DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of claims 1 - 15 in the reply filed on June 23, 2026 is acknowledged. Claims 17 – 20 are withdrawn.
Claim Rejections - 35 USC § 102
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.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1 – 3 and 8 – 9 are rejected under 35 U.S.C. 102(a)(1)/(a)(2) as being anticipated by Luo et al., Post-sulfonation of cellulose nanofibrils with a one-step reaction to improve dispersibility, Volume 181, Pages 247-255, 1 February 2018.
Luo et al. teach a method for treating CNF (mechanically fibrillated pulp) with chlorosulfonic acid and dimethylformamide (DMF) resulting in sulfonated CNF that retained a fibril-like morphology (Abstract). In particular, as discussed in 2. Experimental, freeze dried CNF was sulfonated with varying moles of chlorosulfonic acid (CSA) to anhdyroglucose units (AGU) ratios of 0.5:1, 1.5:1 and 2.5:1. For each different CSA to AGU ratio sulfonation experiment, samples were taken out of the CSA/DMF solution after 5, 30 and 60 min. The Examiner equates this to “reacting for one to sixty minutes”. During the sulfonation reaction, nitrogen was constantly flowed through the system and the CNF was dried in an oven to move all adsorbed water before use. The mixture was followed by another soak and washed multiple times with deionized water and centrifuged (page 248). The Examiner equates the treating with chlorosulfonic acid to Applicant’s steps (a) and (b), the soaking/washing to Applicant step (c) and application of centrifuge to Applicant’s step (d). Note that the sulfonated CNF retained the fibril-like morphology thus it can be considered to “form” the nanofibrils to some extent. Luo et la. teach that CNM are extracted from sources such as wood pulp (page 247, 1. Introduction). Luo teaches that the sulfonating of the CNF results in a high surface charge and significant increase in zeta potential (page 253, 4. Conclusion). The examiner equates this to Applicant’s “simultaneously pretreats and functionalizes the cellulose”.
Claim Rejections - 35 USC § 102/103
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 (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.
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 7 and 15 are rejected under 35 U.S.C. 102(a)(1)/(a)(2) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Luo et al., Post-sulfonation of cellulose nanofibrils with a one-step reaction to improve dispersibility, Volume 181, Pages 247-255, 1 February 2018.
Luo et al. teaches the claimed invention above but does not expressly teach the yield of at least 90% as required by claim 7 and the nanofibril exhibiting amphiphilicity, thixotropy and shear thinning behaviors as required by claim 15. It is reasonable to presume that the yield and behaviors are inherent to Luo et al. Support for said presumption is found in that Luo et al. teaches the same process as Applicant as set forth in the 102 rejection above and therefore are expected to have the same properties of the claimed invention.
Claim Rejections - 35 USC § 103
Claims 10 - 14 are rejected under 35 U.S.C. 103 as being unpatentable over Luo et al., Post-sulfonation of cellulose nanofibrils with a one-step reaction to improve dispersibility, Volume 181, Pages 247-255, 1 February 2018.
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the length, width, height, aspect ratio and cross-sectional shape to include the claimed range. One would have been motivated to provide sulfated nanofibrils with the desired length, width, height, aspect ratio and cross-sectional shape depending on the desired end application. Additionally, Luo et al. specifically teaches that the morphology of the CNF highly depends on the reaction times and ratios of the CSA/AGU (page 249, 3.1 Change in morphology) It has been held that, 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. See MPEP 2144.05(II) absent a showing of unexpected results.
Claims 4 – 6 are rejected under 35 U.S.C. 103 as being unpatentable over Luo et al., Post-sulfonation of cellulose nanofibrils with a one-step reaction to improve dispersibility, Volume 181, Pages 247-255, 1 February 2018 in view of Iwamoto et al., Structure and Mechanical Properties of Wet-Spun Fibers Made from Natural Cellulose Nanofibers, Biomacromolecules 12, 831–836, 2011.
Luo et al. teach that the sulfonated cellulose nanofibrils are useful for a wide range of applications (page 254).
Luo et al. teach the claimed invention above but fail to teach wet-spinning the sulfated cellulose nanofibrils to form fibers as required by claim 4, wet-spinning is conducted in the presence of a coagulant selected from the group consisting of acetone, ethanol, isopropanol, mixtures of calcium chloride and isopropanol, and combinations thereof as required by claim 5 and the fibers are not subjected to drawing as required by claim 6.
Iwamoto et al. is directed to wet-spinning of cellulose nanofibers where the cellulose nanofiber suspensions were spun in an acetone coagulation bath. After the spun fibers were taken from acetone, the fibers were dried at 105 C for 1 hour under weak tension. (Experimental section, page 832). All the spun fibers showed higher Young’s moduli and similar strengths compared with cotton. (Experimental section, page 835).
It would have been obvious to one of ordinary skill in the art the time the invention was filed to wet-spin using an acetone coagulation bath without drawing the sulfated cellulose nanofibrils of Luo et al. with the process as suggested by Iwamoto et al. motivated by the desire to employ the sulfated cellulose nanofibril in one of the wide range of applications to make a useful product, in particular, a spun fiber having higher Young’s modulus and similar strength to cotton.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JENNIFER A BOYD whose telephone number is (571)272-7783. The examiner can normally be reached M-F 8 am - 5 pm with alternating Fridays off.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sri Kumar can be reached at (571) 272-7769. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JENNIFER A BOYD/Supervisory Patent Examiner, Art Unit 1786
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