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 .
Detailed Action
This office action is in response to applicant’s communication filed on 4/7/26.
Claims 1-13 are pending in this application and are being examined in this Office Action. Due to applicant’s amendment to the claims filed 4/7/26, the objection, 112 and 103 rejections are withdrawn. However as new 103 rejection is in order, as shown below. The examiner thanks the applicant for notifying the examiner of the correct CN patent number for Wu. This has been corrected in the new 103 rejection below.
Claim Rejections – 35 USC 103
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 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.
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 of this title, 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-6, 8-9 and 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (CN108358807A, pub date 8/3/2018, the English translation is used herein), in view of Li et al. (CN108862795A, pub date 11/23/2018, the English translation is used herein), further in view of Hu et al. (CN106831472A, pub date 6/13/2017, the English translation is used herein), further in view of Xue et al. (CN101671246A, pub date 3/17/2010, the English translation is used herein).
Determination of the Scope and Content of the Prior Art
(MPEP §2141.01)
Wang et al. teaches a recycling method for acidic DMF and waste sodium acetate. Wang et al. teaches that sucralose production generates wastewater containing DMF and acetic acid (page 3, paragraph 0005).
Wang et al. teaches adding acidic DMF solution and 32% liquid alkali to a neutralization vessel for neutralization reaction, wherein the neutralized solution is sent to a cooling crystallization vessel and a crystalline mixture is obtained (page 5, paragraph 0014; page 7, paragraph 0026).
Wang et al. teaches feeding the crystalline mixture into a filter press for separation, obtaining a filtrate containing acidic DMF and a filter cake of crude sodium acetate, feeding the filtrate containing acidic DMF into an acidic DMF scraped evaporator, and sending distilled DMF to a DMF receiving tank and DMF distillation system, wherein the finished DMF is returned for reuse (page 5, paragraph 0015; page 7, paragraph 0027).
Wang et al. further teaches that the crude sodium acetate filter cake is dissolved, decolorized, crystallized, centrifuged, and the separated filtrate is returned for reuse (page 5, paragraph 0016; page 7, paragraph 0028).
Li et al. teaches a comprehensive recovery and treatment method for DMF wastewater. Li et al. teaches neutralizing acidic DMF wastewater, filtering the wastewater to remove impurities, mixing the neutralized wastewater with an organic solvent in an extraction tower and performing countercurrent extraction, concentrating the extracted wastewater by triple-effect evaporation to recover water and salt, and feeding the extracted organic solution into a distillation column to recover the solvent and DMF respectively (pages 3-5, paragraphs 0009-0015).
Li et al. teaches that the volume ratio of organic solvent to wastewater is 1-2:1. Li et al. further teaches extracting filtered wastewater and chloroform at a 1:1 volume ratio, obtaining a chloroform solution of DMF and extracted wastewater, recovering chloroform by distillation, recovering DMF by vacuum distillation, and recovering water and salt separately by evaporation (page 4, paragraph 0011; pages 7-8, paragraphs 0025-0027).
Hu et al. teaches a DMF-containing saline waste liquor recovery process and system. Hu et al. teaches adding an organic extractant to the liquid phase to selectively leach DMF from the waste liquid, separate and remove salt, and obtain an extractant-DMF mixture, wherein the extractant is petroleum ether, carbon tetrachloride, carbon disulfide, dichloromethane, cyclohexane or benzene (page 7, paragraph 0013).
Hu et al. further teaches that the extraction process involves stirring, obtaining a layered mixture of solvent and solid, keeping warm and filtering to remove salt solids, and yielding an extractant-DMF mixture (pages 7-8, paragraphs 0017-0018).
Hu et al. teaches purifying the extractant-DMF mixture by distillation or rectification to obtain extractant and DMF respectively (page 7, paragraph 0014; page 12, paragraph 0037).
Xue et al. teaches a method for preparing sodium acetate trihydrate and anhydrous sodium acetate. Xue et al. teaches taking a sodium acetate solution, neutralizing to pH 6-9, evaporating and concentrating the sodium acetate solution, transferring the concentrated sodium acetate solution into a crystallization kettle, cooling to 60-57°C, adding sodium acetate trihydrate crystal, stirring for more than 12 hours, and centrifugally separating, wherein the obtained solid phase is sodium acetate trihydrate (page 1, Abstract; pages 3-5; claim 1).
Ascertainment of the Difference Between Scope the Prior Art and the Claims
(MPEP §2141.012)
Wang et al. is deficient in that it does not expressly teach adding the claimed anti-solvent selected from ether, anisole, isopropyl ether, benzene, toluene and xylene, standing for layering, separately evaporating the upper and lower liquid phases, and crystallizing acetate hydrate.
However, Li et al. teaches extracting neutralized DMF wastewater with an organic solvent, separating the extracted organic solution and wastewater, recovering solvent and DMF respectively, and recovering water and salt separately.
Also, Hu et al. teaches benzene as an organic extractant for selectively leaching DMF from DMF-containing waste liquid, forming a layered mixture, separating salt solids, and recovering extractant and DMF.
Additionally, Xue et al. teaches that sodium acetate solution is evaporated, concentrated, cooled, seeded, crystallized and centrifugally separated to obtain sodium acetate trihydrate.
Finding of Prima Facie Obviousness Rationale and Motivation
(MPEP §2142-2143)
Thus, it would have been prima facie obvious to one of ordinary skill in the art at the time of the invention to modify Wang et al.’s acidic DMF recovery process to include Li et al.’s organic solvent extraction and separate recovery of solvent, DMF, water and salt, since both Wang et al. and Li et al. are directed to recovery of DMF-containing wastewater, and Li et al. teaches a simple and efficient process for recovering DMF and separately recovering solvent, water and salt. The motivation would have been to improve recovery of DMF and reduce waste treatment burden.
It would further have been obvious to one of ordinary skill in the art to use Hu et al.’s organic extractant, such as benzene, in the modified process of Wang et al. and Li et al., since Hu et al. teaches benzene as a suitable organic extractant for DMF-containing waste liquid and salt separation. The motivation would have been to use a known extractant for selectively leaching DMF from DMF-containing waste liquid and separating salts from the DMF-containing liquid phase.
It would further have been obvious to one of ordinary skill in the art that the crystallized acetate from Wang et al.’s aqueous neutralized acidic DMF solution may be acetate hydrate, since Xue et al. teaches sodium acetate solution is evaporated, concentrated, cooled, seeded, crystallized and centrifugally separated to obtain sodium acetate trihydrate. Thus, the claimed acetate hydrate would have been expected from aqueous sodium acetate crystallization conditions.
With regard to the claimed layering and evaporation steps, Li et al. teaches extracting neutralized DMF wastewater with organic solvent to obtain an organic solution containing DMF and extracted wastewater, recovering solvent and DMF respectively by distillation, and recovering water and salt separately by evaporation. Hu et al. further teaches a layered mixture and separation of salt solids from the extractant-DMF mixture. Thus, it would have been obvious to stand and layer the mother liquor containing DMF and organic solvent and separately recover useful solvent, DMF, water and salt components, since Li et al. and Hu et al. teach separate recovery of the same types of components from DMF-containing waste liquid.
With regard to claim 13, Li et al. teaches that the volume ratio of organic solvent to wastewater is 1-2:1 (page 4, paragraph 0011), and exemplifies extraction ratios of 1:1 and 1:1.5 (pages 7 and 10, paragraphs 0025 and 0031). Thus, the claimed volume ratio of DMF stock solution:anti-solvent = 1:1 to 3 overlaps and/or is rendered obvious by the ratios taught by Li et al. Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. in view of Li et al., further in view of Hu et al., further in view of Xue et al., as applied to claim 1 above, and further in view of Gu et al. (CN103772230A, pub date 5/7/2014, the English translation is used herein).
Regarding claim 7, Wang et al., Li et al., Hu et al. and Xue et al. teach the method of claim 1 as discussed above.
But, Wang et al., Li et al., Hu et al. and Xue et al. do not expressly teach that the anti-solvent is toluene.
However, Gu et al. teaches an azeotropic extractive distillation and liquid-liquid layering integrated method for separating a mixed solution of sodium salt, DMF, toluene and water (page 1, Abstract; page 2, paragraphs 0001-0004).
Gu et al. teaches that DMF and toluene are important chemical raw materials and solvents and that, in pharmaceutical and pesticide intermediate synthesis, sodium salt, DMF, toluene and water mixed solutions are easily formed (page 2, paragraph 0002).
Gu et al. teaches that after condensation, the mixed gas of toluene and water is divided into a toluene layer and a water layer, wherein the toluene layer contains more than 99% toluene, and that DMF is recovered at more than 99.9% (page 1, Abstract; pages 3-5, paragraphs 0005-0017; claim 1).
Thus, it would have been prima facie obvious to one of ordinary skill in the art at the time of the invention to use toluene in the modified process of Wang et al., Li et al., Hu et al. and Xue et al., since Gu et al. teaches the known separation and recovery of sodium salt, DMF, toluene and water mixed solution, including liquid-liquid layering into a toluene layer and water layer and recovery of DMF. The motivation would have been to use a known organic solvent in a DMF/salt/water recovery process and to recover toluene and DMF for reuse.
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. in view of Li et al., further in view of Hu et al., further in view of Xue et al., as applied to claim 1 above, and further in view of Wu et al. (CN110639345A, pub date 1/3/2020, the English translation is used herein).
Regarding claims 10-11, Wang et al., Li et al., Hu et al. and Xue et al. teach the method of claim 1 as discussed above.
But, Wang et al., Li et al., Hu et al. and Xue et al. do not expressly teach adding an acidic regulator to the crude DMF solution to adjust the pH of the crude DMF solution to 6-8, wherein the acidic regulator is an inorganic acid with a mass concentration of 5% to 50%.
However, Wu et al. teaches a DMF wastewater recovery process in which discharged acid solution and alkali solution are mixed, the pH value is adjusted, and the solution is returned to the DMF wastewater recovery process (page 7; page 9).
Wu et al. further teaches that the fresh acid solution is sulfuric acid or hydrochloric acid water solution with a concentration of 5-30% (page 7; page 9; claim 10 on page 13).
Thus, it would have been prima facie obvious to one of ordinary skill in the art at the time of the invention to use Wu et al.’s sulfuric acid or hydrochloric acid aqueous solution to adjust the pH of the crude DMF solution/recycled DMF-containing stream in the modified process of Wang et al., Li et al., Hu et al. and Xue et al., since Wu et al. teaches acid/alkali pH adjustment and return of the adjusted liquid to the DMF wastewater recovery process. The motivation would have been to control pH of the recycled DMF-containing stream and improve suitability for recycling in the DMF recovery process.
Response to Arguments
Applicant’s arguments have been considered but are not persuasive for the following reasons:
The examiner acknowledges applicant’s argument that Wang et al. fails to teach the extraction and layering step with an anti-solvent.
This argument is not persuasive because the rejection does not rely on Wang et al. alone. Wang et al. is relied upon for acidic DMF/acetic acid wastewater, neutralization, crystallization of sodium acetate, filtration, acidic DMF filtrate evaporation, DMF distillation and reuse. Li et al. is relied upon for organic solvent extraction of neutralized DMF wastewater and separate recovery of solvent, DMF, water and salt. Hu et al. is relied upon for benzene organic extractant, layered mixture formation, salt removal and extractant-DMF recovery. Thus, the references are relied upon for their respective teachings and not for bodily incorporation.
The examiner acknowledges applicant’s argument that Li et al. teaches ordinary liquid-liquid extraction and does not teach anti-solvent crystallization of acetate hydrate.
This argument is not persuasive because Li et al. is relied upon for organic solvent extraction and separate recovery of solvent/DMF/water/salt, while Xue et al. is relied upon for acetate hydrate formation. Xue et al. expressly teaches evaporating and concentrating sodium acetate solution, cooling, adding sodium acetate trihydrate crystal, stirring, centrifugally separating, and obtaining sodium acetate trihydrate as the solid phase. Therefore, acetate hydrate formation from sodium acetate solution was known in the art.
The examiner acknowledges applicant’s argument that the prior art does not teach the amended anti-solvent group.
This argument is not persuasive because Hu et al. expressly teaches benzene as an organic extractant for DMF-containing waste liquid, and benzene is one of the claimed anti-solvents. As to claim 7, Gu et al. further teaches a sodium salt, DMF, toluene and water mixed solution and liquid-liquid layering into a toluene layer and a water layer, with recovery of DMF.
The examiner acknowledges applicant’s argument that the references are incompatible because Wang et al. uses cooling crystallization and Li et al. uses extraction.
This argument is not persuasive. Each reference is directed to recovery and treatment of DMF-containing or sodium acetate-containing waste streams and recovery of useful materials. The combination uses prior art elements according to their known functions: Wang et al. for neutralization/crystallization/DMF recovery, Li et al. for extraction and separate recovery, Hu et al. for DMF extraction and salt separation using benzene, Xue et al. for sodium acetate trihydrate crystallization, Gu et al. for toluene/DMF/water layering and recovery, and Wu et al. for acid pH adjustment.
Applicant’s correction regarding Wu’s publication number has been noted. The reference is identified herein as Wu et al., CN110639345A.
Conclusion
No claims are allowed.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jennifer Cho Sawyer whose telephone number is (571) 270 1690. The examiner can normally be reached on Monday-Friday 9 AM - 6 PM PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Renee Claytor can be reached on (571) 272-8394. The fax phone number for the organization where this application or proceeding is assigned is 571-274-1690.
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Jennifer Cho Sawyer
Patent Examiner
Art Unit: 1691
/RENEE CLAYTOR/Supervisory Patent Examiner, Art Unit 1691
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