DETAILED ACTION
Response to Amendment
The Amendment filed 23 June 2026 has been entered. Claims 1-4 remain pending in the application. Claim 1 was amended. No new claim(s) have been added. Applicant's amendments to the claims have overcome the 112(b) rejections previously set forth in the Non-Final Rejection mailed 02 April 2026.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted between 15 November 2023 and 12 December 2025 were considered by the examiner. The submission is in compliance with the provisions of 37 CFR 1.97.
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 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over JPH02125815A (machine translation) of Iwamoto in view of JPH0230778A (machine translation) of Shimizu, further in view of US6287392B1 of Toda.
Regarding claim 1, Iwamoto teaches the manufacture of grain-oriented silicon steel sheet having superior magnetic characteristic in the same field of endeavor as the claimed invention. Iwamoto teaches a grain-oriented steel sheet with Si in the range of 2.5 to 4.0 wt%, Mn in the range of 0.03 to 0.15 wt%, and S and/or Se in the range of 0.008 to 0.100 wt%, Para[0001]. These overlap with the claimed values. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Iwamoto discloses that the steel sheet is hot-rolled, and then cold-rolled once or twice with intermediate annealing. In a method for producing a unidirectional silicon steel sheet, the method comprises a series of steps of applying an 80% range, finishing to a final sheet thickness, applying an annealing separator mainly composed of MgO after decarburizing annealing and performing final finish annealing, Para[0001]. Iwamoto also teaches a gas flow rate of 2 cc/min*kg (equivalent to 2 L/min per ton), and a dew point of 0°C or less, Para[0001]. Iwamoto discloses that after finish annealing, insulation tension coating is applied and flattening annealing is performed to finish the product, Para[0001]. While Iwamoto teaches pickling, it is not taught after final annealing and prior to the application of the coating solution.
Iwamoto discloses that the annealing separator is mainly composed of MgO. The phrase "mainly composed of MgO" is interpreted as being a majority or more than 50%, which encompasses the claimed range. Furthermore, annealing separators are known to contain large amounts of MgO, as taught by Toda. Toda teaches a solids content of 90.9% by mass or more, col [14]. Toda discloses that any additives other than MgO incorporated into the annealing separator, however small in quantity, greatly affect the film formation as a matter of course, col[3]. Therefore, a person of ordinary skill in the art would have limited the annealing separator to contain MgO in the disclosed amount in order to adequately form the film.
Shimizu teaches the production of grain-oriented silicon steel sheet with excellent electromagnetic characteristic and coating adhesion in the same field of endeavor as the claimed invention. Shimizu discloses pickling prior to coating, Para[0001]. Shimizu teaches that the object of light acid pickling prior to coating is to remove unreacted separating agent, and for the purpose of improving the magnetism, Para[0001]. Shimizu also teaches phosphoric acid with a concentration of 1% or more and 20% or less before overcoating and that light acid pickling was carried out with either hydrochloric acid or sulfuric acid at a liquid temperature of 15 ° C or more for 2 seconds or more and 60 seconds or less to reduce S or Se present in the forsterite coating and in the vicinity of the coating and the iron, Para[0001]. These values for concentration, temperature, and time overlap with the claimed values. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05.
While Shimizu teaches a pickling temperature of 15°C or more, the highest temperature actually disclosed by Shimizu is 40°C, which falls outside of the claimed range.
Toda discloses a grain-oriented silicon steel sheet and process for production thereof in the same field of endeavor as the claimed invention. Toda teaches that the steel sheets were pickled in 5% HCl at 60° C. for 60 seconds, col[9]. Toda also teaches that the resulting mixture was incorporated with 10 pbw of one of any of the compounds shown in Table 2 for 100 pbw of MgO, col[14]. This corresponds to an annealing separator that is 90.9% by weight MgO. Therefore, the values for pickling temperature, time, and MgO content overlap with the claimed ranges. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Toda also discloses that it is an object of the present invention to provide a process for producing grain-oriented steel sheets superior in magnetic properties, having defect-free, uniform forsterite coating with good adhesion over the entire width and length of a coil even though the steel contains Bi in an amount of about 0.005-0.2 wt %, col[5].
Therefore, it would be obvious to one of ordinary skill in the art to pickle the grain-oriented steel sheet disclosed by Iwamoto before coating, as taught by Shimizu, using the temperature and MgO content in the annealing separator disclosed by Toda, in order to remove unreacted separating agents and achieve superior magnetic properties while having defect-free uniform coating with good adhesion over the entire width and length of the steel. Thus, Iwamoto in view of Shimizu and Toda covers all limitations of claim 1.
Claim 2 further limits claim 1 by claiming that the acid is one of phosphoric acid, hydrochloric acid, sulfuric acid, or nitric acid.
Iwamoto is silent on phosphoric acid, hydrochloric acid, sulfuric acid, and nitric acid.
Shimizu discloses Phosphoric acid, hydrochloric acid, and sulfuric acid, Para[0001]. Shimizu teaches that light acid pickling was carried out with either hydrochloric acid or sulfuric acid at a liquid temperature of 15 ° C or more for 2 seconds or more and 60 seconds or less to reduce S or Se present in the forsterite coating and in the vicinity of the coating and the iron, Para[0001]. Therefore, it would be obvious to one of ordinary skill in the art to use one of phosphoric acid, hydrochloric acid, or sulfuric acid, as taught by Shimizu, as the pickling acid in the method disclosed by Iwamoto in order to reduce S or Se in the coating. Thus, Iwamoto in view of Shimizu and Toda covers all limitations of claim 2.
Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over JPH02125815A (machine translation) of Iwamoto in view of JPH0230778A (machine translation) of Shimizu, and US6287392B1 of Toda as applied to claims 1 and 2 above, and further in view of WO9301329A1 (machine translation) of Masui.
Claim 3 further limits claim 1 by claiming that the annealing separator has an ignition loss after the drying of 1.0 mass% or more and 7.0 mass% or less.
Iwamoto and Shimizu are silent on ignition loss.
Toda discloses MgO constituting the annealing separator should preferably be a hydrous one which contains about 1-5% of water. (This water content is determined by ignition at 1000 DEG C. for 1 hour after hydration at 20 DEG C. for 6 minutes.) With a water content less than about 1%, MgO does not form a forsterite coating satisfactorily. On the other hand, with a water content more than about 5%, MgO does not form good forsterite coating; excess water oxidizes the steel sheet excessive, col[14].
Masui teaches a unidirectional silicon steel sheet having excellent film properties in the same field of endeavor as the claimed invention. Masui discloses that the weight change before and after drying of MgO expressed by ignition loss (loss on ignition) should be between 0.5 and 5.0%, Para[0087]. This 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, see MPEP 2144.05. Masui teaches that if this ignition loss value is less than 0.5%, the reaction of MgO will be poor and the coating will be defective, whereas if the ignition loss is more than 5.0%, it will be in a state of peroxidation, resulting in film failure, Para[0087]. Therefore, it would be obvious to one of ordinary skill in the art to use the annealing separator with the ignition loss taught by Toda and Masui in the method disclosed by Iwamoto in view of Shimizu in order to avoid defective coating and film failure. Thus, Iwamoto in view of Shimizu further in view of Masui covers all limitations of claim 3.
Claim 4 further limits claim 2 by claiming that the annealing separator has an ignition loss after the drying of 1.0 mass% or more and 7.0 mass% or less.
Iwamoto and Shimizu are silent on ignition loss.
Toda discloses MgO constituting the annealing separator should preferably be a hydrous one which contains about 1-5% of water. (This water content is determined by ignition at 1000 DEG C. for 1 hour after hydration at 20 DEG C. for 6 minutes.) With a water content less than about 1%, MgO does not form a forsterite coating satisfactorily. On the other hand, with a water content more than about 5%, MgO does not form good forsterite coating; excess water oxidizes the steel sheet excessive, col[14].
Masui discloses that the weight change before and after drying of MgO expressed by ignition loss (loss on ignition) should be between 0.5 and 5.0%, Para[0087]. This 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, see MPEP 2144.05. Masui teaches that if this ignition loss value is less than 0.5%, the reaction of MgO will be poor and the coating will be defective, whereas if the ignition loss is more than 5.0%, it will be in a state of peroxidation, resulting in film failure, Para[0087]. Therefore, it would be obvious to one of ordinary skill in the art to use the annealing separator with the ignition loss taught by Toda and Masui in the method disclosed by Iwamoto in view of Shimizu in order to avoid defective coating and film failure. Thus, Iwamoto in view of Shimizu further in view of Masui covers all limitations of claim 4.
Response to Arguments
Applicant's arguments filed 23 June 2026 have been fully considered but they are not persuasive. Applicant argues that (remarks, page 6-8 of 10) while Shimizu generally teaches pickling using an acid prior to coating can be performed at a temperature of 15°C or more, Shimizu only teaches pickling acid temperatures as high as 40°C, therefore a skilled artisan would not have been motivated to use a specific temperature of 50°C or higher and 70°C or lower with a reasonable expectation of success. Applicant’s arguments are moot because the new ground of rejection necessitated by amendment includes US6287392B1 of Toda which teaches a pickling temperature of 60°C. This range fall within the claimed range.
Applicant also argues that since Shimizu doesn’t specifically teach the effect on uniform coating adhesion of the steel sheet coil over its entirety both lengthwise and widthwise, the temperature range is not covered. Applicant’s arguments are moot because the new ground of rejection necessitated by amendment includes US6287392B1 of Toda which teaches good adhesion over the entire width and length of a coil, col[5]. Thus, Toda considered along with Iwamoto and Shimizu would motivate one of ordinary skill in the art to provide a uniform coating over the entire length and width of the steel sheet coil by using a pickling temperature in the claimed range.
Examiner’s Note
Examiner has attached previously-cited foreign references that were inadvertently omitted in the non-final action. References Included herein: JPH02125815, JPH0230778A, and WO9301329A1
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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/JACOB BENJAMIN STILES/Examiner, Art Unit 1733
/VANESSA T. LUK/Primary Examiner, Art Unit 1733
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