DETAILED ACTION
Summary
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Applicant’s arguments and claim amendments submitted on February 6, 2026 have been entered into the file. Currently claims 1, 12, 14, 20, and 23 are amended, claims 2-3, 5, 10, and 21 are cancelled, and claims 20 and 22-23 are withdrawn, resulting in claims 1, 4, 6-9, and 11-19 pending for examination.
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 (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.
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) 1, 4, 7-9, 13, and 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhu (CN 105970325)1,2,3 in view of Zhang (CN 114481352)1,3 and Whiffen (US 2016/0219926). Supporting evidence provided by Textile School and Yu (CN 114000347)1.
With respect to claims 1, 4, and 7-9, Zhu teaches a continuous cellulose aerogel fiber (paragraph [0008]). The fibers have a diameter of less than 120 microns and a low density of less than or equal to 0.2 g/cm3 (paragraph [0030]). This results in a linear density of 1.8 dtex or less.
It is noted the relationship between a fiber’s diameter (D), fineness (Tex), and density is represented by the following equation from Textile School:
PNG
media_image1.png
86
214
media_image1.png
Greyscale
where k is estimated as 0.04 (2.1 Yarn Diameter (D)). A diameter of 120 microns with a density of 0.2 g/cm3 provides a fiber with a fineness of 1.8 dtex. Lowering the values of diameter and/or density as suggested by Zhu results in a lower fineness, therefore Zhu teaches a linear density of 1.8 dtex or less.
The diameter and fineness ranges of Zhu substantially overlap the claimed range in the instant claims 1, 7, and 9. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I). Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to have selected from the overlapping portion of the range taught by Zhu, because overlapping ranges have been held to establish prima facie obviousness.
Zhu is silent as to the aerogel polymer comprising sodium alginate.
Zhang teaches aerogel fibers (paragraph [n0001]). The polymer solution may include sodium alginate or nanocellulose (paragraph [n0046]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the aerogel fiber of Zhu to be sodium alginate because both sodium alginate and cellulose are known in the art as suitable materials for forming an aerogel fiber, and would provide the predictable result of an aerogel fiber with a porous structure. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See MPEP 2143(I)(B). It is noted that it is known in the art that sodium alginate aerogel can be wet spun into fibers (Yu; paragraphs [n0005], [n0036]) similar to Zhu (paragraphs [0010]-[0011]).
Zhu in view of Zhang is silent as to the sodium alginate being crosslinked with a crosslinking agent, specifically calcium chloride.
Whiffen teaches that treatment of sodium alginate with calcium chloride can result in cross linking of the sodium alginate to produce a calcium alginate coating (paragraph [0050]). Since calcium alginate is insoluble in water, such a coating convers a water insoluble protective coating (paragraph [0050]).
It therefore would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the sodium alginate of Zhu in view of Zhang to be crosslinked with calcium chloride in order to provide a water insoluble fiber.
Zhu in view of Zhang and Whiffen teaches the claimed invention above but does not expressly teach a fiber tenacity of 5 to 20 cN/tex, specifically 15-20 cN/tex, and an elongation at break of 3 to 20%. It is reasonable to presume that the tenacity and elongation at break are inherent to Zhu in view of Zhang and Whiffen. Support for said presumption is found in that Zhu in view of Zhang and Whiffen teaches the same structure as the claimed invention, as described above. Additionally, Zhu teaches a similar method of preparing the aerogel fiber. Paragraphs [26]-[28] of the specification as filed describe the fiber as being wet-spun from a spinning solution containing the aerogel polymer at an extrusion speed between 0.1 to 5 m/min, wet-stretching the filament at a temperature of 30-60oC at a draw ratio between 100-500%; and freeze-drying the wet-stretched filament to form the aerogel fiber. Similarly, Zhu discloses wet-spinning a solution containing the aerogel polymer at an extrusion speed of 2.4 m/min, winding in a coagulation bath, and freeze-drying to obtain the fibers (paragraph [0042]). Therefore, the fibers of Zhu in view of Zhang and Whiffen are expected to have the same properties of the claimed invention.
With respect to Whitten, it is noted that in order for a reference to be proper for use in an obviousness rejection under 35 U.S.C. 103, the reference must be analogous art to the claimed invention. A reference is analogous art to the claimed invention if: (1) the reference is from the same field of endeavor as the claimed invention (even if it addresses a different problem); or (2) the reference is reasonably pertinent to the problem faced by the inventor (even if it is not in the same field of endeavor as the claimed invention). See MPEP 2141.01(a).
In the instant case, the instant specification at paragraph [7] states that the present disclosure relates to an aerogel fiber that exhibits one or more of high thermal insulation, low water retention, high moisture wicking, and low water retention properties. As discussed above, Whiffen teaches that crosslinking sodium alginate provides a material that is water insoluble (Whiffen; paragraph [0050]). Therefore, Whiffen is reasonably pertinent to the problem faced by the inventor of providing low water retention properties.
With respect to claims 13 and 15, Zhu in view of Zhang and Wiffen teaches all the limitations of claim 1 above. The fibers can be used to form functional clothing (textile/garment) (paragraph [0031]).
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhu (CN 105970325)4,5,6 in view of Zhang (CN 114481352)1,3 -and Whiffen (US 2016/0219926) as applied to claim 1 above, and further in view of Oh (US 2018/0179073)3.
With respect to claim 6, Zhu in view of Zhang and Whiffen teaches all the limitations of claim 1 above.
Zhu in view of Zhang and Whiffen is silent as to the aerogel fiber comprising hydrophobic alkylsilanes, aliphatic esters, or a combination thereof grafted on an exterior surface of the aerogel fiber.
Oh teaches a silica aerogel containing blanket using minimal amount of surface modification agents which has low thermal conductivity and excellent flexibility by forming an aerogel having high hydrophobicity and excellent physical properties, in particular high porosity (paragraph [0002]). The base material by be subjected to a hydrophobizing treatment such as surface treating the base material with a compound including a hydrophobic functional group such as alkyl silane (paragraphs [0059]-[0060]).
It therefore would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to surface modify the aerogel of Zhu in view of Zhang and Whiffen with one of the compounds described in paragraph [0060] of Oh, which includes alkylsilane, in order to provide the aerogel with hydrophobicity.
With respect to the selection of alkylsilane, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to try the list of compounds in paragraph [0060] of Oh, which includes alkylsilane, in order to determine which provides the desired level of hydrophobicity. See MPEP 2143.
Claim(s) 11-12 and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhu (CN 105970325)7,8,9 in view of Zhang (CN 114481352)1,3 and Whiffen (US 2016/0219926) as applied to claim 1 above, and further in view of Poe (US 2020/0199323)3.
With respect to claim 11, Zhu in view of Zhang and Whiffen teaches all the limitations of claim 1 above.
Zhu in view of Zhang and Whiffen is silent as to the aerogel fiber comprising pores having an average diameter between 100 to 250 nm.
Poe teaches an aerogel structured such that the majority of the pore volume in the aerogel is made up of macropores (pores having a size greater than 50 nm in diameter). It has been found that the presence of macropores can help facilitate the manufacture of aerogels as macropores are larger than meso- and micropores and less likely to collapse during the drying stage, resulting in a more economically efficient and less complicated drying process (paragraph [0006]). Additionally the presence of macropores can improve the flexibility, strength, gas permeation and/or the strength to density ratio of the formed aerogels (paragraph [0006]).
The pore size range of Poe substantially overlaps the claimed range in the instant claim 11. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I). Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to have selected from the overlapping portion of the range taught by Poe, because overlapping ranges have been held to establish prima facie obviousness.
Since both Zhu in view of Zhang and Whiffen and Poe teach porous aerogels, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the aerogel of Zhu in view of Zhang and Whiffen to include macropores with a pore size of 50 nm and above, in order to provide an aerogel fiber with improved flexibility, strength, gas permeation, and/or strength to density ratio.
With respect to claims 12 and 14, Zhu in view of Zhang and Whiffen teaches all the limitations of claims 1 and 13 above. Zhu further teaches the fibers have a diameter of less than 120 microns and a low density of less than or equal to 0.2 g/cm3 (paragraph [0030]). As described in claim 1 above, this results in a linear density of 1.8 dtex or less.
The diameter and fineness ranges of Zhu substantially overlap the claimed range in the instant claims 12 and 14. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I). Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to have selected from the overlapping portion of the range taught by Zhu, because overlapping ranges have been held to establish prima facie obviousness.
Zhu in view of Zhang and Whiffen is silent as to the aerogel fiber comprising pores having an average diameter between 100 to 250 nm.
Poe teaches an aerogel structured such that the majority of the pore volume in the aerogel is made up of macropores (pores having a size greater than 50 nm in diameter). It has been found that the presence of macropores can help facilitate the manufacture of aerogels as macropores are larger than meso- and micropores and less likely to collapse during the drying stage, resulting in a more economically efficient and less complicated drying process (paragraph [0006]). Additionally the presence of macropores can improve the flexibility, strength, gas permeation and/or the strength to density ratio of the formed aerogels (paragraph [0006]).
The pore size range of Poe substantially overlaps the claimed range in the instant claims 12 and 14. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I). Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to have selected from the overlapping portion of the range taught by Poe, because overlapping ranges have been held to establish prima facie obviousness.
Since both Zhu in view of Zhang and Whiffen and Poe teach porous aerogels, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the aerogel of Zhu in view of Zhang and Whiffen to include macropores with a pore size of 50 nm and above, in order to provide an aerogel fiber with improved flexibility, strength, gas permeation, and/or strength to density ratio.
Zhu in view of Zhang, Whiffen, and Poe teaches the claimed invention above but does not expressly teach a fiber tenacity of 15-20 cN/tex. It is reasonable to presume that the tenacity is inherent to Zhu. Support for said presumption is found in that Zhu in view of Zhang, Whiffen, and Poe teaches the same structure as the claimed invention, as described above. Additionally, Zhu teaches a similar method of preparing the aerogel fiber. Paragraphs [26]-[28] of the specification as filed describe the fiber as being wet-spun from a spinning solution containing the aerogel polymer at an extrusion speed between 0.1 to 5 m/min, wet-stretching the filament at a temperature of 30-60oC at a draw ratio between 100-500%; and freeze-drying the wet-stretched filament to form the aerogel fiber. Similarly, Zhu discloses wet-spinning a solution containing the aerogel polymer at an extrusion speed of 2.4 m/min, winding in a coagulation bath, and freeze-drying to obtain the fibers (paragraph [0042]). Therefore, the fibers of Zhu in view of Zhang and Poe are expected to have the same properties of the claimed invention.
Claim(s) 16-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhu (CN 105970325)10,11,12 in view of Zhang (CN 114481352)1,3 and Whiffen (US 2016/0219926) as applied to claim 1 above, and further in view of Wu (CN 111850729)1,3.
With respect to claims 16-19, Zhu in view of Zhang and Whiffen teaches all the limitations of claim 16 above.
Zhu in view of Zhang and Whiffen is silent as to the textile further comprising wool in a mass ratio of 1:9 to 9:1, preferably 2:3 to 3:2 aerogel fiber to wool.
Wu teaches a thin, warm aerogel textile fiber fabric (paragraph [0002]). The textile comprises 10-90 wt% aerogel fiber with the remainder being cashmere, wool, or cotton fiber (paragraph [0010]). The pore structure of the aerogel fiber provides low thermal conductivity and thus provides good thermal insulation (paragraph [0011]). A blend of aerogel fibers with cashmere, wool, or cotton fiber provides the advantage of being light weight and having good heat insulation performance and overall wearability (paragraphs [0008], [0013]).
The aerogel to wool ratio range substantially of Wu overlaps the claimed range in the instant claim 19. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I). Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to have selected from the overlapping portion of the range taught by Wu, because overlapping ranges have been held to establish prima facie obviousness.
Since both Zhu in view of Zhang and Whiffen and Wu teach textiles comprising porous aerogel fibers, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include 10-90 wt% aerogel fiber of Zhu in view of Zhang and Whiffen with the balance being wool in the textile in order to provide a textile that is light weight and has good heat insulation performance and overall wearability.
Zhu in view of Zhang and Whiffen and Wu teaches the claimed invention above but does not expressly teach the textile having a thermal resistance between 9-25% higher and a lower mass as compared with an equivalent textile consisting of wool. It is reasonable to presume that the thermal resistance and lower weight is inherent to Zhu in view of Zhang, Whiffen, and Wu. Support for said presumption is found in that Zhu, Zhang, Whiffen, and Wu teach the aerogel fibers have low conductivity and thus provide thermal insulation (Zhu, paragraph [0004]; Wu, paragraph [0011]). Wu further teaches that the aerogel fiber is ultra-lightweight (Wu; paragraph [0006]) and therefore will necessarily have a lighter weight when used as a replacement for the heavier wool. Additionally, as described above, Zhu in view of Zhang, Whiffen, and Wu teaches the structure of the claimed invention. Therefore, the fabric of Zhu in view of Zhang, Whiffen, and Wu is expected to have the same properties of the claimed invention.
Response to Arguments
Response – Drawings
The objections to the drawings have been overcome by Applicant’s amendments to the drawings in the response received on February 6, 2026.
Response – Claim Rejections 35 USC §112
The rejections of claim 19 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, are overcome by Applicants arguments in the response filed February 6, 2026.
Response – Claim Rejections 35 USC §103
Applicant’s arguments submitted on February 6, 2026 have been fully considered and are not persuasive.
On pages 7-8 of the response Applicant submits that a person having ordinary skill in the art would not combine Zhu and Zhang because Zhu’s method is specifically devised for regeneration of cellulose. Applicant submits that the wet spinning just facilitates the regeneration of the cellulose and cellulose fiber, thus a person having ordinary skills in the art would not replace cellulose with sodium alginate in view of Zhang.
The Examiner respectfully disagrees. Wet spinning is not a process for regenerating cellulose, but rather is a known method for forming fibers. It is known in the art that sodium alginate aerogel can be wet spun into fibers (Yu; paragraphs [n0005], [n0036]). Therefore the ordinary artisan would have been motivated to replace the cellulose of Zhu with the sodium alginate of Zhang, with a reasonable expectation of success that the sodium alginate aerogel would be successfully wet spun as is known in the art.
The remaining arguments are moot as they do not apply to the combination of references being used in the current rejection. Applicant’s arguments are with respect to Zhu and Retke not teaching the new claim amendments, specifically the newly added feature where the sodium alginate is crosslinked. The newly added reference Whiffen (US 2016/0219926) is used in combination with Zhu and Zhang to address the newly added limitations. The Applicant’s arguments are therefore moot as they do not address the combination of references used in the rejections of the amended claims presented above.
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 Larissa Rowe Emrich whose telephone number is (571)272-2506. The examiner can normally be reached Monday - Friday, 7:30am - 4:00pm EST.
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, Marla McConnell can be reached at 571-270-7692. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
LARISSA ROWE EMRICH
Examiner
Art Unit 1789
/LARISSA ROWE EMRICH/Examiner, Art Unit 1789
1 Machine translation used as reference
2 Cited in IDS
3 Previously presented
4 Machine translation used as reference
5 Cited in IDS
6 Previously presented
7 Machine translation used as reference
8 Cited in IDS
9 Previously presented
10 Machine translation used as reference
11 Cited in IDS
12 Previously presented
Prosecution Insights