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 .
Election/Restrictions
Claims 8-10 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on June 8, 2026.
Applicant’s election without traverse of claims 1-7 in the reply filed on June 8, 2026 is acknowledged.
Priority
Acknowledgment is made of applicant's claim for foreign priority based on an application filed in China on September 8, 2022. It is noted, however, that applicant has not filed a certified copy of the CN202211100599.7 application as required by 37 CFR 1.55.
Drawings
The drawings are objected to because Fig. 3 “LHD-based” of magnetic particle 1 in legend should be corrected to “LDH-based”. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Interpretation
Regarding step S4) in Claim 1, the “coupling agent KH-580” is a known commercial product represented by chemical name “3-Mercaptopropyltriethoxysilane”, often utilized for functionalizing compounds with sulfhydryl groups or mercapto groups. For the purposes of examination, the “coupling agent KH-580” will be interpreted by its chemical name for clarity.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-5 and 7 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.
Regarding claim 1, in step S2) line 4, the “overnight” is left undefined as to what time period is considered overnight, therefore rendering the claim indefinite as to the confines of the scope of the method as claimed.
Regarding claim 1, in step S7) line 2, the “magnetic bead obtained in S6” is allowed to harden in the calcium chloride solution for “a certain period of time”. The phrase “certain period of time” is left undefined as to what dictates a “certain” amount of time before proceeding to the next steps, therefore rendering the claim indefinite as to the confines of the scope of the method as claimed. Claim 6, which is also dependent on claim 1, does cure the deficiency of the “certain period of time” by defining such period as “10 h to 24 h”. Thus, for the purposes of examination and compact prosecution, the definition provided in claim 6 will be read into the interpretation for independent claim 1.
Claims 2-5 and 7 are rejected as being dependent on, and failing to cure the deficiencies of, rejected independent claim 1.
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 1 and 4-7 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al (NPL "Preparation of magnetic alginate-layered...") in view of Shou et al (NPL "Fabrication of Fe3O4/MgAl-layered double hydroxide..."), Wang et al (NPL "Dual functional sites strategies..."), Luo et al (CN112898987A), and Li et al (CN110665471A).
Regarding claim 1, Lee teaches a preparation method of layered double hydroxide-based (LDH-based) magnetic composite particles for use in removing heavy metals via adsorption. Lee prepares Mg-Al LDH powders by co-precipitating mixtures of magnesium nitrate (a water-soluble divalent magnesium salt) and aluminum nitrate (a water-soluble trivalent aluminum salt) in water, thus obtaining a mixed salt solution and meeting the limitation of step S1 as claimed (“S1) dissolving a water-soluble divalent magnesium salt and a water-soluble trivalent aluminum salt in water, to obtain a mixed salt solution;”). Lee differs from the claimed invention by adding the mixed salt solution drop wise into an alkali solution at pH 13 of sodium hydroxide and sodium carbonate but does perform the reaction under “intensive stirring” and uses a “peristaltic pump”. Further, Lee conducts aging overnight in the “mother liquor”. Analogously, Shou et al describe fabrication of Fe3O4/MgAl-layered double hydroxide magnetic composites also for use in heavy metal removal. Similar to Lee, Shou mixes water soluble divalent magnesium and water soluble trivalent aluminum salts in deionized water to prepare a mixed salt solution. Shou, instead, prepares an ammonia solution and slowly drops it into the mixed salt solution under rough stirring (thus performing “reaction I under stirring”) to adjust pH until it reaches ~10. Therefore, Shou demonstrates an analogous procedure known in the art for preparing MgAl-LDH. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute for the basic solution of sodium hydroxide and sodium carbonate the basic solution of ammonia to modulate pH to ~10 and swap the pumping/dripping of solutions as known alternative basic pH-titrators and ordering of steps with predicted results of preparing an MgAl-LDH. Thus, Lee in view of Shou enables one of ordinary skill in the art to arrive at step S2 as claimed “S2) pumping ammonia water into the mixed salt solution, performing reaction I under stirring while monitoring a pH value of a resulting reaction system, adjusting the pH value of the resulting reaction system with the ammonia water until the pH value is stabilized at 9.5 to 10.5, and conducting aging overnight;”. Regarding limitation step S3, Lee further discloses centrifuging the resulting precipitates after aging (thus, a product obtained in S2) and after washing with deionized water. Then Lee obtains the washed precipitates which is understood to be performed by removing the supernatant to obtain such a product (MgAl-LDH) by one of ordinary skill in the art. Both Lee and Shou fail to disclose loading the LDH with a mercapto group (a functional group containing -SH). However, Wang, in an analogous preparation, teaches synthesis of Cysteine loaded MgAl-LDH. Wang loads with L-cysteine due to its thiol (-SH, thus mercapto) functional group which are known as active ligands for heavy metal binding. Wang teaches the low valent S is highly efficient at removing heavy metals such as Pb(II) and Cd(II) via adsorption pathways from aqueous solutions. Wang loads the LDH with a mercapto group by mixing prepared MgAl-LDH (product obtained in S3) with Cysteine via sonication and then stirring (“subjecting mixture to reaction II while stirring”). A mercapto group-loaded layered double hydroxide is thus obtained as described in 2.2.1 of Wang. Thus, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to load the MgAl-LDH obtained in the taught processes of Lee in view of Shou with a mercapto group such as one obtained from Cysteine, as informed by Wang, to improve the efficiency of heavy metal absorption of the subsequently obtained layered double hydroxide. Wang is silent on inclusion of ethanol in the product mixture and subsequent volume/mass ratios of reagents. Analogously, Luo describes preparation of a magnetic composite material for removal of heavy metals in soil. As opposed to a synthetic LDH, Luo loads a natural mixture of clay (attapulgite and zeolite) with sulfhydryl groups (thus mercapto) to similarly improve adsorption capacity to heavy metals (the clay mineral has an original adsorption capacity). In preparing the sulfhydryl attapulgite (equivalent to mercapto-loaded LDH), Luo discloses the mass ratio of attapulgite to water in suspension is 1:(15-25) (overlaps with claimed S4 range of 1:(8.3-18.3)). Although in the disclosed embodiment 1 Luo utilizes a mass ratio of 10g:200mL (1:20), overlapping ranges have been held to present a prima facie case of obviousness over the prior art. In the aforementioned embodiment 1, Luo mixes 10.0g of attapulgite in 200mL deionized water, adds 19.2mL of absolute ethyl alcohol (ethanol), and adds 2.4mL 3-mercaptopropyltriethoxysilane (equivalent to coupling agent KH-580). Thus, the volume ratio of ethanol to water is 19.2:200 or 1:10.4 and the volume ratio of 3-mercaptopropyltriethoxysilane to ethanol is 2.4:19.2 or 1:8 (both ratios falling within claimed range in S4). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute for L-cysteine the 3-mercaptopropyltriethoxysilane as a known alternative mercapto functionalizing group provider and subsequently substitute the downstream mercapto loading process provided by Luo in the pipeline provided by the combined teachings of Lee, Shou and Wang as described as a known alternative loading process for preparing mercapto group-loaded LDH and arrive at the method (steps S1-S4) as claimed.Regarding step S5, Lee teaches mixing prepared LDH (thus product of S4 or mercapto group-loaded LDH) with magnetic iron oxide (Fe3O4 or ferroferric oxide as prepared via coprecipitation of FeSO4 and FeCl3) and sodium alginate in deionized water and subsequently stirring intensively to obtain a homogenous suspension. Although Lee adds the reagents into deionized water as opposed to adding deionized water into a mixture of reagents, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to swap the ordering of addition without an expected change in synthesis of the product and thus an obvious predicted result of preparing a homogenous mixed solution of LDH, ferroferric oxide, sodium alginate and deionized water. Regarding step S6, Lee discloses addition of the homogeneous mixed solution from S5 into a calcium chloride solution via a pump but is silent on the magnetic bead particle size at this step. The final dried product under the Results discussion reveals a particle size of 1.5 mm, thus the wet magnetic bead obtained in S5-S6 would be expected to have a greater size as drying out contained water results in shrinkage. Similarly, Luo discloses in their alginate and Fe3O4 mixing step an addition of the homogeneous solution into a calcium chloride solution via a peristaltic pump which has inner diameter 1-2.4mm (thus beads would be up to 2.4mm and overlapping with particle size of 2 mm to 4 mm). The final magnetic material diameter of Luo is 1-2mm (Fig. 1A, also implying that the wet magnetic beads would be at least 1-2mm). Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed.Regarding step S7, Lee allows the resulting magnetic bead or composite of step S6 to “cure” in the “same CaCl2 solution” (curing is understood to be a hardening) but allows curing to occur in two 24h periods as opposed to a time period of 10-24h (the “certain period of time”). Subsequently, Lee washes the obtained composites with deionized water to remove any excess Ca2+ and allows the composites to dry in an oven to obtain the final product. In an analogous preparation of heavy metal removing colloidal particulate material, Li discloses mixture of magnetic iron oxide particles into a sodium alginate solution whereby the mixture is added into CaCl2 and allowed to “stand overnight” which would be equivalent to a hardening/curing step of Lee. The term “overnight” is generally considered to be under 24h and >8h, thus overlapping with the range of 10-24h or “certain period of time”. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. Thus, Lee, Shou, Wang, Luo, and Li teach the claimed method “A method for preparing a mercapto group-loaded layered double hydroxide- based magnetic composite particle, comprising the steps of S1) dissolving a water-soluble divalent magnesium salt and a water-soluble trivalent aluminum salt in water, to obtain a mixed salt solution; S2) pumping ammonia water into the mixed salt solution, performing reaction I under stirring while monitoring a pH value of a resulting reaction system, adjusting the pH value of the resulting reaction system with the ammonia water until the pH value is stabilized at 9.5 to 10.5, and conducting aging overnight; S3) subjecting a product obtained in S2 to centrifugation while washing with deionized water, and removing a supernatant to obtain a product; S4) mixing the product obtained in S3 with water, ethanol, and a coupling agent KH-580 by stirring to obtain a mixture, and subjecting the mixture to reaction II while stirring, to obtain mercapto group-loaded layered double hydroxide (LDH), wherein a mass ratio of the product obtained in S3 to the water is in a range of 1 : (8.3-18.3), a volume ratio of the ethanol to the water is 1: 10.4, and a volume ratio of the KH-580 to the ethanol is in a range of 1 : (7.9-8.3); S5) mixing the mercapto group-loaded LDH with ferroferric oxide and sodium alginate, adding deionized water thereto, and stirring, to obtain a homogeneous mixed solution; S6) adding the homogeneous mixed solution obtained in S5 into a calcium chloride solution dropwise through a pump to form a magnetic bead with a particle size of 2 mm to 4 mm; and S7) leaving the magnetic bead obtained in S6 to harden in the calcium chloride solution for a certain period of time, and then washing with water and drying, to obtain the mercapto group- loaded LDH-based magnetic composite particle”.
Regarding claim 4, Lee, Shou, Wang, Luo, and Li teach the method of claim 1. Lee discloses preparation of 1g of sodium alginate in 100mL of deionized water (thus mass concentration of 10g/L in mized homogeneous solution) but provides 6g LDH and 2g iron oxide (thus outside of claimed mass concentration and mass ratios). Additionally, Lee is silent on the stirring rate, timing, and ultrasonic treatment outside of providing “intensive stirring”. In Luo’s analogous step S5, Luo provides 2.0g of Fe3O4 in 200mL deionized water (thus 10g/L) and 3.0g total of attapulgite and zeolite (LDH equivalent, thus 3:2 ratio of LDH to Fe3O4). Although Luo provides 3.0g of sodium alginate, Luo describes the mass ratio of Fe3O4 to sodium alginate is (0.5-2):(2-3), thus 2.0g of sodium alginate could be provided as alternative. Further, the ratio of attapulgite+zeolite to Fe3O4 to sodium alginate is (2-4):(0.5-2):(2-3) which overlaps with the claimed range of 3:2 (LDH:oxide and LDH:sodium alginate). Additionally, Luo provides an ultrasonication step of 30-40min. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute the alginate encapsulation process of Luo into the process of Lee as a known alternative encapsulation step for preparing a homogeneous mixed solution prior to addition to CaCl2 for bead preparation. Luo also discloses a mixing step prior to ultrasonication but does so for 10-20min without providing a stirring speed. In an analogous preparation of heavy metal removing colloidal particulate material, Li discloses mixture of magnetic iron oxide particles into a sodium alginate solution whereby the mixture is stirred between 20min-3h at a speed of 300-2000rpm prior to addition into CaCl2 solution. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. Thus, Lee, Shou, Wang, Luo and Li teach the claimed “The method as claimed in claim 1, wherein in S5), the ferroferric oxide and the sodium alginate each have a mass concentration of 9 g/L to 10 g/L in the homogeneous mixed solution; a mass ratio of the mercapto-loaded LDH to the ferroferric oxide is 3 : 2; a mass ratio of the mercapto-loaded LDH to the sodium alginate is 3 : 2; the stirring in S5) is performed at a rate of 2,000 rpm to 5,000 rpm for 2 h to 6 h to obtain the homogeneous mixed solution; and the homogeneous mixed solution is subjected to an ultrasonic treatment for 15 min to 60 min before being added into the calcium chloride solution through the pump”.
Regarding claim 5, Lee, Shou, Wang, Luo, and Li teach the method of claim 1. Lee teaches addition of the homogeneous mixture into a 0.3M CaCl2 solution (200mL deionized water). A 0.3M CaCl2 (0.3mol/L) solution in 200mL corresponds to 0.3mol/L*0.2L or 0.06mol CaCl2. The molecular weight of CaCl2 is 110.98g/mol, thus there are 110.98g/mol*0.06mol or 6.66g CaCl2 in 200mL deionized water. The corresponding mass concentration is 6.66g/200mL (200mL deionized water is roughly 200g) or 0.0333 (3.33%). Thus, Lee, Shou, Wang, Luo, and Li teach the claimed “The method as claimed in claim 1, wherein in S6, the calcium chloride solution has a mass concentration of 2% to 4%”.
Regarding claim 6, Lee, Shou, Wang, Luo, and Li teach the method of claim 1. Lee allows the resulting magnetic bead or composite of step S6 to “cure” in the “same CaCl2 solution” (curing is understood to be a hardening) but allows curing to occur in two 24h periods as opposed to a time period of 10-24h. In an analogous preparation of heavy metal removing colloidal particulate material, Li discloses mixture of magnetic iron oxide particles into a sodium alginate solution whereby the mixture is added into CaCl2 and allowed to “stand overnight” which would be equivalent to a hardening/curing step of Lee. The term “overnight” is generally considered to under 24h and >8h, thus overlapping with the range of 10-24h or “certain period of time”. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. Further, Lee allows the obtained magnetic composite to dry at 60°C (thus within claimed range of 50°C to 110°C). Thus, Lee, Shou, Wang, Luo, and Li teach the claimed “The method as claimed in claim 1, wherein in S7, the magnetic bead obtained in S6 is left to harden in the calcium chloride solution for 10 h to 24 h, and the drying is conducted at a temperature of 50 °C to 110 °C”.
Regarding claim 7, Lee, Shou, Wang, Luo, and Li teach the method of claim 1. Claim 7 is a product-by-process claim whereby the patentability of a product does not depend on its method of production (see MPEP 2113). Regardless, the teachings of Lee, Shou, Wang, Luo and Li would lead one of ordinary skill in the art to arrive at the method as claimed (see rejection of claim 1). Thus, the obtained product in such a method would be “a mercapto group-loaded layered double hydroxide-based magnetic composite particle”. Therefore, Lee, Shou, Wang, Luo, and Li teach the claimed “A mercapto group-loaded layered double hydroxide-based magnetic composite particle prepared by the method as claimed in claim 1.”.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Lee et al in view of Shou et al, Wang et al, Luo et al, and Li et al as applied to claim 1 above, and further in view of Hutter et al (EP2706040A1).
Lee, Shou, Wang, Luo, and Li teach the method of claim 1. As described in the rejection of claim 1, Lee uses divalent magnesium nitrate (Mg(NO3)2*6H2O) and trivalent aluminum nitrate (Al(NO3)3*9H2O) as water-soluble salt precursors in a 2:1 molar ratio (1mol vs 0.5mol). The molecular weights of magnesium nitrate and aluminum nitrate are 256.4g/mol and 375.13g/mol, respectively. Therefore, the corresponding mass ratio in a 2:1 molar ratio as prepared by Lee is 256.4g:187.57 or 1:0.73. A mixed salt mass concentration is considered to be the sum of the masses of the ions per L of deionized water. Magnesium nitrate salt content is 57.83% of the hydrate compound, and aluminum nitrate salt content is 56.77% of the hydrate compound. Thus, in the 2:1 molar ratio at 700mL of water, the corresponding total mass of mixed salt is 256.4g/L*0.7L*0.5783 for grams of Mg(NO3)2 and 187.57g/L*0.7L*0.5677 for grams of Al(NO3)3 or a total of 103.79g+74.54g (178.33g in 0.7L) which is well outside the claimed range of 20-40g/L. Analogously, Hutter describes a preparation of MgAl-LDH (Section 1.3) using 4.16g MgCl2*6H2O and 2.41g AlCl3*6H2O (2:1 molar ratio and water soluble divalent/trivalent salts which is equivalent to preparation of Lee) in 100mL deionized water. The mass% of each salt portion is 46.83% MgCl2 and 55.22% AlCl3. Thus, the mixed salt mass is 4.16g*0.4683 + 2.41g*0.5522 or 3.28g. The mixed salt mass of 3.28g is in 100mL or 0.1L of water, thus a concentration of 32.8g/L which is within the claimed range. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute utilized masses of mixed salts of Lee with a known alternative reagent mass composition informed by Hutter to produce an MgAl-LDH and arrive at the invention as claimed. Thus, Lee, Shou, Wang, Luo, Li, and Hutter teach the claimed “The method as claimed in claim 1, wherein in S1), the water-soluble divalent magnesium salt is selected from the group consisting of magnesium nitrate and magnesium chloride; the water-soluble trivalent aluminum salt selected from the group consisting of aluminum nitrate and aluminum chloride; a mass ratio of the water-soluble divalent magnesium salt to the water-soluble trivalent aluminum salt is in a range of 1 : (0.49-0.73); and the mixed salt solution has a total mixed salt mass concentration of 20 g/L to 40 g/L”.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Lee et al in view of Shou et al, Wang et al, Luo et al, and Li et al as applied to claim 1 above, and further in view of He et al (US PGPub 20120322647) and Dula et al (NPL "Layered double hydroxide-derived...").
Lee, Shou, Wang, Luo, and Li teach the method of claim 1. As described in the rejection of claim 1, Lee pumps the salt solution into sodium hydroxide and sodium carbonate, but the teachings of Shou inform the alternative of pumping ammonia into the salt solution for preparing MgAl-LDH. Lee adds 700mL of mixed salt solution into 1000mL alkali solution (ratio of 1:0.7, outside of claimed range 1:(2-2.5)). However, Lee teaches preparation at a pH of 13 as opposed to ~10, informed by Shou, thus it would be expected that a less basic pH would necessitate a much lower volume of alkali or ammonia solution, thus increasing such a ratio beyond 1:0.7 and towards the claimed range. Shou is silent on the volumes added between mixed solution and ammonia solution. In their LDH preparation, Wang mixes 100mL of salt solution into 10mL NaOH (pH of 10), thus a corresponding ammonia to salt solution volume ratio of 1:10. However, sodium hydroxide is a much stronger base than ammonia, so such a high volume ratio would not be expected when substituting alkali solutions. Thus, by the combined teachings of Lee, Shou, Wang, Luo, and Li, it would be expected that the volume range for achieving such a pH would fall between 1:0.7-10. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. Both Lee and Wang are silent on the alkali solution (ammonia water) concentrations or molarity while Shou discloses a 6wt% ammonia solution. A 6wt% ammonia solution, in for instance 100mL of water, corresponds to 6g of ammonia per 100mL. Ammonia has a molecular weight of 17.03g/mol, thus 0.35mol ammonia per 100mL or 3.5mol/L outside the claimed range of 6-7mol/L. He analogously describes preparation of nitrate-precursor based LDH (divalent M2+ which can be Mg and trivalent M3+ which can be Al, see paragraphs [0020-21]). Further, in their preparation, He describes use of ammonia to control pH in range of 8-12 whereby the molarity of ammonia solution is 1-25mol/L. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the ammonia solution concentration range as informed by He to arrive at the invention as claimed. Further, Shou, as described above, provides a relevant minimum concentration of ammonia to help inform the utilized concentration. To perform reaction I in S2, Lee describes room temperature mixing for an undisclosed time period prior to aging overnight. Analogously, Dula discloses preparation of MgAl-LDH whereby the suspension is stirred overnight at 328K or ~55°C. The period “overnight” is understood to fall within the range of 10h to 20h. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to utilize the disclosed reaction parameters as informed by Dula as a known alternative reaction precursor mixing step in the process of preparing MgAl-LDH and arrive at the process as claimed. Thus, Lee, Shou, Wang, Luo, Li, He, and Dula teach the claimed “The method as claimed in claim 1, wherein in S2), a volume ratio of the ammonia water to the mixed salt solution is in a range of 1 : (2-2.5); the ammonia water has a concentration of 6 mol/L to 7 mol/L; and the reaction I in S2 is conducted at a temperature of 50 °C to 100 °C for 10 h to 20 h”.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Zhang et al (CN114192119A) describe a mercapto modified magnetic particle dispersion liquid and application in heavy metal removal/absorption. Bugajski (WO2022199967A1) describes hardening and setting times for LDH-based particles with and without a prepared binder material. Seftel et al (US PGPub 20200325031) describe relevant co-precipitation temperature parameters relevant to “reaction I”.
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/NWFG/Examiner, Art Unit 1759
/MELVIN C. MAYES/Supervisory Patent Examiner, Art Unit 1759
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