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 .
Response to Amendment and Claim Status
The response filed 11 May 2026 has been entered. Claims 1–20 are pending in the application. Claims 4–20 are withdrawn from consideration.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1–3 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (“A high-performance alginate hydrogel binder for the Si/C anode of a Li-ion battery”; art already of record) in view of Kong et al. (“The Effects of Poly(Ethyleneimine) (PEI) Molecular Weight on Reinforcement of Alginate Hydrogels”; art already of record) and as evidenced by Siwick et al. (“Long-Range Proton Transfer in Aqueous Acid–Base Reactions”; art already of record).
Regarding Claims 1 and 2, Liu discloses a hydrogel binder comprising an anionic polyacid (see alginate hydrogel binder, p. 6386 ¶ “Fig. 1a presents…” and Scheme 1) and a solvent (see deionized water, p. 6386 ¶ “Alginic acid, a…”).
Liu does not disclose wherein the hydrogel binder further comprises a cationic polyamine. However, Liu does disclose (p. 6388 ¶ “These improved…”) the importance of strong mechanical properties for binders used in Si/C-based electrodes.
Kong teaches a hydrogel (see alginate hydrogels reinforced with PEI, p. 780 ¶ “To prepare alginate…”) comprising an anionic polyacid (see alginate, p. 780 ¶ “Alginate rich in…”), a cationic polyamine (see PEIs, p. 780 ¶ “To prepare alginate…”), and a solvent (see deionized water, p. 780 ¶ “Alginate rich in…”). Kong teaches that the addition of cationic polyamine to the hydrogel comprising the anionic polyacid can reinforce and stabilize the hydrogel (p. 779 ¶ “We propose that…”), and enhance and maintain its elastic modulus (p. 781 ¶ “In contrast to…”, p. 783 ¶ “The deterioration in…”, Table 1, and Fig. 6).
Liu and Kong are analogous to the claimed invention as they are in the same field of alginate-based hydrogels. It would therefore have been obvious to a person of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the hydrogel binder of Liu such that it further comprises a cationic polyamine, for the purpose of reinforcing and stabilizing the hydrogel, and enhancing and maintaining its elastic modulus.
Regarding the limitation wherein the anionic polyacid and the cationic polyamine are derived from an acid-base reaction between a polyacid and a polyamine, it is first noted this is considered to be a product-by-process limitation, and even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process (In re Thorpe, 227 USPQ 964,966). Once the Examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to Applicant to come forward with evidence establishing an unobvious difference between the claimed product and the prior art product (In re Marosi, 710 F.2d 798, 802, 218 USPQ 289, 292 (Fed. Cir. 1983), MPEP § 2113). In the instant case, as also set forth above, modified Liu discloses an anionic polyacid (see alginate, Kong p. 780 ¶ “Alginate rich in…”; see also Na alginate (SA), Liu p. 6386 ¶ “To mitigate the…” and “Alginic acid, a…”, and Scheme 1) and a cationic polyamine (see PEIs, Kong p. 780 ¶ “To prepare alginate…”; note that Kong p. 783 ¶ “The minor changes…” discloses that the amines are protonated) which one of ordinary skill in the art will understand are necessarily formed by acid-base reaction(s) wherein the polyacid becomes deprotonated and the polyamine becomes protonated. However, modified Liu does not explicitly disclose that the anionic polyacid and the cationic polyamine are derived specifically from an acid-base reaction between the corresponding polyacid and polyamine, i.e. proton transfer from the polyacid directly to the polyamine. However, one of ordinary skill in the art will understand that regardless of whether the anionic polyacid and cationic polyamine of modified Liu is derived from direct proton transfer from one species to another or e.g. solvent-facilitated proton transfer (as is common for solutions formed in protic solvents such as water, as evidenced by Siwick (p. 378 ¶ “Proton-transfer (PT)…”)), the overall products, i.e. the anionic polyacid and cationic polyamine, of the acid-base reaction(s) will be the same.
Liu does not disclose wherein the anionic polyacid and the cationic polyamine are derived from an acid-base reaction between a polyacid and a polyamine at a weight ratio in the range of 10:100 to 40:100 (Claim 1), or more specifically at a weight ratio of 24:100 (Claim 2).
Kong teaches that the ratio of polyacid to polyamine (expressed by Kong as a concentration ratio) affects the elastic moduli of the formed hydrogels (p. 780 ¶ “Alginate rich…” and “To prepare alginate…”, p. 783 ¶ “The minor changes…”, and Table 1). One of ordinary skill in the art will understand that the concentration ratio of Kong could be equivalently expressed as a weight ratio, with the same trends observed.
A result-effective variable is a variable which achieves a recognized result. The determination of the optimum or workable ranges of a result-effective variable is routine experimentation and therefore obvious (MPEP § 2144.05.II). In the instant case, the weight ratio of polyacid and polyamine is a variable that achieves the recognized result of affecting the elastic moduli of the formed hydrogels, as taught by Kong, thus making the weight ratio of polyacid and polyamine a result-effective variable. Therefore, it would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the hydrogel binder of modified Liu such that the weight ratio of polyacid and polyamine is in the range of 10:100 to 40:100, or more narrowly is 24:100, via routine experimentation, for the purpose of achieving a suitable elastic modulus of the hydrogel.
Regarding Claim 3, modified Liu discloses the hydrogel binder of Claim 1. Modified Liu further discloses wherein the polyacid is a salt of alginic acid (see Na alginate (SA), Liu p. 6386 ¶ “To mitigate the…” and “Alginic acid, a…”; see also alginate, Kong p. 780 ¶ “Alginate rich in…”) the polyamine is polyethyleneimine (see PEIs, Kong p. 780 ¶ “To prepare alginate…”; note that Kong p. 779 ¶ “To improve the…” identifies the acronym PEI as poly(ethyleneimine)), and the solvent is an aqueous medium (see deionized water, Liu p. 6386 ¶ “Alginic acid, a…”; see also deionized water, Kong p. 780 ¶ “Alginate rich in…”).
Response to Arguments
Applicant’s arguments in the Remarks filed 11 May 2026 regarding the 35 U.S.C. § 103 rejections in the office action mailed 9 February 2026 have been fully considered but are not persuasive for the following reasons:
Applicant argues on p. 5–6 of Remarks that:
Kong discloses that what is obtained from the method described therein is a “gel network, as the alginate molecules were cross-linked with calcium and PEI was entrapped in the gel network formed from the cross-linking”;
Kong teaches that the molarity of MPEI/Malginate was varied from 0 to 0.8, i.e. MPEI is always less than Malginate, thus a person skilled in the art would understand in view of the teaching of Kong that alginate must be the major component used to form the network that entraps PEI, while PEI serves as an additive to reinforce the alginate network;
Kong further teaches that “the interaction between the two polymers should be low enough to avoid the formation of polyelectrolyte precipitates”; and
thus, a person of ordinary skill in the art prior to the priority date would not have had any motivation, in view of the teaching of Kong, to increase the amount of PEI with respect to the alginate, as doing so is very likely to increase “the interaction between the two polymers”, which is to be avoided according to the teaching of Kong.
This argument is not persuasive. Firstly, while Kong does indeed emphasize that the interaction between the two polymers should be low enough to avoid the formation of polyelectrolyte precipitates (p 779 ¶ “We propose that…”), Kong teaches that there are multiple other factors affecting the strength of this interaction, specifically the level of branching of the PEI (p. 779 ¶ “We propose that…”) and its ionization degree, which one of ordinary skill in the art will understand is controlled by pH (p. 779 ¶ “We propose that…” and p. 780 ¶ “Titration of PEI…”). Further, Kong teaches that some strength of interaction is necessary and favorable in order to reinforce the gel matrices and maintain their stability (p. 779 ¶ “We propose that…”). Thus, Applicant’s assertion that Kong’s teachings would lead a person of ordinary skill in the art to expect that increasing the amount of PEI with respect to alginate would be detrimental by causing increased interactions between the two polymers is not persuasive, as Kong teaches that there are multiple factors contributing to the strength of these interactions beyond just the ratio of amount of PEI to alginate, and also that there are benefits associated with increased interaction strength. Further, while Kong does teach that the gel network is initially formed via cross-linking of alginate with calcium ions followed by entrapment of PEI, and that the molarity of MPEI/Malginate was varied from 0 to 0.8, Kong does not state that lower weight ratios of alginate to PEI such as those claimed would be unsuccessful. Thus taken together, the above teachings of Kong do not constitute a teaching away from the claimed ranges, and a person of ordinary skill in the art, considering the teachings of Kong, would have found it obvious to routinely experiment and come up with a weight ratio of alginate to PEI within the claimed ranges, as set forth in detail in the rejection above.
Applicant argues on p. 6 pf Remarks that Liu similarly teaches that “[a]n alginate hydrogel binder is prepared through the cross-linking effect of Na alginate with Ca2+ ions…”, where the Ca2+ crosslinker is added at only 1 weight% of the total weight of the alginate, and suggests that this disclosure from Liu further teaches away from the present claims which require the polyamine to be the major component and the polyacid to be the minor component.
This argument is not persuasive. The present claims do not require that Ca2+ be absent from the hydrogel binder, nor alternatively that Ca2+ be present in any specific amount. Thus, the amount of Ca2+ present in Liu pointed out by Applicant does not appear to be relevant in the instant case, and does not appear to support a teaching away.
Applicant argues on p. 6 of Remarks that Siwick is not relevant to the formation of hydrogels and does not remedy the deficit of Kong and Liu.
This argument is not persuasive. It is noted that Siwick is utilized in the rejection as an evidentiary reference used to provide evidence, namely that proton transfer between acidic and basic species in solution often occurs with protic solvents such as water (the Examiner notes that such proton transfer reactions between acidic and basic species do appear to be relevant to the formation of hydrogels, which are formed in water and may comprise charged acidic and/or basic species). Because Siwick is an evidentiary reference, it is not necessary that it disclose all the features of the presently claimed invention.
Applicant argues on p. 7 of Remarks that a person of ordinary skill in the art before the priority date would not have adapted the ratios taught by Kong (especially in view of the potential adverse effects on mechanical properties as mentioned above) to arrive at the present weight ratios which are associated with unexpectedly effective dispersion effects, specifically arguing:
Applicant has unexpectedly found that the weight ratio of polyacid to polyamine, as defined in claim 1, allows the formation of a homogeneous hydrogel binder;
Applicant’s hydrogel binder can have a solid structure that allows an effective dispersion of materials, such as active electrode materials, single-wall nanotubes, or conductive additives in the hydrogel binder (see page 2, lines 21 to 24 of the specification as filed), and that none of the prior art documents cited in the office action disclose the addition of active electrode materials, single-wall nanotubes or conductive additives, and therefore provide no motivation to alter the ratio between the polyacid and the polyamine to influence their dispersion;
therefore, a person of ordinary skill in the art before the priority date would not have adapted the ratios taught by Kong (especially in view of the potential adverse effects on mechanical properties as mentioned above) to arrive at the present weight ratios which are associated with the unexpectedly effective dispersion effects.
This argument is not persuasive. Firstly, as set forth in MPEP § 716.01(c).II, arguments presented by the Applicant cannot take the place of evidence in the record. In re Schulze, 346 F.2d 600, 602, 145 USPQ 716, 718 (CCPA 1965) and In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed. Cir. 1984). Examples of statements which are not evidence and which must be supported by an appropriate affidavit or declaration include statements regarding unexpected results, commercial success, solution of a long-felt need, inoperability of the prior art, invention before the date of the reference, and allegations that the author(s) of the prior art derived the disclosed subject matter from the inventor or at least one joint inventor. In the instant case, Applicant is arguing unexpected results but is not supporting this assertion with an appropriate affidavit or declaration. Secondly, as set forth in MPEP § 716.02(b).I, evidence relied upon should establish “that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance.” Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992). Applicant does not appear to have provided any statistical analysis that would establish these results as unexpected and unobvious. Thirdly, as set forth in MPEP § 716.02(d).II, to establish advantageous results over a claimed range, Applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). In the instant case, Applicant asserts that they have unexpectedly found that the weight ratio of polyacid to polyamine, as defined in claim 1, allows the formation of a homogeneous hydrogel binder, the claimed weight ratio range in question being 10:100 to 40:100. However, it is noted that Applicant discloses (P16L17) that 30 mg of polyacid to 250 mg PEI (put into terms comparable to the claimed range, a weight ratio of polyacid to PEI of 12:100; calculated by solving for x in the proportion 30 mg polyacid / 250 mg PEI = x mg polyacid / 100 mg PEI) is optimal to effect gelation, and that too much alginate resulted in a heterogeneous gel, referring to FIG. 2(a)(v). However, Applicant discloses (P15L11) that FIG. 2(a)(v) is a product of 60 mg of polyacid to 250 mg PEI, which corresponds to a weight ratio in terms comparable to the claimed range of 24:100 (calculated in the same manner as above). Thus, Applicant’s assertion in the present arguments that the weight ratio range defined in claim 1 of 10:100 to 40:100 allows for the formation of a homogenous hydrogel seems to be in conflict with the instant specification, which discloses that a weight ratio of 24:100 results in a non-optimal heterogeneous gel. It thus appears that Applicant has not demonstrated criticality of the claimed range, and indeed appears to disclose in the instant specification that a weight ratio within the claimed range is undesirable. Fourthly, Applicant’s argument that none of the prior art documents cited in the office action disclose the addition of active electrode materials, single-wall nanotubes or conductive additives, does not appear to be correct. Liu discloses active electrode materials (see Si–C composite, p. 6387 ¶ “Si/C anodes consisting…”) and conductive additives (see carbon black, ¶ “Si/C anodes consisting…”). Finally, 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. active electrode materials, single-wall nanotubes, or conductive additives in the hydrogel binder) are not recited in the rejected claims. Although 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).
Conclusion
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.
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/J.M.F./Examiner, Art Unit 1725
/BASIA A RIDLEY/Supervisory Patent Examiner, Art Unit 1725
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