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 .
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.
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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Thies et al. (US 2016/0137680) in view of Lake et al. (US 2011/0294991).
Considering Claims 1, 10, 13, 14: Thies et al. teaches a method for lignin recovery comprising combining a feedstock containing lignin and impurities (¶0030) with a solvent solution comprising water, an organic solvent in an amount of 20 to 80 weight percent, and optionally an inorganic acid (¶0035-36); heating and agitating the mixture (¶0038; 0040) to form a two phase mixture comprising a liquid lignin rich phase and a liquid solvent rich phase (¶0040-41), where the lignin rich phase comprises a higher molecular weight lignin than the solvent rich phase (¶0041).
Thies et al. does not teach the specific inorganic acid used. However, Lake et al. teaches using 1N sulfuric acid to treat a liquid lignin phase to displace sodium ions from the lignin (¶0014; 0045). Thies et al. and Lake et al. are analogous art as they are concerned with the same field of endeavor, namely recovering lignin. It would have been obvious to a person of ordinary skill in the art to have selected sulfuric acid as the inorganic acid of Thies et al., as in Lake et al., and the motivation to do so would have been, as Lake et al. suggests, to reduce the sodium content of the lignin prepared by the process (¶0014).
Considering Claim 2: Thies et al. teaches that the lignin rich phase is reduced in impurities (¶0041-44).
Considering Claims 3-5: Thies et al. teaches preparing the lignin containing feedstock by pretreating a black liquor with carbon dioxide and/or sulfuric acid (¶0031).
Considering Claims 6 and 7: Thies et al. teaches further treating the lignin rich phase with an organic solvent in a multi-stage treatment process (¶0045).
Considering Claim 8: Thies et al. teaches the lignin rich phase as having a sodium content of 50 ppm or less after processing (¶0046).
Considering Claim 9: Thies et al. teaches washing the lignin of the solvent rich phase (¶0049).
Considering Claims 11 and 12: Thies et al. teaches the organic solvent as being acetic acid (¶0035; 0053).
Considering Claims 15 and 16: Thies et al. teaches an example with a ratio of the solvent to the feed as being 6.25:1/about 6:1 (¶0059).
Considering Claims 17 and 20: Thies et al. teaches heating the mixture to a temperature of 30 to 250 ºC (¶0040), preferably 95 ºC (Example 1).
Considering Claim 18: Thies et al. teaches heating the mixture under increased pressure (¶0039).
Considering Claim 19: Thies et al. teaches the purified lignin as comprising an ash content of less than 0.5 weight percent and a sodium content of less than 25 ppm (¶0042).
Response to Arguments
Applicant's arguments filed February 26, 2026 have been fully considered but they are not persuasive, because:
A) The applicant’s argument that a person of ordinary skill in the art would not look to the process of Lake et al. for sodium reduction, because the product produced by Thies et al. has a lower sodium content than the product of Lake et al. is not persuasive. Thies et al. teaches a means of reducing the sodium content by treatment with a mixture of water, an organic solvent, and an inorganic acid (¶0035-36, and 0041). A person of ordinary skill in the art would look to other references concerned with reducing the sodium content to determine the proper inorganic acid and molarity for the inorganic acid. While the inorganic acid alone does not reduce the sodium content as much as the combination of the inorganic acid and organic solvent, this does not negate the teaching that 1N sulfuric acid is useful for reducing the sodium content.
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.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LIAM J HEINCER whose telephone number is (571)270-3297. The examiner can normally be reached M-F 7:30-5:00.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Mark Eashoo can be reached at 571-272-1197. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/LIAM J HEINCER/Primary Examiner, Art Unit 1767