DETAILED ACTION
The communication dated 4/13/2026 has been entered and fully considered. Claims 1, 3, 7, 12, 17, 18, and 20 are amended. Claims 4, 9, 15, 19, 22, and 23 are cancelled. Claim 24-26 are added. Claims 1-3, 5-8, 10-14, 16-18, 20, 21 and 24-26 are pending.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 4/13/2026 has been entered.
Response to Arguments
Applicant argues that prior art, ELLIOT, does not teach the amended limitation of claim 1 directed to “charge density of about 5 meq/g to about 15 meq/g” and prior art teaches away from the higher range.
Applicant’s arguments with respect to claim(s) 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Objections
Claim 11 objected to because of the following informalities: “the papermaking process” is recited but should be “a papermaking process”. Appropriate correction is required.
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.
Claim 16 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.
Claim 16 recites the limitation "the wet end". There is insufficient antecedent basis for this limitation in the claim.
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:
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.
Claims 1, 2, 5-8, 10-14, 16, 17, 20 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over SCHALL (US 7922867 B2) in view of JACKSON (US 20200087859 A1).
For claim 1, SCHALL teaches a process to produce a paper with increased dry strength by adding ligninsulfonic acid to the paper stock [abstract]. This teaches the limitation of “A method of increasing paper strength, comprising: adding a lignin-based compound to a pulp slurry, wherein the lignin-based compound is not a lignosulfonate”. SCHALL teaches the addition of vinylamine as a polymeric cationic component to the paper stock [col 3 line 10]. The vinylamine has a molecular weight of 40,000 Da to 400,000 Da [col 3 line 22]. This range overlaps the instant claim range of “and adding a cationic polymer to the pulp slurry, wherein the cationic polymer has a weight average molecular weight of about 5,000 Da to about 2,000,000 Da”.
SCHALL does not teach the charge density of the cationic vinylamine polymer. JACKSON teaches a similar combination of cationic vinylamine polymer to strengthen paper [0026]. JACKSON teaches the polyvinylamine has a charge density of 0.1-5.5 meq/g [0034]. This range overlaps the instant claim range of “and wherein the cationic polymer has a charge density of about 5 meq/g to about 15 meq/g”. JACKSON teaches the advantage of the polymer composition is an increased drainage and tensile strength [0018]. It would be obvious to one skilled in the arts to substitute the vinylamine of JACKSON for the vinylamine in SCHALL. One would be motivated to modify the art based on the improved drainage and tensile strength as taught by JACKSON.
For claim 2, SCHALL and JACKSON teaches the method of claim 1, as above. SCHALL teaches the ligninsulfonic acid is soluble in water [col 4 line 35] with a pH of 4.5-8 [col 8 line 55], and present at 0.1 to 10% [col 4 line 49]. The pH range and concentration are within the claim range of the instant claim of “wherein the lignin-based compound is soluble in water at a pH of about 4 to about 14 at a concentration of about 1 wt% to about 20 wt% of the lignin-based compound at about 25 °C”.
For claim 5, SCHALL and JACKSON teach the method of claim 1, as above. The ligninsulfonic acid is without pulp before adding to furnish [abstract]. This teaches the limitation of “wherein the lignin-based compound is free of pulp”.
For claim 6, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the addition of vinylamine as a polymeric cationic component to the paper stock [col 3 line 10]. This teaches the limitation of “wherein the cationic polymer comprises monomers selected from the group consisting of: acrylamide, methacrylamide, diallyldimethylammonium chloride (DADMAC), N-vinylamine, 2-dimethylaminoethyl acrylate (DMAEA), N,N,N-trimethylethanaminium chloride, diallylamine, poly(amidoamine), polyethylenimine, and any combination thereof”.
For claim 7, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the addition of polyvinylamine as a polymeric cationic component to the paper stock [col 3 line 49]. This teaches the limitation of “wherein the cationic polymer is polyvinylamine, polyDADMAC, crosslinked epichlorohydrin-dimethylamine (EPI-DMA), poly(amidoamine), or polyethylenimine”.
For claim 8, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the addition of vinylamine as a polymeric cationic component to the paper stock [col 3 line 10]. The vinylamine has a molecular weight of 40,000 Da to 400,000 Da [col 3 line 22]. This range is within the instant claim range of “wherein the cationic polymer has a weight average molecular weight of about 5,000 Da to about 1,000,000 Da”.
For claim 10, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the polymer are added to the paper stock [col 3 line 7]. The examiner understands the paper stock only feeds from the wet end of the papermaking process. This teaches the limitation of “wherein the lignin-based compound and the cationic polymer are added to the pulp slurry in a wet end of a papermaking process”.
For claim 11, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches both of the polymer components are added to the paper stock before sheet formation and drying [col 4 line 44]. The examiner understands this can be anywhere before formation including the pulp stock storage chest, blend chest, machine chest, and headbox. This teaches the limitation of “wherein the lignin-based compound and the cationic polymer are added to the pulp slurry in a whitewater system, pulp stock storage chest, blend chest, machine chest, headbox, saveall chest, or any combination thereof in the papermaking process”.
For claim 12, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the ligninsulfonic acid is present at 0.5 to 2% by weight (equivalent to 10 lb/ton to 40 lb/ton) in the slurry [col 4 line 51]. This range overlaps the claimed range of “wherein the lignin-based compound is added to the pulp slurry in an amount ranging from about 20 lb/ton to about 100 lb/ton”.
For claim 13, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the vinylamine and ligninsulfonic acid are used in a weight ratio of 2:1 to 1:2 [col 4 line 60]. This teaches the vinylamine is present at 0.25 to 4% by weight (equivalent to 5 lb/ton to 80 lb/ton) in the slurry. This range overlaps the claimed range of “wherein the cationic polymer is added to the pulp slurry in an amount ranging from about 1 lb/ton to about 30 lb/ton”.
For claim 14, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the ligninsulfonic acid can be added separately from the vinylamine cationic polymer [col 4 line 45]. This teaches the limitation of “wherein the lignin-based compound is added to the pulp slurry before or after the cationic polymer is added”.
For claim 16, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the vinylamine can be added to the high consistency stock and the ligninsulfonic acid is added to the low consistency stock [col 8 line 61 and 67]. This teaches the limitation of “wherein the lignin-based compound and the cationic polymer are added to the pulp slurry at different locations in the wet end”.
For claim 17, SCHALL teaches a composition of ligninsulfonic acid and vinylamine [col 8 line 2-9]. This teaches the limitation of “A composition, comprising: a lignin-based compound, wherein the lignin-based compound is not a lignosulfonate; and a cationic polymer”. SCHALL teaches the addition of vinylamine as a polymeric cationic component to the paper stock [col 3 line 10]. The vinylamine has a molecular weight of 40,000 Da to 400,000 Da [col 3 line 22]. This range is within the instant claim range of “wherein the cationic polymer has a weight average molecular weight of about 5,000 Da to about 2,000,000 Da”.
SCHALL does not teach the charge density of the cationic vinylamine polymer. JACKSON teaches a similar combination of cationic vinylamine polymer to strengthen paper [0026]. JACKSON teaches the polyvinylamine has a charge density of 0.1-5.5 meq/g [0034]. This range overlaps the instant claim range of “and wherein the cationic polymer has a charge density of about 5 meq/g to about 15 meq/g”. JACKSON teaches the advantage of the polymer composition is an increased drainage and tensile strength [0018]. It would be obvious to one skilled in the arts to substitute the vinylamine of JACKSON for the vinylamine in SCHALL. One would be motivated to modify the art based on the improved drainage and tensile strength as taught by JACKSON.
For claim 20, SCHALL and JACKSON teach the composition of claim 17, as above. SCHALL teaches the addition of vinylamine as a polymeric cationic component to the paper stock [col 3 line 49]. This teaches the limitation of “wherein the cationic polymer is polyvinylamine, polyDADMAC, crosslinked epichlorohydrin- dimethylamine (EPI-DMA), poly(amidoamine), or polyethylenimine”.
For claim 21, SCHALL and JACKSON teach the composition of claim 17, as above. SCHALL teaches the composition is added to pulp but contains no pulp [col 4 line 41-44]. This teaches the limitation of “wherein the composition is free of pulp”.
Claims 24-26 are rejected under 35 U.S.C. 103 as being unpatentable over SCHALL (US 7922867 B2) and JACKSON (US 20200087859 A1) in view of ZHU (US 20190233596 A1).
For claim 24, SCHALL and JACKSON teach the composition of claim 17, as above. SCHALL does not teach the zeta potential value of the lignin based compound. ZHU teaches a similar lignin based sulfonic acid composition [0009]. ZHU further teaches the composition has a zeta potential of -40 mV [Table 7]. This range abuts to the claim range of “wherein the lignin-based compound has a zeta potential of about -40 mV to about -100 mV”. ZHU teaches the advantage of the invention is good ionic strength [0099]. It would be obvious to one skilled in the arts at the time of invention to modify the composition of SCHALL with the lignin of ZHU to produce an easier to use composition. One would be motivated to combine the art based on the increased ionic strength taught by ZHU.
For claim 25, SCHALL and JACKSON teach the composition of claim 17, as above. SCHALL does not teach the zeta potential value of the lignin based compound. ZHU teaches a similar lignin based sulfonic acid composition [0009]. ZHU further teaches the composition has a zeta potential of -40 mV [Table 7]. This range abuts to the claim range of “wherein the lignin-based compound has a zeta potential of about -40 mV to about -100 mV”. ZHU teaches the advantage of the invention is good ionic strength [0099]. It would be obvious to one skilled in the arts at the time of invention to modify the composition of SCHALL with the lignin of ZHU to produce an easier to use composition. One would be motivated to combine the art based on the increased ionic strength taught by ZHU.
For claim 26, SCHALL and JACKSON teach the composition of claim 1, as above. SCHALL does not teach the particle size of the lignin based compound. ZHU teaches a similar lignin based sulfonic acid composition [0009]. ZHU further teaches the composition has a particle size of 349.7 nm [Table 7]. This value is within the claim range of “wherein the lignin-based compound has a particle size of less than about 500 nm”. ZHU teaches the advantage of the invention is good ionic strength [0099]. It would be obvious to one skilled in the arts at the time of invention to modify the composition of SCHALL with the lignin of ZHU to produce an easier to use composition. One would be motivated to combine the art based on the increased ionic strength taught by ZHU.
Claims 3 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over SCHALL (US 7922867 B2) and JACKSON (US 20200087859 A1) in view of KRIGSTIN (US 9850623 B2).
For claim 3, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the lignin composition has a molecular weight of 10,000 to 200,000 g/mol [col 4 line 22]. This range overlaps the instant claim range of “wherein the lignin-based compound has a weight average molecular weight of less than about 100,000 g/mol”. See MPEP 2144.05(I).
SCHALL and JACKSON do not teach the zeta potential of the composition. KRIGSTIN teaches a similar composition of lignin and polymer [column 7 line 9]. The compositions also has a negative zeta potential [column 10 line 12]. KRIGSTIN further teaches that as the negative zeta potential decreased the viscosity decreases as well allowing the composition to flow more freely [column 10 line 25]. This teaches the limitation of “wherein the lignin-based compound has a negative zeta potential”. It would be obvious to one skilled in the arts at the time of invention to modify the composition of SCHALL with the lignin of KRIGSTIN to produce an easier to use composition. One would be motivated to combine the art based on the decreased viscosity and easier flowability taught by KRIGSTIN.
For claim 18, SCHALL and JACKSON teach the method of claim 1, as above. SCHALL teaches the lignin composition has a molecular weight of 10,000 to 200,000 g/mol [col 4 line 22]. This range overlaps the instant claim range of “wherein the lignin-based compound has a weight average molecular weight of less than about 100,000 g/mol”.
SCHALL and JACKSON do not teach the zeta potential of the composition. KRIGSTIN teaches a similar composition of lignin and polymer [column 7 line 9]. The compositions also has a negative zeta potential [column 10 line 12]. KRIGSTIN further teaches that as the negative zeta potential decreased the viscosity decreases as well allowing the composition to flow more freely [column 10 line 25]. This teaches the limitation of “and a negative zeta potential”. It would be obvious to one skilled in the arts at the time of invention to modify the composition of SCHALL with the lignin of KRIGSTIN to produce an easier to use composition. One would be motivated to combine the art based on the decreased viscosity and easier flowability taught by KRIGSTIN.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHEN M RUSSELL whose telephone number is (571)272-6907. The examiner can normally be reached Mon-Fri: 7:30 to 4:30 EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Abbas Rashid can be reached at (571) 270-7457. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/S.M.R./ Examiner, Art Unit 1748
/Abbas Rashid/ Supervisory Patent Examiner, Art Unit 1748
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