MTU Aero Engines AG

Patent Trials and Appeals Board

Nov 22, 2021

2020005232 (P.T.A.B. Nov. 22, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
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
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
15/425,451 02/06/2017 Philipp DOEBBER 6570-P50358 7190
13897 7590 11/22/2021
Abel Schillinger, LLP
12414 Alderbrook Drive
Suite 201
Austin, TX 78758
EXAMINER
OMORI, MARY I
ART UNIT PAPER NUMBER
1784
NOTIFICATION DATE DELIVERY MODE
11/22/2021 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):
hmuensterer@abel-ip.com
mail@Abel-IP.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte PHILIPP DOEBBER and FRANK SEIDEL
Appeal 2020-005232
Application 15/425,451
Technology Center 1700
Before LINDA M. GAUDETTE, JOHN E. SCHNEIDER, and
DEBRA L. DENNETT, Administrative Patent Judges.
GAUDETTE, Administrative Patent Judge.

DECISION ON APPEAL1
The Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision finally rejecting claims 1, 4, 7, 9–11, 13, 15, 16, 18, and 21–29.3
We affirm.

1 The following documents are of record: Specification filed Feb. 6, 2017
(“Spec.”); Final Office Action dated Oct. 24, 2019 (“Final Act.”); Appeal
Brief filed Mar. 20, 2020 (“Appeal Br.”), citations to pages 21–24 being to
the Claims Appendix; Examiner’s Answer dated May 6, 2020 (“Ans.”); and
Reply Brief filed July 2, 2020 (“Reply Br.”).
2 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. The
Appellant identifies the real party in interest as MTU Aero Engines AG.
Appeal Br. 3.
3 We have jurisdiction under 35 U.S.C. § 6(b).
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CLAIMED SUBJECT MATTER
The invention relates to a thermal barrier coating system for metal
components of a turbomachine, such as high temperature-stressed or hot gas-
stressed components of a turbomachine or of an aero engine. Spec. 1:11–14.
Claims 1 and 21, reproduced below, are illustrative of the claimed subject
matter:
1. A thermal barrier coating system for a component of a
turbomachine, wherein the thermal barrier coating system
comprises a ceramic coating of fully or partially stabilized
zirconium oxide, and an oxide cover coating as an outermost
coating which comprises aluminum oxide and at least one
element selected from lanthanum, silicon, calcium, and sodium,
the oxide cover coating comprising at least 50 vol.-% of the
aluminum oxide which exists at least partially as free α-Al2O3.
21. The thermal barrier coating system of claim 1, wherein the
coating is produced by a method comprising applying the
ceramic coating of fully or partially stabilized zirconium oxide
to a substrate or to an adhesion promoting coating on the
substrate by thermal spraying or electron beam physical vapor
deposition, followed by applying the oxide cover coating which
comprises aluminum and at least one element selected from
lanthanum, silicon, calcium, and sodium to the ceramic coating
by thermal spraying or electron beam physical vapor
deposition, and, after application of the oxide cover coating,
subjecting the thermal barrier coating system to a heat treatment
so that free α-Al2O3 exists in the oxide cover coating.
Appeal Br. 21–22.
Claim 22, the only other independent claim on appeal, includes
limitations similar to claim 1’s limitations. See id. at 22–23.
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REFERENCES
Name Reference Date
Pearson US 4,847,064 July 11, 1989
Bruce US 5,683,761 Nov. 4, 1997
Ivkovich US 6,165,600 Dec. 26, 2000
Stowell US 2005/0282020 A1 Dec. 22, 2005
S. Akbulut et al., Mechanical Behaviour and Wear Resistance of Ce-PSZ
Alumina Matrix Composites, Key Eng’g Materials (2004).
Jiri Skorpik, Turbomachine, http://www.transformacni-
technologie.cz/en_11.html (2009) (“Turbomachines”).
Chemical Book, alpha-Alumina (1344-28-1) MSDS Melting Point Boiling
Point Density Storage Transport,
https://www.chemicalbook.com/ProductMSDSDetailCB9853056_EN.htm.
Azom.com, Silica–Silicon Dioxide (SiO2),
https://web.archive.org/web/20110516131158/https://www.azom.com/article
.aspx?ArticleID=1114 (“AZO Materials”).
REJECTIONS4
1. Claims 1, 9, 11, 13, 15, 16, 18, 21–23, 26, 27, and 29 are
rejected under 35 U.S.C. § 103 as unpatentable over Stowell, as evidenced
by Pearson, Chemical Book, and AZO Materials, and, as to claims 16 and
18, as further evidenced by Turbomachines. Final Act. 4–10.
2. Claims 1, 4, 7, 11, 13, 15, 16, 18, and 21 are rejected under 35
U.S.C. § 103 as unpatentable over Bruce in view of Negahdari.5 Final Act.
10–17.

4 The Examiner has withdrawn the rejection of claims 21 and 29 under 35
U.S.C. § 112(d). Ans. 20.
5 The Examiner has withdrawn this rejection as to claims 9 and 10. Ans. 20.
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3. Claims 1, 4, 7, 9–11, 13, 15, 16, 18, and 21–29 are rejected
under 35 U.S.C. § 103 as unpatentable over Ivkovich in view of Akbulut.
Final Act. 17–23.
OPINION
Rejection over Stowell
The Examiner rejected claims 1, 9, 11, 13, 15, 16, 18, 21–23, 26, 27,
and 29 as obvious over Stowell. Final Act. 4–10. The Appellant argues the
patentability of the following three claim groupings: (1) claims 1 and 22; (2)
claims 9, 26, and 27; and (3) claims 21 and 29. See Appeal Br. 6–11.
Claims 1 and 22
The Appellant argues that the record evidence does not support the
Examiner’s finding that Stowell discloses or suggests an outermost coating
comprising silicon and aluminum oxide, at least 50 vol.-% of the aluminum
oxide existing, at least partially, as free α-Al2O3 (claims 1, 22). See generally
Appeal Br. 6–9. As to this limitation, the Examiner found that Stowell
discloses an outer layer (32) containing, by weight, about 5 to 85% alumina,
about 0 to 35% zinc titanate, about 0 to 35% glass material, and a silica-
containing matrix material as the remainder. Final Act. 5. The Examiner
found that when Stowell’s outer layer 32 contains only alumina and a silica
matrix material, the volume percent of alumina ranges from 3.39 vol. % (5
wt. % alumina, 95 wt. % silica) to about 79 vol. % (85 wt. % alumina, 15
wt.% silica). Id. at 6. The Examiner provides the following exemplary
calculations: 0.05g alumina÷3.97 g/cm3 alumina = 0.0126 cm3 alumina;
0.95g silica÷2.65 g/cm3 = 0.358 cm3 silica; vol.% alumina =
𝑣𝑣𝑣𝑣𝑣𝑣 𝑎𝑎𝑣𝑣𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎
𝑣𝑣𝑣𝑣𝑣𝑣 𝑎𝑎𝑣𝑣𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎+𝑣𝑣𝑣𝑣𝑣𝑣 𝑠𝑠𝑎𝑎𝑣𝑣𝑎𝑎𝑠𝑠𝑎𝑎
× 100 = 0.0126
0.0126+0.358
× 100 = 3.39%. Id.
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The Appellant argues that the Examiner’s finding is based on
erroneous assumptions that Stowell’s (1) outer layer 32 is a completely
dense mixture of oxide and silica, and (2) the silica is in the form of quartz.
Appeal Br. 8. The Appellant explains that outer layer 32 is produced by
thermal decomposition of a liquid silicone, resulting in a porous layer of
aluminum oxide in a silica matrix. Id. The Appellant further contends that
the Examiner has not cited evidence to support a finding that the silica in
outer layer 32 is in the form of quartz rather than fused silica, which has a
lower density of 2.2 g/cm3. Id.
The Appellant’s arguments are not persuasive of reversible error for
the reasons explained in the Answer. See Ans. 20–21. As the Examiner finds
(see id.), Stowell discloses a combustor component having a thermal barrier
coating, the outer layer of which “consist[s] essentially of about 5 to about
85 weight percent alumina, about 0 to about 35 weight percent of a glass
material, about 0 to about 35 weight percent zinc titanate, . . . the balance
being a second silica containing matrix material consisting essentially of at
least one of silica, silicate and mullite.” Stowell ¶ 36 (claim 1); see also id.
¶ 26. These findings are sufficient to support a prima facie case of
obviousness, thereby shifting the burden to the Appellant to come forward
with evidence or argument in rebuttal. See In re Piasecki, 745 F.2d 1468,
1472 (Fed. Cir. 1984); In re Peterson, 315 F.3d 1325, 1330 (Fed. Cir. 2003)
(“[T]he existence of overlapping or encompassing ranges shifts the burden
to the applicant to show that his invention would not have been obvious.”).
In other words, the Appellant is incorrect in stating that the Examiner had
the burden to explain why the structure of the coating—alumina in a silica
matrix—would not have affected the weight percentages of the materials
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present in the composition. Rather, it was the Appellant’s burden to show
why the coating’s structure would have affected the composition’s content.
The Examiner has further shown that, regardless of whether outer layer 32’s
silica component is in the form of quartz or fused silica, the volume percent
of alumina overlaps the claimed range. See Ans. 21.
The Appellant also argues that the Examiner did not provide evidence
or explanation to support a finding that outer layer 32’s aluminum oxide is
present as free α-Al2O3. Appeal Br. 9. The Appellant’s argument does not
persuasively rebut the Examiner’s determination that claim term “free α-
Al2O3” (claims 1, 22) reads on Stowell’s alumina which exists as particles or
a separate phase within the outer layer’s matrix material. Ans. 22; see Spec.
5:14–16 (“The aluminum oxide existing as a separate phase with aluminum
oxide structure is therefore understood by ‘free’ with regard to the aluminum
oxide in the oxide cover coating.”).
The rejection of independent claims 1 and 22 as obvious over Stowell
is sustained.
Claims 9, 26, 27
Claims 9, 26, and 27 recite that the oxide cover coating has a porosity
of 10–30 vol.-%, 5–30 vol.-%, and 10–25 vol.-%, respectively. Appeal Br.
21, 23. For a teaching of these limitations, the Examiner relies on Stowell’s
disclosure that “[a] suitable level of porosity for the outer coating 28 appears
to be on the order of about 10% porosity, though lesser and greater levels of
porosity are foreseeable” (Stowell ¶ 32).
The Appellant asserts that Stowell’s outer coating 28 comprises two
layers—inner layer 30 and outer layer 32—having different compositions
and produced by different procedures. Appeal Br. 9–10; Reply Br. 3. The
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Appellant argues that, given these differences, and the lack of an explicit
teaching regarding the inner and outer layers’ porosities, the Examiner had
no basis for finding that, individually, outer layer 32 has a porosity of about
10%. Appeal Br. 10; Reply Br. 3.
The Appellant’s argument is not persuasive. In our view, Stowell’s
disclosure that the outer coating 28’s porosity is about 10% provided a
reasonable basis for the Examiner to determine that the inner and outer
layers 30, 32 that form outer coating 28 each have a porosity of about 10%.
“[W]hen the prior art evidence reasonably allows the PTO to conclude that a
claimed feature is present in the prior art, the evidence ‘compels such a
conclusion if the applicant produces no evidence or argument to rebut it.’” In
re Crish, 393 F.3d 1253, 1259 (Fed. Cir. 2004) (quoting In re Spada, 911
F.2d 705, 708 n.3 (Fed. Cir. 1990)); see also In re Best, 562 F.2d 1252, 1255
(CCPA 1977) (“Whether the rejection is based on ‘inherency’ under 35
U.S.C. § 102, on ‘prima facie obviousness’ under 35 U.S.C. § 103, jointly or
alternatively, the burden of proof is the same, and its fairness is evidenced
by the PTO’s inability to manufacture products or to obtain and compare
prior art products.”).
Because the Appellant relies solely on attorney argument, the
Appellant has not provided persuasive argument or evidence to refute the
Examiner’s finding that outer layer 32 would be expected to have a porosity
similar to that of outer coating 28, i.e., within the claimed ranges. Therefore,
the rejection of claims 9, 26, and 27 as obvious over Stowell is sustained.
Claims 21 and 29
The Appellant agrees with the Examiner’s determination that claims
21 and 29 are product-by-process claims, but argues that the Examiner failed
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to explain why or provide evidence that “despite the completely different
ways of producing” the claimed and Stowell’s oxide cover coatings, they
“can reasonably be assumed to be not significantly different from each
other.” Appeal Br. 11. The Appellant again misplaces the burden of proof.
The Examiner provided a detailed comparison of the claimed coating to
Stowell’s coating. See Final Act. 5–6. Because the Examiner demonstrated
that these coatings appear to be identical, the burden shifted to the Appellant
to provide evidence that the claimed method produces a coating that
structurally differs from the prior art coating. In re Marosi, 710 F.2d 799,
803 (Fed. Cir. 1983) (“Where a product-by-process claim is rejected over a
prior art product that appears to be identical, although produced by a
different process, the burden is upon the applicants to come forward with
evidence establishing an unobvious difference between the claimed product
and the prior art product.”). The Appellant has not met this burden.
Therefore, the rejection of claims 21 and 29 as obvious over Stowell is
sustained.
Claims 11, 13, 15, 16, 18, and 23
The Appellant does not separately argue the patentability of claims
11, 13, 15, 16, 18, and 23. Because we sustain the rejection of independent
claims 1 and 22, we also sustain the rejection of dependent claims 11, 13,
15, 16, 18, and 23 over Stowell.

Rejection over Bruce and Negahdari
The Examiner rejected claims 1, 4, 7, 11, 13, 15, 16, 18, and 21 as
obvious over Bruce in view of Negahdari. The Appellant’s argument is
essentially that the ordinary artisan would not have had a reason to modify
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Bruce based on Negahdari’s teachings, because Bruce is concerned with
erosion resistance of ceramic coatings whereas Negahdari is concerned with
mechanical properties of articles made from composite ceramics. Appeal Br.
13–14. The Appellant further contends that because the references do not
explicitly list the same ceramic materials, the ordinary artisan would not
have had a reasonable expectation of success in using Negahdari’s
lanthanum hexaaluminate in Bruce’s coatings. See generally Appeal Br. 11–
15. We agree with the Examiner’s determination that these arguments are
not persuasive of reversible error for the reasons stated in the Answer. See
Ans. 24–25.
The rejection of claims 1, 4, 7, 11, 13, 15, 16, 18, and 21 as obvious
over Bruce in view of Negahdari is sustained.

Rejection over Ivkovich and Akbulut
The Examiner rejected claims 1, 4, 7, 9–11, 13, 15, 16, 18, and 21–29
as obvious over Ivkovich in view of Akbulut. Final Act. 17–23. The
Appellant argues the patentability of the following three claim groupings:
(1) claims 1 and 22; (2) claims 9, 10, 27, and 28; and (3) claims 21 and 29.
Appeal Br. 15–19.
Claims 1 and 22
The Appellant argues that the Examiner’s rejection is based on an
unreasonably broad interpretation of “an oxide cover coating as an
outermost coating which comprises aluminum oxide and at least one element
selected from silicon, calcium, and sodium” (claim 22; see claim 1) as
reading on an outer layer containing only A-16SG, which “is an α-Al2O3
having a composition of, in wt.%, 99.800% Al2O3, 0.070% Na2O, 0.020%
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Fe2O3, 0.030% SiO2, 0.001% B2O3, [and] 0.003% MgO” (Final Act. 18
(calculating a 99.8 vol.% Al2O3 in A-16SG)). Appeal Br. 16. More
specifically, the Appellant argues that the ordinary artisan, upon review of
the Specification, would not have understood the claim recitation of “at least
one element” as reading on the trace amounts of silicon or sodium present in
A-16SG. Id. (citing Spec. 4:12–21, 4:27–5:14, 8:16–21).
Having reviewed the entire Specification, we are not persuaded that
the Examiner’s interpretation of claims 1 and 22 is unreasonably broad.
First, the Appellant has not directed us to, nor do we find, any indication in
the Specification that silicon or sodium must “serve a[] useful purpose.” See
Appeal Br. 16. Second, the Specification discloses that “[t]he oxide cover
coating may comprise . . . at least about 90 vol.-% of aluminum oxide”
(Spec. 5:21–23), but neither places an upper limit on the aluminum oxide
content nor provides exemplary silicon, sodium, calcium, or lanthanum
amounts. And third, the Appellant’s argument as to the understanding of the
ordinary artisan lacks persuasive evidentiary support. See In re Geisler, 116
F.3d 1465, 1471 (Fed. Cir. 1997) (explaining that argument by counsel
cannot take the place of evidence).
The Appellant also argues that because Ivkovich indicates the
desirability of including glass and silicon-based materials in outermost
ceramic layer 30, the ordinary artisan would not have been motivated to use
only aluminum oxide in that layer. Appeal Br. 17. This argument is not
persuasive because “[a] reference must be considered for everything that it
teaches, not simply the described invention or a preferred embodiment.” In
re Applied Materials, Inc., 692 F.3d 1289, 1298 (Fed. Cir. 2012). As
explained by the Examiner (Ans. 26), Ivkovich teaches that outermost
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ceramic layer 30 may include “one or more” of “alumina, zirconia, stabilized
zirconia and silica” (Ivkovich 4:45–47, 55–56).
Because the Appellant has not identified reversible error, we sustain
the Examiner’s rejection of claims 1 and 22 over Ivkovich and Akbulut.
Claims 9, 10, 27, 28
The Appellant argues the Ivkovich teaches away from claims 9, 10,
27, and 28, each of which recites an oxide cover coating having a minimum
porosity of 10 vol.-%. Appeal Br. 18. In support of this argument, the
Appellant quotes Ivkovich column 4, lines 28–37. Id. Ivkovich discloses that
“outermost ceramic layer 30 is . . . very dense . . . , preferably . . . a porosity
of less than 10%.” Ivkovich 4:28–33 (emphasis added). A statement that a
particular feature is preferred is not a teaching away absent clear
discouragement. See Syntex (U.S.A.) LLC v. Apotex, Inc., 407 F.3d 1371,
1379–80 (Fed. Cir. 2005). The Appellant has not identified any disclosure in
Ivkovich that would have clearly discouraged the ordinary artisan from
forming outermost ceramic layer 30 with a porosity of 10%. See generally
Appeal Br. 17–18; Reply Br. 5.
A prima facie case of obviousness exists where, as here, the prior art
and claimed ranges, though not overlapping, are sufficiently close that one
skilled in the art would have expected them to have the same properties.
See, e.g., In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003). The
Appellant has not provided persuasive evidence of criticality in the claimed
porosity ranges of 10–30 vol.-% (claims 9, 10) and 10–25 vol.% (claims 27,
28). To the contrary, the Specification explicitly teaches that a porosity as
low as 5 vol.-% is acceptable. See Spec. 3:27–28, 6:6–8. Therefore, we are
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not persuaded of reversible error, and sustain the Examiner’s rejection of
claims 9, 10, 27, and 28 over Ivkovich and Akbulut.
Claims 21 and 29
The Appellant does not dispute that claims 21 and 29 are product-by-
process claims, but argues that Ivkovich’s process produces a different
product than the claimed product. Appeal Br. 19. In support of this
argument, the Appellant quotes Ivkovich, column 4, lines 33–37: “the
surface finish of the ceramic layer 30 made possible by this invention is
beyond the capability of spray and PVD processes, and therefore
distinguishes ceramic coatings of the present invention from the prior art.”
Appeal Br. 19.
The Manual of Patent Examining Procedure (MPEP) instructs as
follows:
The structure implied by the process steps should be considered
when assessing the patentability of product-by-process claims
over the prior art, especially where the product can only be
defined by the process steps by which the product is made, or
where the manufacturing process steps would be expected to
impart distinctive structural characteristics to the final product.
MPEP § 2113 (8th ed. Rev. 8 July 2010) (emphasis added); see also
Greenliant Sys., Inc. v. Xicor LLC, 692 F.3d 1261, 1268 (Fed. Cir. 2012)
(“[I]f the process by which a product is made imparts ‘structural and
functional differences’ distinguishing the claimed product from the prior art,
then those differences ‘are relevant as evidence of no anticipation’ although
they ‘are not explicitly part of the claim.’” (quoting Amgen Inc. v. F.
Hoffman-La Roche Ltd., 580 F.3d 1340, 1370 (Fed. Cir. 2009))).
The present record does not include evidence that the Examiner
considered Ivkovich column 4, lines 33–37. We find that this disclosure
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supports the Appellant’s argument that the claim 21 and claim 29 processes
impart structural and functional differences that distinguish the claimed
coating system from Ivkovich’s coating system. See Final Act. 21–22; Ans.
28–29. Accordingly, we are persuaded of reversible error, and do not sustain
the rejection of claims 21 and 29 over Ivkovich and Akbulut.
Claims 4, 7, 11, 13, 15, 16, 18, and 23–26
The Appellant does not separately argue the patentability of claims 4,
7, 11, 13, 15, 16, 18, and 23–26. Because we sustain the rejection of
independent claims 1 and 22, we also sustain the rejection of dependent
claims 4, 7, 11, 13, 15, 16, 18, and 23–26 over Ivkovich and Akbulut.
DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 9, 11,
13, 15, 16,
18, 21–23,
26, 27, 29
103 Stowell, Pearson,
Chemical Book,
AZO Materials,
Turbomachines
1, 9, 11,
13, 15, 16,
18, 21–23,
26, 27, 29

1, 4, 7, 11,
13, 15, 16,
18, 21
103 Bruce, Negahdari 1, 4, 7, 11,
13, 15, 16,
18, 21

1, 4, 7, 9–
11, 13, 15,
16, 18, 21–
29
103 Ivkovich, Akbulut 1, 4, 7, 9–
11, 13, 15,
16, 18, 22–
28
21, 29
Overall
Outcome:

1, 4, 7, 9–
11, 13, 15,
16, 18, 21–
29

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TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED