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 .
This action is responsive to Applicant’s response to election/restriction filed 05/12/2026.
Claims 1-17 and 20-22 are currently pending.
The IDS statements filed 10/04/2023, 12/10/2024, and 11/19/2025 have been considered. Initialed copies accompany this action.
It is noted that, for many of the foreign patent references (FOR Cite No. 1, 2, & 6-11 cited on the IDS filed 10/04/2023), Applicant has merely provided translations of the abstracts of the foreign patent references (i.e., incomplete translations of the references and no original copies of the references). Only the submitted abstracts of these references have been considered.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-15, in the reply filed on 05/12/2026 is acknowledged.
Claims 16, 17, and 20-22 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 also provisionally elected a species for examination of “a foam stabilizing composition comprising a) colloidal silica having a particle size of 1 nm to 100 nm and b) a siloxane cationic surfactant having general formula (b-I)” with traverse on the ground(s) that the office action does not clearly identify the disclosed species to which claims are to be restricted. However, a species election requirement was not made in the requirement for restriction/election mailed 04/23/2026 rendering Applicant’s traverse (and election) of a species election moot.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-15 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
In claim 1, the recitation of “1≤y’3;” in defining the structure/variables of the recited formulae renders the claim indefinite. While neither is truly recited, it is unclear whether the relationship is three times y’ (i.e., 3y’) is greater than or equal to one or y’ is greater than or equal to one and less than or equal to 3. While the Examiner personally believes Applicant meant to recite “1≤y’≤3;” (like the relationship for the y variable in the line immediately preceding the y’ relationship) the claim is nevertheless indefinite due to the unclear recitation.
Claims 2-15 are also indefinite for their dependency on claim 1.
For purposes of further examination (or else the siloxane cationic surfactant of general formula (b-II) could not be fairly compared to prior art), the claim is interpreted as if it recited “1≤y’≤3;” instead of “1≤y’3;”. The Office notes this interpretation is supported by [0049] of the original specification that “superscript y’ may be as described above for superscript y” and the most broad definition for superscript y is “1≤y≤3” described earlier/above in [0013].
Appropriate correction/clarification is required.
Claim Interpretation
In claim 1, the limitation “where the colloidal silica is present in a weight ratio of 1:10-4 to 1:1 with respect to the siloxane cationic surfactant and, when present, the organic cationic surfactant” is interpreted as there is 1 part colloidal silica (relatively fixed) per 10-4 to 1 parts (variable) cationic surfactant(s) (required b) plus optional c) in the composition.
In claim 5, the claim recites/limits structure of the siloxane cationic surfactant b) of “where in the siloxane cationic surfactant b): (i) subscript a is 1; (ii) superscript y is 1; (iii) R is H; or (iv) any combination of (i)-(iii)”. It is noted both siloxane cationic surfactant b) species/formulae (b-I) and (b-II) include/require an “a”, “y”, and “R” and one or both of siloxane cationic surfactant of formula (b-I) and siloxane cationic surfactant of formula (b-II) are required. Accordingly, the claim is interpreted as clearly and definitely meaning the siloxane cationic surfactant b) (of formulae (b-I) and/or (b-II), whichever are present) includes at least one of or a combination of structure(s) (i), (ii), or (iii).
Allowable Subject Matter
While claims 1-15 are subject to a 112(b) rejection (Id.), claims 1-15 are allowable over the prior art. The closest prior art of record fail to teach or suggest a foam stabilizing composition (or a firefighting foam or method of extinguishing a fire thereof) comprising a blend of nanosized colloidal silica with a siloxane cationic surfactant of formulae (b-I) and/or (b-II) as instantly claimed.
Liu et al. (WO 2020/142380 A1) teach a branched organosilicon compound useful as a surfactant, a surface treating agent, and/or an aqueous film-forming foam ingredient (abstract, para. 0092, and claim 19). The compound has the general formula
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where at least one R1 is -OSi(R4)3, X is a divalent linking group, R2 is a hydrocarbyl group, Z is O or N, and R7 is H or a hydrocarbyl group (para. 0019). While the ISR cited as an X reference, the Office disagrees with the characterization Liu et al. is an X reference reading on any of the claims whether alone or in combination with other references. Liu et al. fail to teach or suggest their compound has a quaternary ammonium group required by the claim (-D-NR13+, the claimed Y group). Liu et al.’s compound is not cationic and is merely nonionic with no teaching or suggestion to protonate/quaternize any of the nitrogen atoms necessary to approach/arrive at the claimed cationic charge. In embodiments separate from the compound’s sein foam compositions, Liu et al. further teach the compound may be used to treat metal oxide particles surfaces such as silica (para. 00145-00146) but fails to teach or suggest a foam or foam stabilizing composition further comprising colloidal silica, as claimed.
Liu et al. (WO 2021/138147 A1) teach a cationic surfactant foam stabilizing composition comprising a siloxane cationic surfactant (A) equivalent to the claimed (b-I) and an organic cationic surfactant (B) equivalent to the claimed optional c) (abstract). While the siloxane surfactants are similar, if not the same, Liu et al. fail to teach or suggest further provision of nanosized colloidal silica at the prescribed weight ratio with respect to the cationic surfactant(s), let alone merely colloidal silica, as claimed.
The ISR and EP both cite Fink et al. (US 3,655,554 A), Wang et al. (CN 111514510 A), and GB 1,175,760 A as Y references to allegedly meet claims 1-15 that provision of the claimed siloxane cationic surfactant with a colloidal silica is merely an arbitrary choice that a skilled person would arrive at. However, the Office disagrees with this characterization because the references, whether alone or in combination, do not arrive at, or even remotely approach, the claimed foam stabilizing composition requiring particular siloxane cationic surfactant(s) combined with colloidal silica.
Fink et al. (US 3,655,554 A) teach foam forming liquids for use as a fire extinguishing agent comprising surface active substances that are enhanced by incorporating 1-10 wt.% of finely dispersed silica such as colloidal (colloidally dissolved) silica (abstract, Table 3, etc.). Exemplary surface active substances, i.e., surfactants, for provision with the silica include anionic silicone sulfonate surfactants with a cationic amine counter anion (compound A in Table 1), a nonionic polysiloxane (compound B in Table 1), protein foam concentrate, sodium lauryl sulfate, and sodium lauryl ether sulfate (Table 1 & examples thereof w/ the silica in Table 3). However, none of the surfactants correspond to or are even similarly close to the claimed siloxane cationic surfactants (b-I) or (b-II).
Wang et al. (CN 111514510 A) teach a method of preparing a foam extinguishing agent comprising, inter alia, addition of anionic surfactant, water-soluble cationic polymer with a hydrophilic group, and nano silicon dioxide (abstract). While Wang et al.’s composition broadly comprises nano-sized silicon dioxide one might regard as colloidal silica, Wang et al. never discloses the structure/identity of the water-soluble cationic polymer and fails to teach or suggest a siloxane cationic surfactant of formulae (b-I) or (b-II) as claimed.
GB 1,175,760 A teaches aqueous foam composition comprising 2-60 wt.% of colloidal silica and a nitrogen onium compound or amine containing 1 or 2 alkyl chains of at least 8 carbon atoms (p.1 lines 11-25, p.2, claims, etc.). While the reference’s composition broadly comprises colloidal silica, the reference’s onium/amine compound co-additive is not disclosed or suggested to contain a siloxane moiety and thus fails to teach, suggest, or even begin to approach a siloxane cationic surfactant of formulae (b-I) or (b-II) as claimed.
Gozenbach et al. ("Ultrastable particle-stabilized foams", Angew. Chem. Int. Ed. 2006, 45, 3526-3530) teach the use of colloidal particles such as alumina, silica, zirconia, and calcium phosphate to stabilize foams by surface modifying/lyphobizing the colloidal particles with short amphiphiles (typically <8 carbon atoms) (p.3526-3527) However, Gozenbach et al. fail to teach or suggest the presence of a siloxane cationic surfactant of formulae (b-I) or (b-II), let alone any siloxane cationic surfactant, as claimed.
Shishatskiy et al. (“Quaternary ammonium membrane materials for CO2 separation”, Journal of Membrane Science, 2010, 359, 44-53), teaches a siloxane compound for use as a membrane in separating CO2 from other gases (i.e., a different field of endeavor than the claimed foam-related compositions) having the following structure:
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Such a compound reads on the siloxane of general formula (I) wherein R1 is a hydrocarbyl group with 1 carbon atom, a is 1, R is H, y is 1, X is Cl, and n is 1. However, Shishatskiy et al. does not teach the siloxane in a composition with colloidal silica, and there is no teaching or suggestion to modify the material of Shishatskiy et al. to further include the claimed siloxane together with colloidal silica.
The remaining references listed on Forms 892, 1449, and PCT 210 have been reviewed by the examiner and are considered to be cumulative to or less material than the prior art references relied upon or described above.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MATTHEW R DIAZ whose telephone number is 571-270-0324. The examiner can normally be reached Monday-Friday 9:00a-5:00p EST.
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/MATTHEW R DIAZ/Primary Examiner, Art Unit 1761
/M.R.D./
June 8, 2026
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