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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim Objections
Claim 3 is objected to because of the following informalities: Claim 3 recites inter alia “wherein the NH4FSI salt in the form of a solvate is: comprises from 50 to 99 wt.%, of the NH4FSI salt, and from 1 to 50 wt.%, of at least one solvent S2,” which appears to be a grammatical typographic error. Appropriate correction is required. Correction to fix “is comprises” and the extra commas is requested.
For clarity of the record, in claim 3 the limitation of “comprises from 50 to 99 wt.%, of the NH4FSI salt, and from 1 to 50 wt.%, of at least one solvent S2” has been interpreted (in light of the specification [page 7]) to mean that the NH4FSI solvate has a NH4FSI-to-solvent ratio falling between 99:1 to 50:50.
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 1-15 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 reaction solution” in step iii); this limitation lacks antecedent basis in the claims, since a reaction solution is not found previously in the claim. Claims 1-15 are therefore indefinite in scope since claims 2-15 depend upon claim 1 but do not rectify the issue.
Claim 8 recites the limitation “the solvent S2” which lacks antecedent basis in the claims, since claim 8 depends upon claim 1 which does not recite a solvent S2. Claim 8 is therefore indefinite in scope.
Claim 15 recites inter alia “removing, by azeotropic distillation, at least a part of any water being present in the reaction solution from the reaction solution more than 99.0 wt.% of the water, and at least a part of the solvent S2 present in the NH4FSI solvate more than 99.0 wt.% of the solvent S2.” This language is unclear. It is unclear how to interpret the percentages as a part of the limitation taken in whole.
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, 6, 8-9, and 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Sato et al. 2013 (US 20130068991 A1), in view of Malone et al. 2000, “Reactive Distillation.” Ind. Eng. Chem. Res. 6 November 2000; 39 (11): 3953–3957, cited on the IDS filed on 2/27/2024.
Regarding claim 1, Sato teaches a method for producing fluorosulfonylimide salts (title) according to the formula (I) wherein M" represents a metal cation or an onium cation, wherein the onium cation is not an ammonium cation, and n corresponds to the valency of the metal cation or the onium cation and is an integer of from 1 to 4 (“alkali metal salts of … bis(fluorosulfonyl)imide,” 0001, n being 1); comprising the following steps:
ii) reacting ammonium bis(fluorosulfonyl)imide with a metal compound (lithium hydroxide, Example 1, Cation exchange step 2, 0116) in at least one solvent S3 (butyl acetate, 0116); and
iii) removing at least a part of any water being present in the reaction solution from the reaction solution (“aqueous layer was removed from the reaction solution,” 0116).
Sato does not teach the following limitation:
Wherein the steps ii) and iii) are carried out simultaneously.
However, Malone teaches methods of reactive distillation (title) which are considered analogous art to the teachings of Sato because Sato teaches the removal of solvent by distillation (0079, 0119). Malone teaches simultaneously conducting a reaction and a distillation process at the same time (Introduction col. 1), motivating such a simultaneous process by the teaching of capital productivity improvements, selectivity improvements, reduced energy use, and reduction or elimination of solvents (Introduction col. 1). It would therefore be obvious to one skilled in the art to combine the teachings of Sato and Malone and arrive at the claimed process prior to the effective filing date of the present invention.
Regarding claim 2, Sato and Malone teach the invention as applied to claim 1. Sato further teaches that the NH4FSI is in the form of a solvate with at least one solvent S2 (butyl acetate, 0115). The solution of NH4FSI in butyl acetate is interpreted to meet the limitation of “a solvate” as is typically understood in the art; this interpretation is consistent with claim 3 and the instant specification which state that crystallization of the solvate is an optional embodiment (p. 7 line 15). Sato further teaches equivalent solvents including tetrahydrofuran and other cyclic and acyclic ethers (0053, 0064).
Regarding claim 3, Sato and Malone teach the invention as applied to claim 2. Sato further teaches that the NH4FSI salt in the form of a solvate comprises a range overlapping with the instant claimed range of “from 50 to 99 wt.%, of the NH4FSI salt, and from 1 to 50 wt.%, of at least one solvent S2” (1% to 70% by mass of the sulfonyl imide in the reaction solution, 0067, wherein the butyl acetate provides the remaining 99% to 30% of the solvate formed in 0115). As interpreted previously, the claimed range of weight percents overlaps with the range taught by Sato, since 1% to 70% converts to a salt-to-solvent ratio of 1:99 to 70:30. As set forth in MPEP 2144.05, in the case where the claimed range "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. 1990).
Regarding claim 4, Sato and Malone teach the invention as applied to claim 2. They further teach the cyclic and acyclic ethers as known equivalents to the embodiment of butyl acetate disclosed in the example (0064, 0053). It would be obvious to one skilled in the art to substitute these solvents as the solvent S2 taught by Sato; the courts have held that the substitution of known elements in the prior art is prima facie obvious (see MPEP 2143(I)(B); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007)). In the instant case, one skilled in the art would reasonably expect the selection of an ether as disclosed by Sato to perform predictably in that it would have a low boiling point and be capable of forming a two-layered state with water, as Sato teaches (0053). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Regarding claim 6, Sato and Malone teach the invention as applied to claim 1. Sato further teaches that the compound C of step ii) is lithium hydroxide LiOH (15% by mass lithium hydroxide, 0116).
Regarding claim 8, Sato and Malone teach the invention as applied to claim 1. Sato further teaches that the solvent S2 present in the NH4FSI solvate is removed from the reaction solution by distillation (“solvent was distilled off,” 0119, this solvent being the solvent from the cation exchange step of ammonium FSI, 0115-0116).
Regarding claim 9, Sato and Malone teach the invention as applied to claim 1. Sato further teaches that the reaction of step iii) occurs at room temperature (0116), which falls within the claimed temperature range of 0°C to about 100°C.
Regarding claim 12, Sato and Malone teach the invention as applied to claim 2. Sato teaches that the NH4FSI is in the form of a solvate with at least one solvent S2 (butyl acetate, 0115). Sato further teaches equivalent solvents including tetrahydrofuran and other cyclic and acyclic ethers (0053, 0064). It would be obvious to one skilled in the art to substitute the solvents as taught by Sato, and arrive at the claimed invention wherein the solvent S2 is selected from the group consisting of diethyl ether, diisopropylether, methyl-t-butyl ether, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2- methyl tetrahydrofuran, dioxolane, 1,3-dioxane, 4-methyl-1,3-dioxane, and 1,4-dioxane, and mixtures thereof. The courts have held that the substitution of known elements in the prior art is prima facie obvious (see MPEP 2143(I)(B); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007)). In the instant case, one skilled in the art would reasonably expect the selection of an ether as disclosed by Sato to perform predictably in that it would have a low boiling point and be capable of forming a two-layered state with water, as Sato teaches (0053). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Regarding claim 13, Sato and Malone teach the invention as applied to claim 1. Sato further teaches that the solvent is butyl acetate (0116); this meets the claimed limitation of EMC or n-butyl acetate, where n-butyl acetate is understood in the art to be interchangeably defined as butyl acetate.
Claims 5 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Sato and Malone, as applied to claim 1 above, and further in view of Schmidt et al. 2021 (US 20210323823 A1).
Regarding claim 5, Sato and Malone teach the invention as applied to claim 1. They do not teach that the process further comprises before step ii), a step i) of preparing a NH4FSI solvate comprising the following steps: i1) providing a crude salt of NH4FSI; i2) dissolving the crude salt of NH4FSI in at least one solvent S1; i3) crystallizing the crude salt of NH4FSI by means of at least one solvent S2; and i4) separating the NH4FSI salt from at least part of the solvents S1 and S2.
However, Schmidt teaches an analogous process for the drying and purification of a bis(fluorosulfonyl)imide salt in solution in an organic solvent S1 (abstract) wherein Schmidt teaches a step i) of preparing a LiFSI solvate comprising 1) providing a salt of LiFSI (lithium bis(fluorosulfonyl)imide salt, 0031); 2) dissolving the salt of LiFSI in a solvent S1 (0014, 0031); 3) crystallizing the salt of LiFSI by means of a solvent S2 (0017); and 4) separating the LiFSI salt from at least part of the solvents S1 and S2 (0018).
It would be obvious to one skilled in the art to combine the teachings of Sato, Malone, and Schmidt, to purify the NH4FSI of Sato by substituting the crude yield of NH4FSI of Sato (0115) for the LiFSI of Schmidt; one would be motivated to do so because Sato teaches that the yield of ammonium FSI from the first cation exchange step is considered a “crude” amount (0115) and teaches that when the concentration of the sulfonyl imide skeleton is too low, the cation exchange steps are not economical and have low productivity per batch (0067). One skilled in the art would therefore reasonably be motivated to optimize the concentration of the NH4FSI by subjecting it to the purification steps taught by Schmidt and therefore arrive at the claimed invention prior to the effective filing date.
Regarding claim 11, Sato, Malone, and Schmidt teach the invention as applied to claim 5. Schmidt further teaches that the solvent S1 is butyl acetate (0033) and may also be acetonitrile or other nitriles (0033), falling within the claimed Markush grouping of acetonitrile, valeronitrile, adiponitrile, benzonitrile, methanol, ethanol, 1-propanol, 2-propanol, 2,2,2,-trifluoroethanol, n-butyl acetate, isopropyl acetate, and mixtures thereof.
Claims 7 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Sato and Malone, as applied to claim 1 above, and further in view of Maekawa 2016 (US 20160016797 A1).
Regarding claim 7, Sato and Malone teach the invention as applied to claim 1. Sato further teaches that at least a part of any water being present in the reaction solution is removed from the reaction solution (0116). Sato and Malone do not teach that in step iii) the removal of the aqueous portion is by distillation. However, Maekawa teaches an analogous method for the formation of LiFSI (0051) wherein Maekawa teaches the azeotropic distillation of the organic solvent to remove water (Dean-Stark apparatus, removal of moisture from the solution, 0051). Malone further motivates the attempt to conduct this distillation simultaneously with the reaction, as claimed, since Malone teaches the simultaneous conducting of reactions and azeotropic distillations (p. 3953-3954) and teaches that the pursuit of these methods is worthwhile for economic and energy reasons as discussed for claim 1 (Introduction, column 1; Concluding Remarks, Experiments). It would therefore be obvious to one skilled in the art to combine the teachings of Sato, Malone, and Maekawa, to azeotropically distill water and solvent simultaneously with conducting the reaction, thereby arriving at the claimed invention prior to the effective filing date.
Regarding claim 10, Sato and Malone teach the invention as applied to claim 1. Sato further teaches that at least a part of any water being present in the reaction solution is removed from the reaction solution (0116). Sato and Malone do not teach that in step iii) the removal of the aqueous portion is conducted at a reaction pressure of from atmospheric pressure to about 0.01 mbar, as claimed. However, Sato teaches that distillation occurs at reduced pressure (0119, 0120) and further Maekawa teaches an analogous method for the formation of LiFSI (0051) wherein Maekawa teaches the azeotropic distillation of the organic solvent to remove water (Dean-Stark apparatus, removal of moisture from the solution, 0051) at a pressure of 13.33 kPa (equal to 0.13 atm or 130 mbar), falling within the claimed range of atmospheric pressure to 0.01 mbar, or 1013.25--0.01 mbar. Malone further motivates the attempt to conduct this distillation simultaneously with the reaction, as claimed, since Malone teaches the simultaneous conducting of reactions and azeotropic distillations (p. 3953-3954) and teaches that the pursuit of these methods is worthwhile for economic and energy reasons as discussed for claim 1 (Introduction, column 1; Concluding Remarks, Experiments). It would therefore be obvious to one skilled in the art to combine the teachings of Sato, Malone, and Maekawa, and thereby arrive at the claimed invention prior to the effective filing date, since the reaction of step iii) would be conducted simultaneously as the distillation and therefore at the disclosed pressure.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Sato and Malone, as applied to claim 1 above, and further in view of He et al. 2016 (WO 2016184176 A1). A machine translation of He, as provided with this Office action, is cited herein.
Regarding claim 14, Sato and Malone teach the invention as applied to claim 1. They do not teach that the compound (C) of step ii) is added to the ammonium bis(fluorosulfonyl)imide (NH4FSI) over a time range of from about 0.5 hr. to about 10 hr. However, He teaches an analogous method for the production of bis-(fluoro-sulfonyl) imide lithium salt (title) wherein HFSI is added dropwise over 2 hours to lithium hydroxide (Example 3, page 7) to form the product of LiFSI (page 6). It would be obvious to combine the teachings of Sato, Malone, and He, to arrive at the presently claimed invention where the step of reacting FSI with LiOH is conducted over 2 hours as He teaches; one would be motivated to do so in order to control the precipitation and solubility of the LiFSI in the byproduct of water formed from the reaction, as He teaches (page 4 paragraph 2), since Malone motivates the simultaneous removal of water as discussed for claim 1 above, and He teaches that LiFSI is highly soluble in the byproduct of water formed by the reaction of LiOH with FSI (page 4 paragraph 2). He teaches the addition of the HFSI to LiOH, in comparison to the instant claimed method of adding LiOH to FSI; regarding the order of such process steps, it has been held that differences in the order of performing process steps are obvious in the absence of new or unexpected results (see MPEP 2114.04.IV.C.). It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to perform the method as suggested by Sato, Malone, and He where the reaction to form LiFSI is conducted in any order including adding LiOH to FSI for the purpose of forming LiFSI as taught by Sato and He.
Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Sato and Malone, as applied to claim 1 above, and further in view of Schmidt and Maekawa.
Regarding claim 15, Sato and Malone teach the invention as applied to claim 1. Sato teaches ii) reacting the NH4FSI solvate from step i) with a lithium compound (C*) in at least one solvent S3; and iii) removing at least a part of any water being present in the reaction solution from the reaction solution, and the combination of Sato and Malone teaches that the steps ii) and iii) are carried out simultaneously, as applied to claim 1 above. Sato further teaches the NH4FSI salt in the form of a solvate (butyl acetate, 0115).
Sato and Malone do not teach that the process further comprises before step ii), a step i) of preparing a NH4FSI solvate comprising the following steps: i1) providing a crude salt of NH4FSI; i2) dissolving the crude salt of NH4FSI in at least one solvent S1; i3) crystallizing the crude salt of NH4FSI by means of at least one solvent S2; and i4) separating the NH4FSI salt from at least part of the solvents S1 and S2.
However, Schmidt teaches an analogous process for the drying and purification of a bis(fluorosulfonyl)imide salt in solution in an organic solvent S1 (abstract) wherein Schmidt teaches a step i) of preparing a LiFSI solvate comprising 1) providing a salt of LiFSI (lithium bis(fluorosulfonyl)imide salt, 0031); 2) dissolving the salt of LiFSI in a solvent S1 (0014, 0031); 3) crystallizing the salt of LiFSI by means of a solvent S2 (0017); and 4) separating the LiFSI salt from at least part of the solvents S1 and S2 (0018).
It would be obvious to one skilled in the art to combine the teachings of Sato, Malone, and Schmidt, to purify the NH4FSI of Sato by substituting the crude yield of NH4FSI of Sato (0115) for the LiFSI of Schmidt; one would be motivated to do so because Sato teaches that the yield of ammonium FSI from the first cation exchange step is considered a “crude” amount (0115) and teaches that when the concentration of the sulfonyl imide skeleton is too low, the cation exchange steps are not economical and have low productivity per batch (0067). One skilled in the art would therefore reasonably be motivated to optimize the concentration of the NH4FSI by subjecting it to the purification steps taught by Schmidt.
Sato, Malone, and Schmidt do not teach step iii) removing by azeotropic distillation, at least a part of any water and at least a part of the solvent S2. However, Maekawa teaches an analogous method for the formation of LiFSI (0051) wherein Maekawa teaches the azeotropic distillation of the organic solvent to remove water (Dean-Stark apparatus, removal of moisture from the solution, 0051). Additionally, Sato teaches distilling off the organic solvent by a rotary evaporator (0120), from a concentration of 45% by mass of the LiFSI (0119) to 73% by mass (0120) which correlates approximately to a removal of 51% of solvent removed (since (55-27)/55 = 0.509). Malone further motivates the attempt to conduct these distillation processes simultaneously, as claimed, since Malone teaches the simultaneous conducting of reactions and azeotropic distillations (p. 3953-3954) and teaches that the pursuit of these methods is worthwhile for economic and energy reasons as discussed for claim 1 (Introduction, column 1; Concluding Remarks, Experiments). It would therefore be obvious to one skilled in the art to combine the teachings of Sato, Malone, Schmidt, and Maekawa. While Sato, Malone, Schmidt, and Maekawa do not teach the claimed ranges of more than 99% of water removed or more than 99% of solvent S2 removed, Sato teaches that the presence of impurities in the FSI salt can be caused by the presence of excess water inducing decomposition products (0033, 0035) and that the presence of residual solvent has similarly adverse effects on heat resistance and electrochemical performance of the salt (0036), and therefore teaches that the quantities of water and solvent removed would both be result effective variables which affect the quality of the final product. Therefore one skilled in the art would reasonably be motivated to optimize the amounts of water and solvent removed and thereby arrive at the claimed ranges of at least 99.0 wt.% water and at least 99.0 wt.% solvent S2 removed, and thereby arrive at the claimed limitation before the effective filing date.
Regarding claim 16, Sato, Malone, Schmidt, and Maekawa teach the invention as applied to claim 15. Schmidt teaches step i4 (solvent S1 separated in 0015, solvent S2 separated in 0018). Schmidt further teaches an additional step i5) of drying the LiFSI solvate obtained in step i4) (step d, 0022), and therefore the combination of teachings as applied to claim 15 above would result in the drying step being applied to NH4FSI as instantly claimed. One skilled in the art would be motivated to make such a modification because Shmidt teaches that the embodiments that contain this step advantageously result in less water content of the resulting FSI (0126) which is necessary in the field of endeavor as Schmidt teaches (0012) and as Sato teaches (0036).
With respect to the claimed wt.% ranges of more than 99.0 wt.% of solvent S1 and 50-99 wt.% of solvent S2, Schmidt teaches that the final concentrate contains less than 10% by weight of residual solvent (0079), which teaches a range that overlaps with the claimed range, since as much as all of the residual solvent may be solvent S2 therefore yielding 100% of S1 removed, and before the concentration step as much as 80% of the FSI solution is solvent S2 (0063) thus yielding approximately 87% of solvent S2 removed (since ((80-10)/80 = 0.875), which falls within the claimed range. As set forth in MPEP 2144.05, in the case where the claimed range "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. 1990).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Tang et al. 2021 (US 20230373788 A1) disclose a method for purifying a salt of bis(fluorosulfonyl)imide, and a method for producing an alkali salt of bis(fluorosulfonyl)imide.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Eileen Moudou whose telephone number is (571)272-1768. The examiner can normally be reached M-Th 8 AM - 4 PM EST.
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/Eileen Moudou/Examiner, Art Unit 1738
/SALLY A MERKLING/SPE, Art Unit 1738
