DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 6/15/2026 has been entered.
Claim Status
An amendment, filed 6/15/2026, is acknowledged. Claim 1 is amended. Claims 1-9 are currently pending, claims 4-9 are withdrawn.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 3 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 3 recites “wherein the austenitic stainless steel has an interfacial contact resistance of at most 10 mΩcm2.” This statement may be interpreted as the steel, itself, having the claimed interfacial contact resistance. Claim 1, however, also requires that the steel comprise a conductive film on a surface thereof. Applicant argues, in the remarks of 6/15/2026, “The basic and novel characteristics of the present invention include achieving an interfacial contact resistance of at most 10 mΩcm2.” In view of these arguments, claim 3 may alternatively be interpreted such that the conductive film, father than the stainless steel, has the stated interfacial contact resistance. As a result, claim 3 is indefinite as to whether the interfacial contact resistance is required of the stainless steel or of a conductive film formed thereon.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Nishiyama (US 2013/0177837)(previously cited) in view of Inoue (US 2016/0032434)(previously cited).
With respect to Claim 1, Nishiyama teaches an austenitic stainless steel for a fuel cell separator with a composition, in weight%, as follows (para. 27, 60-66, 134-156):
Claim 1
Nishiyama
C
>0 to 0.03
≤ 0.08
Si
>0 to 3.0
0.01-1.5
Mn
>0 to 3.0
0.001-2.5
Cr
20-22
16-30
Ni
8-20
7-40
S
≤ 0.003
-
P
≤ 0.03
-
Mo
>0 to 0.6
0.1-10.0
Cu
>0 to 0.8
0.01-3.0
N
0.1-0.3
≤ 2.0, pref. 0.01-0.3
W
>0 to 2.0
-
Fe
Balance with inevitable impurities
Balance with inevitable impurities
Compositional ranges including zero (e.g. the claimed ranges of S and P) are interpreted as optional elements. Thus, Nishiyama teaches an austenitic stainless with compositional ranges overlapping each of the instantly claimed ranges with the exception of tungsten (W).
Inoue teaches an austenitic stainless steel sheet with compositional ranges substantially overlapping those of Nishiyama (para. 20-37) and teaches, in particular, the addition of 0.01-0.5 weight% of tungsten to improve the high temperature strength of the steel.
It would have been obvious to one of ordinary skill in the art to modify the austenitic stainless steel of Nishiyama to include 0.01-0.5 wt% tungsten (W), as taught by Inoue, in order to improve the high temperature strength of the steel. In addition, it would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Finally, Nishiyama wherein the austenitic stainless steel sheet, useful for a fuel cell separator, is provided with a conductive plating film on a surface thereof, the film exhibiting improved contact resistance. (para. 18-19, 33, 41, 51, 57, 62, 134-156). Thus, the austenitic stainless steel sheet of Nishiyama in view of Inoue teach an austenitic stainless steel sheet for a fuel cell separator with improved contact resistance meeting the instantly claimed composition and comprising a conductive film on a surface thereof.
With respect to Claim 2, Nishiyama in view of Inoue teaches a tungsten (W) content overlapping the claimed range and Inoue further teaches an example (Ex. 22; Table 1A) with a content of 0.1 wt% W, falling within the claimed range. (see rejection of claim 1). Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claim 3, Nishiyama in view of Inoue teach a stainless steel sheet with a conductive film having improved contact resistance. (see rejection of claim 1 above). Claim 3 does not make clear whether the contact resistance is measured on the stainless steel itself, or from the required conductive film on its surface. Nishiyama teaches wherein the stainless steel having a conductive film exhibits a contact resistance of approximately 6 mΩcm2 or less, falling within the claimed range. (Table 1).
Claim(s) 3 is rejected under 35 U.S.C. 103 as being unpatentable over Nishiyama (US 2013/0177837)(previously cited) in view of Inoue (US 2016/0032434)(previously cited), as applied to claim 1 above in view of Ide (US 2013/0302718)(previously cited).
With respect to claim 3, Nishiyama in view of Inoue teach an austenitic stainless steel comprising a conductive film with a contact resistance falling within the claimed range (see rejection of claim 3 above) deemed to meet the instant limitation.
In the alternative, if the contact resistance is drawn to a surface of the stainless steel not having a conductive film, Nishiyama is silent as to the contact resistance of the austenitic stainless steel surface.
Ide teaches a stainless steel for a fuel cell separator, wherein the stainless steel may be an austenitic stainless steel with compositional ranges of C, Si, Mn, Cr, Ni overlapping the instantly claimed ranges and those of Inoue, and further teaches processing the stainless steel to minimize the interfacial contact resistance to a value of, preferably, 5 mΩcm2 or less. (para. 1, 60-74, 94-95).
It would have been obvious to one of ordinary skill in the art to modify the austenitic stainless steel of Nishiyama in view of Inoue, to perform the treatment of Ide to obtain an interfacial contact resistance of 5 mΩcm2 or less, in order to obtain a steel with enhanced utility for a fuel cell separator.
Claim(s) 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Igarashi (JPWO2009060900A1)(machine translation provided).
With respect to Claim 1, Igarachi teaches an austenitic stainless steel for a fuel cell separator and having low contact resistance, wherein the steel has a composition, in weight%, as follows (pgs. 1 and 4 of translation; Table 2):
Claim 1
Igarashi
C
>0 to 0.03
0.001-0.2
Si
>0 to 3.0
0.01-1.5
Mn
>0 to 3.0
0.01-2.5
Cr
20-22
15-30
Ni
8-20
20-60
S
≤ 0.003
≤ 0.01
P
≤ 0.03
≤ 0.04
Mo
>0 to 0.6
≤ 7
Cu
>0 to 0.8
≤ 2
N
0.1-0.3
≤ 0.4
W
>0 to 2.0
≤ 4.0
Fe
Balance with inevitable impurities
Balance with inevitable impurities
Compositional ranges including zero (e.g. the claimed ranges of S and P) are interpreted as optional elements. Thus, Igarashi teaches an austenitic stainless with compositional ranges overlapping each of the instantly claimed ranges. It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Finally, Igarashi wherein the austenitic stainless steel sheet, useful for a fuel cell separator and having low contact resistance and good conductivity, is provided with a Ni and Cr containing passive film contributing to its utility as a fuel cell separator, and therefore, deemed comprise “a conductive film on a surface thereof. (pgs. 2-3 of translation).
With respect to Claim 2, Igarashi teaches a tungsten (W) content overlapping the claimed range. (see rejection of claim 1 above). Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claim 3, Igarashi teach a stainless steel sheet for a fuel cell separator having low contact resistance, in particular, drawn to inventive examples having a contact resistance of below 10 mΩcm2 or less, falling within the claimed range. (Table 2; pg. 8 of translation). It would have been obvious to one of ordinary skill in the art to select a stainless steel sheet from the teachings of Igarashi having a contact resistance within the overlapping portions of the ranges. MPEP § 2144.05.
Response to Arguments
Applicant’s arguments, filed 6/15/2026, with respect to the rejection(s) of claims 1-3 under 35 U.S.C. 103 over Inoue in view of Nishiyama and Claim 3 under 35 U.S.C. 103 over Inoue in view of Nishiyama and Ide have been fully considered and are persuasive in view of Applicant’s amendment to the claims. Specifically, prior art Inoue teaches carbon and chromium contents outside the amended ranges of claim 1. Therefore, the rejections have been withdrawn; however, after further search and consideration, a new grounds of rejection over Igarashi is made, as detailed above.
Applicant’s arguments with respect to the rejection of claims 1-3 under 35 U.S.C. 103 over Nishiyama in view of Inoue and Claim 3 under 35 U.S.C. 103 over Nishiyama in view of Inoue and Ide, have been fully considered but are not found persuasive.
Applicant argues that “the rejection still does not identify a teaching, suggestion, or reason to select and combine all of the presently claimed features: C at >0 to 0.03 wt%, Cr at 20-22 wt%, W, the exclusion of intentional Al/Ti additions under the “consisting essentially of” transition, and a conductive film providing the claimed interfacial contact resistance.” (Remarks, p. 4). Applicant argues that Nishiyama “discloses Al at up to 0.2 wt% and Ti, Nb, V, and Zr as optional additions” and concludes that the references and combination with Inoue fail to meet the consisting essentially of transitional phrase. (Remarks, pgs. 4-5). Applicant further argues that isolating features of prior art Inoue would constitute a hindsight reconstruction of the claimed composition. These arguments have been fully considered but are not found persuasive.
Nishiyama teaches compositional ranges of C and Cr clearly overlapping the claimed ranges, as amended. It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Nishiyama, as admitted by Applicant, does not require Al nor Ti and therefore, Applicant’s argument with respect to these elements is moot.
With respect to the secondary reference Inoue, the rejection does not require importing the entire composition of Inoue and therefore, Applicant’s arguments drawn the content C, Cr, Ti, and Al are not found persuasive. One of ordinary skill in the art would recognize that the teaching of Inoue with respect to tungsten (W), is applicable to a broader range of alloys than only that of Inoue. In other words, one of ordinary skill in the art would recognize that certain elements are known to be added to steel alloys for particular purposes, and that such minor modifying elements are not strictly limited in their functionality to a single specific composition. Moreover, the claims require only a non-zero content of tungsten that could be fulfilled even by an unintentional impurity content. For these reasons, the inclusion of a very minor of tungsten, as taught by Inoue, would have be prima facie obvious to one of ordinary skill in the art and Applicant’s arguments are not found persuasive.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Applicant fails to demonstrate criticality or unexpected results with respect to the content of tungsten, commensurate with the scope of the claims. Specifically, the instant specification does not provide any comparative examples with tungsten absent and/or outside the claimed range.
It is further noted, with respect to Applicant’s arguments drawn to the transitional phrase “consisting essentially of,” that Applicant’s arguments are not found persuasive. Applicant states “The basic and novel characteristics of the present invention include achieving an interfacial contact resistance of at most 10 mΩcm2 by providing a conductive film formed through an alternating current electrolysis after bright annealing.” (Remarks, p.2). Nishiyama teaches a steel falling well within the claimed interfacial contact resistance range and therefore, any argued additions outside the claimed composition do not affect the basic and novel characteristics of the claimed steel under Applicant’s understanding.
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., an interfacial contact resistance achieved by providing a conductive film) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Specifically, Claim 1 does not require an interfacial contact resistance and none of the claims make clear that the interfacial contact resistance is that of a film, rather than of the steel itself. (see also 112(b) rejection above).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN A HEVEY whose telephone number is (571)270-0361. The examiner can normally be reached Monday-Friday 9:00-5:30.
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/JOHN A HEVEY/ Primary Examiner, Art Unit 1735
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