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 .
This application is in response an amendment filed on 10/22/2025.
Claims 1-4 and 7 are pending and under examination. Applicant has amended claims 1, 7 and cancel claims 5-6.
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.
Claims 1-4, 7 are rejected 35 U.S.C. 103 as being unpatentable over Yinghao et al (CN113957264, machine translation) in view of Patel et al (NPL: “The effect of pH and hydrogen bond donor on the dissolution of metal oxides in deep eutectic solvents” published 2020, pages 5476-5486, IDS cited reference by applicant).
Regarding Claims 1, 3-4 and 7, Yinghao discloses method for preparing nickel sulfate used in batteries, electroplating, nickel-metal hydride batteries comprising adding sulfuric acid solution and oxidant to nickel for acid leaching reaction and the separating solid and liquid to obtain filtrate and filter residue and add extractant to nickel containing filtrate for extraction, separate the nickel-containing organic phase and then use the sulfuric acid solution to back extract nickel from the nickel-containing organic phase to obtain a nickel sulfate solution (paragraphs 0010-0013, reads also on claim 7 for back extraction performance after nickel leachate with hydrophobic deep eutectic solvent) wherein sulfuric acid has concentration of 3-5 mol/L (paragraph 0024).
Yinghao discloses separate (i.e., leach) nickel-containing organic phase but does not explicitly disclose or suggest organic phase contains hydrophobic deep eutectic solvent and an organic acid, the hydrophobic deep eutectic solvent including a hydrogen bond donor and a hydrogen bond acceptor, the hydrogen bond donor is an acidic hydrogen bond donor and organic acid a strong acid.
However, Patel discloses leaching of metal oxides (i.e., nickel oxide, wherein nickel oxides are considered nickel oxide ore based on definition of applicant specification paragraph 0017) which are important technologies found in lithium-ion batteries and also exist in low metal-containing industrial residues such as smelter slag, red mud or electric arc furnace dust (see pages 5476-5477, figure 5b) . Patel further discloses in figure 5b the dissolution of NiO in contact with a deep eutectic solvent formed by ethylene glycol, acetic acid, levulinic acid, oxalic acid, lactic acid (i.e. acidic hydrogen bond donor), choline chloride (i.e., hydrogen bond acceptor, reads also on claim 3 as quaternary ammonium halide) and trifluoromethanesulfonic acid (i.e., TFSA-strong organic acid and reads also on claim 4 of organic sulfonic acid compound, page 5477, throughout the pages 5478-5486).
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the method for producing nickel sulfate of Yinghao to include organic phase comprising a hydrophobic deep eutectic solvent of Patel to ensure that speciation of the dissolved metals did not change with varying pH as taught by Patel (see 5478-5480).
Regarding claim 2, Patel discloses leaching of metal oxides (i.e., nickel oxide) as disclosed above in claim 1 and further discloses hydrogen bond donor (i.e., acetic acid) to ChCl molar ratio is 2:1 while 10-1, 10-2, 10-3, 10-4 M TFSA (pages 5480), but does not explicitly disclose or suggest mass proportion of the organic acid with respect to the hydrophobic deep eutectic solvent is 9 mass% or more and 20 mass% or less.
However, since Patel discloses hydrogen bond donor (i.e., acetic acid) to ChCl molar ratio is 2:1 while 10-1, 10-2, 10-3, 10-4 M TFSA (pages 5480), therefore it would have been obvious to one of the ordinary skill in the art at before the effective filing date of applicant invention to optimize the mass proportion of organic acid (i.e., TFSA) with respect to DES to 9 mass% or more and 20 mass% or less to ensure that speciation of the dissolved metals did not change with varying pH as taught by Patel (see 5478-5480, see MPEP 2144.05).
Response to Arguments
Applicant’s arguments filed on 10/22/2025, see remarks on pages 4-8, with respect to the rejection(s) of claims 1 and 3-4 under 35 U.S.C. § 102(a)(1) as being anticipated by Patel et al ("The effect of pH and hydrogen bond donor on the dissolution of metal oxides in deep eutectic solvents" 2020, pages 5476-5486), claim 2 under U.S.C. § 103 as being unpatentable over Patel et al and claims 5-7 under U.S.C. § 103 as being unpatentable over Patel et al in view of P 2007077459 to Hiromasa et al ("Hiromasa") have been fully considered and are persuasive. Rejections have been withdrawn.
In response to the amendment filed on 10/22/2025, upon further consideration of applicant’s remarks, regarding Patel and Patel in view of Hiromasa that Patel does not disclose method for producing nickel sulfate and performing back extraction on nickel using sulfuric acid and Hiromasa discloses performing back extraction but does not disclose utilizing sulfuric acid on an organic phase. Therefore the rejections have been withdrawn and all the arguments are moot in view of new ground of rejections as set forth above.
However, upon further consideration and further amendment filed by applicant which constituted a new ground(s) of rejection for Claims 1-4 and 7 under U.S.C. § 103 as being unpatentable over Yinghao et al (CN113957264, machine translation) in view of Patel et al (NPL: “The effect of pH and hydrogen bond donor on the dissolution of metal oxides in deep eutectic solvents” published 2020, pages 5476-5486) as set forth above.
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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/SMITA S PATEL/Primary Examiner, Art Unit 1732 02/25/2026