of
trichlorosilane than the yield in the example from Appellants' Specification
(i.e., Wacker Example in Table 1 of Rudinger Declaration) thereby rebutting
the argument that the claimed invention resolves a long felt need to improve
the productivity of preparing trichlorosilane from tetrachlorosilane (Ans. 7-
9). To the Examiner's point, Appellants have not proffered sufficient
evidence regarding the capital and operational cost of Weigert's heat
exchanger used in the quench process of Example 3 relative to the capital
and operational costs of the claimed heat exchanger as a basis for
determining the economics of each method (Ans. 8-9, 18). The evidence in
Table 1 on page 10 of the Rudinger Declaration compares the specific
energy costs per ton of trichlorosilane of Weigert' s Example 3 relative to
Appellants' Example 1, but that does not establish that total cost (including
capital costs) of Appellants' Example 1 results is a more economical process
as compared to Weigert's Example 3. Id. In other words, it is unclear if
Appellants have actually achieved a more economical process of producing
trichlorosilane from tetrachlorosilane and satisfied a long felt need as
argued.
With respective to the data in the Rudinger Declaration relied upon by
Appellants to show criticality of the heat exchanger's hydraulic diameter
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Appeal2014-006052
Application 13/585,235
comparing Weigert's Example 1 with Appellant's Example 1, we agree with
the Examiner that Weigert is not limited to Example 1 and that Example 3,
which uses a heat exchanger, provides a yield of 37.1 %, which is greater
than that of Appellants' Example 1 in the Declaration (Ans. 11). We also
agree that the comparison of these examples in the Declaration is insufficient
to overcome the primafacie obviousness rejection because the comparative
data failed to demonstrate whether or not, aside from the hydraulic diameter,
other differences in the heat exchanger/process contributed to the produced
yield between the two examples, such as heat transfer coefficient and surface
area to volume ratio (Ans. 20).
Moreover, the evidence on pages 14-15 of the Rudinger Declaration is
not commensurate in scope with the claims in that it fails to provide
evidence that any alleged unexpected results occurs over the entire range of
hydraulic diameters recited in claim 1 (i.e.,< 5 mm). In re Clemens,
622 F.2d 1029, 1036 (CCPA 1980). The only showing we have of an
embodiment falling within the range recited in the claim is at 2 mm
hydraulic diameter.
Based upon this record, the preponderance of the evidence favors the
Examiner's obviousness conclusion. No criticality has been shown for the
hydraulic diameter range recited in claim 1 in that the comparative data was
not commensurate in scope with the present claims. Accordingly, the
ordinarily skilled artisan would have tailored the hydraulic diameter to a
value within the claimed range as an optimization of the device to attain a
suitable heat exchanger for the conversion of trichlorosilane from
tetrachlorosilane as concluded by the Examiner.
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Application 13/585,235
CLAIIvI 14
With respect to claim 14, it limits the heat exchanger of claim 1 to be
positioned outside the reactor. Appellants contend that because Hamster
teaches its heat exchanger as integrated within an insulated reactor shell
requires, it does not suggest an outside heat exchanger (App. Br. 22).
We agree with Examiner's finding that the heat exchanger setup
disclosed in Hamster is not limited to a particular design choice but instead
Hamster suggests designing a heat exchanger that can achieve fast cooling
(as in Weigert) while also heating reactants by using hot product gases
( Ans.13-15). Appellants do not respond this finding of the Examiner.
(Reply Br. generally). Accordingly, it would have been obvious to modify
Weigert's "outside" heat exchanger in accordance with the teachings in
Hamster as stated by the Examiner.
CLAIM 15
Claim 15 depends from claim 14, and recites the product gas mixture
exiting the reactor as fed into the heat exchanger through a heated line and
that the product gas mixture has substantially the same temperature as it had
upon exiting the reactor when it enters the heat exchanger. Appellants argue
that because Hamster teaches an integrated heat exchanger, there would be
no need to employ the heated line recited in the claim (App. Br. 23; Reply
Br. 2). The Examiner argues that, regardless where the heat exchanger is
located, Hamster suggests the step of preheating reactants by using hot
product gases and that Shah teaches that a heat exchanger's setup for its
various gas and liquid streams can be designed based on any given
requirement, such as providing a heated line to adjust the starting and ending
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Application 13/585,235
temperature of the stream to be cooled and the cooling stream (Ans. 15-17).
Appellants do not respond to these findings of the Examiner (Reply Br.
generally).
On this record and for the above reasons, we affirm the Examiner's §
103 rejection in view of Weigert, Hamster and Shah.
DECISION
The Examiner's decision is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § l.136(a).
AFFIRMED
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