DETAILED ACTION
The communication dated 12/23/2025 has been entered and fully considered. Claims 1, 3, 8, 9, and 17 are amended. Claims 4, 19, and 22 are cancelled. Claim 23 is added. Claims 1-3, 5-18, 20, 21 and 23 are pending.
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 Arguments
Applicant argues the amendment of claim 1 limitations “wherein the lignin-based compound is not a lignosulfonate” and “wherein the cationic polymer has a weight average molecular weight of about 5,000 Da to about 2,000,000 Da, and wherein the cationic polymer has a charge density of about 0.1 meq/g to about 15 meq/g” overcome the 102 rejection of claim 1.
Applicant’s arguments, see REMARKS, filed 12/23/2025, with respect to the rejection(s) of claim(s) under 1, 5, 6, 10, 11, 13, 15, 17 and 21 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of ELLIOT.
For claim 1, ELLIOT teaches a method of adding a composition to papermaking furnish [column 9 line 25]. ELLIOT teaches the composition has lignin and polymer [column 10 line 26]. This teaches the limitation of “A method of increasing paper strength, comprising: adding a lignin-based compound to a pulp slurry”. ELLIOT also teaches the modified lignin compound can be oxidized lignin as an alternative to sulfonated lignin and other modified lignins [column 5 line 10]. The Examiner notes the teaching of multiple optional compounds for similar use does not suggest the preference of a particular option over others and the use of a specific selection from the listed options does not negate/suggest the use of other listed alternatives. This teaches the limitation of “wherein the lignin-based compound is not a lignosulfonate”. The composition includes a cationic polymer [column 9 line 1]. This teaches the limitation of “and adding a cationic polymer to the pulp slurry”. ELLIOT teaches the use of dimethyl diallylammonium chloride (DADMAC) as the cationic polymer [column 7 line 3]. ELLIOT also teaches the cationic copolymer has a weight average molecular weight of about 300,000 to above about 1,000,000 [column 7 line 43]. This range overlaps 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”.
ELLIOT does not teach the charge density of the polymer used. SMITH teaches a similar process of using diallyldimethylammounium chloride (DADMAC) cationic polymer [column 4 line 54] and oxidized lignin in solution [column 8 line 14 and column 5 line 31]. SMITH also teaches the solubilized oxidized lignin is advantageous to increasing the strength of the paper [column 10 line 47]. The solution uses a cationic DADMAC polymer with a charge density of less than 5 meq/g [abstract]. This range overlaps the range of the instant claim. This teaches the limitation of “wherein the cationic polymer has a charge density of about 0.1 meq/g to about 15 meq/g”. It would be obvious to one skilled in the arts at the time of the arts to substitute the DADMAC of SMITH in for the DADMAC of ELLIOT to produce a better if not equivalent paper. One would be motivated to combine the art based on the resulting increased strength from the DADMAC charge density as taught by SMITH.
Applicant argues that the combination of ELLIOT and SMITH is improper and prior rejection does not suggest motivation to combine the art.
Applicant's arguments filed 12/23/2025 have been fully considered but they are not persuasive.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, SMITH teaches the same process of using diallyldimethylammounium chloride (DADMAC) cationic polymer [column 4 line 54] and oxidized lignin in solution [column 8 line 14 and column 5 line 31] as ELLIOT. SMITH further the use of teaches the solubilized oxidized lignin is advantageous to increasing the strength of the paper [column 10 line 47]. It would be obvious to one skilled in the arts at the time of the arts to substitute the DADMAC of SMITH in for the DADMAC of ELLIOT to produce a better if not equivalent paper. One would be motivated to combine the art based on the resulting increased strength from the DADMAC charge density as directly taught by SMITH.
The Examiner notes the teaching of multiple optional compounds for similar use does not suggest the preference of a particular option over others and the use of a specific selection from the listed options does not negate/suggest the use of other listed alternative.
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, 5-11, 13, 15, 17, 20 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over ELLIOT (US 5567277) in view of SMITH (US 5338406 A).
For claim 1, ELLIOT teaches a method of adding a composition to papermaking furnish [column 9 line 25]. ELLIOT teaches the composition has lignin and polymer [column 10 line 26]. This teaches the limitation of “A method of increasing paper strength, comprising: adding a lignin-based compound to a pulp slurry”. ELLIOT also teaches the modified lignin compound can be oxidized lignin as an alternative to sulfonated lignin and other modified lignins [column 5 line 10]. The Examiner notes the teaching of multiple optional compounds for similar use does not suggest the preference of a particular option over others and the use of a specific selection from the listed options does not negate/suggest the use of other listed alternatives. This teaches the limitation of “wherein the lignin-based compound is not a lignosulfonate”. The composition includes a cationic polymer [column 9 line 1]. This teaches the limitation of “and adding a cationic polymer to the pulp slurry”. ELLIOT teaches the use of dimethyl diallylammonium chloride (DADMAC) as the cationic polymer [column 7 line 3]. ELLIOT also teaches the cationic copolymer has a weight average molecular weight of about 300,000 to above about 1,000,000 [column 7 line 43]. This range overlaps 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”.
ELLIOT does not teach the charge density of the polymer used. SMITH teaches a similar process of using diallyldimethylammounium chloride (DADMAC) cationic polymer [column 4 line 54] and oxidized lignin in solution [column 8 line 14 and column 5 line 31]. SMITH also teaches the solubilized oxidized lignin is advantageous to increasing the strength of the paper [column 10 line 47]. The solution uses a cationic DADMAC polymer with a charge density of less than 5 meq/g [abstract]. This range overlaps the range of the instant claim. This teaches the limitation of “wherein the cationic polymer has a charge density of about 0.1 meq/g to about 15 meq/g”. It would be obvious to one skilled in the arts at the time of the arts to substitute the DADMAC of SMITH in for the DADMAC of ELLIOT to produce a better if not equivalent paper. One would be motivated to combine the art based on the resulting increased strength from the DADMAC charge density as taught by SMITH.
For claim 2, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches that the lignin composition is water soluble [column 7 line 27]. ELLIOT teaches that the lignin is dissolved in an aqueous cellulosic furnishes at a pH of about 3 to 10 [column 7 line 54]. ELLIOT teaches that the composition of the additive is 10 parts cationic polymer to 1 part modified lignin (equivalent to 9%) [column 5 line 4]. It would be obvious to one skilled in the arts to expect the composition when added at the conditions outlined by ELLIOT to be completely dissolved in the aqueous furnish because ELLIOT teaches that the composition is water soluble. This teaches the limitation 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 ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the use of a purified lignin [column 6 line 6]. This lignin is purified from the kraft process leaving just lignin. This teaches the limitation of “wherein the lignin-based compound is free of pulp”.
For claim 6, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the use of acrylamide in combination with other polymer [column 9 line 56]. 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, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT does not teach the specific polymer of the instant claim. SMITH teaches a similar process of using polymer and lignin in solution [column 8 line 14]. SMITH also teaches the solubilized lignin is advantageous to increasing the strength of the paper [column 10 line 47]. SMITH also pairs the lignin with cationic polythyleneimine (polyethylenimine). This teaches the limitation of “wherein the cationic polymer is crosslinked epichlorohydrin-dimethylamine, poly(amidoamine), or polyethylenimine”. It would be obvious to one skilled in the arts at the time of the arts to try the cationic polymer used to increase the strength of the final paper. One would be motivated to modify the art based on the resulting increased strength taught by SMITH.
For claim 8, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the cationic polymer used has a molecular weight of above about 300,000 to above about 1,000,000 [column 7 line 43]. This range is within the range of the instant claim. This teaches the limitation of “wherein the cationic polymer has a weight average molecular weight of about 50,000 Da to about 1,000,000 Da”.
For claim 9, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT does not teach the charge density of the polymer used. SMITH teaches a similar process of using polymer and lignin in solution [column 8 line 14]. SMITH also teaches the solubilized lignin is advantageous to increasing the strength of the paper [column 10 line 47]. The solution uses a cationic polymer with a charge density of less than 5 meq/g [abstract]. This range overlaps the range of the instant claim. This teaches the limitation of “wherein the cationic polymer has a charge density of about 1 meq/g to about 10 meq/g”. It would be obvious to one skilled in the arts at the time of the arts to modify the structure of the lignin used to maintain a higher charge density to increase the strength of the final paper. One would be motivated to modify the art based on the resulting increased strength taught by SMITH.
For claim 10, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the solution is added to the aqueous cellulose furnish [column 12 line 57]. The examiner understands one skilled in the arts would reasonably understand an aqueous furnish is only exists in the wet end of the paper machine in a 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, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the solution is added to the aqueous cellulose furnish [column 12 line 57]. The examiner understands one skilled in the arts would reasonably understand the stock aqueous furnish synonymous with the pulp stock chest. 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, save-all chest, or any combination thereof in the papermaking process”.
For claim 13, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the cationic polymer is added at a rate of 2 lb/ton [Table 1]. This value is in the range of the instant claim. This teaches the limitation 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 15, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the lignin compound is added after the polymer [column 5 line 25-29]. This teaches the limitation of “wherein the lignin-based compound is added to the pulp slurry after the cationic polymer is added”.
For claim 17, ELLIOT teaches a method of adding a composition to papermaking furnish [column 9 line 25]. ELLIOT teaches the composition has lignin [column 10 line 20] and polymer [column 10 line 1]. ELLIOT also teaches the modified lignin compound can be oxidized lignin as an alternative to sulfonated lignin and other modified lignins [column 5 line 10]. The Examiner notes the teaching of multiple optional compounds for similar use does not suggest the preference of a particular option over others and the use of a specific selection from the listed options does not negate/suggest the use of other listed alternatives. This teaches the limitation of “A composition, comprising: a lignin-based compound; wherein the lignin-based compound is not a lignosulfonate”. The composition includes a cationic polymer [column 9 line 1]. ELLIOT teaches the use of dimethyl diallylammonium chloride (DADMAC) as the cationic polymer [column 7 line 3]. ELLIOT also teaches the cationic copolymer has a weight average molecular weight of about 300,000 to above about 1,000,000 [column 7 line 43]. This range overlaps the instant claim range of “and a cationic polymer wherein the cationic polymer has a weight average molecular weight of about 5,000 Da to about 2,000,000 Da”.
ELLIOT does not teach the charge density of the polymer used. SMITH teaches a similar process of using diallyldimethylammounium chloride (DADMAC) cationic polymer [column 4 line 54] and oxidized lignin in solution [column 8 line 14 and column 5 line 31]. SMITH also teaches the solubilized oxidized lignin is advantageous to increasing the strength of the paper [column 10 line 47]. The solution uses a cationic DADMAC polymer with a charge density of less than 5 meq/g [abstract]. This range overlaps the range of the instant claim. This teaches the limitation of “wherein the cationic polymer has a charge density of about 0.1 meq/g to about 15 meq/g”. It would be obvious to one skilled in the arts at the time of the arts to substitute the DADMAC of SMITH in for the DADMAC of ELLIOT to produce a better if not equivalent paper. One would be motivated to combine the art based on the resulting increased strength from the DADMAC charge density as taught by SMITH.
For claim 20, ELLIOT and SMITH teach the composition of claim 17, as above. ELLIOT does not teach the specific polymer of the instant claim. SMITH teaches a similar process of using polymer and lignin in solution [column 8 line 14]. SMITH also teaches the solubilized lignin is advantageous to increasing the strength of the paper [column 10 line 47]. SMITH also pairs the lignin with cationic polythyleneimine (polyethylenimine). This teaches the limitation of “wherein the cationic polymer is crosslinked epichlorohydrin-dimethylamine, poly(amidoamine), or polyethylenimine”. It would be obvious to one skilled in the arts at the time of the arts to try the cationic polymer used to increase the strength of the final paper. One would be motivated to modify the art based on the resulting increased strength taught by SMITH.
For claim 21, ELLIOT and SMITH teach the composition of claim 17, as above. ELLIOT teaches the use of a purified lignin [column 6 line 6]. This lignin is purified from the kraft process leaving just lignin. This teaches the limitation of “wherein the composition is free of pulp”.
Claims 3 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over ELLIOT (US 5567277) in view of KRIGSTIN (US 9850623 B2).
For claim 3, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the lignin composition has a molecular weight of greater than 50000 g/mol [column 8 line 18]. 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).
ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT does 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 ELLIOT 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, ELLIOT and SMITH teach the composition of claim 17, as above. ELLIOT teaches the lignin composition has a molecular weight of greater than 50,000 g/mol [column 8 line 18]. 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”. ELLIOT does 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 ELLIOT 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.
Claims 12, 14, and 23 are rejected under 35 U.S.C. 103 as being unpatentable over ELLIOT (US 5567277) and SMITH (US 5338406 A) in view of LUO (US 20190309480 A1).
For claim 12, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT teaches the addition of 1 lb/ton and does not teach a higher composition [column 11 line 27]. LUO teaches a similar composition of soluble lignin added to solution [0097]. The lignin is added to the wet end at 18 lbs./ton [0097]. LUO teaches the addition of lignin at this rate does not diminish strength when added before the rest of the solution [0099]. This value is within the range of the instant claim. This teaches the limitation of “wherein the lignin-based compound is added to the pulp slurry in an amount ranging from about 10 lb/ton to about 100 lb/ton”. It would be obvious to one skilled in the arts at the time of invention to try the addition rate of LUO to composition of ELLIOT to increase the strength of the final paper. One would be motivated to increase the rate based on the similar usage and the evident increase in strength as taught by LUO.
For claim 14, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT does not teach the addition of lignin to the composition before the polymer. LUO teaches a similar composition of soluble lignin added to solution [0097]. LUO teaches the addition of lignin is best done in the wet end prior to the addition of other strengthening component [0099]. This teaches the limitation of “ wherein the lignin-based compound is added to the pulp slurry before the cationic polymer is added”. LUO teaches this order of addition results in a stronger final sheet [0099]. It would be obvious to one skilled in the arts at the time of invention to modify the addition point of compositions taught by ELLIOT with that of LUO to increase the strength of the final paper. One would be motivated to increase the rate based on the evident increase in strength as taught by LUO.
For claim 23, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT does not teach the polymer used as polyvinylamine. LUO teaches a similar composition of soluble lignin added to solution [0097]. LUO teaches the use of DADMAC or polyvinylamine polymer as synthetic strength additive [0057 and 0066]. This teaches the limitation of “ wherein the cationic polymer is polyvinylamine”. It would be obvious to one skilled in the arts at the time of invention to modify the polymer composition taught by ELLIOT with that of LUO to increase the strength of the final paper. One would be motivated to increase the rate based on the evident increase in strength as taught by LUO.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over ELLIOT (US 5567277) and SMITH (US 5338406 A) in view of EHRHARDT (US 20170335520 A1).
For claim 16, ELLIOT and SMITH teach the method of claim 1, as above. ELLIOT does not teach the addition of lignin to the composition before the polymer. EHRHARDT teaches a similar composition of lignin and polymer to ELLIOT [0002]. EHRHARDT also teaches the strength additives are added to the pulp in a series of in-line mixers [0051]. The stock is then pumped to a second pump where further chemical additions can be made [0051]. 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”. It would be obvious to one skilled in the arts at the time of invention to try the addition location of EHRHARDT with the composition of ELLIOT to increase the strength of the final paper. One would be motivated to increase the rate based on the similar usage and the evident increase in strength as taught by EHRHARDT.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
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