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 .
Claim Status
An amendment, filed 1/15/2026, is acknowledged. Claim 1 is amended. Claims 1-9 are currently pending, claims 4-9 are withdrawn.
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 Inoue (US 2016/0032434)(previously cited) in view of Nishiyama (US 2013/0177837).
With respect to Claim 1, Inoue teaches an austenitic stainless steel with a composition, in weight%, as follows (para. 20-37; Table 1A):
Claim 1
Inoue
Inoue, Ex. 22
C
>0 to 0.1
0.05-0.15
0.10
Si
>0 to 3.0
1.0-3.5
2.0
Mn
>0 to 3.0
0.5-2.0
1.5
Cr
20-30
23.0-26.0
24.0
Ni
8-20
10.0-15.0
12.0
S
≤ 0.003
≤ 0.01
0.0005
P
≤ 0.03
≤ 0.04
0.026
Mo
>0 to 0.6
0.50-1.20
0.5
Cu
>0 to 0.8
Optionally, 0.01-2
0.2
N
0.1-0.3
0.1-0.3
0.20
W
>0 to 2.0
Optionally, 0.1-0.5
0.1
Fe
Balance with inevitable impurities
Balance
Balance
Other
-
Ti: ≤ 0.1
Al: 0.01-0.10
Ti: 0.01
Al: 0.04
C: 0.1
Nb: 0.04
V: 0.1
Co: 0.2
B: 0.0004
Sn: 0.01
Compositional ranges including zero are interpreted as optional elements. Thus, Inoue teaches an austenitic stainless with compositional ranges overlapping the instantly claimed ranges and a specific example, (Ex. 22) with a composition falling within each of the instantly claimed ranges.
Nishiyama teaches an austenitic stainless steel sheet for a fuel cell separator, wherein the stainless steel may have a composition substantially overlapping that of Inoue and the instant claims, wherein the stainless steel exhibits low contact resistance, and wherein the stainless steel sheet may be provided with a conductive plating film on its surface. (para. 18-19, 33, 41, 51, 57, 62, 134-156).
It would have been obvious to one of ordinary skill in the art to modify the stainless steel sheet of Inoue to comprise a conductive film, as taught by Nishiyama, in order to enhance its utility in applications such as for a fuel cell separator. Furthermore, in view of the teachings of Nishiyama, it would have been obvious to one of ordinary skill in the art to minimize the contact resistance of the austenitic stainless steel sheet of Inoue, in order to enhance its utility in applications such as for a fuel cell separator.
With respect to the preamble limitation “for a fuel cell separator with improved contact resistance,” is drawn to an intended use of the stainless steel. A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. Here, Inoue in view of Nishiyama teach a stainless steel having austenitic structure, the same composition, and having a conductive film on a surface, and therefore, teaches all of the required structure of the claim. Moreover Nishiyama specifically teaches the utility of such a stainless steel sheet for a fuel cell separator.
Furthermore, with respect to “improved contact resistance,” the limitation does not require any specific or relative measurement. Nishiyama teaches a stainless steel sheet for use as a fuel cell separator having a conductive film with improved contact resistance. (para. 18, 83-86). Accordingly, the stainless steel sheet of Inoue in view of Nishiyama, including said conductive film, is deemed to exhibit improved contact resistance.
With respect to Claim 2, Inoue teaches a tungsten (W) content overlapping the claimed range and an example (Ex. 22; Table 1A) with a content of 0.1 wt% W, falling within the claimed range. (see rejection of claim 1).
With respect to Claim 3, Inoue in view of Nishiyama 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). It would have been obvious to one of ordinary skill in the art to modify the stainless steel of Inoue in view of Nishiyama to form an austenitic stainless steel sheet having a conductive film on a surface thereof, and exhibiting a contact resistance of 6 mΩcm2 or less, as taught by Nishiyama, in order to improve its properties for use as a fuel cell separator.
Claim(s) 3 is rejected under 35 U.S.C. 103 as being unpatentable over Inoue (US 2016/0032434)(previously cited) in view of Nishiyama (US 2013/0177837), as applied to claim 1 above in view of Ide (US 2013/0302718)(previously cited).
With respect to claim 3, Inoue in view of Nishiyama 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, Inoue 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 Inoue in view of Nishiyama, 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 Nishiyama (US 2013/0177837) 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
Inoue
C
>0 to 0.1
0.08
0.05-0.15
Si
>0 to 3.0
0.01-1.5
1.0-3.5
Mn
>0 to 3.0
0.001-2.5
0.5-2.0
Cr
20-30
16-30
23.0-26.0
Ni
8-20
7-40
10.0-15.0
S
≤ 0.003
-
≤ 0.01
P
≤ 0.03
-
≤ 0.04
Mo
>0 to 0.6
0.1-10.0
0.50-1.20
Cu
>0 to 0.8
0.01-3.0
Optionally, 0.01-2
N
0.1-0.3
≤ 2.0, pref. 0.01-0.3
0.1-0.3
W
>0 to 2.0
-
Optionally, 0.1-0.5
Fe
Balance with inevitable impurities
Balance with inevitable impurities
Balance
Other
-
Ti: ≤ 0.1
Al: 0.01-0.10
Compositional ranges including zero 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 substantially overlapping compositional ranges to those of Nishiyama and the instant claim (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.
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 an example (Ex. 22; Table 1A) with a content of 0.1 wt% W, falling within the claimed range. (see rejection of claim 1).
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) 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.
Response to Arguments
Applicant’s arguments, filed 1/15/2026, with respect to the rejection(s) of claim(s) 1-3 under 35 U.S.C. 102 over Inoue and Claim 3 under 35 U.S.C. 103 over Inoue in view of Ide have been fully considered and are persuasive in view of Applicant’s amendment to the claims. Specifically, prior art Inoue is silent as a conductive film provided on a surface of the stainless steel. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Inoue in view of Nishiyama and Nishiyama in view of Inoue, as detailed above.
Applicant’s arguments are deemed moot in view of the new grounds of rejection.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/JOHN A HEVEY/Primary Examiner, Art Unit 1735