Ex Parte Seitz et al

Board of Patent Appeals and Interferences

Apr 14, 2003

09402552 (B.P.A.I. Apr. 14, 2003)

The opinion in support of the decision being entered today was not
written for publication and is not binding precedent of the Board.
Paper No. 16
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte KATHARINA SEITZ,
STEPHAN SÜßBRICH,
MICHAEL HORNUNG,
HEINRICH KÜHN,
and
FRANK HILTMANN
_____________
Appeal No. 2002-0895
Application No. 09/402,552
______________
ON BRIEF
_______________
Before PAK, WALTZ, and TIMM, Administrative Patent Judges.
PAK, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from
the examiner’s final rejection of claims 20 and 21. Claims
1 through 10 and 12 through 16, the remaining claims in the
above-identified application, have been indicated to be
allowable.
Appeal No. 2002-0895
Application No. 09/402,552
2
APPEALED SUBJECT MATTER
The subject matter on appeal is directed to a process for
producing a coating having a titanium diboride content of at
least 80% by weight. Details of the appealed subject matter are
defined by claims 20 and 21 which are reproduced below:
20. A process for producing a coating having a
titanium diboride content of at least 80% by weight, which
comprises applying a spray powder coating of titanium
diboride having a thickness of from 0.1 mm to 1 mm, a
porosity of not more than 10% by volume and an oxygen
content of less than 1% by weight to the surface of a
substrate by plasma spraying in an atmosphere which is
virtually or completely free of oxygen, with no metal powder
being added to the spray powder, and wherein a spray powder
having a mean powder particle size of from 10 to 55
m is
substantially or completely melted in a plasma flame in
order to apply the coating, the spray powder having an
oxygen content in the absence of carbon in the powder of
less than or equal to 1% by weight.
21. The process as claimed in claim 20, wherein plasma
spraying is carried out in a virtually or completely oxygen-
free atmosphere at a pressure of at least 500 mbar.
THE EVIDENCE
The examiner relies on the following prior art references:

Boxall et al. (Boxall) 4,354,918 Oct. 19, 1982
Gruenr 4,808,487 Feb. 28, 1989

Mills, et al., “Surface Cleaning, Finishing, and Coating,” Metal
Handbook, pp. 363-366 and 368 (9th Ed., Vol. 5, Am. Society for
Metals 1982)(hereinafter referred to as “Mills”).
Appeal No. 2002-0895
Application No. 09/402,552
1 We observe that the appellants have proffered only the
first page of this article. We presume that the remaining pages
of this article are not material to the examination of this
application since the appellants have not submitted them to the
examiner in compliance with 37 CFR § 1.56.
3
Appellants rely on the following reference:
Ananthapadmanabhan et al., “Electrical resistivity of plasma-
sprayed titanium diboride coatings,” Journal of Materials
Science, p. 1655 (1993)(hereinafter referred to as
“Ananthapadmanabhan”).1
THE REJECTION
Claims 20 and 21 stand rejected under 35 U.S.C. § 103 as
unpatentable over the combined disclosures of Boxall, Mills, and
Gruenr.
OPINION
We have carefully reviewed the claims, specification, and
evidence, including all of the arguments advanced by both the
examiner and the appellants in support of their respective
positions. This review has led us to conclude that the
examiner’s Section 103 rejection is well founded. Accordingly,
we will sustain the examiner’s Section 103 rejection for the
reasons set forth in the Answer and below.
The examiner finds (the Answer, pages 3-4), and we agree,
that:
Appeal No. 2002-0895
Application No. 09/402,552
4
Boxall teaches [a] method for producing a coating
having a titanium diboride of at least 80% by weight.
Column 4, lines 40-55 and column 2, line 50 through column
3, line 10 (the coating can be 100% titanium diboride). A
coating of about 10 mils (about .25 mm) can be applied.
Column 4, lines 45-55. The coating is applied by plasma
spraying. Column 4, lines 40-55. The porosity of the
coating is less than 10% by volume. Column 3, lines 35-45
(the coating is desired to be nonporous). The titanium
diboride is to be sprayed at using argon/hydrogen gas.
Column 4, lines 40-55. The spray powder is of 100% titanium
diboride, so the oxygen content of the powder to be sprayed
would be less than 1% by weight.
The examiner states that Boxall does not expressly state that its
plasma spraying is carried out in an inert atmosphere and its
spray powder has a mean particle size of from 10 to 55
micrometer. See the Answer, page 4. To remedy this deficiency,
the examiner relies on the disclosures of Mills and Gruenr.
Mills teaches that “throughout the coating industry,” plasma
spraying is carried out in an inert atmosphere and/or low
pressure chamber. See page 364, column 1. The inert atmosphere
chamber restricts the formation of undesired oxide, minimizes
changes in chemistry of the coating and reduces environmental
problems, such as dust and noise. See page 364, columns 2 and 3.
Mills teaches (page 364, column 2) that:
In any good inert gas chamber, oxygen levels can be
easily maintained below 30 ppm. Metal powders tend to
cleanup when sprayed in an inert gas chamber by the
Appeal No. 2002-0895
Application No. 09/402,552
5
reduction of surface oxides. By the same mechanism, some
oxide powders tend to reduce when sprayed in an inert
atmosphere.
Mills further states that the optimum spray conditions will vary
with the chemistry and the particle size of each spray material.
See page 364, column 3. Consistent with Mills’ and Boxall’s
teachings, Gruenr also teaches forming a 100% titanium diboride
coating or intermediate layer having the claimed thickness by
plasma spraying a spray powder having an optimum particle size of
25 micrometer maximum. See column 3, lines 41-60 and column 4,
lines 13-27. Specifically, Gruenr teaches (column 3, lines 53-
60) that:
The grade of sprayed powder is advantageously 25

m maximum, which ensures that all spray powder
particles form the spray layer as molten drops not only
during the spraying of the coating layer of the
adherence layer but also particularly during the
spraying of the intermediate layer. In this way and
including the effect of the high mechanical impact
energy, the compactness of the spray layer is ensured.
Given the above circumstances, we concur with the examiner
that one of ordinary skill in the art would have been led to
plasma spray titanium diboride powder having the claimed
characteristics, including the optimum particle size, such as
that claimed, in an inert atmosphere chamber virtually free of
oxygen to form a spray powder coating of titanium diboride having
the claimed thickness, motivated by a reasonable expectation of
Appeal No. 2002-0895
Application No. 09/402,552
6
successfully obtaining the advantages indicated supra.
The appellants argue that Boxall does not teach or suggest
forming a spray powder coating of titanium diboride having an
oxygen content of less than 1% by weight. See, e.g., the Brief,
page 3. This argument fails at the outset since it is well
settled that an applicant cannot show nonobviousness by attacking
prior art references individually where, as here, the rejection
is based on a combination of prior art references. In re Young,
403 F.2d 754, 757, 159 USPQ 725, 728 (CCPA 1968). It is
important to recognize that the test for obviousness is what the
combined teachings of the prior art references would have
suggested to those of ordinary skill in the art. See In re
Keller, 642, F.2d 413, 425, 208 USPQ 871, 881 (CCPA 1981).
In the present case, we determine that the combined
teachings of the prior art references would have suggested
forming a spray powder coating of titanium diboride in an inert
gas chamber virtually free of oxygen (30 ppm oxygen or less) as
indicated supra. This inert gas chamber, as indicated supra, is
said to prevent the formation of undesirable oxides, reduce any
oxide present and minimize changes in chemistry of the coating.
It then follows that the applied prior art references as a whole
would have suggested to one of ordinary skill in the art to form
Appeal No. 2002-0895
Application No. 09/402,552
7
a spray powder coating of titanium diboride having a low or no
oxygen content, such as that claimed, via the employment of an
inert gas chamber. The spray powder coating of titanium diboride
having the claimed oxygen content would necessarily follow from
the suggestions of the prior art references. See, e.g., Ex parte
Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Int. 1985).
The appellants rely on Ananthapadmanabhan to demonstrate
that Boxall does not form a spray powder coating of titanium
diboride having the claimed oxygen content. Specifically, the
appellants state (the Brief, page 4) that:
Ananthapadmanabhan et al[.] (J. Mat. Sci., copy
attached) have shown that partial oxidation could not be
avoided, even when Ar is used as a shield gas. Therefore,
it is not within ordinary skill to modify the process of
Boxall such that high quality coatings as obtainable from
the claimed process herein can be produced (see for example,
specification page 5, lines 29-33 and Page 6, lines 21-36).
The appellants again improperly focus on individual prior
art references. Young, 403 F.2d at 757, 159 USPQ at 728.
Considering the applied prior art references as a whole, as we
must, we determine that the examiner correctly pointed out at
pages 8 and 9 of the Answer that they would not only have
suggested employing a shield gas (argon and hydrogen (reducing
gas)), but have also suggested using an inert gas chamber to
prevent partial oxidation during plasma spraying. The appellants
Appeal No. 2002-0895
Application No. 09/402,552
8
do not argue, much less point to any evidence, including
Ananthapadmanabhan, that one of ordinary skill in the art would
not have reasonably expected to form a spray powder coating of
titanium diboride having the claimed oxygen content from the
process suggested by the applied prior art references, i.e.,
plasma spraying of a 100% titanium diboride in an inert gas
chamber. See the Brief in its entirety.
The appellants argue that the applied prior art references
do not teach or suggest the claimed spray powder having a mean
particle size of 10 to 55 microns. See. e.g., the Brief, page 4.
We do not agree.
As indicated supra, Mill teaches that spray powder particles
sizes are a result effective variable in a plasma spray coating
process. See In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d
1934, 1936-37 (Fed. Cir. 1990) (when the difference between the
claimed invention and the prior art is some variable within the
claims, the appellants must show that the particular variable is
critical); In re Boesch, 617 F.2d 272, 276, 205 USPQ 215, 219
(CCPA 1980)(the optimization of result effective variables is
well within the ambit of one of ordinary skill in the art).
Thus, we conclude that it would have been prima facie obvious to
employ the optimum plasma spray particle sizes, such as those
Appeal No. 2002-0895
Application No. 09/402,552
9
claimed, in the process suggested by Boxall and Mills to obtain a
desired titanium diboride coating. This is especially true in
this case since as indicated supra, Gruenr teaches that plasma
spray particles having the claimed sizes, i.e., 10 to 25 microns,
are useful for forming a desired titanium diboride coating having
the claimed thickness. See also the Answer, page 8.
The appellants argue that the prior art references do not
teach or suggest a titanium diboride coating having a porosity of
not more than 10% by volume. See the Brief, page 4. According
to the appellants (the specification, page 6),
the porosity should be at most 10% by volume . . . .
Preference is given to a porosity of from 4 to 6% by
volume, since here the pores do not allow bonding
between substrate and medium even at relatively low
layer thicknesses . . . .
We find that Boxall teaches that it is desirable to form a
spray powder coating of titanium diboride on studs made of, e.g.,
a stainless steel material. See, e.g., column 3, lines 35-40.
We find that Boxall states that “a non-porous or impervious
coating is most desirable.” See column 3, lines 40-42. We find
that Boxall subsequently bonds titanium diboride to stainless
steel materials in the form of a coating using a plasma spraying
technique. See column 4, lines 15-52. We find that Boxall does
not suffer from any bonding problem. See Boxall in its entirety.
Appeal No. 2002-0895
Application No. 09/402,552
10
Under these circumstances, it is reasonable to conclude that
Boxall necessarily or inherently forms a titanium diboride
coating having the claimed porosity since being able to bond, as
indicated supra, is dependent on the porosity of a coating.
In any event, the tenor of Boxall indicates that the
formation of a substantially non-porous or impervious corrosion-
resistant coating is well within the level of one of ordinary
skill in the art. See, e.g., column 3, lines 19-60. Thus, we
determine that Boxall would have at least suggested the formation
of a titanium diboride coating having the claimed porosity. This
is buttressed by Mills which teaches the formation of coatings
having higher densities and higher bond strength using plasma
spraying. See page 363, column 1.
The appellants argue that the pressure condition recited in
dependent claim 21 is not taught or suggested by the applied
prior art references. We disagree for the reasons well
articulated by the examiner at page 9 of the Answer. In
particular, we agree with the examiner that the claimed pressure
of “at least 500 mbar” includes any pressure above approximately
0.493 atmosphere, thus including the normal or close to normal,
atmospheric condition or pressure taught by both Mills and
Boxall. Moreover, we determine that the optimization of
Appeal No. 2002-0895
Application No. 09/402,552
11
pressure conditions is well within the ambit of one of ordinary
skill in the art since Mills teaches at page 364 that different
pressures (normal or low pressures) can be used in plasma
spraying to form desired coatings. Woodruff, 919 F.2d at 1578,
16 USPQ2d at 1936-37.
Thus, on this record, we concur with the examiner that the
claimed subject matter as a whole would have been obvious to one
of ordinary skill in the art within the meaning of 35 U.S.C.
§ 103. Accordingly, we affirm the examiner’s decision rejecting
all of the claims on appeal under 35 U.S.C. § 103.
Appeal No. 2002-0895
Application No. 09/402,552
12
No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED
CHUNG K. PAK )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
THOMAS A. WALTZ ) APPEALS AND
Administrative Patent Judge ) INTERFERENCES
)
)
)
JAMES T. MOORE )
Administrative Patent Judge )
CKP:hh
Appeal No. 2002-0895
Application No. 09/402,552
13
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