DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 April 1, 2026 has been entered.
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 .
Priority
Receipt is acknowledged of a certified copy of JP 2020-117921 filed July 8, 2020 as required by 37 CFR 1.55. Receipt is also acknowledged of WO 2022/009849, the WIPO publication of PCT/JP2021/025374 filed July 8, 2020.
Claim Status
This Office Action is in response to Applicant’s Remarks and Claim Amendments filed April 1, 2026.
Claims Filing Date
April 1, 2026
Amended
2
New
4
Cancelled
3
Pending
1, 2, 4
Withdrawn
1
Under Examination
2, 4
Withdrawn Claim Rejections - 35 USC § 112
The following 112(a) rejection is withdrawn due to argument:
Claim 2 lines 5-6 “a step of predetermining a rolling reduction ratio based on blister defect occurrence rate”.
The applicant persuasively argues [0028]-[0029] support that the rolling reduction ratio is predetermined based on the defect occurrence rate and Fig. 2 discloses a relationship between rolling reduction ratio and blister defect occurrence rate as explained in [0027]-[0028], such that one of ordinary skill in the art would understand there is support (p. 4 para. 3, para. spanning pp. 4-5).
Applicant’s [0029] recites “the relationship between the cold rolling reduction ratio and the blister defect occurrence is grasped in advance by an experiment or the like.” Grasped in advance supports predetermining.
Response to Remarks filed April 1, 2026
Satou in view of Eckel; Nonaka in view of Eckel and optionally Araya; Urabe in view of Eckel and optionally Araya; Satou in view of Noguchi; Nonaka in view of Noguchi and optionally Araya; Urabe in view of Noguchi and optionally Araya
Applicant’s arguments, see Remarks p. 6 paras. 2-3, filed April 1, 2026, with respect to Satou, Nonaka, Eckel, and Noguchi have been fully considered and are persuasive. The rejections in the December 19, 2025 Final Rejection have been withdrawn.
The applicant persuasively argues Satou discloses an overall width reduction of 20% or more in the rough rolling of the hot rolling and Nonaka discloses width reduction of 20 to 400 mm, but neither reference considers blister rate defect occurrence rate in predetermining an amount of width reduction (p. 6 para. 2), and, while Eckel and Noguchi relate to cold rolling reduction ratio, neither consider blister defect occurrence rate in predetermining an amount of width reduction (p. 6 para. 3).
New Grounds
In light of claim amendment and upon further consideration new grounds of rejection are made over Satou in view of Noguchi and Nishimura and over Nishimura in view of Noguchi.
Claim Interpretation
Claim 2 lines 5-6 “in a direction orthogonal to the rolling direction of the slab” is given the broadest reasonable interpretation of referring to “width reduction” and/or “slab width”, where the width reduction reduces the width of the slab.
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.
Claims 2 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Satou (JP S60-082616 machine translation) in view of Nishimura (JP 2001-279331 machine translation) and Noguchi (JP H02-73916 machine translation).
Regarding claim 2, Satou discloses a method for producing an ultra-low carbon steel product (Abstract, p. 1) having a carbon concentration of 0.005% by mass or less (0.004% or less) (p. 1), the method comprising, at least,
a refining step of adjusting a carbon concentration of molten iron to obtain molten steel (melting using a combination of a converter and a degassing device to produce a steel having the specified components) (p. 2 para. 1),
a casting step of casting the molten steel into a slab (continuous casting) (p. 2 para. 1),
a width reduction step of performing width reduction on the slab (width reduction of 20% or more prior to hot rolling) (p. 2),
a hot rolling step of hot rolling the slab to obtain a hot-rolled steel sheet (p. 2 para. 2), and
a cold rolling step of cold rolling the hot- rolled steel sheet to obtain a cold-rolled steel sheet (p. 2 para. 2),
wherein the method results in production of the ultra-low carbon steel product having a carbon concentration of 0.005% by mass or less (0.004% or less) (p. 1).
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Satou is silent to a step of predetermining a width reduction amount based on blister defect occurrence rate, wherein in the width reduction step, width reduction is performed with the predetermined width reduction amount in a direction orthogonal to the rolling direction.
Nishimura discloses a method for producing an ultra (very)-low carbon steel product ([0007], [0009]) comprising a step of predetermining a width reduction amount based on blister defect occurrence rate (limit width reduction to 170 mm or less to avoid the occurrence of blister defects), wherein in the width reduction step, width reduction is performed with the predetermined width reduction amount in a direction orthogonal to the rolling direction (reduce the width to 90 mm) ([0009], [0013], [0022], [0024], Fig. 2).
It would have been obvious to one of ordinary skill in the art in the width reduction step of Satou to predetermine the width reduction amount based on blister defect occurrence rate to not exceed 170 mm so that blister defects do not occur (Nishimura [0013], [0022]), which improves the yield of steel sheets for enamel treatment (Nishimura [0031]).
Satou is silent to a step of predetermining a rolling reduction ratio based on blister defect occurrence rate, wherein in the cold rolling step, cold rolling is performed at the predetermined rolling reduction ratio.
Noguchi discloses a method for producing low carbon steel sheets (less than 0.010 wt% C) (Abstract, p. 2) including a step of predetermining a rolling reduction ratio based on blister defect occurrence rate, wherein in the cold rolling step, cold rolling is performed at the predetermined rolling reduction ratio (“blister defects can be suppressed by performing the primary cold rolling with a cold rolling ratio of 80% or less”) (para. spanning pp. 1-2).
It would have been obvious to one of ordinary skill in the art in the process of Satou for the cold rolling to be a primary cold rolling with a ratio of 80% or less to reliably reduce the defect (blister) index, such that it is small (Noguchi p. 2 para. 2), improving workability and formability (Noguchi p. 1 para. 1). In support of the combination, Satou discloses hot rolling then cold rolling reduction of 75 to 79% to obtain a strip having a thickness of 0.8 mm (Satou p. 2 para. 2), which is within the scope of the primary cold rolling of Noguchi being 80% or less (Noguchi p. 1).
Regarding claim 4, Satou in view of Nishimura and Noguchi discloses the method of claim 2 as cited above, wherein:
the step of predetermining the width reduction amount is performed in accordance with a slab width (Satou p. 2; Nishimura [0009], [0013], [0022], [0024], Fig. 2), and
the step of predetermining the rolling reduction ratio is performed in accordance with a thickness of the hot-rolled steel sheet (Satou p. 2 para. 2; Noguchi para. spanning pp. 1-2).
Claims 2 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Nishimura (JP 2001-279331 machine translation) in view of Noguchi (JP H02-73916 machine translation).
Regarding claim 2, Nishimura discloses a method for producing an ultra (very)-low carbon steel product having a carbon concentration of 0.005% by mass or less (0.01% or less) ([0007], [0009], [0010], [0014]), the method comprising, at least,
a refining step of adjusting a carbon concentration of molten iron to obtain molten steel (adjust to the preferred composition including 0.01% or less C) ([0010], [0014], [0021]),
a casting step of casting the molten steel into a slab ([0021], [0024]),
a step of predetermininq a width reduction amount based on blister defect occurrence rate (limit width reduction to 170 mm or less) ([0013], [0022], Fig. 2),
a width reduction step of performinq width reduction on the slab ([0022], [0024]),
a hot rolling step of hot rolling the slab to obtain a hot-rolled steel sheet ([0023], [0024]), and
a cold rolling step of cold rolling the hot-rolled steel sheet to obtain a cold-rolled steel sheet ([0023], [0024]),
wherein in the width reduction step, width reduction is performed with the predetermined width reduction amount in a direction orthoqonal to the rollinq direction ([0009], [0022]), and
wherein the method results in production of the ultra (very)-low carbon steel product having a carbon concentration of 0.005% by mass or less (0.01% or less) ([0010], [0014]).
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Nishimura is silent to a step of predetermining a rolling reduction ratio based on the blister defect occurrence rate, wherein in the cold rolling step, cold rolling is performed at the predetermined rolling reduction ratio.
Noguchi discloses a method for producing low carbon steel sheets (less than 0.010 wt% C) (Abstract, p. 2) including a step of predetermining a rolling reduction ratio based on blister defect occurrence rate, wherein in the cold rolling step, cold rolling is performed at the predetermined rolling reduction ratio (“blister defects can be suppressed by performing the primary cold rolling with a cold rolling ratio of 80% or less”) (para. spanning pp. 1-2).
It would have been obvious to one of ordinary skill in the art in the process of Nishimura for the cold rolling to be a primary cold rolling with a ratio of 80% or less to reliably reduce the defect (blister) index, such that it is small (Noguchi p. 2 para. 2), improving workability and formability (Noguchi p. 1 para. 1). In support of the combination, Nishimura discloses hot rolling then cold rolling reduction of 75 to 75 to 90% with an example cold rolling reduction ratio of 80% ([0023]-[0024]), which overlaps with and is within the scope of, respectively, the primary cold rolling of Noguchi being 80% or less (Noguchi p. 1).
Regarding claim 4, Nishimura in view of Noguchi discloses the method of claim 2 as cited above, wherein:
the step of predetermining the width reduction amount is performed in accordance with a slab width (Nishimura [0013], [0022], Fig. 2), and
the step of predetermining the rolling reduction ratio is performed in accordance with a thickness of the hot-rolled steel sheet (Noguchi para. spanning pp. 1-2).
Related Art
Nonaka (JP H06-262245 machine translation)
Nonaka discloses a method for producing an ultra-low carbon steel product (Abstract, [0001]) having a carbon concentration of 0.005% by mass or less (0.003%) ([0012], Table 1), the method comprising, at least, a refining step of adjusting a carbon concentration of molten iron to obtain molten steel (a low carbon steel slab having the chemical composition shown in Table 1) ([0012]), a casting step of casting the molten steel into a slab ([0012]), a hot rolling step of hot rolling the slab to obtain a hot-rolled steel sheet ([0012]), and a cold rolling step of cold rolling the hot- rolled steel sheet to obtain a cold-rolled steel sheet ([0012]), wherein the method results in the product of the ultra-low carbon steel product having a carbon concentration of 0.005% by mass or less (0.003%) ([0012], Table 1) and the process includes a width reduction step (width reduction of 20 to 400 mm using a sizing press) ([0008]-[0012]).
Eckel (US 1,998,045)
Eckel discloses a method for producing low carbon steel sheets (1:1-2, 40-44) including a step of predetermining a rolling reduction ratio based on blister defect occurrence rate (process eliminates the formation of defects, which include bubbles or blisters, by heavy cold reduction) (1:8-12, 39-44, 2:25-28), wherein in the cold rolling step, cold rolling is performed at the predetermined rolling reduction ratio (not less than about 30% and not more than approximately 90%) (1:44-52) to prevent and eliminate the formation of defects, including bubbles or blisters (1:8-12, 39-44, 2:25-28).
Araya (JP H10-46243 machine translation)
Arraya discloses a method for producing a steel product ([0010]-[0015], [0028]-[0029]), the method comprising, at least, a refining step of adjusting a carbon concentration of molten iron to obtain molten steel (vacuum degassing to adjust the C content) to improve the cleanliness of the steel ([0040]).
Urabe (JP H04-247827 machine translation)
Urabe discloses a method for producing an ultra-low carbon steel product (Abstract, [0001]) having a carbon concentration of 0.005% by mass or less (upper limit of C is set to 0.0030 wt%) ([0015]), the method comprising, at least, a refining step of adjusting a carbon concentration of molten iron to obtain molten steel (above mentioned composition) ([0033]), a casting step of casting the molten steel into a slab (continuous casting) ([0033]), a hot rolling step of hot rolling the slab to obtain a hot-rolled steel sheet ([0033], [0037]), and a cold rolling step of cold rolling the hot- rolled steel sheet to obtain a cold-rolled steel sheet ([0033], [0038]), wherein the method results in the production of the ultra-low carbon steel product having a carbon concentration of 0.005% by mass or less (upper limit of C is set to 0.0030 wt%) ([0015]).
Kizu (US 2015/0252456)
Kizu discloses a steel sheet ([0001], [0007]) with 0.0010 to 0.0030% C ([0035]) manufactured by producing molten steel with the disclosed composition ([0052]), hot rolling ([0053]-[0057]), then cold-rolling at 90% or less ([0061]), where when the cold rolling reduction is low, then the thickness of the hot-rolled sheet needs to be reduced with respect to the predetermined thickness of products ([0062]).
Kukuminato (JP H06-041683 machine translation)
Kukuminato discloses a steel sheet ([0001]) with 0.004% or less C ([0020]) manufactured by melting, RH vacuum degassing to decarburize the steel, hot rolling to a thickness of 2.0 mm, then cold rolling at a reduction rate of 90% to a thickness of 0.2 mm ([0044]).
KR ‘580 (KR 950018580 Abstract and Claim)
KR ‘580 discloses an ultra-low carbon steel with 0.005% or less C hot rolled by a conventional method then cold rolled at a reduction ratio of 50 to 85% to produce a steel without bubble (blister) defects (Abstract and Claim).
Mochinaga (JP H06-17130 machine translation)
Mochinaga discloses the relationship between the amount of width reduction per pass and the rate of blistered defect during wide-width reductio rolling, where in horizontal width reduction rolling, a single-pass reduction amount that exceeds 60 mm results in more frequent blister-like defects due to significant horizontal pressure that causes a greater spreading force to act against central segregation, whereas applying a light pressure in one pass and increasing the number of passes distributes the stress and suppresses blister-like defects ([0015], Fig. 2).
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/STEPHANI HILL/Examiner, Art Unit 1735
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