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 .
Response to Arguments
Applicant's arguments filed 2/26/2026 have been fully considered but they are not persuasive.
Applicant argues that Lintinen does not teach a method comprising a “single organic solvent”. This argument is unpersuasive since Lintinen’s broad disclosure teaches a method comprising a single solvent even if a mixture of solvents is a preferred embodiment. Lintinen discloses that very dilute dispersions both with and without a co-solvent, produce colloidal lignin nanoparticles with an average diameter of ca. 70 nm (see Page 8, Ln 13-15). Although Lintinen discloses that the process comprises a “preferred embodiment where lignin is dissolved in a mixture of solvents, which both enable high solubility of lignin and suppress aggregation in colloid formation (see Page 6, Ln 9-110), a reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including non-preferred embodiments. See MPEP 2123.I.
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.
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.
Claim(s) 42-51 are rejected under 35 U.S.C. 103 as being unpatentable over Lintinen et al (WO-2019/081819) and in further view of Wu et al (CN 111398120).
Lintinen discloses a process for large-scale production of colloidal lignin particles, the method comprising:
Dissolving lignin in an organic solvent without co-solvent where the lignin is a Kraft lignin (see Page 8, Ln 13-18 and Page 4, Ln 10-11);
Feeding said solution into water or adding water into the lignin solution and forming the colloidal dispersion of lignins (see Page 6, Ln 9-12);
Wherein the lignin and water are mixed within the reactor by mixing elements or in a reactor comprising an agitator (see Page 15, Ln 7-10 and Figure 4 and Page 10, Ln 25-28 and Figure 5).
Regarding a colloidal dispersion having an average diameter size ranging from 9 nm to 70 nm, Lintinen further discloses the method producing an average colloidal particle diameter of ca. 70 nm (see Page 8, Ln 13-18). 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.Cir. 1990). It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform the method as disclosed by Lintinen to perform the process for preparing lignin dispersions of nanoparticles where the average particle diameter is in any range overlapping with about 70 nm including the claimed range.
Further regarding the imaging techniques (i.e. Helium ion microscopy and scanning electron microcopy), Wu discloses a Helium Ion Microscope and Scanning Electron Microscope combined method for characterizing porous medium pores (see Abstract). Wu further discloses that the resolution and signal to noise ratio of helium ion microscope is far superior to the scanning electron microscope for imaging pores of tens of nanometers or less (See BACKGROUND). Wu further discloses that when HIM and SEM are combined together, it produces a more accurate result (see Abstract). It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform the method as disclosed by Lintinen where the measurement is performed by SEM and HIM to obtain an accurate result.
Regarding a solution having a Kraft lignin concentration of at least 15 mg/ml, as set forth in MPEP 2144.05, it has been held that differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. Here, Lintinen teaches that the organic solvent should be capable of dissolving lignin at a concentration of at least 5 wt% (i.e., for THF 44 mg/mL) (see Page 4, Ln 21-22). Lintinen also teaches an example comprising 8.24 g solution of Kraft lignin in a mixture of THF, ethanol, and water with mass ratios of 38:32:30 wt% where a final lignin concentration of a dispersion is 2.8 wt% and where the final water content is 76 wt% of the solvents (See Example 1). Since the density of a 38:32 wt ratio mixture of THF:EtOH is about 0.834 g/mL then the initial concentration of lignin in organic solvent is 2.8 g / (24 g / 0.834 g/mL) = 0.097 g/mL or 97 mg/mL.
However, Lintinen also discloses that very dilute dispersions both with and without a co-solvent, produce colloidal lignin nanoparticles with an average diameter of ca. 70 nm (see Page 8, Ln 13-15). Therefore, one of ordinary skill in the art would recognize that Lintinen discloses that the lignin solution concentration is a result effective variable on the lignin nanoparticle average diameter. Here, applicant claims a range of 15 mg/mL and Lintinen teaches an example comprising 97 mg/ml but also suggests that the concentration of lignin dissolved in organic solvent is a result-effective variable on lignin average particle size in the colloid. It would have been prima facie obvious to one of ordinary skill in the art at the time of the invention to improve upon the known concentration to determine optimum or workable lignin solution concentration including the claimed concentration of 15 mg/mL or more as a matter of routine optimization in order to obtain the desired particle size. Applicants can rebut a prima facie case of obviousness based on optimization of ranges by showing the criticality of the claimed range.
Regarding claims 43-44, Lintinen discloses a method where the solvent comprising dimethyl sulfoxide (see Page 4, Ln 21-24).
Regarding claim 45, It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform the method as disclosed by Lintinen with any workable or optimum lignin solution concentration including the claimed concentration of 15 mg/mL to 35 mg/mL as a matter of routine optimization in order to obtain the desired particle size.
Regarding claims 46-47, Lintinen discloses a method where the organic solvent comprises tetrahydrofuran (see Page 4, Ln 21-24).
Regarding claim 48, It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform the method as disclosed by Lintinen with any workable or optimum lignin solution concentration including the claimed concentration of 15 mg/mL to 55 mg/mL as a matter of routine optimization in order to obtain the desired particle size.
Regarding claim 49, Lintinen discloses the process performed in a batch reactor (see Page 11, Ln 19-20) (i.e., where all reactants are fed to a single reactor).
Regarding claim 50, Lintinen further discloses a step of recovery of organic solvent after the formation of the colloidal lignin particles (See Page 13, Ln 1-2).
Regarding claim 51, Lintinen further discloses that the recovery of organic solvents can be accomplished by any means known in the art (See Page 12, Ln 6-7). Lintinen disclose a method comprising a step for solvent recovery by rotary evaporation (see Page 5, Ln 6-11).
Claim(s) 52 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lintinen as applied to claim 50 and in further view of Siddiqui et al (“Assessing the potential of lignin nanoparticles as drug carrier: Synthesis, cytotoxicity and genotoxicity studies”, International Journal of Biological Macromolecules, Vol. 152, pp. 786-802, 2020 submitted in the IDS filed 7/3/2022).
As applied to claim 50, Lintinen discloses a method for manufacturing lignin nanoparticles comprising providing Kraft lignin, dissolving the Kraft lignin into a single organic solvent at the claimed concentration; adding the lignin solution into water to produce a colloidal dispersion of nanoparticles having the claimed average diameter size where the one or more organic solvents is removed from the colloidal dispersion.
Regarding claim 52, Lintinen further discloses that the recovery of organic solvents can be accomplished by any means known in the art (See Page 12, Ln 6-7). Lintinen does not disclose a method characterized in that step (d) of removing said one or more organic solvents is performed by dialysis.
Siddiqui discloses a method for lignin nanoparticle synthesis comprising dissolving lignin in DMSO wherein after the lignin molecules are assembled into nano-aggregates by stirring in dilute aqueous HCl, the DMSO and acid was removed by dialysis in deionized water (See Page 787, 2.2.2 Lignin nanoparticle synthesis). It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform the method as disclosed by Lintinen where the recovery of the organic solvent is performed by dialysis as disclosed by Siddiqui as a known technique for removing DMSO (an organic solvent) with the predictable result that DMSO can be recovered.
Claim(s) 53 is rejected under 35 U.S.C. 103 as being unpatentable over Lintinen as applied to claim 50 and in further view of Alqahtani et al (US 10,420,731).
As applied to claim 50, Lintinen discloses a method for manufacturing lignin nanoparticles comprising providing Kraft lignin, dissolving the Kraft lignin into a single organic solvent at the claimed concentration; adding the lignin solution into water to produce a colloidal dispersion of nanoparticles having the claimed average diameter size where the one or more organic solvents is removed from the colloidal dispersion.
Regarding claim 53, Lintinen further discloses the drying of the colloidal lignin particles can be accomplished by any means known to the art, specifically, but not limited to spray drying (See {age 14, Ln 1-2). Lintinen does not disclose freeze-drying.
Alqahtani discloses a method for synthesizing lignin-based nanocompositions comprising dissolving lignin in ethanol, adding to an aqueous phase to produce a colloidal dispersion where the nanoparticles are filtered and dried using freeze-drying or spray-drying (see Col 8, Example 1). It has been established that substitution of one equivalent known for the same purpose for another is obvious. See MPEP 2144.06.II. Here, Alqahtani discloses that lignin nanoparticles can be dried by freeze-drying or by spray-drying. It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform the method as disclosed by Lintinen where the lignin nanoparticles are dried by freeze-drying as a known process for drying lignin particles as the mere substitution of equivalents known for the same purpose.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL FORREST whose telephone number is (571)270-5833. The examiner can normally be reached Monday-Friday (10AM-6PM).
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sally A Merkling can be reached at (571)272-6297. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/MICHAEL FORREST/Primary Examiner, Art Unit 1738
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