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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 March 30, 2026 has been entered.
Reissue Applications
For reissue applications filed on or after September 16, 2012, all references to 35 U.S.C. 251 and 37 CFR 1.172, 1.175, and 3.73 are to the current provisions. This application, filed April 18, 2023, is a reissue of U.S. Patent 10,982,391 (hereafter the '391 patent), which issued from U.S. application Serial No. 16/305,967 (the ‘967 application) with claims 1-18 on April 20, 2021.
Rejections Overcome
The rejection of claims 19-28 under 35 USC 251 for impermissible recapture has been overcome by Applicant’s amendment of claim 19 to require the following features: a paper sheet precursor; the dialdehyde-modified polyacrylamide copolymer and the polyacrylamide copolymer are in a molar ratio of from about 10:90 to about 90:10, wherein the dialdehyde-modified polyacrylamide copolymer is a cationic dialdehyde-modified polyacrylamide copolymer, and the polyacrylamide copolymer is an amphoteric polyacrylamide copolymer; the polyaluminum salt is dosed at about 0.5 kilograms per ton of dry fibers to about 20 kilograms per ton of dry fiber; and the strengthening agent is dosed at about 3 kilograms per ton of dry fibers to about 30 kilograms per ton of dry fibers.
With respect to the rejections of claim 19 and its dependent claims under 35 USC 103 based on Zhu in view of Ban ‘549, Jehn-Rendu and Krapsch, it is noted that claim 19 has been amended so as to recite the same composition that is ultimately formed in the method of claim 1. Accordingly, as was done during prosecution of the ‘391 patent, the rejection is withdrawn in view of the unexpected results in Figs. 1 and 2 of the ‘391 patent (see col. 16, lines 44-49 and 62-67, Figs. 1 and 2; p. 6 of the Remarks filed 12/07/2020; Reasons for Allowance mailed 01/14/2021; pp. 12-13 of the Remarks filed 03/30/2026).
Non-Compliant Amendment
The amendment filed 03/30/2026 is improper. The amendment does not comply with 37 CFR 1.173 which sets forth the manner of making amendments in reissue applications. While the improper amendment has been entered and considered, a supplemental paper correctly amending the reissue application is required with Applicant’s next response. An amendment filed after final rejection that fails to comply with 37 CFR 1.173 will not be entered.
All amendment changes must be made relative to the patent to be reissued, not relative to a previous submitted amendment. Pursuant to 37 CFR 1.173(d), any such changes which are made to the specification, including the claims, must be shown by employing the following markings:
(1) the matter to be omitted by reissue must be enclosed in brackets, i.e., single brackets; and (2) the matter to be added by reissue must be underlined.
The non-compliance issue is as follows:
In claim 14, the phrase “or wherein the polyaluminum salt and the strengthening agent are delivered individually to the paper sheet precursor” is newly added relative to issued claim 14, and thus, the phrase must be underlined. Also, the status identifier for claim 14 should be “Amended”.
Rejection - 35 USC 251 New Matter
Claims 27 and 31 are rejected under 35 U.S.C. 251 as being based upon new matter added to the patent for which reissue is sought.
The added material which is not supported by the prior patent is as follows:
In each of claims 27 and 31, the requirement that paper sheet precursor has a particle charge density of greater than about 500 µeq/L is new matter. In particular, the use of the approximation term “about” to modify the range is unsupported by the ‘391 patent disclosure.
For support, Applicant points to, in particular, col. 2, lines 25-27 of the ‘391 patent (see p. 7 of the Remarks filed 03/30/2026). However, col. 2, lines 25-27 teaches a particle charge density of “greater than 500 µeq/L”, i.e., not modified by “about”. The use of the “about” approximation opens the disclosed range of “greater than 500 µeq/L” to values equal to and lower than 500 µeq/, but there are no teachings in the ‘391 patent that support such values. In fact, the only particle charge density values disclosed in the ‘391 patent are much greater than 500 µeq/L (see col. 16, lines 39-40; col. 17, line 44-46; Figs. 4 and 5).
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 25 is 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 25 is indefinite because it depends from claim 24, which has been cancelled. To any extent claim 25 was intended to depend from independent claim 1 or claim 19, “the cationic polyacrylamide copolymer” in claim 25 lacks positive antecedent basis in claims 1 and 19, which recite an amphoteric polyacrylamide copolymer. It is suggested that claim 25 be cancelled and presented as a new claim (e.g., claim 32) dependent from claim 30.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 1-3, 5, 7, 9-11, 14, 16, 17, 19, 20, 22, 25, 26, 28 and 29 are rejected under 35 U.S.C. 103 as being unpatentable over JP 62-125096 to Yoshioka et al (hereinafter “Yoshioka”) in combination with WO 2015/038905 A1 to Zhu et al (hereafter “Zhu”). The English translation attached to Yoshioka is hereinafter referred to below. The translation does not have page numbers, but is a total of 18 pages. The translation page numbers are hereinafter referred to as first, second, third, etc.
With respect to claims 1, 2, 11, 17, 19, 20 and 22, Yoshioka teaches a method of improving filler retention in a papermaking process, wherein the method also provides an excellent paper strength-enhancing effect (see the fourth and seventh pages). The method comprises treating raw pulp, i.e., instant paper sheet precursor, with a combination of an amphoteric polyacrylamide copolymer and an aluminum compound such as polyaluminum chloride or polyaluminum hydroxide (see the sixth and seventh pages).
Yoshioka teaches that the aluminum compound is dosed at preferably 0.05 to 1% by weight of the dry weight of the pulp, i.e., dry fibers, in the papermaking raw material (see the second and seventh pages). The 0.05 to 1% by weight is equivalent to 0.5 to 9.1 kg/ton, which overlaps the claimed range. In fact, for example, in Yoshioka’s Example 2, the “PAC”, i.e., polyaluminum chloride, content is 0.1% or 0.12%. i.e., 0.9 kg/ton or 1.8 kg/ton, respectively.
Yoshioka teaches that the amphoteric polyacrylamide copolymer is dosed at preferably 0.1 to 3% by weight of the dry weight of the pulp, i.e., dry fibers, in the papermaking raw material (see the second and sixth pages). The 0.1 to 3% by weight is equivalent to 0.9 to 27.2 kg/ton, which closely overlaps the claimed range of about 3 to about 30 kg/ton. Yoshioka’s Example 2 uses 0.4%, i.e., 3.6 kg/ton, of the amphoteric polyacrylamide copolymer.
Yoshika teaches that the combination of an amphoteric polyacrylamide copolymer and aluminum compound shows a tremendous synergistic effect (see eighth page). Yoshioka teaches that other papermaking additives can be added in the usual manner (see seventh page). Yoshioka’s invention does not in any way preclude the use of other papermaking additives (see seventh page).
Yoshioka differs from the instant claims in not teaching further treating the pulp with a cationic dialdehyde-modified polyacrylamide copolymer.
Zhu teaches a papermaking composition for addition to pulp, wherein the composition includes a strengthening agent comprising a dialdehyde-modified polyacrylamide and a polyacrylamide (see ¶¶ 0008-0009, 0024, 0037 and 0071-0075). The dialdehyde-modified polyacrylamide-type strengthening agent is selected from the group consisting of cationic dialdehyde-modified polyacrylamide-type strengthening agents, anionic dialdehyde-modified polyacrylamide-type strengthening agents and amphoteric dialdehyde-modified polyacrylamide-type strengthening agents (see ¶ 0009). The polyacrylamide strengthening agent is selected from the group consisting of cationic polyacrylamide copolymer strengthening agents, anionic polyacrylamide copolymer strengthening agents and amphoteric polyacrylamide copolymer strengthening agents (see ¶¶ 0009 and 0034).
Zhu teaches that the dosage of the sum of the dialdehyde-modified polyacrylamide-type strengthening agent(s) and the polyacrylamide-type strengthening agent(s) relative to the dry fiber in the pulp slurry is between 0.1 kg/ton dry fiber and 10 kg/ton dry fiber, e.g., between 1 kg/ton dry fiber and 10 kg/ton dry fiber (see ¶¶ 0071 and 0094).
Zhu teaches that the weight ratio between the dialdehyde-modified polyacrylamide and the polyacrylamide can be suitably selected by one skilled in the art according to the strength properties of the desired paper (see ¶ 0044). In particular, Zhu teaches that in order to effectively increase ash retention in the finished paper and/or paper strength, the dialdehyde-modified polyacrylamide-type strengthening agent and amphoteric polyacrylamide strengthening agent can have a ratio of solid contents such as 1:99-99:1, e.g., 10:90-90:10, e.g., 30:70-70:30, e.g., 40:60-60:40, e.g., 50:50 (see ¶ 0044). In fact, Zhu’s Example 2 (¶¶ 00144-00145) uses a 1:1 weight ratio of dialdehyde-modified polyacrylamide copolymer, i.e., GPAM copolymer solution 1, and amphoteric polyacrylamide copolymer 1, which each have a molecular weight of 1.2 million Daltons (see ¶¶ 00116 and 00133-00134). Thus, Zhu’s Example 2 has a molar ratio of 50:50 as per claim 1 and its dependent claims, and claim 22.
Zhu further teaches that the paper-making composition can may contain other chemical aids for paper-making (see ¶ 0046).
Zhu teaches that its composition containing the dialdehyde-modified polyacrylamide and the polyacrylamide provides the advantages of substantially increased ash retention and/or increased strength of the paper (see ¶¶ 0012 and 0067-0068).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have further included a cationic dialdehyde-modified polyacrylamide copolymer in Yoshioka’s pulp treatment that already uses a combination of an amphoteric polyacrylamide copolymer and an aluminum compound because Yoshioka specifically teaches that the treatment does not preclude the use of other paper-making additives, and the use of a combination of a dialdehyde-modified polyacrylamide and a polyacrylamide, e.g., an amphoteric polyacrylamide copolymer, provides the advantages of substantially increased ash retention and/or increased strength of the paper, as taught by Zhu.
Alternatively, Zhu differs from the instant claims in not teaching that its papermaking composition further comprises a polyaluminum salt. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included Yoshioka’s aluminum compound, such as polyaluminum chloride or polyaluminum hydroxide, in Zhu’s paper-making composition because Zhu specifically teaches that other chemical aids can be contained in the composition, and so as to take advantage of the fact that the combination of an amphoteric polyacrylamide copolymer (already present in Zhu’s composition) and an aluminum compound provides for a synergistic effect, improves filler retention and provides for an excellent paper strength-enhancing effect, as taught by Yoshioka. Indeed, Zhu teaches use of fillers (see ¶¶ 0075 and 0083).
With respect to claim 3, Zhu teaches that the dialdehyde-modified polyacrylamide copolymer comprises acrylamide and one or more cationic monomer(s) derived from a monomer selected from diallyldimethylammonium chloride, N-(3-dimethylaminopropyl)methacrylamide, N-(3-dimethylaminopropyl)acrylamide, trimethyl-2-methacroyloxyethylammonium chloride, trimethyl-2-acroyloxyethylammonium chloride, methylacryloxyethyldimethyl benzyl ammounium chloride, acryloxyethyldimethyl benzyl ammounium chloride, (3-acrylamidopropyl)trimethylammonium chloride, (3-methacrylamidopropyl)trimethylammonium chloride, (3-acrylamido-3-methylbutyl)trimethylammonium chloride 2-vinylpyridine, 2-(dimethylamino)ethyl methacrylate, and 2-(dimethylamino)ethyl acrylate (see ¶¶ 0018 and 0024).
With respect to claim 5, Zhu teaches that the dialdehyde of the dialdehyde-modified polyacrylamide copolymer can be glyoxal, malonaldehyde, succinic aldehyde or glutaraldehyde (see ¶ 0023).
With respect to claim 7, Zhu teaches that the amphoteric polyacrylamide polymer comprises acrylamide and a cationic monomer which can be one or more selected from the group consisting of diallyldimethylammonium chloride, N-(3-dimethylaminopropyl)methacrylamide, N-(3-dimethylaminopropyl)acrylamide, trimethyl-2-methacroyloxyethylammonium chloride, trimethyl-2-acroyloxyethylammonium chloride, methylacryloxyethyldimethyl benzyl ammounium chloride, acryloxyethyldimethyl benzyl ammounium chloride, (3-acrylamidopropyl)trimethylammonium chloride, (3-methacrylamidopropyl)trimethylammonium chloride, (3-acrylamido-3-methylbutyl)trimethylammonium chloride 2-vinylpyridine, 2-(dimethylamino)ethyl methacrylate, and 2-(dimethylamino)ethyl acrylate (see ¶¶ 0018, 0034-0035 and 0037).
Likewise, Yoshioka teaches that the amphoteric polyacrylamide polymer contains acrylamide and a cationic monomer such as di- or tri-alkylaminoalkyl acrylates, di- or tri-alkylaminoalkyl methacrylates, di- or tri-alkylaminoalkyl acrylamides, di- or tri-alkylaminoalkyl methacrylamides, etc. (See the fifth page).
With respect to claims 9 and 29, Zhu teaches that the dialdehyde-modified polyacrylamide copolymer has a weight average molecular weight of 100,000-10,000,000 Daltons, i.e., 100 kDa to 10,000 kDa, as here claimed (see ¶ 0029).
With respect to claims 10 and 29, Yoshioka teaches that the amphoteric acrylamide polymer has a molecular weight of preferably 200,000 to 3,000,000, i.e., 200 kDa to 3,000 kDa, as here claimed (see the sixth page). Likewise, Zhu teaches that its polyacrylamide polymer has a weight average molecular weight of 100,000-10,000,000 Daltons, i.e., 100 kDa to 10,000 kDa, as here claimed.
With respect to claims 14 and 16, as noted above, it would have been obvious to have included Yoshioka’s polyaluminum compound in Zhu’s paper-making composition. Thus, the polyaluminum compound, dialdehyde-modified polyacrylamide copolymer and amphoteric polyacrylamide copolymer are combined into a composition prior to being delivered to the pulp, and thus, are delivered simultaneously to the pulp.
Alternatively, Yoshioka teaches that the amphoteric polyacrylamide copolymer and aluminum compound can be added in any order, i.e., individually, or they can be delivered simultaneously (see the last ¶ on the seventh page). Zhu’s paper-making additive is a composition containing dialdehyde-modified polyacrylamide copolymer and amphoteric polyacrylamide copolymer. Thus, it would have been obvious for a skilled artisan to have added Zhu’s paper-making additive composition and Yoshioka’s aluminum compound individually or simultaneously, as per the teachings of Yoshioka. Further, any order of performing process steps is prima facie obvious in the absence of new or unexpected results. See MPEP § 2144.04(IV)(C).
With respect to claim 25, Yoshioka and Zhu do not require the presence of a cationic polyacrylamide copolymer in addition to Yoshioka’s amphoteric polyacrylamide copolymer.
However, Zhu teaches that its paper-making composition can contain plural polyacrylamide-type strengthening agents, and that the polyacrylamide strengthening agent is selected from the group consisting of cationic polyacrylamide copolymer strengthening agents, anionic polyacrylamide copolymer strengthening agents and amphoteric polyacrylamide copolymer strengthening agents (see ¶¶ 0009 and 0034).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included a cationic polyacrylamide copolymer in the paper-making additive composition of Yoshioka and Zhu because Zhu teaches that plural polyacrylamide strengthening agent selected from the group consisting of cationic polyacrylamide copolymer strengthening agents, anionic polyacrylamide copolymer strengthening agents and amphoteric polyacrylamide copolymer strengthening agents can be present in the composition.
Further with respect to claim 25, Zhu teaches that the cationic polyacrylamide copolymer comprises from 0.1-50 mol%, e.g., 1-20 mol% cationic monomer (see ¶0037).
With respect to claim 26, Zhu teaches that the paper-making composition has a pH value of 6.0 or above, e.g., 6.5-13.0, e.g., 7.0-12.0, e.g., 7.5-11.0, e.g., 8.0-10.0 (see ¶ 0048), each of which overlaps and thus, renders obvious the claimed pH range of about 6 to about 9. See MPEP 2144.05.I. In fact, the compositions in Zhu’s Examples 1, 2, 4, 5 and 6 have a respective pH of 6.8, 7.5. 7.8, 8.5 and 8.1, as here claimed (see ¶¶ 00142, 00145, 00149, 00151, and 00153).
With respect to claim 28, Zhu teaches that the paper-making composition can be in the form of a solution or a dispersion, and is added to pulp forming a suspension (see ¶¶ 0066, 0075 and 0078).
Claims 13 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Yoshioka and Zhu as applied to claims 1-3, 5, 7, 9-11, 14, 16, 17, 19, 20, 22, 25, 26, 28 and 29 above, and further in view of WO 97/11029 A2 to Dulko (hereinafter “Dulko”).
Yoshioka and Zhu, as relied upon for the reasons stated above in Rejection No. 3, differ from claims 13 and 21 in that Yoshioka does not specifically teach the aluminum compound, e.g., polyaluminum chloride, has a basicity of from about 40% to 83%.
Dulko teaches that polyaluminum chlorides and polyaluminum chlorosulfates are compounds used as flocculents and coagulants for water and wastewater treatment, and are also used in the production of paper (see p. 1, lines 7-12). Dulko teaches a process for production of polyaluminum chlorides and polyaluminum chlorosulfates (see abstract).
Dulko prepares the polyaluminum chlorides and polyaluminum chlorosulfates with basicities of greater than 70% using, as starting material, basic aluminum chlorides and basic aluminum chlorosulfates of low basicity (25% or less). The polyaluminum chlorides and polyaluminum chlorosulfates produced remain fluid, i.e., they do not coalesce into a gel, and the formation of calcium sulfate precipitates can be avoided. Further, they can be produced without the addition of heat, thus avoiding the formation of undesirable byproducts. As a result, the process is particularly well-suited to large scale industrial applications. (See p. 2, lines 19-26).
In Example 8, Dulko prepares polyaluminum chloride having a basicity of 83% (see p. 20, lines 12-24). In Example 6, Dulko prepares polyaluminum chlorosulfate having a basicity of 50% (see p. 19, lines 20-29).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used Dulko’s polyaluminum salt having a basicity of, e.g., 83% or 50%, as the aluminum compound in the method and composition of Yoshioka and Zhu because Dulko teaches that its polyaluminum salt, i.e., polyaluminum chlorides or polyaluminum chlorosulfates, can be used in the production of paper, and because the polyaluminum chlorides or polyaluminum chlorosulfates can be produced for large scale industrial applications, as taught by Dulko.
Claims 27 and 31 are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Yoshioka and Zhu as applied to claims 1-3, 5, 7, 9-11, 14, 16, 17, 19, 20, 22, 25, 26, 28 and 29 above, and further in view of U.S. Patent Application Publication 2019/0276578 to Heitaniemi et al (hereinafter “Heitaniemi”).
The following teachings in Heitaniemi are supported by Heitaniemi’s foreign priority document filed 12/16/2016, which is present (in English) in Heitaniemi’s U.S. application 16/462,560. Accordingly, Heitaniemi has an effectively filed date of 12/16/2016.
Applicant cannot rely upon their certified copy of the foreign priority application to overcome this rejection because a translation of said application has not been made of record in accordance with 37 CFR 1.55. When an English language translation of a non-English language foreign application is required, the translation must be that of the certified copy (of the foreign application as filed) submitted together with a statement that the translation of the certified copy is accurate. See MPEP §§ 215 and 216. Accordingly, instant claims 27 and 31 have an effective filing date of 05/31/2017, i.e., later than Heitaniemi’s effectively filed date of 12/16/2016.
Yoshioka and Zhu, as relied upon for the reasons stated above in Rejection No. 3, differ from claims 27 and 31 in not specifically teaching that the pulp has a particle charge density greater than about 500 µeq/L.
Heitaniemi teaches that polymers, such as polyacrylamide, are used in paper and board making for improving the drainage during web formation. The challenge in drainage is to combine good initial flocculation with dense floc structure. Problems in flocculation lead to reduced web quality and problems in floc structure reduce water drainage in press dewatering, which increases the drying demand in the succeeding drying steps, which thus may become the limiting part for the paper machine productivity. (See ¶ 0002).
Heitaniemi surprisingly found out that clear improvements in drainage and dewatering are obtained with a polymer composition, which is obtained by polymerizing first and second polymers that are copolymers of (meth)acrylamide (see ¶¶ 0023-0024). In use for paper and board manufacture, the polymer composition is added to an aqueous fiber-containing medium, where the liquid phase of the aqueous medium has a cationic demand >300 μeq/L, sometimes even >500 μeq/L (see ¶ 0056).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included Heitaniemi’s polymer in the pulp of Yoshioka and Zhu so as to improve drainage during web formation and permit treatment of a cationic demand >500 μeq/L, as taught by Heitaniemi.
Claim 30 is rejected under 35 U.S.C. 103 as being unpatentable over Zhu in view of U.S. Patent Application Publication 2012/0103549 to Ban (hereinafter “Ban ‘549”), U.S. Patent Application Publication No. 2012/0073773 to Jehn-Rendu et al (hereafter “Jehn-Rendu”), U.S. Patent Application Publication No. 2014/0284011 to Krapsch et al (hereafter “Krapsch”) and U.S. Patent Publication 2011/0126995 to Turumen et al (hereinafter “Turumen”).
Zhu teaches a papermaking composition for addition to pulp, wherein the composition includes a strengthening agent comprising a dialdehyde-modified polyacrylamide and a polyacrylamide (see ¶¶ 0008-0009, 0024, 0037 and 0071-0075). The dialdehyde-modified polyacrylamide-type strengthening agent can be an anionic dialdehyde-modified polyacrylamide-type strengthening agents (see ¶ 0009). The polyacrylamide strengthening agent can be a cationic polyacrylamide copolymer strengthening agent (see ¶¶ 0009 and 0034).
Zhu teaches that the dosage of the sum of the dialdehyde-modified polyacrylamide-type strengthening agent and the polyacrylamide-type strengthening agent relative to the dry fiber in the pulp slurry is between 0.1 kg/ton dry fiber and 10 kg/ton dry fiber, e.g., between 1 kg/ton dry fiber and 10 kg/ton dry fiber (see ¶¶ 0071 and 0094).
Zhu teaches that the weight ratio between the dialdehyde-modified polyacrylamide and the polyacrylamide can be suitably selected by one skilled in the art according to the strength properties of the desired paper (see ¶ 0044). In particular, Zhu teaches that in order to effectively increase ash retention in the finished paper and/or paper strength, the dialdehyde-modified polyacrylamide-type strengthening agent and amphoteric polyacrylamide strengthening agent can have a ratio of solid contents such as 1:99-99:1, e.g., 10:90-90:10, e.g., 30:70-70:30, e.g., 40:60-60:40, e.g., 50:50 (see ¶ 0044). In fact, Zhu’s Example 2 (¶¶ 00144-00145) uses a 1:1 weight ratio of dialdehyde-modified polyacrylamide copolymer, i.e., GPAM copolymer solution 1, and amphoteric polyacrylamide copolymer 1, which each have a molecular weight of 1.2 million Daltons (see ¶¶ 00116 and 00133-00134).
Zhu further teaches that the paper-making composition can may contain other chemical aids for paper-making (see ¶ 0046).
Zhu differs from claim 30 in not teaching that the papermaking composition further comprises a polyaluminum salt in an amount of about 0.5 kg/ton of dry fibers to about 20 kg/ton of dry fibers.
Ban ‘549 teaches an enhanced additive system for improving wet-end drainage and ash retention in papermaking using ionic crosslinked polymeric microparticles (see ¶ 0006). In particular, a coagulant, organic flocculant, or both, can be added to the pulp, as sequentially, simultaneously, or as a blend with the polymeric microparticles. The coagulant can be a cationic coagulant component, which can be or include a cationic organic polymer coagulant, an inorganic cationic coagulant, or combinations thereof. Cationic organic polymer coagulants can be, for example, a copolymer of vinylamine and acrylamide, i.e., polyacrylamide copolymer. Inorganic cationic coagulants which can be used can be, or include, inorganic cationic chemicals, e.g., aluminum sulfate (alum), polyaluminum chloride (PAC) and polyaluminum sulfate (PAS) (¶ 0042), each of which reads on the claimed polyaluminum salt.
Jehn-Rendu teaches a process for the production of paper, board and cardboard having high dry strength comprising the addition of (a) at least one trivalent cation in the form of a salt, (b) at least one water-soluble cationic polymer and (c) at least one water-soluble amphoteric polymer to the paper stock (see Abstract and claim 1). Examples of trivalent cation salt that may be used are polyaluminum chloride, aluminum sulfate or aluminum lactate (see ¶¶ 0035-0036).
Krapsch teaches that strength polymers (also referred to as strength resins, strength aids, strength additives and the like) are extensively utilized in paper manufacture. It is often distinguished between dry strength polymers and wet strength polymers, though dry strength polymers often impart a certain degree of wet strength to the paper, and vice versa. Today, the most common types of synthetic dry and/or wet strength polymers are based on polyvinylamine or polyacrylamide. (See ¶ 0004).
Krapsch’s paper-making process includes adding a dry and/or wet strength polymer to the cellulosic material (see ¶ 0023). Krapsch further teaches that a retention aid, such as polyaluminum chloride, polyaluminum sulfate, etc., may be used in combination with the dry and/or wet strength polymer (see ¶¶ 0304-0311).
Turumen is directed to papermaking (see ¶ 0001). Turumen exemplifies the use of 7 kg/ton of polyaluminum chloride in a retention system (see ¶ 0064).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included a polyaluminum salt, such as polyaluminum chloride or polyaluminum sulfate, etc., in Zhu’s papermaking composition containing strengthening aids because Zhu teaches that the papermaking composition can contain other chemical aids for paper making, and it is well known in the art to include polyaluminum chloride, polyaluminum sulfate, etc., in such composition so as to take advantage of their known intended functions as coagulants, providing strength, and as retention aids, as taught by Ban ‘549, Jehn-Rendu, Krapsch and Turumen. It further would have been obvious to have included the polyaluminum salt in an amount of, for example, 7 kg/ton, because such is a suitable amount when using polyaluminum chloride as a retention aid, as taught by Turumen.
Response to Arguments
Applicant's arguments filed March 30, 2026 have been fully considered but they are not persuasive.
Arguments with respect to the rejection of claims 1-3, 5, 7, 9-11, 14, 16, 17, 19, 20, 22, 25, 26, 28 and 29 over Yoshioka in combination with Zhu, and the rejection of claims 13 and 21 over Yoshioka and Zhu further in view of Dulko:
Applicant argues that a prima facie case of obviousness has not been established for the rejected claims on the grounds that a person of ordinary skill in the art would not be motivated to modify the teachings of either of Yoshioka or Zhu, or combine the teachings thereof to arrive at independent claims 1 and 19 (Remarks, p. 10). In particular, Applicant argues that the Office has used hindsight analysis and fails to provide an adequate explanation as to why a person of ordinary skill in the art would have been motivated to modify Yoshioka or Zhu; the Office has not identified deficiencies with either the composition of Yoshida or Zhu; and that “each of the Yoshioka and Zhu references already disclose compositions that can be used for enhancing paper properties, and there is no apparent reason to modify the composition of Yoshioka to further include a dialdehyde-modified polyacrylamide taught by Zhu, or to modify the composition of Zhu to further include a polyaluminum salt taught by Yoshioka.” (Remark, pp. 10-11).
Applicant’s arguments are unpersuasive. As noted above, Rejection No. 3 identifies the difference between the instant claims and either Yoshioka or Zhu. In particular, the rejection identifies that Yoshioka differs from the instant claims in not teaching further treating the pulp with a cationic dialdehyde-modified polyacrylamide copolymer, or alternatively, Zhu differs from the instant claims in not teaching that its papermaking composition further comprises a polyaluminum salt.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
The reasons for modification of Yoshioka or Zhu are set forth in the rejection and are based on the specific teachings in Yoshioka and Zhu. In particular, as noted above (bold emphasis added):
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have further included a cationic dialdehyde-modified polyacrylamide copolymer in Yoshioka’s pulp treatment that already uses a combination of an amphoteric polyacrylamide copolymer and an aluminum compound because Yoshioka specifically teaches that the treatment does not preclude the use of other paper-making additives, and the use of a combination of a dialdehyde-modified polyacrylamide and a polyacrylamide, e.g., an amphoteric polyacrylamide copolymer, provides the advantages of substantially increased ash retention and/or increased strength of the paper, as taught by Zhu.
Alternatively, … [i]t would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included Yoshioka’s aluminum compound, such as polyaluminum chloride or polyaluminum hydroxide, in Zhu’s paper-making composition because Zhu specifically teaches that other chemical aids can be contained in the composition, and so as to take advantage of the fact that the combination of an amphoteric polyacrylamide copolymer (already present in Zhu’s composition) and an aluminum compound provides for a synergistic effect, improves filler retention and provides for an excellent paper strength-enhancing effect, as taught by Yoshioka. Indeed, Zhu teaches use of fillers (see ¶¶ 0075 and 0083).
Arguments with respect to the rejection of claim 30 over Zhu in view of Ban ‘549, Jehn-Rendu, Krapsch and Turumen:
Applicant argues that there is no reason to modify Zhu to include a polyaluminum salt and provide a composition including the particular amounts of strengthening agent and polyaluminum salt as here claimed (Remarks, p. 12).
This argument is unpersuasive. As noted in the rejection, Zhu teaches that the dosage of the sum of the dialdehyde-modified polyacrylamide-type strengthening agent and the polyacrylamide-type strengthening agent relative to the dry fiber in the pulp slurry is between 0.1 kg/ton dry fiber and 10 kg/ton dry fiber, e.g., between 1 kg/ton dry fiber and 10 kg/ton dry fiber (see ¶¶ 0071 and 0094).
As further noted in the rejection, there is ample rationale for including a polyaluminum salt in Zhu’s composition in the claimed amount. In particular, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included a polyaluminum salt, such as polyaluminum chloride or polyaluminum sulfate, etc., in Zhu’s papermaking composition containing strengthening aids because Zhu teaches that the papermaking composition can contain other chemical aids for paper making, and it is well known in the art to include polyaluminum chloride, polyaluminum sulfate, etc., in such composition so as to take advantage of their known intended functions as coagulants, providing strength, and as retention aids, as taught by Ban ‘549, Jehn-Rendu, Krapsch and Turumen. It further would have been obvious to have included the polyaluminum salt in an amount of, for example, 7 kg/ton, because such is a suitable amount when using polyaluminum chloride as a retention aid, as taught by Turumen.,
Applicant cites Examples 1-3 of the ‘391 patent for the proposition of unexpected results (Remark, pp. 12-13). However, this is unpersuasive because Examples 1-3 are not commensurate in scope with claim 30. Examples 1-3 of the ‘391 patent use a cationic dialdehyde-modified polyacrylamide copolymer and an amphoteric polyacrylamide copolymer. In contradistinction, claim 30 calls for an anionic dialdehyde-modified polyacrylamide copolymer and a cationic polyacrylamide copolymer.
Duty to Disclose
Applicant is reminded of the continuing obligation under 37 CFR 1.178(b), to timely apprise the Office of any prior or concurrent proceed-ing in which Patent No. 10,982,391 is or was involved. These proceedings would include interferences, reissues, reexaminations, and litigation. Applicant is further reminded of the continuing obligation under 37 CFR 1.56, to timely apprise the Office of any information which is mate-rial to patentability of the claims under consideration in this reissue appli-cation. These obligations rest with each individual associated with the filing and prosecution of this application for reissue. See also MPEP §§ 1404, 1442.01 and 1442.04.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALAN D DIAMOND whose telephone number is (571)272-1338. The examiner can normally be reached Monday through Thursday 5:30 am to 3:00 pm, and Fridays from 5:30 am to 9:30 am.
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Signed:
/ALAN D DIAMOND/Patent Reexamination Specialist
Central Reexamination Unit 3991
Conferee:
/JOSEPH R KOSACK/Patent Reexamination Specialist
Central Reexamination Unit 3991
/Patricia L Engle/SPRS, Art Unit 3991
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