DETAILED ACTION
Response to Amendment
The Amendment filed 05/26/2026 has been entered. Claims 1, 3-4 and 6-21 remain pending in the application. Claims 7-15 have been withdrawn. Claims 2 and 5 have been canceled. New claims 17-21 have been added. Claims 1, 3-4, 6, and 16-21 are presented for examination on the merits. The 112(b) rejections previously set forth in the Non-Final Rejection mailed 02/23/2026 are maintained and updated herein to reflect claim amendments.
Claim Objections
Claim 1 is objected to because of the following informalities: amended claim 1 is missing the term “and” before the limitation “wherein the ceramic coating layer has a surface roughness of 1 μm or less” at the end of the claim. Appropriate correction is required.
Claim Rejections - 35 USC § 112
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, 3-4, 6, and 16-21 are 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 1 recites the limitation “wherein the grain-oriented electrical steel sheet has a weather resistance of less than 35%, the weather resistance meaning a rust-generating region formed on the surface of the base steel sheet including the ceramic coating layer after treatment under the conditions of 65°C, 95% humidity and 72 hours” in lines 4-7. This limitation renders the claim indefinite. It is unclear what is intended and encompassed by the term “weather resistance” and what types of “weather” are included by the phrase. It is further unclear what is intended and encompassed by the term "resistance", as it is unclear if this means that there is no deterioration, or some deterioration, and if the latter, how much and within what time period would be required in order to meet the required "resistance" property. The amended limitation reciting
The instant specification only states a base steel sheet “may have a weather resistance of less than 35% under the conditions of 65°C, 95% humidity and 72 hours (page 17, line 21 - page 18, line 1) and does not explain how one may determine and calculate this percentage.
The information provided in the instant specification therefore also relies upon relative and indefinite terminology, and does not provide a specific definition sufficient to define the claimed invention.
Claims 3-4, 6, and 16-21 depend on claim 1, do not resolve the aforementioned issues, and are thereby also indefinite.
Further regarding claim 1, the limitation “the weather resistance meaning a rust-generating region formed on the surface of the base steel sheet including the ceramic coating layer after treatment” renders the claim indefinite. The claimed definition of “weather resistance” does not clarify how to obtain or measure the claimed “weather resistance” property. Furthermore, the claim does not state that rust is actually formed, but only that it has the potential to generate rust. Therefore, it is unclear how this would further limit and explain the claimed phrase with respect to "weather resistance". The specification does not provide a standard for ascertaining the requisite degree of “weather resistance”, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
Claims 3-4, 6, and 16-21 depend on claim 1, do not resolve the aforementioned issues, and are thereby also indefinite.
Further regarding claim 1, the limitation “weather resistance of less than 35%” renders the claim indefinite since it is unclear whether this refers to 35% of the surface area, and if so, whether this is intended to be a continuous surface area, a total of unconnected areas, a thickness of the coating removed under the stated conditions (i.e. at least 65% remaining), or some other interpretation.
Claims 3-4, 6, and 16-21 depend on claim 1, do not resolve the aforementioned issues, and are thereby also indefinite.
Further regarding claim 1, the limitation “weather resistance of less than 35%” renders the claim indefinite since it is unclear what the 35% refers to with respect to the resistance; i.e. it is unclear if only 35% or less of the steel sheet resists weather, or if this is intended to mean something different.
Claims 3-4, 6, and 16-21 depend on claim 1, do not resolve the aforementioned issues, and are thereby also indefinite.
Further regarding claim 1, the limitation “the weather resistance meaning a rust-generating region formed on the surface of the base steel sheet including the ceramic coating layer after treatment” renders the claim indefinite. It is unclear whether the “rust-generating region” is formed on the surface of the base steel sheet, on the surface of the ceramic coating layer, on both surfaces, or a different interpretation.
Claims 3-4, 6, and 16-21 depend on claim 1, do not resolve the aforementioned issues, and are thereby also indefinite.
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, 3-4, 6, 16-21 are rejected under 35 U.S.C. 103 as being unpatentable over JP 2004/060029 A of Hina (as cited in prior Office action with reference to provided translation) in view of US 2005/224142 A1 of Hayakawa (as cited in prior Office action), as applied to claim 1 above, and further in view of KR 101736627 B1 of Posco (as cited in prior Office action with reference to provided translation).
Regarding claims 1, 3-4, 6, and 16-21, Hina teaches a method for producing a low iron loss grain-oriented electrical steel sheet in which excellent coating adhesion is maintained in the coating (Abstract).
Hina teaches a base steel sheet and a ceramic coating layer located in contact with a surface of the base steel sheet ([0015]-[0016], a coating of nitrides, carbides, etc. is formed on the surface of the base steel sheet; nitrides and carbides are ceramics). Hina teaches the steel sheet is free of forsterite coating (Example 1, [0047], [0053]).
Hina teaches a ceramic coating is formed by chemical vapor deposition on the base steel sheet ([0015]) with a coating thickness of 0.01 μm to 5 μm ([0029]).
Hina therefore reads on the limitation of a grain-oriented electrical steel sheet comprising: a base steel sheet; and a ceramic coating layer located in contact with a surface of the base steel sheet of claim 1.
Regarding the ceramic coating of claims 1, 4, 17, 18, 20, and 21, Hina teaches the coating material thus obtained is, for example, a nitride, carbide, carbonitride, or oxide of Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Al, B, or Si, and two or more of these may be laminated ([0028], TiO2, Al2O3, ZrO2, SiO2, and Ti3O4 are included since they are oxides of Ti, Al, Zr, and Si). Hina teaches the suitable thickness of the coating is in the range of 0.01 μm or more and 5 μm or less ([0029]), which overlaps with the claimed range. In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Hina therefore reads on the limitation wherein the ceramic coating layer is at least one selected among TiO2, Al2O3, ZrO2, MgO, SiO-2 and Ti3O4 of claim 1, wherein the ceramic coating layer has a thickness of 0.1 to 10 μm of claim 4, wherein the ceramic coating layer comprises Al2O3 of claim 17, wherein the ceramic coating layer comprises ZrO2 of claim 18, wherein the ceramic coating layer comprises SiO2 of claim 20, and wherein the ceramic coating layer comprises Ti3O4 of claim 21.
Hina teaches a base steel sheet with a chemical composition of 0.06 mass% C, 3.5 mass% Si, 0.022 mass% Al, 81 mass ppm N, 0.02 mass% Sb, 0.04 mass% Mn, 0.02 mass% Se and 0.03 mass% Bi (page 4, lines 193-194). Hina teaches N has an upper limit of about 100 ppm to prevent the occurrence of blister defects and that it is economically difficult to industrially reduce the concentration to 20 ppm or less ([0035]). Hina teaches the S content is limited to 0.003 mass % or less ([0038]). Hina teaches Sn is known to be an inhibitor component suitable for the production of known grain-oriented electrical steel sheets, and these elements can be contained alone or in combination ([0038]), but is silent to the content range of Sn.
Regarding the Sn content, it would have been necessary and obvious to look to the prior art for exemplary amounts of Sn used in grain-oriented electrical steel sheets. Hayakawa provides this teaching showing a grain oriented electromagnetic steel sheet suitably used for iron core materials of transformers, motors, electric generators, etc. ([0001]). Hayakawa teaches a Sn content of 0.01-1.50% for improving iron loss, where less than 0.01% results in the effect of improving iron loss being small, and exceeding 1.5% makes it difficult to obtain a good iron loss ([0157]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the grain-oriented electrical steel sheet of Hina, and adjust the Sn content, such as within the claimed ranges, as taught by Hayakawa, in order to form a base steel sheet using known and tested amounts of Sn predictably suitable for grain-oriented electrical steel sheets with good iron loss properties, as taught by Hayakawa.
Modified Hina therefore reads on the limitation wherein the base steel sheet comprises Si: 2.0 to 7.0 wt%, Sn: 0.01 to 0.10 wt%, Sb: 0.01 to 0.05 wt%, acid soluble Al: 0.020 to 0.040 wt%, Mn: 0.01 to 0.20 wt%, C: 0.04 to 0.07 wt%, N: 10 to 50 ppm, S: 0.001 to 0.005 wt%, the balance Fe and other inevitable impurities based on total 100 wt% of the base steel sheet of claim 3.
Regarding the insulating coating of claim 6, Hina teaches further comprising an insulation coating layer on the ceramic coating layer ([0031]).
Modified Hina therefore reads on the limitation further comprising an insulation coating layer on the ceramic coating layer of claim 6.
Regarding the CVD process of claim 16, Hina teaches a base steel sheet and a ceramic coating layer located in contact with a surface of the base steel sheet ([0015]-[0016], a coating of nitrides, carbides, etc. is formed on the surface of the base steel sheet; nitrides and carbides are ceramics). Hina teaches the steel sheet is free of forsterite coating (Example 1, [0047], [0053]). Hina teaches a ceramic coating is formed by chemical vapor deposition on the base steel sheet ([0015], chemical vapor deposition reads on claimed chemical vapor deposition (CVD) process) with a coating thickness of 0.01 μm to 5 μm ([0029]). Hina teaches chemical vapor deposition is carried out on the surface of the steel sheet ([0043], reads on the claimed wherein the ceramic coating layer is formed on a portion or a whole of one surface or two sides of the base steel sheet). Therefore, the steel sheet of Hina has a coating on the steel sheet without an annealing separator, and the coating of Hina is applied using CVD and without applying an annealing separator.
Since the claim is interpreted as a product-by-process claim and modified Hina teaches a steel with overlapping composition, ceramic coating composition and thickness, and ceramic coatings formed by chemical vapor deposition with no annealing separator, modified Hina reads on the limitation wherein the ceramic coating layer is formed on a portion or a whole of one surface or two sides of the base steel sheet by a chemical vapor deposition (CVD) process without applying an annealing separator of claim 16.
However, modified Hina is silent to wherein the grain-oriented electrical steel sheet has a weather resistance of less than 35%, the weather resistance meaning a rust-generating region formed on the surface of the base steel sheet including the ceramic coating layer after treatment under the conditions of 65°C, 95% humidity and 72 hours of claim 1, wherein the ceramic coating layer has a surface roughness of 1 μm or less of claim 1, and wherein the ceramic coating layer comprises MgO of claim 19.
Since modified Hina teaches an overlapping composition and a ceramic coating formed by chemical vapor deposition and overlapping coating thickness between the prior art and the claimed invention, one of ordinary skill in the art would reasonably expect the steel sheet of modified Hina to have the claimed weather resistance, despite Hina not explicitly disclosing it.
Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP § 2112.01 I. “Products of identical chemical composition can not have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112.01 II. Therefore, it is expected that the steel sheet of the prior art possesses the properties as claimed in the instant claims since a) the claimed and prior art products are identical or substantially identical in composition (see compositional analysis above), b) the claimed and prior art products are produced by identical or substantially identical processes (see processing analysis above). Since the Office does not have a laboratory to test the reference alloy, it is applicant’s burden to show that the reference alloy does not possess the properties as claimed in the instant claims. See In re Best, 195 USPQ 430, 433 (CCPA 1977); In re Marosi, 218 USPQ 289, 292-293 (Fed. Cir. 1983); In re Fitzgerald et al., 205 USPQ 594 (CCPA 1980).
Modified Hina therefore reads on the limitation wherein the grain-oriented electrical steel sheet has a weather resistance of less than 35%, the weather resistance meaning a rust-generating region formed on the surface of the base steel sheet including the ceramic coating layer after treatment under the conditions of 65°C, 95% humidity and 72 hours of claim 1.
As further evidence that one of ordinary skill in the art would reasonably expect the steel of modified Hina to possess the claimed weather resistance, the instant specification recites weather resistance is 60% or more when the final annealing was completed by applying an existing MgO annealing separator since the ceramic layer formed was non-uniform and the rust generated worsened iron loss and surface quality (page 29, lines 11-17). The instant specification further recites that weather resistance is excellent when the ceramic precursor is vapor-deposited, but when the ceramic coating layer is formed to be too thick, the weather resistance is shown to be inferior, which is considered to be due to the generation of film peeling (page 29, line 17 – page 30, line 7). In the instant case, the ceramic coating layer of Hina is deposited by chemical vapor deposition and has overlapping thickness with the claimed invention. Absent any clear and convincing evidence and/or arguments to the contrary, one of ordinary skill in the art would expect the steel of Hina to possess the claimed weather resistance.
Regarding the surface roughness of claim 1, Hina teaches minimizing surface roughness of the steel sheet surface through pickling, thermal etching, chemical polishing, etc. ([0029]). Hina teaches that coatings may also be smoothed to achieve ultra-low iron loss ([0031]), but does not explicitly disclose a surface roughness of the ceramic layer.
Therefore, Hina is silent to wherein the ceramic coating layer has a surface roughness of 1 μm or less of claim 1.
Regarding the surface roughness of the ceramic layer, it would have been necessary and obvious to look to the prior art for exemplary amounts of surface roughness of ceramic coatings in grain-oriented electrical steel sheets. Posco provides this teaching showing a grain oriented electrical steel sheet having a low core loss and an excellent insulation property comprising a steel sheet and a ceramic layer (Abstract). Posco and Hina are considered analogous art since they are similarly concerned with grain oriented electrical steel sheets with a ceramic layer. Posco teaches the ceramic layer may have a surface roughness (Ra) of 1 μm or less ([0045]) and when the surface roughness exceeds 1 μm, the dot ratio may be poor, which may cause a problem in which the transformer no-load loss is reduced ([0046]). Posco teaches when the surface roughness exceeds 1 μm, a dense ceramic layer cannot be formed, and the magnetic properties and insulating properties are inferior ([0079]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the grain-oriented electrical steel sheet of Hina, and adjust the surface roughness of the ceramic layer, such as within the claimed ranges, as taught by Posco, in order to form a dense ceramic coating using known and tested amounts of surface roughness predictably suitable for grain-oriented electrical steel sheets with good magnetic and insulating properties, as taught by Posco.
Modified Hina therefore reads on the limitation wherein the ceramic coating layer has a surface roughness of 1 μm or less of claim 1.
Regarding the MgO coating of claim 19, Hina teaches the coating material thus obtained is, for example, a nitride, carbide, carbonitride, or oxide of Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Al, B, or Si, and two or more of these may be laminated ([0028]).
However, Hina does not explicitly disclose wherein the ceramic coating layer comprises MgO of claim 19.
Posco teaches a grain oriented electrical steel sheet having a low core loss and an excellent insulation property comprising a steel sheet and a ceramic layer (Abstract). Posco and Hina are considered analogous art since they are similarly concerned with grain oriented electrical steel sheets with a ceramic layer.
Posco teaches a grain-oriented steel sheet with a ceramic layer (claim 1), the ceramic layer made of an oxide, nitride, carbide, or oxynitride containing at least one or more selected from Li, B, Ca, Sr, Mg, Al, Si, P, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Zr, Sn and Ba (claim 4). Posco teaches the ceramic layer is added to maximize the iron loss improvement effect of the grain-oriented electrical steel sheet ([0039], one of ordinary skill in the art understands “oxide of Mg” includes MgO).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the ceramic layer of Hina with the MgO ceramic layer of Posco to maximize iron loss improvement in the grain-oriented electrical steel sheet.
Additionally, or alternatively, since Posco teaches MgO is an alternative to oxides of Al, Zr, Si, and Ti as ceramic layers in grain-oriented electrical steel sheets and Hina teaches ceramic layer of oxides of Al, Zr, Si, and Ti, it would have been obvious to one of ordinary skill in the art to modify the ceramic layer of Hina and use the MgO ceramic layer of Posco because Posco teaches that a known alternative to oxides of Al, Zr, Si, and Ti as ceramic layers in grain-oriented electrical steel sheets, as taught by Hina, is a ceramic layer of magnesium oxides. The claim would have been obvious because the substitution of one known element for another would have yielded predictable results to one of ordinary skill in the art before the effective filing date of the invention. See MPEP § 2143 I. B.
Modified Hina therefore reads on the limitation wherein the ceramic coating layer comprises MgO of claim 19.
Modified Hina therefore reads on all the limitations of claims 1, 3-4, 6, and 16-21.
Response to Arguments
Applicant's arguments filed 05/26/2026 have been fully considered but they are not persuasive.
Applicant argues that surface-roughness control is not an arbitrary parameter (remarks, page 7). Applicant argues that Posco's teaching of Ra < 1 μm is not presented as a generally applicable surface-finish teaching for ceramic coatings on bare base steel, but rather as part of a system that necessarily begins with (and depends upon) a forsterite film (remarks, page 8). Applicant further argues that a person of ordinary skill in the art would not have been motivated to modify Hina, which is applied on the premise of a steel sheet without a forsterite film, with Posco, which necessarily presupposes a forsterite film, to arrive at the claimed embodiment (remarks, page 8).
In response, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, both Hina and Posco teach a grain-oriented electrical steel with a ceramic layer coating. Hina and Posco are considered analogous art since they are similarly concerned with grain-oriented electrical steels with ceramic coatings and are therefore in the same field of endeavor and solve similar problems (i.e. obtaining low iron loss by applying a ceramic coating).
As taught by the references, Hina teaches minimizing surface roughness of the steel sheet surface through pickling, thermal etching, chemical polishing, etc. ([0029]). Hina teaches that coatings may also be smoothed to achieve ultra-low iron loss ([0031]). Posco teaches when the surface roughness exceeds 1 μm, a dense ceramic layer cannot be formed, and the magnetic properties and insulating properties are inferior ([0079]). Since both Hina and Posco are aiming to achieve low iron loss and good magnetic properties, one of ordinary skill in the art would reasonably apply the surface roughness teachings of Posco to the ceramic coating of Hina to achieve superior magnetic properties. Hina explicitly teaches smoothing the coatings ([0031]), which one of ordinary skill in the art understands implies modifying the surface roughness and therefore, Hina implicitly recognizes surface roughness of the ceramic coating as a parameter. The presence or absence of a forsterite coating does not negate the teachings of Hina and Posco and does not render the references incompatible. While the surface roughness of Posco is influenced by the forsterite coating in the steel of Posco, there are other methods to achieve surface roughness, such as smoothing, as taught by Hina.
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 extension fee 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 date of this final action.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MAYELA ALDAZ whose telephone number is (571)270-0309. The examiner can normally be reached Monday -Thursday: 10 am - 7 pm and alternate Friday: 10 am - 6 pm.
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/M.A./Examiner, Art Unit 1733
/REBECCA JANSSEN/Primary Examiner, Art Unit 1733
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