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 .
Response to Arguments
Applicant’s arguments, see Remarks, filed 6/23/2026, with respect to the 35 U.S.C. 102/103 rejection over Fujisawa (US 2007/0163679), the 35 U.S.C. 102 and 103 rejections over Hauser (US 6,096,441), and over Kim (US 2023/0043454), have been fully considered and are persuasive in view of Applicant’s amendments and arguments. The rejections have been withdrawn. However, upon further search and consideration, new grounds of rejection have been entered.
The claim objections are withdrawn in view of Applicant’s amendments.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2 and 5-11 are rejected under 35 U.S.C. 103 as being unpatentable over Yano et al. (WO 2022/131204). For convenience, reference is made to English language equivalent US 2024/0006621.
Regarding claims 1 and 5, Yano teaches a stainless steel for fuel cell separators (¶ 1). The stainless steel may be an austenitic/ferritic duplex stainless steel (¶ 133), and contains the following composition as compared to the claimed composition:
Claim 1
Yano, ¶¶ 106-132
Cr
18%-24%
15%-25%
Ni
≤3%
0.01%-30% (pref. 2% for duplex stainless steel)
N
0.1%-0.3%
≤0.1%
Fe
Balance
Balance
Optional Elements:
C
≤0.2%
≤0.1%
Si
≤1%
≤2%
Mn
≤7%
≤3%
P
≤0.1%
≤0.05%
S
≤0.03%
≤0.01%
Al
≤0.1%
≤0.5%
Cu
≤4%
≤2.5%
Mo
≤4%
≤4%
Ti
≤0.5%
≤1%
Nb
≤0.5%
≤1%
V
≤0.5%
-
Zr
≤0.5%
≤1%
Sn
≤0.5%
-
B
≤0.01%
-
Ca
≤0.01%
-
Mg
≤0.01%
-
REM
≤0.1%
-
Yano does not disclose the presence of other elements. The composition of Yano overlaps the claimed composition, creating a prima facie case of obviousness. See MPEP 2144.05 I. As the composition of the stainless steel in Yano is similar to that claimed, one of ordinary skill in the art would expect a similar microstructure and properties, absent objective evidence to the contrary. See MPEP 2112. Yano teaches forming a coating on the stainless steel comprising a metal layer, an alloy layer, a metal carbide layer, a metal nitride layer, a carbon material, a conductive polymer layer, a resin layer, or a mixed layer thereof (¶ 170).
Regarding claim 2, Yano teaches a stainless steel thickness of 0.03-0.30 mm (¶ 134).
Regarding claims 6-11, the composition of Yano discloses a total C+N content of ≤0.2% (see Table above). This overlaps the claimed ranges, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Claims 1-2 and 5-11 are rejected under 35 U.S.C. 103 as being unpatentable over Nishiyama et al. (US 2013/0177837).
Regarding claims 1 and 5, Nishiyama teaches a stainless steel for fuel cell separators (¶¶ 1, 62). The stainless steel may be an austenitic/ferritic duplex stainless steel (¶ 62), and contains the following composition as compared to the claimed composition:
Claim 1
Nishiyama, ¶¶ 157-179
Cr
18%-24%
16%-30%
Ni
≤3%
1%-10%
N
0.1%-0.3%
0.1%-0.3%
Fe
Balance
Balance
Optional Elements:
C
≤0.2%
≤0.08%
Si
≤1%
0.01%-1.0%
Mn
≤7%
0.001%-2.0%
P
≤0.1%
-
S
≤0.03%
-
Al
≤0.1%
-
Cu
≤4%
0.01%-2.5%
Mo
≤4%
0.5%-7%
Ti
≤0.5%
0.01%-0.5%
Nb
≤0.5%
0.01%-0.5%
V
≤0.5%
0.01%-0.5%
Zr
≤0.5%
0.01%-0.5%
Sn
≤0.5%
-
B
≤0.01%
≤0.01%
Ca
≤0.01%
≤0.01%
Mg
≤0.01%
≤0.01%
REM
≤0.1%
≤0.01%
Nishiyama does not disclose the presence of other elements. The composition of Nishiyama overlaps the claimed composition, creating a prima facie case of obviousness. See MPEP 2144.05 I. As the composition of the stainless steel in Nishiyama is substantially similar to that claimed, one of ordinary skill in the art would expect a similar microstructure and properties, absent objective evidence to the contrary. See MPEP 2112. Nishiyama teaches forming a coating on the stainless steel comprising a Ni-Sn alloy (¶ 64), with conductive particles such as carbon black, titanium carbide, or titanium nitride included in the coating (¶ 88).
Regarding claim 2, Nishiyama teaches a stainless steel thickness of 0.02-0.8 mm (¶ 182). This overlaps the claimed range, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding claims 6-11, the composition of Nishiyama discloses a total C+N content of 0.1%-0.38% (see Table above). This overlaps the claimed ranges, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Claims 1-2 and 5-11 are rejected under 35 U.S.C. 103 as being unpatentable over Miyazaki et al. (US 2022/0109163) in view of Kim et al. (US 2023/0420697).
Regarding claims 1 and 5, Miyazaki discloses a fuel cell separator having a titanium layer and a carbon layer, or a titanium nitride layer, formed on the surface thereof (¶¶ 11-13). Miyazaki teaches the separator base material is a stainless steel, such as a duplex austenite/ferrite stainless steel, but does not disclose the composition of the stainless steel (¶ 44).
Kim teaches a stainless steel for fuel cell separators (¶ 1). The stainless steel may be an austenitic/ferritic duplex stainless steel (¶ 56), and has the following composition as compared to the claimed composition:
Claim 1
Kim, ¶¶ 58-84
Table 1, Steel 7
Cr
18%-24%
15%-34%
20.1%
Ni
≤3%
≤25% (pref. 2% for duplex stainless steel)
0.92%
N
0.1%-0.3%
≤0.3%
0.25%
Fe
Balance
Balance
Balance
C
≤0.2%
≤0.3%
0.028%
Si
≤1%
≤0.7%
0.7%
Mn
≤7%
≤10%
3.1%
P
≤0.1%
≤0.04%
0.01%
S
≤0.03%
≤0.02%
0.001%
Al
≤0.1%
-
-
Cu
≤4%
0.01%-1.5%
0.84%
Mo
≤4%
0.01%-5%
0.01%
Ti
≤0.5%
0.01%-0.5%
-
Nb
≤0.5%
0.01%-0.4%
-
V
≤0.5%
0.01%-0.6%
-
Zr
≤0.5%
-
-
Sn
≤0.5%
-
-
B
≤0.01%
-
-
Ca
≤0.01%
-
-
Mg
≤0.01%
-
-
REM
≤0.1%
-
-
Kim does not disclose the presence of other elements. The steel of Kim overlaps the claimed composition, creating a prima facie case of obviousness. See MPEP 2144.05 I. In addition, Kim teaches a stainless steel composition which lies within the claimed ranges (see Table 1, Steel 7). As the composition of the stainless steel in Kim is similar to that claimed, one of ordinary skill in the art would expect a similar microstructure and properties, absent objective evidence to the contrary. See MPEP 2112.
It would have been obvious at the effective time of filing for the claimed invention for one of ordinary skill in the art to use the duplex stainless steel of Kim for the fuel cell separator of Miyazaki because the prior art recognizes this stainless steel composition as suitable for a fuel cell separator and there is an expectation of success in the substitution of known elements.
Regarding claim 2, Miyazaki teaches a stainless steel thickness of 0.1-1 mm (¶ 45). This overlaps the claimed range, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding claims 6-11, the steel composition of Kim suggests a total C+N content of ≤0.6% (see Table above). This overlaps the claimed ranges, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Claims 1-2 and 5-11 are rejected under 35 U.S.C. 103 as being unpatentable over Yano et al. (US 2018/0175401) in view of Kim et al. (US 2023/0420697).
Regarding claims 1 and 5, Yano discloses a fuel cell separator having a surface layer coating of a metal layer, an alloy layer, a metal carbide layer, a metal nitride layer, a carbon material layer, a conductive polymer layer, an organic resin layer containing a conductive substance, or a mixed layer thereof (¶ 68). Yano teaches the separator base material is a stainless steel, such as a ferritic, austenitic, or dual-phase stainless steel, but does not disclose the composition of the stainless steel (¶ 64).
Kim teaches a stainless steel for fuel cell separators (¶ 1). The stainless steel may be an austenitic/ferritic duplex stainless steel (¶ 56), and has the following composition as compared to the claimed composition:
Claim 1
Kim, ¶¶ 58-84
Table 1, Steel 7
Cr
18%-24%
15%-34%
20.1%
Ni
≤3%
≤25% (pref. 2% for duplex stainless steel)
0.92%
N
0.1%-0.3%
≤0.3%
0.25%
Fe
Balance
Balance
Balance
C
≤0.2%
≤0.3%
0.028%
Si
≤1%
≤0.7%
0.7%
Mn
≤7%
≤10%
3.1%
P
≤0.1%
≤0.04%
0.01%
S
≤0.03%
≤0.02%
0.001%
Al
≤0.1%
-
-
Cu
≤4%
0.01%-1.5%
0.84%
Mo
≤4%
0.01%-5%
0.01%
Ti
≤0.5%
0.01%-0.5%
-
Nb
≤0.5%
0.01%-0.4%
-
V
≤0.5%
0.01%-0.6%
-
Zr
≤0.5%
-
-
Sn
≤0.5%
-
-
B
≤0.01%
-
-
Ca
≤0.01%
-
-
Mg
≤0.01%
-
-
REM
≤0.1%
-
-
Kim does not disclose the presence of other elements. The steel of Kim overlaps the claimed composition, creating a prima facie case of obviousness. See MPEP 2144.05 I. In addition, Kim teaches a stainless steel composition which lies within the claimed ranges (see Table 1, Steel 7). As the composition of the stainless steel in Kim is similar to that claimed, one of ordinary skill in the art would expect a similar microstructure and properties, absent objective evidence to the contrary. See MPEP 2112.
It would have been obvious at the effective time of filing for the claimed invention for one of ordinary skill in the art to use the duplex stainless steel of Kim for the fuel cell separator of Yano because the prior art recognizes this stainless steel composition as suitable for a fuel cell separator and there is an expectation of success in the substitution of known elements.
Regarding claim 2, Yano teaches a stainless steel thickness of 0.03-0.30 mm (¶ 66).
Regarding claims 6-11, the steel composition of Kim suggests a total C+N content of ≤0.6% (see Table above). This overlaps the claimed ranges, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Yano (US 2018/0083294), Yano (US 2018/0026276), Yano (US 2017/0033372) disclose subject matter similar to Yano (2018/0175401), which already forms the basis of a 35 U.S.C. 103 rejection. A rejection over Yano ‘294, Yano ‘276, or Yano ‘372 is therefore considered cumulative and not included in this Office Action. See MPEP 2120 I. Nishiyama (US 2017/0237084) discloses a duplex stainless steel fuel cell separator having a metal layer coating on the surface thereof, which is also similar to the subject matter disclosed by Yano ‘401. Iseki (US 2012/0231374) discloses a duplex stainless steel fuel cell separator having an electrically conductive amorphous carbon film on the surface thereof, which is also similar to the subject matter disclosed by Yano ‘401.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to XIAOBEI WANG whose telephone number is (571)270-5705. The examiner can normally be reached M-F 8AM-5PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Humera Sheikh can be reached at 571-272-0604. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/XIAOBEI WANG/Primary Examiner, Art Unit 1784
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