DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. 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 Amendments
2. Applicant’s response dated 06 July 2026 is acknowledged. The applicant has amended Claim 1 and Claim 4. The amendments were directed toward correcting the clarity errors rather than a change in the scope of the claims. Currently, Claims 1, 2, 3, 4, 5, and 6 are pending and under examination. Claims 7 and 8 are withdrawn.
Priority
3. Acknowledgment is made of applicant's claim for foreign priority based on an application filed in China on 29 June 2021. The certified copy of the priority document has been entered into the record following a request from the applicant to the USPTO to obtain CN202110724235.5.
Specification
4. The applicant failed to respond to the objection to the specification in their response dated 06 July 2026.
The attempt to incorporate subject matter into this application by reference to Chinese Patent Application Ser. No. 60/864,925 filed 8 November 2006 is ineffective because said application is not listed in an IDS, no translation is provided, and it is a different priority date than priority document on the application data sheet (i.e.: than CN202110724235.5 filed 29 June 2021). Additionally, the examiner was unable to locate CN App. Ser. No. 60/864,925.
Claim Rejections - 35 USC § 103
5. 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.
6. 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.
7. Claims 1, 3, and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Gui et al., Wang et al., and Zhang et al.
Gui et al. (CN103146197B – previously presented) is directed toward a method of fabricating hydrophobic materials with micro/nano core-shell structures (title). Wang et al. (“Superhydrophobic fabrics from hybrid silica sol-gel coatings: Structural effect of precursors on wettability and washing durability,” J. Mater. Res. 2010, 25(7), 1336-1343 – previously presented) is directed toward the treatment of fabric with hydrophobic coatings (pg. 1336: title and abstract). Zhang et al. (CN110003735A – previously presented) is directed towards a superhydrophobic coating (title).
Regarding Claim 1, Gui et al. is discloses the formation of SiO2 hydrophobic particles prepared from a mixture of aqueous ammonia, tetraalkyl orthosilicate (i.e.: alkyl = ethyl or propyl) in a mixture of ethanol and water which is isolated to yield silica particles which are subsequently treated with a coupling silane agent (¶15-16, 18-19, 46-47, and 49-50). The mass ratios (i.e.: wt. %) when converted from the volume ratios listed in ¶15-16 of Gui et al. using the densities of material are: 6.1-7.4 wt.% for aqueous ammonia, 3.8-6.0 wt.% for tetraethyl orthosilicate, and ~80 wt.% for the solvent mixture (water and ethanol). Gui et al. does not disclose the relative amount of SiO2 particles treated with the silane coupling agent (¶18-19 and ¶49-50). Gui et al. further indicates that the silane coupling agent is a mixture selected from KH-550 (i.e.: 3-aminopropyltriethoxysilane), KH-560 (i.e.: 3-glycidoxypropyltrimethoxysilane), and KH-570 (3-Methacryloxypropyltrimethoxysilane) in ¶29, which are analogous to the hydrophobic treatment agent of Claim 1 and would form a waterborne siloxane species under the alkaline conditions of the reaction. Gui et al. further indicates the particle size of the hydrophobic SiO2 is 10-200 nm (¶16), the hydrophobic treatment time is 8-12 hours (¶16), and the hydrophobic agent treatment steps falls within the 15-30 wt.% solids meeting the limitations of Claim 1. Gui et al. isolated the hydrophobic SiO2 particle using centrifugation and subsequent drying which is an analogous isolation process to the spray drying limitation of Claim 1. However, Gui et al. does not disclose the use of the specific hydrophobic treatment agents listed in the limitations of Claim 1.
Wang et al. is directed toward the formation of superhydrophobic materials by formation of superhydrophobic silica particles/coatings (pg. 1336: title and abstract) such that Wang et al. and Gui et al. are analogous art. Wang et al. discloses a single step process for the formation of hydrophobized SiO2 by the addition of silanes (e.g.: 3-glycidoxypropyltrimethoxysilane, methyl triethoxysilane, or octyl triethoxysilane) to ammonia/TEOS (pg. 1337: II. Experimental – A. Materials and measurements & B. Synthesis of coating solution). Under the alkaline reaction conditions (i.e.: pH >7; analogous to 8 < pH < 9 of Claim 1), octyl triethoxysilane and propyloctyl siloxane are the same material which thus satisfies the limitations of Claim 1 pertaining to the hydrophobic treatment agent. Wang et al. further indicates that the longer alkyl chain on the siloxane/silane increases the hydrophobicity of the treating silica meaning that octyl triethoxysilane has a higher contact angle than methyl triethoxysilane or 3-glycidoxypropyltrimethoxysilane. Therefore, it would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the hydrophobic treatment agent of Gui et al. with octyl triethoxysilane (i.e.: propyloctyl siloxane) as taught by Wang et al. with the reasonable expectation of forming an enhanced hydrophobic SiO2 particle. Additionally, the substitution of octyl triethoxysilane (i.e.: propyloctyl siloxane) for the mixture of silane disclosed by Gui et al. provides a more simplified and predictable process with less reagents.
Gui et al. in view of Wang et al. indicates that an organic silane (i.e.: octyl triethoxysilane or hydrophobic treatment agent of the instant application) when co-hydrolyzed with tetraethyl orthosilicate (“TEOS”) results in a hybrid silica with the non-hydrolysable groups in both the silica matrix and on the surface (Wang et al. on pg. 1337: III. Results and Discussion) meaning the ratio of the hydrophobic treatment agent to the tetraalkyl orthosilicate (i.e.: TEOS) is a result-effective variable, i.e., a variable which achieves a recognized result, and the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation (See MPEP 2144.0.II.B.). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have discovered the optimum or workable ranges of the (relative concentration) of the hydrophobic treatment agent, including values within the claimed range, through routine experimentation. One would have been motivated to do so in order to have the desired surface properties of the hydrophobic SiO2 particle.
Therefore, Gui et al. in view of Wang et al. disclose the use of tetraethyl orthosilicate (TEOS) as the SiO2 source, but not a nanoparticulate SiO2 sol. Both of these species (i.e.: TEOS and nanoparticulate SiO2 sol) are expected to provide small particle sized silica upon further processing to drive polymerization of SiO2 groups. Zhang et al. discloses the formation of a hybrid particle comprised of a hydrophobic nanoparticle SiO2 and a microparticle ceramic species and employs a nanoparticle silicon dioxide sol (¶15). It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to substitute the TEOS of Gui et al. in view of Wang et al. with the nanoparticle SiO2 sol of Zhang et al. with the reasonable expectation of the simple substitution resulting in the successful formation of a SiO2 nanoparticles.
Therefore, the combination Gui et al., Wang et al., and Zhang et al. render all of the limitations of step (i) of the method of preparing the impregnated powder of Claim 1 obvious.
Further pertaining to step (ii) of Claim 1 for the formation of the impregnated porous powder, Gui et al., Wang et al., and Zhang et al. disclose the elements of said step. In ¶15-16, Zhang et al. teaches the following process of adding: a porous ceramic micro-powder (i.e.: diatomaceous earth with a diameter of 20-30 microns at 12-24 parts by weight), aqueous ammonia (4-5 parts by weight), a hydrophobic treatment agent (1-2 parts by weight), a solvent (mixture of water and ethanol at 100 parts by weight) and the hydrophobic SiO2 nanoparticles (i.e.: resulting from the nano-SiO2 sol at 12-20 parts by weight). The resultant mixture is then processed using a rotary evaporation step and a freeze-drying step to isolate the impregnated porous powder as per ¶15-16 of Zhang et al. Zhang et al. further indicates that the total reaction time is 22-28 hours (mixing time + settling time). Zhang et al. indicates that the hydrophobic treatment agent is selected from alkyl triethoxysilanes or alkyl trimethoxysilanes (¶19) which would include octyl triethoxysilane (as taught in Wang et al.). As indicated above, octyl triethoxysilane forms a waterborne siloxane material under the basic reaction conditions. The claim limitations of the weight ratios of the chemicals species in step (ii) are met by the weight parts listed above. Given the description of the preceding, Gui et al., Wang et al., and Zhang et al. render all of the limitations of step (ii) of the method of preparing the impregnated powder of Claim 1 obvious.
Regarding Claim 3, Gui et al., Wang et al., and Zhang et al. discloses the method according to Claim 1, wherein the final step to isolate the impregnated porous powder includes an evaporation step to concentrate the material followed by freeze drying as per ¶16 in Zhang et al. The purpose of this last step is to remove the residual solvent/blocking group and drive formation of the Si-O-Si inorganic polymer network. One of ordinary skill in the art can employ a variety of different heating, drying, or filtration methods to complete the aforementioned process meaning this final step could be described as routine optimization. As part of the optimization process, the skilled artisan would also select the operational parameters (i.e.: pressure, rotating speed, time, and temperature) of the isolation step method. Therefore, one of ordinary skill in the art would investigate different approaches and operation parameters to isolate the impregnated porous powder including the different processes listed in the limitations of Claim 3 and the associated process parameters of those processes.
Regarding Claim 4, Gui et al., Wang et al., and Zhang et al. disclose the method of Claim 1, wherein the hydrophobic treatment agent is octyl triethoxysilane (Wang et al. in the abstract). Under the aqueous alkaline reaction conditions described in Wang et al. on pg. 1337 in the “Synthesis of coating solution” section, octyl triethoxysilane forms an equivalent material to waterborne propyloctyl siloxane oligomer of the instant application. The other chemical species listed in Claim 4 are being treated as optional since they are further narrowing the optional claim limitations of Claim 1.
8. Claims 5 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Gui et al., Wang et al., and Zhang et al. with evidentiary support from Vrieling et al.
Gui et al. (CN103146197B – previously presented) is directed toward a method of fabricating hydrophobic materials with micro/nano core-shell structures (title). Wang et al. (“Superhydrophobic fabrics from hybrid silica sol-gel coatings: Structural effect of precursors on wettability and washing durability,” J. Mater. Res. 2010, 25(7), 1336-1343 – previously presented) is directed toward the treatment of fabric with hydrophobic coatings (pg. 1336: title and abstract). Zhang et al. (CN110003735A – previously presented) is directed towards a superhydrophobic coating (title). Vrieling et al. (“Salinity-dependent diatom biosilicification implies an important role of external ionic strength,” PNAS 2007, 104(25), 10441-10446 – previously presented) is directed toward characterizing diatom biosilification (pg. 10441: title).
Regarding Claim 5 and Claim 6, Gui et al., Wang et al., and Zhang et al. disclose the method of Claim 1, wherein the porous ceramic micro-powder (i.e.: diatomaceous earth or “DE”) has a diameter of 20-30 microns (i.e.: particle size), is column or disc shaped, and is nanoporous (Zhang et al. in ¶21). However, the combination of references is silent on the size of the nanopores (i.e.: pore diameter), specific surface area, and the pore volume.
Vrieling et al. provides data on general properties of diatomaceous earth including: pore diameter, specific surface area, and the pore volume. On pg. 10442, Vrieling et al. discloses a BET surface area range of ~10 m2/g to ~40 m2/g and a (BJH) pore diameter of ~3 nm to ~45 nm according to TABLE 1. On pg. 10443, Vrieling et al. indicated that the pore volume which depends on the pore diameter ranges from ~0.02 cm3/g to 0.16 cm3/g (FIG. 2b). Therefore, Vrieling provides evidentiary support for DE having the pore diameter, specific surface area, and the pore volume as per the limitations of Claim 5 and Claim 6.
A prima facie case of obviousness exists when range disclosed in the prior art overlaps with the claimed range. See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS
Further regarding Claim 6, the raw micro-powder (i.e.: diatomaceous earth) is a hydrophilic material owing to the polar and hygroscopic nature of silicon dioxide-based materials. The superhydrophobicity of the porous micro-powder forms after treatment of the steps (i) and (ii) described in Claim 1 which includes a drying/annealing step. The temperature and time range of the annealing step of Claim 6 would be obvious to one of ordinary skill in the art as part of the optimization process since the residual solvents need to be removed. The residual solvents include alcohols and water all which require a temperature of at least 78 degrees C (i.e.: the boiling point of ethanol) to be removed from the composite hydrophobic particle.
9. Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Gui et al., Wang et al., and Zhang et al. as applied to Claim 1 above, and further in view of Mo et al.
Gui et al. (CN103146197B – previously presented) is directed toward a method of fabricating hydrophobic materials with micro/nano core-shell structures (title). Wang et al. (“Superhydrophobic fabrics from hybrid silica sol-gel coatings: Structural effect of precursors on wettability and washing durability,” J. Mater. Res. 2010, 25(7), 1336-1343 – previously presented) is directed toward the treatment of fabric with hydrophobic coatings (pg. 1336: title and abstract). Zhang et al. (CN110003735A) is directed towards a superhydrophobic coating (title). Mo et al. (“Formation of SiO2/polytetrafluoroethylene hybrid superhydrophobic coating,” Appl. Surface Sci. 2012, 258, 9859-9863 previously presented) is directed toward silica based hydrophobic coatings (pg. 9859: title).
Regarding Claim 2, Gui et al., Wang et al., and Zhang et al. discloses the method according to Claim 1 wherein the nanoparticle sol is silicon dioxide based with a particle size of 10-100 nm, a solids content of 15-30 wt.%, and an alkaline pH value as explained above. However, Gui et al., Wang et al., and Zhang et al does not disclose modifying the nanoparticle sol with organic species as required by the limitation of Claim 2.
Mo et al. is directed toward hydrophobic coatings based on SiO2 making it analogous art to Gui et al., Wang et al., and Zhang et al. Mo et al. indicates the silica sol is modified by 3-glycidoxypropyltrimethoxysilane (pg. 9859: abstract and pg. 9860: FIG. 1) and further modified using a PTFE (polytetrafluoroethylene) emulsion (pg. 9860: FIG.1 and 2.1 Sample preparation). Mo et al. further explains that PTFE is known to have very hydrophobic properties, but is difficult to incorporate into coating compositions. As a result, a PTFE emulsion is often used to improve the compatibility with the wet coating composition as per the introduction of Mo et al. (pg. 9850-9860). Fig. 7 clearly shows the effect of PTFE incorporation into the SiO2-based coating with contact angle of 156o indicating the resultant treatment is superhydrophobic (ph. 9862-3: 3. Results and Discussion, 4. Conclusion).
It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method of forming an impregnated porous particle of Gui et al., Wang et al., and Zhang et al. with the PTFE emulsion of Mo et al. with
reasonable expectation of forming a silica particle with enhanced hydrophobicity (i.e.: superhydrophobicity) and better mechanical properties.
Response to Arguments
10. The applicant’s amendments to remove the trademark and/or product names from the claims have resulted in the withdrawal of the rejections of Claims 1, 2, 3, 4,5 and 6 under 35 USC § 112(b)
11. Applicant's arguments filed 06 July 2026 have been fully considered but they are not persuasive. Therefore, the previous obviousness rejections from the first office action on the merits dated 08 April 2026 are maintained.
12. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., 1. the structure, 2. characteristic, and 3. performance discussed on pg. 9-10 of their response) are not recited in the rejected method claims. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
13. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
14. The applicant has argued on pg. 10 of their response that Zhang uses ethanol as modification solvent, but water is also present in the formulation as explained above. Since the instant application also uses water and does not expressly limit the presence of any other solvents, Zhang et al. meets the modification solvent limitation. Additionally, the formation of titanium, silicon, or aluminum sol gels will have alcohol present in their solution since metal alkoxides are often the source of the sol. Finally, Claim 4 of the instant application recites different alkoxysilanes are used in the method of the instant application and these materials also have ethanol present in their composition,
15. In response to applicant's argument that Vrieling et al. is nonanalogous art, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case, Vrieling simply provided evidentiary support for different properties pertaining to diatomaceous earth (which is a biologically derived material) such as pore diameter, specific surface area, and the pore volume which were not specified in the other references (i.e.: Gui et al., Wang et al., and Zhang et al.).
16. In response to applicant's argument that Mo et al. is nonanalogous art, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case, Mo et al. was used to support the use of a PTFE emulsion to improve the compatibility (of a hydrophobic additive) with the wet coating composition or formulation. The limitations of Claim 2 are directed toward using a wet coating or impregnation composition meaning that Mo et al. is analogous art since it is used in the same type of composition.
Conclusion
17. THIS ACTION IS MADE FINAL. 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.
18. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KEVIN SYLVESTER whose telephone number is (703)756-5536. The examiner can normally be reached Mon - Fri 8:15 AM to 4:30 PM EST.
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/KEVIN SYLVESTER/Examiner, Art Unit 1794
/CIEL P CONTRERAS/Primary Examiner, Art Unit 1794
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