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 .
Election/Restrictions
Applicant's election with traverse of claims 1-3, 5-6, 9, 11, 14, 16, and 18-19 in the reply filed on 10/07/2025 is acknowledged. The traversal is based on arguments that the Qin reference used in the restriction is not prior art under 35 U.S.C. 102(a)(1) or 35 U.S.C. 102(a)(2).
However, these arguments are moot since the shared technical feature of a sub-micron fiber is known in the prior art (see teachings of both references cited in the 103 rejection of claim 1 below). Therefore, this feature is not a special technical feature and there is lack of unity between groups I-IV.
The requirement is still deemed proper and is therefore made FINAL.
Claims 21-22, 24-28, and 34-35 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 10/07/2025.
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.
Claims 1-3, 5-6, 9, 11, 14, 16, and 18-19 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 pre-AIA the applicant regards as the invention.
Claim 1, line 6 recites "the frozen suspension". It is unclear which of the two frozen suspensions produced earlier in the claim are being referenced on this line. For the purpose of examination, claim 1, line 6 reads on "the frozen aqueous suspension". Dependent claims fall herewith.
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, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 1-3, 5-6, 9, 11, 16, and 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Hsieh (US PG Pub 2019/0309144) in view of Chu (US PG Pub 2011/0198282).
Regarding claim 1, Hsieh teaches a method of preparing an aerogel (abstract), the method comprising:
freezing a suspension comprising nanofibrils and a solvent (para. 0006 wherein water is a type of solvent) at a first temperature (e.g. any of the temperatures cited in paras. 0072 and 0098);
freezing an aqueous suspension comprising sub-micron fibers (para. 0006) at a second temperature (e.g. any of the temperatures cited in paras. 0072 and 0098); and
freeze-drying the frozen aqueous suspension to obtain the aerogel (para. 0006).
Hsieh does not teach that the two freezing steps are performed using separate suspensions as implied by claim 1. Furthermore, Hsieh also does not teach freeze-drying the frozen suspension comprising nanofibrils and a solvent to obtain sub-micron fibers, but does teach that “The cellulose sub-micron fibers useful in the method of the present invention can be any cellulose sub-micron fibers known by one of skill in the art”, which thus encompasses all methods known in the art for obtaining sub-micron fibers.
For example, Chu teaches that sub-micron fibers may be obtained by steps of:
freezing a suspension comprising nanofibrils and a solvent (e.g. para. 0136 or dispersed slurry of para. 0141 in water solvent) at a first temperature (implicit per paras. 0135 or 0141);
freeze-drying the frozen suspension (paras. 0135 and 0141-0142) to obtain sub-micron fibers (fibers having diameters of “(b) 1000 nm, (c) 500 nm, (d) 200 nm, (e) 100 nm” per para. 0142 are sub-micron fibers).
The courts have held that selection of a known material on the basis of suitability for its intended use is obvious and within the capability of one of ordinary skill in the art. Per MPEP § 2144.07, "…selecting a known compound to meet known requirements is no more ingenious than selecting the last piece to put in the last opening in a jig-saw puzzle." 325 U.S. at 335, 65 USPQ at 301. See also Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
In view of the teachings of Hsieh and Chu and the above considerations, it would have been obvious to one of ordinary skill in the art at the time of filing to modify Hsieh’s process to include Chu’s steps for obtaining the sub-micron fibers to predictably obtain suitable means for providing the sub-micron fibers of Hsieh’s process in a convenient manner using the same equipment used by Hsieh for processing of a suspension by steps of freezing and freeze-drying.
Regarding claim 2, Hsieh teaches the solvent in the suspension comprising the nanofibrils is water (para. 0006). Chu also teaches the solvent in the suspension comprising the nanofibrils is water (para. 0141).
Regarding claim 3, Hsieh and Chu both teach the suspension comprising nanofibrils is an aqueous suspension comprising the nanofibrils in various exemplary amounts falling within the range of about 0.01 wt% to about 1 wt%, based on the total weight of the aqueous suspension (Hsieh para. 0097 and Chu para. 0142).
Regarding claims 5-6, Hsieh teaches the aqueous suspension comprising the sub-micron fibers comprises the sub-micron fibers in various exemplary amounts falling within the range of from about 0.01 wt% to about 2 wt% and about 0.2 wt% to about 2 wt%, based on the total weight of the aqueous suspension (para. 0097).
Regarding claim 9, Hsieh and Chu both teach the nanofibrils comprise cellulose nanofibrils (Hsieh para. 0006 and Chu paras. 0135-0136).
Regarding claim 11, Hsieh and Chu both teach the cellulose nanofibrils are oxidized cellulose nanofibrils prepared by a method comprising oxidizing a cellulose source and mechanically dispersing the oxidized cellulose source (Hsieh para. 0172 and Chu paras. 0135-0136, 0141).
Regarding claim 16, Hsieh teaches the second temperature is various exemplary values falling within the range of about -4°C to about -50°C (para. 0098).
Regarding claims 18-19, Hsieh teaches the method further comprises modifying a surface of the aerogel with a hydrophobic surface modifying agent (para. 0003) and modifying the surface comprises chemical vapor deposition of various species structurally and functionally similar to methyltrimethoxysilane (paras. 0003, 0099-0100, 0154), thus rendering the claimed species an obvious selection to one of ordinary skill providing the predictable result of making the surface more hydrophobic.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Hsieh in view of Chu, as applied to claim 1 above, further in view of Xie (US PG Pub 2021/0212949).
Regarding claim 14, neither Hsieh nor Chu explicitly teaches the first temperature is in the range of from about -80°C to about -200°C.
However, Xie teaches a method of obtaining sub-micron fibers and aerogels (para. 0146), wherein the first temperature used for freezing the suspension of nanofibrils is less than about -80°C (para. 0050), thus encompassing the claimed range and rendering it prima facie obvious.
A prior art range which encompasses, partially overlaps, or touches the claimed range is sufficient to establish a prima facie case of obviousness, in the absence of any unexpected results. See MPEP § 2144.05.I and In re Harris, 409 F.3d 1339, 74 USPQ2d 1951 (Fed. Cir. 2005); In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003).
Furthermore, Xie teaches that the freezing temperature affects aerogel pore size (para. 0118), and thus this temperature would be a parameter routinely optimized by one of ordinary skill for a particular aerogel application.
“[W]here 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 and In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Conclusion
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/JIMMY R SMITH JR./Examiner, Art Unit 1745