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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Drawings
The drawings filed 06 September 2023 are accepted by the examiner.
Information Disclosure Statement
Three information disclosure statements have been submitted: two on 12 January 2024 and one on 25 July 2025. The two submitted 12 January 2024 appear to be duplicates of each other, with one presented as a proper IDS and the other presented as a text-based document. All of the references have been considered, but the text-based duplicate is marked as “not considered” solely because it is a duplicate.
Claim Interpretation
Claim 1 recites the preamble, “A conductive and swellable backfill material for earthing applications”. The recitation of “for earthing applications” is considered an intended use, as it does not impart any meaningful structural differences over a comparable composition directed towards a different application (see MPEP 2111.02(II)). Furthermore, the recitation of “backfill material” does not impart a meaningful distinction over comparable compositions. “Backfill material” refers to material used to fill in holes in the ground, but the claimed invention is a conductive cement with embedded polymer, which is not necessarily limited to use in backfill applications. The examiner will consider any prior art reciting a conductive and swellable material to be capable of being used as a “backfill material for earthing applications”.
If Applicants disagree with this interpretation, they are respectfully requested to clarify how their claimed invention’s intended use imparts a structural difference over a comparable composition in their response.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
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.
Claims 1, 2, 4, 6, and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Sirola et al. (US 2007/0187854 A1, hereinafter “Sirola”) and Lu et al. (CN 107140885 A, hereinafter “Lu”).
Regarding claim 1, Sirola teaches a conductive backfill material for earthing applications (see generally abstract; the invention is drawn to a deep-well grounding system, which means it meets the intended use of “earthing applications”; the “swellable” limitation will be discussed more below), comprising a conductive material selected from the group of graphite, coke powder, and a combination thereof (see paragraph 0005 teaching graphite and coke as conductive forms of carbon; see paragraph 0058 specifically teaching the use of coke breeze [“breeze” is defined in paragraph 0005 as small cinders or spherical particles]), and a binder comprising cement (see paragraph 0059 teaching the use of cement as a binder).
Sirola fails to teach the limitations wherein the material comprises polyacrylamide powder, and hence it lacks the “swellable” property recited in the preamble. Sirola further fails to teach the optional inclusion of magnesium sulfate, sodium sulfate, or a combination thereof.
Lu teaches a conductive and swellable material (by virtue of containing conductive and swellable components; see paragraph 0008) which is suitable for earthing applications (see the above Claim Interpretation section). Lu teaches the use of coal powder as a filler, but coal (amorphous carbon) is generally not considered conductive. Instead, the conductive component of Lu’s composition is a metal powder (see paragraph 0008). Lu further teaches the inclusion of polyacrylamide powder and a cement binder (see paragraph 0025). Lu fails to explicitly teach the optional inclusion of MgSO4 or Na2SO4, but as these components are claimed to be optional, they are not required to render the claim obvious.
Although Lu fails to explicitly teach the claimed intended use (see Lu, paragraph 0008 referring to the disclosed composition as a coating formula; also see the above Claim Interpretation section), Lu’s composition is suitable for such an intended purpose based on its similarity to the composition of Sirola, which is explicitly recited as being used as backfill material for earthing applications (see Sirola, abstract; also see MPEP 2144.07 regarding art-recognized suitability for an intended purpose). Furthermore, because Sirola and Lu both teach a conductive, cement-based composition for grounding (see Sirola, abstract; see Lu, paragraph 0004) which can both be applied as backfill material (as described above, in view of MPEP 2144.07), the two are art-recognized equivalents for the same purpose. MPEP 2144.06(I) states that it is prima facie obvious to combine two compositions, each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose. In the instant case, a person of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to combine the disclosures of Sirola and Lu by modifying Sirola’s composition to use polyacrylamide powder as taught by Lu, because polyacrylamide is well-known in the art to be highly water-absorbent and swellable, and because Sirola teaches that other components can be included in the composition to reduce the permeability of the cement to the desired level (see paragraph 0036; a swellable constituent would reduce porosity and thus permeability). This modification arrives at the claimed invention, thus rendering claim 1 obvious.
Regarding claim 2, Sirola, as modified by Lu, teaches the backfill material of claim 1, and further teaches the limitation wherein the polyacrylamide powder comprises an anionic polyacrylamide powder (see Lu, paragraph 0008 teaching the polyacrylamide powder as an anionic polyacrylamide dry powder).
Regarding claim 4, Sirola, as modified by Lu, further teaches the limitation wherein the binder comprises a cement selected from inter alia Ordinary Portland Cement (see Sirola, paragraph 0036 teaching the use of Type 10 cement; Ordinary Portland Cement [OPC] is a broad descriptor that includes commonly used Type I cement [classified according to ASTM standards] and the Canadian equivalent Type 10 cement [classified according to CSA standards]). Since Type 10 cement is considered a general-purpose type of OPC, claim 4 is rendered obvious.
Regarding claims 6 and 7, Sirola, as modified by Lu, further teaches the limitations wherein the backfill material further comprises fly ash (see Sirola, paragraph 0038 teaching the inclusion of fly ash), and wherein the dry backfill material comprises 10 wt.% or less of fly ash (see Sirola, claim 6 teaching fly ash as comprising 10–40 wt.% of the composition; also see MPEP 2144.05(I), paragraph 1 regarding the prima facie obviousness of two ranges with overlapping endpoints).
Allowable Subject Matter
Claims 3, 5, and 8–10 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Claim 3 limits the polyacrylamide powder to having at least one of the three recited properties. Lu fails to teach any properties of the polyacrylamide powder, and the claimed properties do not describe a general polyacrylamide powder. Technical data sheets for polyacrylamide powder from online retailers indicate that particle size is widely variable, bulk densities are generally lower than what is claimed, and gelling index is concentration-dependent. Because Lu fails to teach any specific properties of the polyacrylamide powder, and because the claimed properties don’t represent any sort of intrinsic standard form of polyacrylamide powder, a person of ordinary skill in the art would not find it obvious to utilize polyacrylamide powder with the claimed properties, and as a result, claim 3 is allowable over the prior art.
Claim 5 limits the amounts of each component in the claimed composition. Both Sirola and Lu teach a composition which uses a minimum of 20 wt.% cement (see Sirola, paragraph 0049; see Lu, paragraph 0008), which far exceeds the claimed range of 5 to 6 wt.%. Furthermore, Sirola explicitly teaches away from using less than 20 wt.% cement, stating that if less than about 20 wt.% cement it used, the resulting composition has unacceptable strength as an anode sheathing material (see Sirola, paragraph 0049). Therefore, claim 5 is allowable over the prior art.
Claims 8–10 each recite properties of the resulting composition, namely water absorption, electrical resistivity, and pH. Sirola teaches a water absorption of 20% after 4 hours (see paragraph 0062 and Table 3), but measured using a sample that was cured for longer than applicants’ samples, so the data is not extrapolatable out to 24 hours to compare to the claimed value. Sirola teaches resistance measurements, but for samples that have far more cement than what is claimed (see Table 2; the closest composition to the claimed composition, with 30 wt.% cement, has a resistance of 5 Ω, which works out to be a resistivity of 0.51 Ω·m, far above the claimed resistivity of 0.12 Ω·m or less). Finally, neither Sirola nor Lu teach pH for the backfill material. Claims 8–10 could be rendered obvious as intrinsic properties of any substantially similar composition, but as described above, neither Sirola nor Lu teaches compositional amounts that could render these claims obvious. While both references teach the claimed components of the backfill material, the proportions are what give rise to the claimed properties, and so if claim 5 cannot be rendered obvious, then claims 8–10 also cannot.
The Examiner believes Sirola and Lu to be the most pertinent prior art. Conductive cement compositions are known, but incorporation of polyacrylamide to grant swellability is not widely reported. Use of conductive carbon is also not widely reported, with conductive metals or salts being much more common. As such, the claimed invention appears to contain patent-eligible subject matter.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Muraki et al. (JP H06163134 A) teaches a conductive backfill material, wherein the conductive material is selected from graphite or coke, and which can optionally include a polyacrylamide-based thickener (which is not explicitly stated to be an anionic powder). The binder is described as gypsum, which is a component of OPC, but is not a cement on its own. The composition further includes sodium sulfate, and may optionally include fly ash. However, despite the similar components, the compositional amounts differ greatly from what is claimed, particularly the use of 90 wt.% gypsum, which far exceeds what is claimed. While Muraki is currently not relied upon for the above rejection, if Applicants were to amend claim 1 to require the inclusion of MgSO4 or Na2SO4 (currently recited as optional), Muraki would be cited in new grounds of rejection.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Ryan P Loughran whose telephone number is (571)272-2173. The examiner can normally be reached M, T, Th, F 6:30-4:30.
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/R.P.L./Examiner, Art Unit 1731
/ANTHONY J GREEN/Primary Examiner, Art Unit 1731