Method for preparing aldehyde-functionalized polymers

Abstract

Providing a method for producing GPAM. A method for making an aldehyde-functionalized polymer, such as a GPAM, is provided in which the progress of the aldehyde-functionalized polymer formation is monitored by measuring the viscosity using an online viscometer. A method for enhancing paper strength is also provided, which includes making an aldehyde-functionalized polymer, such as a GPAM according to the present disclosure, and combining the aldehyde-functionalized polymer with a fiber slurry or coating it onto a flat sheet.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Patent Application No. 63 / 271,079, filed October 22, 2021, the contents of which are incorporated herein by reference in their entirety.

[0002] FIELD OF THEINVENTION The present invention relates to a method for making aldehyde-functionalized polymers for papermaking, and more specifically to a method using process control that includes viscosity measurements. [Background technology]

[0003] Glyoxalated polyacrylamide (GPAM) is a common strength aid used in the paper industry. GPAM may contain a polyacrylamide backbone modified to contain charged monomers, often cationic. This modified polyacrylamide backbone reacts with glyoxal, a crosslinking agent used to build branching and increase molecular weight. The resulting GPAM is used in the papermaking process, typically by wet-end addition or spraying onto formed flats, to increase interfiber bonding and enhance strength. GPAM can also increase paper machine efficiency through enhanced press dewatering.

[0004] Crosslinking is typically carried out until the desired molecular weight of the GPAM is reached. The molecular weight must be high enough to promote fiber / fiber bonding, but not so high as to cause excessive aggregation and poor plate formation, which can reduce strength. The reaction end point is often determined by either turbidity or viscosity.

[0005] Viscosity measurements have been used to measure reaction progress during the preparation of GPAM materials. To avoid runoff, end-point viscosity measurements are made periodically during the reaction on aliquots removed from the reaction mixture (commonly referred to as "spot checks" or "grab-and-run methods"). In other examples, viscosity measurements are made in real time in continuous reactions using an in-line viscometer, such as a spindle viscometer (i.e., a viscometer with a spindle fixture), in which a spindle is placed directly into the reaction mixture and viscosity measurements are made frequently or essentially continuously. See, for example, U.S. Patent Publication No. 2005 / 0161181. See also U.S. Patent No. 8,920,606.

[0006] In-line viscometers, which have a spindle or other probe through which fluid must flow to obtain viscosity measurements, tend to become clogged with too viscous fluids, such as gels. For example, U.S. Pat. No. 7,875,676 describes a method for preparing a cellulose-reactive polyvinylamide adduct, in which an aqueous reaction mixture of a vinylamide polymer and a cellulose-reactive agent is reacted continuously while measuring the viscosity during the reaction. When the viscosity reaches a target level (e.g., 30 cP or less at a temperature of 25° C.), the reaction is stopped. Such a method for measuring the viscosity of the adduct is problematic in that if the moment to stop the reaction is overlooked, the viscosity may increase excessively and a water-insoluble gel may form, which may significantly impede further viscosity readings. This is because the gelation of the GPAM product tends to jam the viscometer probe or spindle.

[0007] Due to the challenge of monitoring the formation of GPAM and other aldehyde-functionalized polymers (AFPs) by measuring the change in viscosity, turbidity measurements are frequently used as an alternative method. For example, US Patent No. 8,920.606 describes a method for preparing cellulose reactive polyvinylamide adducts. The adduct formation disclosed showed only a very moderate increase in viscosity, a slight decrease in viscosity, or no increase at all. In the method disclosed therein, it was observed that the turbidity of the reaction solution increased as the glyoxalation of the vinylamide polymer proceeded. Thus, the adduct formation process can be monitored using a turbidimeter or viscometer.

[0008] The '606 patent further discloses that turbidity measurements can be useful to monitor adduct formation if the reaction occurs below a critical concentration. Turbidity can be measured using a conventional turbidimeter, such as a SURFACE SCATTER 7SC turbidimeter, which is a continuous monitoring instrument designed to measure turbidity in fluids. The instrument design is based on the nephelometric principle of measuring light scattered by particles suspended in a fluid to determine the relative amount of particulate matter in the fluid. Viscosity can typically be measured during the reaction using a UL adapter for a BROOKFIELD LV series viscometer (spindle viscometer). One difference between the adducts disclosed in the '606 patent and the GPAM polymer products of the present invention (exemplary embodiments) is that the change in viscosity of the adducts disclosed in the '606 patent is much less than the change in viscosity of the GPAM products of the present invention (including a viscosity increase of more than 100%). A significant challenge with using conventional viscometers (such as spindle viscometers) to monitor the preparation of aldehyde-functionalized polymers (such as GPAM) is that these polymers tend to continue crosslinking, resulting in the formation of gelled products, and the accumulation of gelled products tends to clog the viscometer. Thus, monitoring with a spindle viscometer is ineffective. As a result, the preparation of aldehyde-functionalized polymers (such as GPAM) is typically monitored by assessing changes in turbidity. The main problem with using turbidity to monitor the progress of the reaction is that turbidity measurements are unreliable as they vary from batch to batch.

[0009] There is a long-felt need for a method of preparing GPAM using a suitably configured viscometer that can continuously monitor the reaction viscosity without malfunctioning if gelation of the reaction mixture occurs. Additionally, there is a long-felt need to provide a feedback loop that includes continuous viscosity measurement to allow reliable reaction control, such as automatic quenching of the reaction mixture upon reaching a target viscosity level for the preparation of the GPAM. This is a particularly important need when the increase in viscosity during the preparation of the GPAM occurs very rapidly, thereby missing the opportunity to monitor the progress of the reaction by grab samples or spot checks.

[0010] For the preparation of GPAM, quenching of the crosslinking reaction presents a unique challenge; the glyoxal-mediated crosslinking reaction is driven by a basic pH and is usually quenched by lowering the pH to below about pH 3, typically by adding a strong acid such as sulfuric acid to the reaction mixture. The use of such strong acids can pose various safety risks, especially when used at a manufacturing scale. Thus, there is a need for milder acid quenching agents that can effectively quench the reaction to form the GPAM product while still providing a useful shelf life for the product.

[0011] Despite the quench process used to produce GPAM, latent crosslinking can still occur, and over time, the polymer solution will gel and become unusable. This results in a short shelf life for the product (15-45 days at room temperature). Heat increases the crosslinking reaction, further shortening the shelf life in warm climates. To extend shelf life, the polymer solids content of the GPAM solution is often kept very low (less than 10%). Thus, there are significant issues with GPAM produced away from the chemical plant site, as the low solids content requires large quantities of product to meet paper manufacturer demands. The short shelf life also increases the complexity of chemical logistics and storage at customer sites. Safety is also a concern due to the large amount of chemicals that plant workers must handle. There are also issues from a sustainability standpoint in that the product being shipped is largely water (>90% by weight). There is a need for a process to make GPAM that eliminates or significantly reduces these shelf life issues.

[0012] Another challenge is when viscosity changes occur rapidly at the end of the reaction without significantly changing the clarity of the reaction solution. Turbidity measurements require a significant difference in the clarity of the solutions being monitored. Thus, turbidity is not effective for monitoring product formation when there is little, if any, change in the clarity of the polymer product. One feature of the methods for preparing GPAM described herein is that the clarity of the resulting GPAM polymer product does not change significantly or significantly. As a result, turbidity is not useful for assessing the end point of the reactions described herein.

[0013] However, as mentioned above, conventional viscometers are not useful because they are susceptible to fouling and clogging due to gelation of the GPAM product. Furthermore, in-line viscometers that require spot checks are not effective because the reaction is completed so quickly that the end point is easily missed. In fact, the increase in viscosity at the end of the method of the present invention is so large (approximately 100-500%) that spot check monitoring is not effective because the end point is easily missed. Without wishing to be bound by any particular theory, it is believed that the commercially available GPAM prepared by conventional manufacturing methods is more suitable for transportation and has a longer shelf life, while the GPAM of the present invention is more suitable for on-site preparation and use.

[0014] In some embodiments, the reaction is quenched by adjusting the pH of the reaction solution to a value in the range of about 2 to about 4, about 3 to about 4, about 3.5 to about 4. In some embodiments, the methods described herein include quenching the crosslinking reaction at a higher pH (about 4 to 6) than is typically used when preparing conventional commercially available GPAM. For example, the reaction is quenched by adjusting the pH of the reaction solution to a value in the range of about 4.2 to about 6, about 4.4 to about 6, about 4.6 to about 6, about 4.8 to about 6, about 5 to about 6, about 5.5 to about 6. In some embodiments, the shelf life of GPAM prepared according to the methods disclosed herein is shorter than conventional commercially available GPAM prepared off-site and therefore is not suitable for long distance transportation (which typically occurs in the preparation of most commercially available GPAM).

[0015] This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. It is not necessarily intended, nor should it be construed, that any of the preceding information constitutes prior art against the present invention. Moreover, the preceding information should not be construed as implying that a search has been conducted or that other relevant information as specified in 37 CFR § 1.56(a) does not exist. Summary of the Invention

[0016] The present disclosure provides methods of making and using GPAM. Unlike the bireactive species, the monoreactive species (e.g., the species with a free aldehyde) is believed to be responsible for increasing paper strength because the monoreactive species can form covalent bonds with cellulose fibers.

[0017] To achieve the appropriate level of crosslinking that maximizes the one-reacting amide, higher levels of glyoxal are used relative to the level of acrylamide (G / A). The same is true when other aldehydes besides glyoxal are used in the crosslinking reaction. These reactions are typically performed at alkaline pH (e.g., pH above 7, pH above 8, pH about 8-9.5) and when an acrylamide copolymer with a weight average molecular weight of less than 30,000 Daltons is used, the viscosity increases by 300-400% relative to the starting viscosity with little turbidity or gelation. Unfortunately, the end point of this viscosity increase is difficult to predict, posing a risk during production that the product is quenched prior to gelation. This obstacle has prevented the in situ production of GPAMs of the MW described herein to date. There has been a long-standing need in the art to produce GPAMs with high G / A ratios in situ. The percentage increase in viscosity observed during the creation of the critical concentration reacted polymers detailed herein (typically less than a 50% increase) is small.

[0018] Periodic or continuous testing of viscosity by various spindle type meters typically utilized in the preparation of GPAM with highly reacted crosslinking is currently known to those skilled in the art. Turbidity - a traditional alternative method for measuring viscosity - is not suitable for monitoring the formation of GPAM for the methods disclosed herein. As a result, it is necessary to monitor the progress of the formation of GPAM by measuring the increase / change in viscosity, and the means of knowing when the end point of the reaction in step (a) disclosed herein is reached is a 300-500% increase in viscosity relative to the starting point until the desired reacted polymer end point is reached.

[0019] Under these circumstances, there is a need for an online open flow tube viscometer that reliably measures viscosity while providing continuous feedback. The advantage of using this type of viscometer is that it does not have any form of probe or spindle that can become blocked with GPAM over time, causing erroneous viscosity measurements and subsequent off-spec batches. This online viscometer allows for the acid quench step to be activated immediately at the desired time while providing continuous feedback of viscosity, which is necessary since the preparation of GPAM disclosed herein involves a rapid increase / change in viscosity over a short period of time (see Figure 1). Figure 1 shows how the viscosity increases rapidly in the latter part of the reaction.

[0020] The online viscometer also allows for feedback relative to the caustic pump (i.e., alkali source) to allow the reaction rate to be increased or decreased depending on the time required to reach the end point of the crosslinking reaction of step (a).

[0021] [Table 1]

[0022] GPAM prepared according to the method disclosed herein has exceptional press dewatering properties due to its high monoamide content. To achieve this, more glyoxal is often required, which increases the probability of producing a more viscous material that may be prone to gelation. The disadvantage is that doing so increases the probability of gelation. The accuracy of the repeatable online viscometer disclosed herein allows this to be done by measuring the flow characteristics of the fluid viscosity change without the attention to sample monitoring required when using conventional in-line viscometers that are known to foul in a short time due to gelation of GPAM.

[0023] One aspect of the invention is a method of making a GPAM, comprising the steps of: combining at least polyacrylamide and glyoxal to obtain a reaction solution; quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 10 to obtain GPAM; Including, The present invention relates to a method in which the progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscometer (eg, via a feedback loop).

[0024] Another aspect of the invention is a method of making a GPAM comprising the steps of: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain GPAM; Including, The progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscometer (e.g., via a feedback loop); the polyacrylamide has a weight average molecular weight of about 7,000 to 50,000 daltons; The reaction is quenched when the reaction solution has a viscosity in the range of about 12 cP to about 40 cP.

[0025] A further aspect of the invention is a method of making a GPAM comprising the steps of: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain GPAM; Including, The progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscometer (e.g., via a feedback loop); the polyacrylamide has a weight average molecular weight of about 50,000 to 200,000 daltons; The reaction is quenched when the reaction solution has a viscosity in the range of about 20 cP to about 1,000 cP.

[0026] Another aspect of the invention is a method of making a GPAM comprising the steps of: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain GPAM; Including, The progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscometer (e.g., via a feedback loop); the polyacrylamide has a weight average molecular weight of about 15,000 daltons; The reaction is quenched when the reaction solution has a viscosity in the range of about 10 cP to about 100 cP.

[0027] 1. A method for enhancing paper strength and press section drainage of a flat sheet on a papermaking machine, comprising adding to the flat sheet from about 0.05 lb / ton to about 20 lb / ton on a dry fiber basis of an aqueous composition, the aqueous composition comprising: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution, thereby initiating a cross-linking reaction to produce GPAM; (b) quenching the reaction once the target viscosity of the GPAM is achieved by adjusting the pH of the reaction to a value in the range of about 2 to about 6 (or about 4 to about 6), and monitoring the progress of GPAM formation by measuring the viscosity of the reaction solution from an online viscometer (e.g., an oscillatory viscometer) (e.g., via a feedback loop); (c) combining the GPAM of step (c) with a fiber slurry or applying the GPAM to a flat sheet; The method is prepared by a method comprising:

[0028] A further aspect of the invention relates to a GPAM composition comprising a GPAM prepared according to the method of preparing a GPAM disclosed herein, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol, and the GPAM has a glyoxal to acrylamide (G / A ratio) in the range of about 0.1:1 to about 20:1, 0.1:about 1 to about 20:about 1, about 0.4:about 1 to about 20:about 1, or 0.4:1 to 20:1, or 0.4:1, or 0.8:1.

[0029] Yet another aspect of the present invention is a method of making an aldehyde-functionalized polymer, comprising the steps of: (a) combining at least one polymer containing at least one amide or amino group with an aldehyde to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain the aldehyde-functionalized polymer; Including, The present invention relates to a method in which the progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscometer (eg, via a feedback loop).

[0030] Detailed Description definition The following definitions are provided to determine how terms used in this application, particularly the claims, should be interpreted. The organization of the definitions is intended for convenience only, and none of the definitions are intended to be limited to any particular category.

[0031] In the context of describing the invention (particularly in the context of the claims which follow), the use of the terms "a," "an," "the," "at least one," and similar referents are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term "at least one" followed by a list of one or more items (e.g., "at least one of A and B") should be construed as meaning one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" should be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise indicated. The recitation of numerical ranges herein, unless otherwise stated herein, is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, and each separate value is incorporated herein as if it were individually recited herein.

[0032] All methods described herein may be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context.

[0033] The use of any and all examples or exemplary language (e.g., "etc.") provided herein is intended merely to better describe the invention and does not limit the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0034] "AA" means acrylic acid.

[0035] "AcAm" means acrylamide.

[0036] "Wet end" means that part of the papermaking process prior to the press section where the liquid medium, such as water, typically constitutes more than 45% of the substrate's mass, and additives added in the wet end typically penetrate and distribute within the slurry.

[0037] "Dry end" means that portion of the papermaking process after the press section where the liquid medium, such as water, typically constitutes less than 45% of the substrate's mass, including but not limited to the size press portion of the papermaking process, and additives added in the dry end typically remain in a separate coating layer on the outside of the slurry.

[0038] "Acrylamide monomer" refers to a compound of the formula

[0039] [ka] (In the formula, R 1 H, C1~C 16 Alkyl, aryl, arylalkyl, C2-C 16 Alkenyl, C2-C 16 R is selected from the group consisting of alkynyl, heteroaryl, alkylheteroaryl, C-C cycloalkyl, and halogen; 2 is hydrogen, C1-C 16 Alkyl, aryl, arylalkyl, C2-C 16 Alkenyl, C2-C 16 By this is meant a monomer of the formula (I) selected from the group consisting of alkynyl, heteroaryl, alkylheteroaryl, and hydroxyl.

[0040] "Aldehyde" refers to a compound containing one or more aldehyde (-CHO) groups that can react with the amino or amido groups of the amino or amido group-containing polymers described herein. Representative aldehydes include formaldehyde, paraformaldehyde, glutaraldehyde, glyoxal, and the like.

[0041] "Aldehyde-functionalized polymer" (used interchangeably with the acronym "AFP") refers to a polymer resulting from the reaction between a polymer containing at least one amide or amino group and an aldehyde. The term "aldehyde-functionalized polymer" includes aldehyde-functionalized polymer compositions or mixtures that contain unreacted aldehyde. The term "aldehyde-functionalized polymer" also includes aqueous aldehyde-functionalized polymer compositions or mixtures that contain unreacted aldehyde.

[0042] "Alkenyl" refers to a straight or branched chain hydrocarbon, preferably having 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 carbons, and having one or more carbon-carbon double bonds. Alkenyl groups include, but are not limited to, ethenyl, 1-propenyl, 2-propenyl (allyl), iso-propenyl, 2-methyl-1-propenyl, 1-butenyl, and 2-butenyl. Alkenyl groups can be unsubstituted or substituted by one or more suitable substituents.

[0043] "Alkyl" refers to a straight chain or branched alkyl substituent. Examples of such substituents include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isoamyl, hexyl, and the like.

[0044] "Alkylheteroaryl" refers to an alkyl group attached to a heteroaryl group.

[0045] "Alkynyl" refers to a straight or branched chain hydrocarbon, preferably having 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 carbons, and having one or more carbon-carbon triple bonds. Alkynyl groups include, but are not limited to, ethynyl, propynyl, and butynyl. Alkynyl groups can be unsubstituted or substituted with one or more suitable substituents.

[0046] An "amide group" is a group represented by the formula -C(O)NHY1, where Y1 is hydrogen, C1-C 16 Alkyl, aryl, arylalkyl, C2-C 16 Alkenyl, C2-C 16 alkynyl, heteroaryl, alkylheteroaryl, or hydroxyl.

[0047] An "amino group" is a group represented by the formula -NH(Y)2, where each Y2 may be the same or different, and each Y is hydrogen, C1-C 16 Alkyl, aryl, arylalkyl, C2-C 16 Alkenyl, C2-C 16 alkynyl, heteroaryl, alkylheteroaryl, or hydroxyl.

[0048] "Amphoteric polymer" refers to a polymer derived from both cationic and anionic monomers, and optionally other nonionic monomer(s). Exemplary amphoteric polymers include copolymers composed of terpolymers composed of acrylic acid, DADMAC, and acrylamide, and the like.

[0049] "Aryl" refers to an unsubstituted or substituted aromatic carbocyclic substituent as generally understood in the art, and the term "C6-C 10 "Aryl" includes phenyl and naphthyl. It is understood that the term aryl applies to cyclic substituents which are planar and contain 4n+2n electrons according to Huckel's rule.

[0050] "Arylalkyl" means an aryl-alkylene group, where aryl and alkylene are defined herein. Representative arylalkyl groups include benzyl, phenylethyl, phenylpropyl, 1-naphthylmethyl, and the like.

[0051] 19. The method of claim 18, further comprising combining the GPAM prepared according to any one of the preceding claims with a fiber slurry or coating the GPAM onto a flat sheet.

[0052] "Contacting," as used herein in connection with the application of the GPAM products prepared according to the methods disclosed herein, refers to combining the GPAM with a fiber slurry or applying the GPAM to a flat sheet.

[0053] "Chain transfer agent" refers to any molecule used in free radical polymerization that reacts with polymer radicals to form dead polymers and new radicals. In particular, the addition of a chain transfer agent to a polymerization mixture causes chain scission and a concomitant decrease in the size of the polymer chains. Thus, the addition of a chain transfer agent limits the molecular weight of the polymer prepared.

[0054] "Consisting essentially of" means that the methods and compositions may include additional steps, components, ingredients, etc., but only if the additional steps, components, and / or ingredients do not materially alter the basic and novel characteristics of the claimed methods and compositions.

[0055] As used herein, "continuously measuring" refers to monitoring the progress of the reaction in step (a) by measuring the viscosity of the reaction solution from an online viscometer (e.g., via a feedback loop). In some embodiments, the continuous measurement of the progress of the reaction may be done in real time, optionally with feedback control.

[0056] "Crosslinking agent" or "branching agent" means a multifunctional monomer that, when added to polymerized monomer(s), results in a "branched" or "crosslinked" polymer in which the branch(es) from one polymer molecule attaches to another polymer molecule.

[0057] "DADMAC" refers to monomeric units of diallyldimethylammonium halide, such as diallyldimethylammonium chloride. DADMAC can be present in a homopolymer or in a copolymer with other monomeric units.

[0058] "Diallyl-N,N-disubstituted ammonium halide monomer" refers to a monomer having the formula: (H2C=CHCH2)2N + R3R4X - (In the formula, R3 and R4 are independently C1 to C 20 alkyl, aryl, or arylalkyl, and X is an anionic counterion. Representative anionic counterions include halogens, sulfates, nitrates, phosphates, and the like. A preferred anionic counterion is a halogen. A preferred diallyl-N,N-disubstituted ammonium halide monomer is diallyldimethylammonium chloride.

[0059] "Halogen" or "halo" refers to a moiety selected from the group consisting of fluorine, chlorine, bromine, and iodine.

[0060] As used herein, "GPAM" refers to glyoxalated polyacrylamide, a polymer made from polymerized acrylamide monomers (which may or may not be copolymers further including one or more other monomers) in which the acrylamide polymer units have been reacted with glyoxal groups; representative examples of GPAM are described in US Patent Application Publication No. 2009 / 0165978. As used herein, the term "GPAM" encompasses GPAM compositions or mixtures containing unreacted aldehydes (glyoxals). Additionally, as used herein, the term "GPAM" encompasses aqueous GPAM compositions or mixtures containing unreacted aldehydes (glyoxals). GPAM is used herein as an exemplary embodiment. The present invention contemplates the substitution of all other AFPs as defined herein in place of GPAM.

[0061] "Monomer" means a polymerizable allylic, vinylic, or acrylic compound. The monomer may be anionic, cationic, nonionic, or zwitterionic.

[0062] Representative nonionic water-soluble comonomers include acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-vinylformamide, N-vinylmethylacetamide, N-vinylpyrrolidone, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, Nt-butylacrylamide, N-methylolacrylamide, vinyl acetate, vinyl alcohol, and the like.

[0063] Representative anionic monomers include acrylic acid and its salts including but not limited to sodium and ammonium acrylates, methacrylic acid and its salts including but not limited to sodium and ammonium methacrylates, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), the sodium salt of AMPS, sodium vinylsulfonate, styrene sulfonate, maleic acid and its salts including but not limited to the sodium and ammonium salts, sulfonates, itaconates, sulfopropyl acrylate or methacrylate, or other water-soluble forms of these or other polymerizable carboxylic or sulfonic acids, sulfomethylated acrylamide, allyl sulfonate, sodium vinylsulfonate, itaconic acid, acrylamidomethylbutanoic acid, fumaric acid, vinylphosphonic acid, vinylsulfonic acid, allylphosphonic acid, sulfomethylated acrylamide, phosphonomethylated acrylamide, itaconic anhydride, and the like.

[0064] Representative cationic comonomers include allylamine, vinylamine, dialkylaminoalkyl acrylates and methacrylates and their quaternary or acid salts, such as, but not limited to, dimethylaminoethyl acrylate methyl chloride quaternary salt (DMAEA.MCQ), dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride sulfate ... acrylate hydrochloride, dialkylaminoalkyl acrylamide or methacrylamide, and their quaternary or acid salts, such as acrylamidopropyl trimethyl ammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamide propyl trimethyl ammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, diallyl diethyl ammonium chloride, and diallyl dimethyl ammonium chloride (DADMAC). The alkyl group is generally selected from the group consisting of C 1~4 It is an alkyl.

[0065] The term "molecular weight" or "MW" as used herein refers to weight average molecular weight. Weight average molecular weight may be determined by any suitable technique. Although alternative techniques are contemplated, in some embodiments, weight average molecular weight is determined using size exclusion chromatography (SEC) equipped with a set of TSKgel PW columns (TSKgel Guard+GMPW+GMPW+G1000PW), Tosoh Bioscience LLC, Cincinnati, Ohio) and a Waters 2414 (Waters Corporation, Milford, Mass.) refractive index detector or a DAWN HELEOS II multi-angle light scattering (MALS) detector (Wyatt Technology, Santa Barbara, Calif.). Additionally, weight average molecular weight is determined either from calibration with polyethylene oxide / polyethylene glycol standards in the range of 150-875,000 daltons, or from direct use of light scattering data with known refractive index increments ("dn / dc").

[0066] The term "real-time" as used herein refers to monitoring the pH of the crosslinking reaction as it progresses. Measurements may be made continuously or intermittently at regular intervals.

[0067] The term "viscosity" as used herein refers to the internal friction or molecular attraction of a given material that manifests itself as resistance to flow. It is measured in liquids by standard test procedures and is usually expressed in poise or centipoise (cP) at a specified temperature. The viscosity of a fluid is an indication of a number of behavioral patterns of a liquid at a given temperature, including pumping characteristics, flow rate, wetting characteristics, and the tendency or ability to suspend insoluble particulate materials. As used herein, viscosity is based on measurements at ambient temperature and at a solids concentration of about 6% to about 15% of the reaction solution.

[0068] The term "viscometer" is used interchangeably with "viscometer" herein.

[0069] The term "online viscometer" as used herein refers to an open flow tube viscometer or the like that (i) has no spindle or probe, (ii) is not susceptible to complete blockage or fouling due to gelation of the aldehyde-functionalized polymer (such as GPAM), and (iii) can provide continuous real-time viscosity measurement via a feedback loop. As used herein, an online viscometer includes viscometers such as concentric cylinder (Couette) viscometers that can provide viscosity measurements at defined shear conditions (i.e., Couette viscometers, e.g., BROOKFIELD TT-100 viscometer), vibrometers, viscometers based on Coriolis mass flow measurement systems (e.g., those in which the measurement is based on the torsional motion of the measuring tube, e.g., Endress+Hauser Proline 83I), and the like. An online viscometer can enable reliable reaction control and facilitate automatic quenching of the reaction mixture when the target viscosity level is reached.

[0070] "Zwitterionic monomer" refers to a polymerizable molecule that contains cationic and anionic (charged) functional groups in equal proportions such that the molecule is net neutral overall. Representative zwitterionic monomers include N,N-dimethyl-N-acryloyloxyethyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, 2-(methylthio)ethyl methacryloyl-S-(sulfopropyl)-sulfonium betaine, 2-[(2-acryloylethyl)dimethylammonio]ethyl 2-methylphosphate, 2-(acryloyloxyethyl)-2'-(trimethylammonio) ... ammonium)ethyl phosphate, [(2-acryloylethyl)dimethylammonio]methylphosphonic acid, 2-methacryloyloxyethyl phosphorylcholine (MPC), 2-[(3-acrylamidopropyl)dimethylammonio]ethyl 2'-isopropyl phosphate (AAPI), 1-vinyl-3-(3-sulfopropyl)imidazolium hydroxide, (2-acryloxyethyl)carboxymethyl methylsulfonium chloride, 1-(3-sulfopropyl)-2-vinylpyridinium betaine, N-(4-sulfobutyl)-N-methyl-N,N-diallylamine ammonium betaine (MDABS), N,N-diallyl-N-methyl-N-(2-sulfoethyl)ammonium betaine, and the like.

[0071] "Papermaking process" means any part of the process for making paper products from pulp, including forming an aqueous cellulosic papermaking furnish, draining the furnish to form a sheet, and drying the sheet. The steps of forming, draining and drying the papermaking furnish can be performed in any conventional manner generally known to those skilled in the art. The papermaking process may also include a pulping stage, i.e., making pulp from lignocellulosic raw materials, and a bleaching stage, i.e., chemically treating the pulp to improve brightness, and papermaking is further described in the references Handbook for Pulp and Paper Technologists, 3rd Edition, by Gary A. Smook, Angus Wilde Publications Inc., (2002) and The Nalco Water Handbook (3rd Edition), by Daniel Flynn, McGraw Hill (2009) in general and in particular pp. 32.1-32.44. "Papermaking process" includes a method of making paper products from pulp, including forming an aqueous cellulosic papermaking furnish, draining the furnish to form a flat sheet, and drying the flat sheet. The steps of forming, draining, and drying the papermaking furnish can be performed in any conventional manner generally known to those skilled in the art. Although conventional particulates, alum, cationic starch, or combinations thereof may be utilized as adjuvants with the polymer treatment of the present invention, it should be emphasized that an adjuvant is not required for effective dewatering activity.

[0072] "Structure-modifying agent" means an agent added to an aqueous polymer solution to control the structure and solubility properties of the polymer. The structure-modifying agent is selected from the group consisting of crosslinking agents and chain transfer agents.

[0073] "Surface strength" refers to the tendency of a paper substrate to resist damage from abrasive forces.

[0074] "Dry strength" means the tendency of a paper substrate to resist damage from shear force(s), including but not limited to surface strength.

[0075] "Wet strength" refers to the tendency of a paper substrate to resist damage from shear force(s) upon rewet.

[0076] "Wet web strength" refers to the tendency of a paper substrate to resist shear force(s) while the substrate is still wet.

[0077] "Substrate" means a mass containing paper fibers that passes or has passed through a papermaking process, and includes wet webs, paper mats, slurries, flats, and paper products.

[0078] "Paper products" means the end products of the paper-making process, including, but not limited to, writing paper, printer paper, tissue paper, cardboard, paperboard, and wrapping paper.

[0079] The term "initial viscosity" as used herein is obtained by measuring the viscosity of the reaction solution up to about 5 minutes after combining a polymer containing at least one amide or amino group with an aldehyde. The initial viscosity can be measured via a feedback loop from an online viscometer or by other means. For example, the initial viscosity encompasses the viscosity of the reaction solution up to 5 minutes after combining polyacrylamide with glyoxal.

[0080] The term "target viscosity change" as used herein refers to when the change in viscosity of the reaction solution reaches a viscosity increase of more than 50% relative to the initial viscosity of the reaction solution. In some embodiments, the target viscosity change occurs when the viscosity of the reaction solution reaches a viscosity increase of more than 100% relative to the starting viscosity. The target viscosity change may occur when the viscosity of the reaction solution reaches a viscosity increase of about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 200%, about 300%, about 400%, about 500%, about 100% to about 500%, about 200% to about 500%, or about 300% to about 500% relative to the starting viscosity.

[0081] The term "shelf life" as used herein refers to when the aldehyde-functionalized polymer has a viscosity of less than 5000 cP for at least about 12 hours. In some embodiments, the aldehyde-functionalized polymer may have a viscosity of less than 5000 cP for about 12 to about 48 hours. In further embodiments, the aldehyde-functionalized polymer may have a viscosity of less than 5000 cP for about 12 to about 96 hours.

[0082] The term "reaction solution," as used herein, refers to the reaction mixture formed after combination of a polymer containing at least one amide or amino group (such as polyacrylamide) with an aldehyde (e.g., glyoxal) in the preparation of an AFP, such as GPAM. The reaction solution may contain portions of the AFP (such as GPAM), unreacted aldehyde (such as glyoxal), unreacted polyacrylamide, intermediates in the formation of the AFP, and the like. Additionally, the reaction solution may also contain unreacted acrylamide and unreacted ionic monomer.

[0083] In the event that the above definitions or explanations set forth elsewhere in this application contradict (either explicitly or implicitly) the meaning commonly used in dictionaries or set forth in sources incorporated by reference in this application, it is understood that the terms in this application and in the claims in particular are to be interpreted according to the definitions or explanations in this application, rather than according to the common definitions, dictionary definitions, or definitions incorporated by reference. In view of the above, if a term can only be understood as interpreted according to a dictionary, then if the term is defined by the Kirk-Othmer Encyclopedia of Chemical Technology, 5th Edition, (2005) (published by Wiley, John & Sons, Inc.), then this definition shall govern how the term is defined in the claims. [Brief description of the drawings]

[0084] [Figure 1] Viscosity change over the course of the crosslinking reaction between polyacrylamide and glyoxal. [Diagram 2] Schematic of the GPAM fabrication process (exemplary embodiment). [Diagram 3] 13 is a chart of strength test improvements for GPAM samples made according to the methods of the present disclosure. [Figure 4] 1 is an exemplary embodiment of an online viscometer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0085] preparation One aspect of the invention is a method of making a GPAM, comprising the steps of: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution, thereby initiating a cross-linking reaction to produce GPAM; (b) once the target viscosity of the GPAM has been achieved, quenching the reaction of step (a) by adjusting the pH of the reaction to a value in the range of about 2 to about 6 (or about 4 to about 6); Including, The progress of GPAM formation is monitored by measuring the viscosity of the reaction solution via a feedback loop from an online viscometer.

[0086] In some embodiments, step (a) includes combining the polyacrylamide with water to obtain a mixture and adding the glyoxal to the mixture to obtain the reaction solution.

[0087] In a further embodiment, step (a) comprises combining the glyoxal with water to obtain a mixture and adding the polyacrylamide to the mixture of step (i) to obtain the reaction solution.

[0088] In some embodiments, step (a) includes adjusting the temperature to about 65-85° F. For example, the temperature can be adjusted to about 60-80° F, about 70-about 75° F, or about 75° F.

[0089] In some embodiments, step (a) followed by step (b) may be repeated at least two times. For example, step (a) followed by step (b) may be repeated three, four, etc. The reactor in which steps (a) and (b) are carried out may be cleaned between each cycle (i.e., step (a) followed by step (b)).

[0090] In some embodiments, the adjustment of pH in step (b) may be monitored in real time, which may be done by using a pH meter, or possibly two or more pH meters.

[0091] A further aspect of the present invention relates to a GPAM composition comprising a GPAM prepared according to the method for preparing a GPAM disclosed herein, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol, and the GPAM has a glyoxal to acrylamide (G / A ratio) in the range of about 0.4:1 to about 20:1, or in the range of 0.4:1 to 20:1, or 0.4:1, or 0.8:1.

[0092] Further embodiments of the invention relate to GPAM compositions prepared according to the invention, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol, 10,000 g / mol to 7,000,000 g / mol, 10,000 g / mol to 5,000,000 g / mol, 3,000,000 g / mol to 4,000,000 g / mol, and 3,000,000 g / mol to 4,000,000 g / mol, and the GPAM has a glyoxal to acrylamide (G / A ratio) of about 0.4:about 1 to about 20:about 1.

[0093] Yet another aspect of the present invention is a method of making an aldehyde-functionalized polymer, comprising the steps of: (a) initiating a crosslinking reaction to form the aldehyde-functionalized polymer by combining at least one polymer containing at least one amide or amino group with an aldehyde to obtain a reaction solution; (b) quenching the reaction of step (a) once the target viscosity of the aldehyde-functionalized polymer has been achieved by adjusting the pH to a value in the range of about 4 to about 6; Including, The present invention relates to a method in which the progress of aldehyde-functionalized polymer formation is monitored by measuring the viscosity of the reaction solution via a feedback loop from an online viscometer.

[0094] Further embodiments of the invention relate to aldehyde-functionalized polymer compositions prepared according to the invention, wherein the aldehyde-functionalized polymer has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol, 10,000 g / mol to 7,000,000 g / mol, 10,000 g / mol to 5,000,000 g / mol, 1,000,000 g / mol to 4,000,000 g / mol, 3,000,000 g / mol to 4,000,000 g / mol, and 3,000,000 g / mol to 4,000,000 g / mol, and the aldehyde-functionalized polymer has an aldehyde to acrylamide (A / A ratio) of about 0.4:about 1 to about 20:about 1.

[0095] In a further embodiment, the method according to the present disclosure includes continuously measuring the viscosity of the reaction mixture in real time.

[0096] In a further embodiment, the method according to the present disclosure includes continuously monitoring the viscosity of the reaction mixture using an online flow-through viscometer, which does not require "grab-and-spot" or "spot checking."

[0097] In some embodiments, the method according to the present disclosure includes continuously feeding viscosity values ​​from an online viscometer into a feedback loop for in-line control of the pH in step (a) and / or step (b).

[0098] In a further embodiment, the method according to the present disclosure includes continuously monitoring the reaction mixture using an in-line open flow-through viscometer.

[0099] In some embodiments, the method according to the present disclosure includes continuously sending viscosity values ​​from the viscometer to a feedback loop for in-line control of the pH in step (a).

[0100] In a further embodiment, the method according to the present disclosure includes maintaining the pH of the reaction mixture in the range of about 8 to about 9 by adding a caustic solution before the target viscosity is reached, and optionally further diluting the caustic solution with water.

[0101] In a further embodiment, the method according to the present disclosure includes modulating the quenching of the reaction in step (a) by adding an organic acid, such as citric acid.

[0102] In a further embodiment, the method according to the present disclosure includes preparing the GPAM at the paper production site (i.e., "on-site") in a semi-batch or full batch.

[0103] In a further embodiment, the method according to the present disclosure includes automatically adjusting (via addition of acid) using in-line pH control once a target viscosity of the aldehyde-functionalized polymer (e.g., GPAM) is reached.

[0104] In a further embodiment, the method according to the present disclosure includes that the GPAM has a shelf life ranging from about 24 hours to about 2.5 months.

[0105] In a further embodiment, the method according to the present disclosure comprises step (a) and / or step (b) being carried out at a paper production site.

[0106] In some embodiments, the polyacrylamide is obtained by combining at least water, a copolymer of acrylamide and an ionic monomer, hi further embodiments, the method according to the present disclosure includes that the ionic monomer in the copolymer of acrylamide and an ionic monomer is a cationic, anionic, or zwitterionic monomer.

[0107] Representative anionic monomers include acrylic acid and its salts including but not limited to sodium and ammonium acrylates, methacrylic acid and its salts including but not limited to sodium and ammonium methacrylates, 2-acrylamido-2-methylpropanesulfonic acid, the sodium salt of AMPS, sodium vinylsulfonate, styrene sulfonate, maleic acid and its salts including but not limited to the sodium and ammonium salts, sulfonates, itaconates, sulfopropyl acrylate or methacrylate, or other water-soluble forms of these or other polymerizable carboxylic or sulfonic acids, sulfomethylated acrylamide, allyl sulfonate, sodium vinylsulfonate, itaconic acid, acrylamidomethylbutanoic acid, fumaric acid, vinylphosphonic acid, vinylsulfonic acid, allylphosphonic acid, sulfomethylated acrylamide, phosphonomethylated acrylamide, and the like.

[0108] Representative cationic monomers include dialkylaminoalkyl acrylates and methacrylates, as well as dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dialkylaminoalkyl acrylamides or methacrylamides and their quaternary or acid salts, such as acrylamidopropyl trimethylammonium chloride, dimethylaminoethyl acrylate methyl chloride quaternary salt. , dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, methacrylamide propyl trimethyl ammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamide propyl trimethyl ammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, diallyl diethyl ammonium chloride, diallyl dimethyl ammonium chloride, and the like.

[0109] Representative zwitterionic monomers include N,N-dimethyl-N-acryloyloxyethyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, 2-(methylthio)ethyl methacryloyl-S-(sulfopropyl)-sulfonium betaine, 2-[(2-acryloylethyl)dimethylammonio]ethyl 2-methylphosphate, 2-(acryloyloxyethyl)-2'-(trimethylammonio) ... ammonium)ethyl phosphate, [(2-acryloylethyl)dimethylammonio]methylphosphonic acid, 2-methacryloyloxyethyl phosphorylcholine (MPC), 2-[(3-acrylamidopropyl)dimethylammonio]ethyl 2'-isopropyl phosphate (AAPI), 1-vinyl-3-(3-sulfopropyl)imidazolium hydroxide, (2-acryloxyethyl)carboxymethyl methylsulfonium chloride, 1-(3-sulfopropyl)-2-vinylpyridinium betaine, N-(4-sulfobutyl)-N-methyl-N,N-diallylamine ammonium betaine (MDABS), N,N-diallyl-N-methyl-N-(2-sulfoethyl)ammonium betaine, and the like.

[0110] In certain embodiments, the amino groups, amide groups, or combinations thereof of amino and amide groups are mono-reacted and di-reacted in a ratio of at least about 3:1, and the GPAM has a weight average molecular weight of about 10,000 g / mol to about 10,000,000 g / mol, about 50,000 g / mol to about 5,000,000 g / mol, about 100,000 g / mol to about 3,000,000 g / mol, about 200,000 g / mol to about 1,000,000 g / mol, about 300,000 g / mol to about 1,000,000 g / mol, or about 500,000 g / mol to about 1,000,000 g / mol.

[0111] In certain embodiments, the amino groups, amide groups, or combinations thereof of amino and amide groups are mono-reacted and di-reacted in a ratio of at least about 4:1, and the GPAM has a weight average molecular weight of about 10,000 g / mol to about 10,000,000 g / mol, about 50,000 g / mol to about 5,000,000 g / mol, about 100,000 g / mol to about 3,000,000 g / mol, about 200,000 g / mol to about 1,000,000 g / mol, about 300,000 g / mol to about 1,000,000 g / mol, or about 500,000 g / mol to about 1,000,000 g / mol.

[0112] In certain embodiments, the GPAM prepared using the methods disclosed herein is a glyoxalated DADMAC / acrylamide polymer. In certain embodiments, an acrylamide / DADMAC copolymer (e.g., a 95 / 5 mol% acrylamide / DADMAC copolymer) may be used to prepare the GPAM of the present invention. The 95 / 5 mol% acrylamide / DADMAC copolymer may be prepared according to the methods described in U.S. Patent Application Publication No. 2005 / 016118 (the disclosure of which is incorporated by reference to the extent that it does not conflict with the present disclosure) (see Example 1). U.S. Patent Nos. 10,006,170 and 8,894,817 are also incorporated by reference to the extent that their disclosures do not conflict with the present disclosure.

[0113] A mono-reactive amide or amine refers to a polymer formed when one glyoxal reacts with one amide or amine, and a di-reactive amide or amine refers to a polymer formed when one glyoxal reacts with two amides or amines.

[0114] The aldehyde-functional polymers (including GPAMs) of the present disclosure may contain amino groups, amide groups, or both amino and amide groups substituted with aldehydes in a ratio of one-reacting amide to two-reacting amide of at least about 1.5:1. Without wishing to be bound by any particular theory, it is believed that the one-reacting aldehydes in the polymer are partially responsible for the enhanced paper strength observed in the presence of aldehyde-functionalized polymers. Thus, it is believed that the one-reacting species (e.g., species with free aldehydes) are responsible for the increased paper strength because, unlike the two-reacting species, the one-reacting species can form covalent bonds with cellulose fibers.

[0115] In certain embodiments, the aldehyde-functionalized polymers of the invention (such as GPAMs) contain amino groups, amide groups, or a combination of amino and amide groups that react mono- and di-react with aldehydes in a ratio of at least about 1.5:1. In certain embodiments, the GPAMs contain amino groups, amide groups, or a combination of amino and amide groups that react mono- and di-react with glyoxal in a ratio of at least about 3:1. Thus, in certain embodiments, the GPAMs of the invention contain amino groups, amide groups, or both amino and amide groups that react mono- and di-react with glyoxal in a ratio of at least about 3:1, at least about 3.5:1, at least about 4:1, at least about 4.5:1, at least about 5:1, at least about 5.5:1, or at least about 6:1. In certain embodiments, the GPAMs contain amino groups, amide groups, or a combination of amino and amide groups that react mono- and di-react with glyoxal in a ratio of greater than about 3:1. In certain embodiments, the GPAMs of the present invention contain amino groups, amide groups, or combinations of amino and amide groups that are mono- and di-reactive with glyoxal in a ratio of at least about 3.5: 1. In certain embodiments, the GPAMs of the present invention contain amino groups, amide groups, or combinations of amino and amide groups that are mono- and di-reactive with glyoxal in a ratio of at least about 4: 1.

[0116] In certain embodiments, the GPAM of the present invention comprises amino groups, amide groups, or a combination of amino and amide groups that are mono- and di-reactive with glyoxal in a ratio of about 3:1 to about 20:1. Thus, in certain embodiments, the GPAM of the present invention comprises amino groups, amide groups, or a combination of amino and amide groups that are mono- and di-reactive with glyoxal in a ratio of about 3:1 to about 20:1, about 3.5:1 to about 20:1, about 4:1 to about 20:1, about 4.5:1 to about 20:1, about 5:1 to about 20:1, about 5.5:1 to about 20:1, or about 6:1 to about 20:1.

[0117] In certain embodiments, the composition comprises the mono-reacted glyoxal and the di-reacted glyoxal in a ratio of at least about 7:1, at least about 8:1, at least about 9:1, at least about 10:1, at least about 11:1, or at least about 12:1. In certain embodiments, the composition comprises the mono-reacted glyoxal and the di-reacted glyoxal in a ratio of about 9:1 to about 50:1.

[0118] The GPAM of the present invention may contain any amount of monoreacted amino groups, amide groups, and combinations thereof. In certain embodiments, at least about 10 mole percent of the amino groups, amide groups, and combinations thereof are monoreacted with at least one aldehyde. In certain embodiments, at least about 15 mole percent of the amino groups, amide groups, and combinations thereof are monoreacted with at least one aldehyde. In certain embodiments, at least about 20 mole percent of the amino groups, amide groups, and combinations thereof are monoreacted with at least one aldehyde.

[0119] In certain embodiments, the GPAMs of the present invention are formed by functionalizing an acrylamide copolymer containing amino groups, amide groups, or a combination of amino and amide groups with one or more glyoxals, where the glyoxal reacts with at least about 15 mole percent of the amino groups, amide groups, or a combination thereof. Thus, in certain embodiments, the GPAMs are formed by reacting at least one copolymer of acrylamide and an ionic monomer, which may contain amino and / or amide groups, with glyoxal, where the glyoxal reacts with at least about 15 mole percent of the amino and / or amide groups, at least about 16 mole percent of the amino and / or amide groups, at least about 17 mole percent of the amino and / or amide groups, at least about 18 mole percent of the amino and / or amide groups, at least about 19 mole percent of the amino and / or amide groups, at least about 20 mole percent of the amino and / or amide groups, at least about 21 mole percent of the amino and / or amide groups, at least about 22 mole percent of the amino and / or amide groups, at least about 23 mole percent of the amino and / or amide groups, at least about 24 mole percent of the amino and / or amide groups, at least about 25 mole percent of the amino and / or amide groups, at least about 26 mole percent of the amino and / or amide groups, at least about 27 mole percent of the amino and / or amide groups, at least about 28 mole percent of the amino and / or amide groups, at least about 29 mole percent of the amino and / or amide groups, at least about 30 mole percent of the amino and / or amide groups, at least about 31 mole percent of the amino and / or amide groups, at least about 32 mole percent of the amino and / or amide groups, at least about 33 mole percent of the amino and / or amide groups, at least about 34 mole percent of the amino and / or amide groups, at least about 35 mole percent of the amino and / of the amino and / or amido groups, at least about 20 mole percent of the amino groups and / or amido groups, at least about 22 mole percent of the amino groups and / or amido groups, at least about 24 mole percent of the amino groups and / or amido groups, at least about 25 mole percent of the amino groups and / or amido groups, at least about 30 mole percent of the amino groups and / or amido groups, at least about 35 mole percent of the amino groups and / or amido groups, at least about 40 mole percent of the amino groups and / or amido groups, at least about 45 mole percent of the amino groups and / or amido groups, or at least about 50 mole percent of the amino groups and / or amido groups.

[0120] In certain embodiments, the method includes combining at least polyacrylamide and glyoxal to obtain a reaction solution, the polyacrylamide having a weight average molecular weight of about 7,000 g / mol to about 50,000 g / mol (about 10,000 g / mol to about 45,000 g / mol, about 15,000 g / mol to about 40,000 g / mol, about 20,000 g / mol to about 30,000 g / mol, about 7,000 g / mol to about 30,000 g / mol), and the reaction is quenched when the viscosity of the reaction solution is in the range of about 12 cP to about 40 cP (about 15 cP to about 40 cP, about 18 cP to about 30 cP, about 20 cP to about 40 cp, about 25 cP to about 40 cP, about 12 cP to about 30 cP).

[0121] In certain embodiments, the method includes combining at least polyacrylamide and glyoxal to obtain a reaction solution, the polyacrylamide having a molecular weight of about 50,000 g / mol to about 200,000 g / mol (about 50,000 g / mol to about 150,000 g / mol, about 75,000 g / mol to about 200,000 g / mol, about 80,000 g / mol to about 180,000 g / mol, or the like). The reaction is quenched when the viscosity of the reaction solution is in the range of about 20 cP to about 1000 cP (about 50 cP to about 500 cP, about 100 cP to about 800 cP, about 150 cP to about 600 cP, about 75 cP to about 400 cP, about 200 cP to about 500 cP).

[0122] In certain embodiments, the GPAM of the present invention has a weight average molecular weight of about 10,000 g / mol to about 10,00,000 g / mol, about 10,000 g / mol to about 7,000,000 g / mol, about 10,000 g / mol to about 5,000,000 g / mol, 1,000,000 g / mol to about 10,000,000 g / mol, about 1,000,000 g / mol to about 5,000,000 g / mol, about 3,000,000 g / mol to about 4,000,000 g / mol, or about 3,000,000 g / mol to about 5,000,000 g / mol.

[0123] In certain embodiments, the polymerization and / or post-polymerization reaction conditions are selected such that the resulting polymer containing amino and / or amide groups has a molecular weight of from about 1,000 g / mole to about 10,000,000 g / mole.

[0124] In some embodiments, the GPAM can be prepared using the manufacturing process outlined in Figure 2. One aspect of the invention is a method of making a GPAM, comprising: (a) combining (e.g., via pumping) at least water, a copolymer of acrylamide and an ionic monomer ("PAM backbone") (e.g., acrylamide / DADMAC), and glyoxal in a reaction vessel (e.g., tank) to provide a reaction mixture; (b) maintaining a desired concentration of the mixture of step (a); and (c) optionally, recycling the reaction mixture; and (d) continuously monitoring the viscosity of the reaction mixture in real time; and (e) once the target viscosity is reached, adjusting the pH of the reaction mixture (e.g., by addition of citric acid) to a value in the range of about 4 to about 6 to obtain GPAM; The present invention relates to a method comprising the steps of:

[0125] During the reaction, the pH can be maintained between about 8 and about 9 by relying on a caustic pump flowing in parallel with the dilution water using in-line pH control. Once the desired viscosity is reached, the reaction is quenched and an acid pump (such as a citric acid pump) is started to lower the pH of the resulting solution to a range of about 4 to about 6 depending on the level of shelf life required.

[0126] In FIG. 2, the process inputs include water, a PAM framework material (e.g., a copolymer of acrylamide and an ionic monomer), glyoxal, and a pH adjustment solution including an aqueous solution of a caustic material (e.g., NaOH) and an aqueous solution of an acid. The inputs are pumped to a run tank according to a control system. A feedback loop includes a pump to recirculate the contents of the tank through an in-line viscometer. Feedback readings from the viscometer are used to measure the progress of the reaction. During the reaction of the PAM framework material with the glyoxal, the pH is maintained in the range of about 8 to about 9. Once the viscosity reading reaches a predetermined level, the reaction is quenched by adding acid, which is then pumped to a holding tank.

[0127] viscometer It is particularly advantageous to monitor the viscosity continuously and in real time to enable a feedback control system of the reaction. The reaction time of the method disclosed herein can be controlled by adjusting the pH level, and the adjustment of the pH can be under automatic control by including a continuous real-time measurement of the viscosity of the reaction mixture. Of the various viscometers available, some are more suitable than others for continuous real-time measurement of viscosity. Viscometers with spindle arrangements are not suitable (e.g., BROOKFIELD LV series viscometers with UL adapters--see U.S. Pat. No. 8,920,606, also see U.S. Pat. Publication No. 2005 / 0161181). On the other hand, "open flow-through" in-line viscometers, such as the Brookfield TT-100 viscometer (e.g., found at https: / / www.brookfieldengineering.com / products / viscometers / in-line-process-viscometers / tt-100-viscometer), which can be used to monitor the progress of the formation of the aldehyde-functionalized polymer (e.g., GPAM) in step (a), are better options. In addition, viscometers operating in an open flow tube, such as the Proline Promass83I(E+H), may be suitable for monitoring the progress of the formation of the aldehyde-functionalized polymer (e.g., GPAM) in step (a).

[0128] Another type of viscometer that can be used to monitor the progress of the formation of the aldehyde-functionalized polymer (e.g., GPAM) in step (a) is a "vibrometer," which measures the vibrational deflection of a flow tube under electromechanical excitation. An example of such a vibrometer is described in U.S. Pat. No. 7,520,162 (see, e.g., columns 6-9), the disclosure of which is incorporated herein by reference. FIG. 3 shows a simplified schematic cross-sectional view of a vibrometer transducer assembly 10. The transducer assembly 10 includes a straight, flexible flow tube 13 having an inlet end 11, an outlet end 12, and an elastically deformable lumen on the inner surface of the flow tube 13. The transducer assembly 10 also includes a rigid support frame 14, which is surrounded by a housing 100 and clamps the flow tube 13 such that it is capable of oscillatory motion. "Elastic deformation" of a lumen, as used herein, means that the three-dimensional shape and / or spatial position of the fluid-conducting lumen changes periodically, especially periodically, within the elastic range of the flow tube 13. The elastic deformation occurs during operation of the transducer assembly 10 in response to forces that describe the fluid, i.e., Coriolis forces, mass inertia forces, and / or shear forces.

[0129] The measurement of the vibration mode of the flow tube 13 is carried out by the signals from the electrodynamic sensors 17 and 18, the excitation current i exc The fluid can be analyzed using a meter electronics module that includes a signal from the flow tube 13 and an evaluation circuit that estimates the damping of the vibrations of the flow tube 13 and derives a viscosity value representative of the viscosity of the fluid based on the estimated damping. Further details regarding the functioning of the meter electronics module are described in U.S. Pat. No. 7,520,162, see e.g., columns 6-9.

[0130] A particularly suitable material for the flow tube 13 is, for example, a titanium alloy. Other materials commonly used for such flow tubes, especially bent tubes, such as stainless steel or zirconium, may also be used. The transducer assembly 10 is connected to an excitation current i excThe sensor arrangement 60 further includes an electromechanical excitation arrangement 16 that operates by a current source to spatially deflect the flow tube 13 from a stationary static position during operation and to elastically deform the flow tube 13 with lateral and torsional motions. The sensor arrangement 60 includes velocimetry electrodynamic sensors 17 and 18 that function to sense the movement of the flow tube 13 as it bends. The sensor arrangement 60 is configured to provide an excitation current i to the excitation arrangement 16 for recording and analyzing signals from the sensors. exc . The meter is connected to a meter electronics module (not shown) to deliver

[0131] In some embodiments, the online viscosity meter comprises: (a) a transducer assembly, (i) at least one flow tube inserted into the pipe, the flow tube having a lumen through which an aldehyde-functionalized polymer of the invention (e.g., GPAM) is conducted, the flow tube being clamped at an inlet end and an outlet end so as to be vibrated; (ii) an electromechanical excitation arrangement for driving the flow tube into vibration in a bending mode to at least partially induce viscous friction within the fluid; and (iii) a sensor arrangement for generating at least one sensor signal representative of lateral deflection of the flow tube in response to vibration of the flow tube; a transducer assembly including: (b) Meter electronics: (i) an excitation circuit for generating an excitation current for powering the excitation equipment; and (ii) an evaluation circuit for estimating a damping of the vibration of the flow tube from the at least one sensor signal and an excitation current, and for deriving a viscosity value representative of the viscosity of the aldehyde-functionalized polymer of the present invention based on the estimated damping; meter electronics, Includes.

[0132] In certain embodiments, the online viscosity meter comprises: (a) a transducer assembly, (i) at least one flow tube inserted into the pipe, the flow tube having a lumen for conducting the GPAM, the flow tube being clamped at its inlet and outlet ends so as to be vibrated; (ii) an electromechanical excitation arrangement for driving the flow tube into vibration in a bending mode to at least partially induce viscous friction within the fluid; and (iii) a sensor arrangement for generating at least one sensor signal representative of lateral deflection of the flow tube in response to vibration of the flow tube; a transducer assembly including: (b) Meter electronics, (i) an excitation circuit for generating an excitation current for powering the excitation equipment; and (ii) an evaluation circuit for estimating a damping of the vibration of the flow tube from the at least one sensor signal and the excitation current and for deriving a viscosity value representative of the viscosity of the GPAM of the present invention based on the estimated damping; meter electronics, Includes.

[0133] Advantageously, there are no parts or protrusions in flow tube 13 that can become fouled with the GPAM, for example if the GPAM begins to gel. A recirculation pump can be used to pump the flow of the GPAM through flow tube 13, allowing for continuous real-time measurement of viscosity.

[0134] In some embodiments, a viscometer comprising the transducer assembly of Figure 3 is connected in-line with a pipe through which the reaction mixture is continuously pumped, thereby allowing the viscosity of the reaction mixture to be continuously measured in real time. Such a configuration of an in-line flow-through viscometer allows for continuous sampling of the reaction mixture.

[0135] In some embodiments, the online viscometer used in the present invention may rely on the Coriolis effect and measure the vibrational deflection of one or more meandering tubes, as described in U.S. Patent Application Publication No. 2020 / 0166444, which is incorporated herein by reference. In some embodiments, a Coriolis mass flow measurement system (such as one in which the measurement is based on the torsional motion of a measuring tube) may be used to control the reaction time by monitoring the viscosity of the GPAM being formed. For example, viscometers that can be used in the preparation of the GPAM according to the present invention may include: a measuring system having at least one measuring tube, which during the measuring operation is filled with a fluid (i.e. a GPAM) or through which the GPAM flows and which has at least one tube section which can be excited to perform oscillations; an excitation system for exciting at least two desired vibration modes of different frequencies, in each of which at least one of the tube sections is excited to carry out a vibration, in particular a resonant vibration; a sensing system embodied for determining, for the desired vibration modes excited during the measurement operation, the frequency and damping, in particular the frequency, amplitude and damping, of the resulting vibration of at least one pipe section excited to perform a vibration of one of the desired vibration modes in each case; and An evaluation system embodied to determine a shear rate value and a viscosity measurement value each time based on the excitation determined frequency and damping, in particular frequency, amplitude and damping, of the resulting vibrations based on calibration data stored in a memory for each desired vibration mode excited during the measurement operation, wherein the viscosity measurement value corresponds to the dynamic viscosity of the GPAM at a static shear rate corresponding to the shear rate value.

[0136] Coating A further aspect of the invention relates to a method for enhancing the paper strength and press section drainage of a flat sheet on a paper machine, comprising adding an aqueous composition prepared according to the method for preparing a GPAM disclosed herein to the flat sheet at about 0.05 lb / ton to about 20 lb / ton based on dry fiber, and combining the GPAM with a fiber slurry or coating the GPAM to the flat sheet. In some embodiments, the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol. In further embodiments, the aldehyde-functionalized polymer (such as a GPAM) has a glyoxal to acrylamide (G / A ratio) of about 0.4:1 to about 20:1, or 0.4:1 to 20:1, or 0.4:1, or 0.8:1.

[0137] Another aspect of the invention is a method for enhancing paper strength and press section drainage of a flat sheet on a papermaking machine, comprising adding to the flat sheet from about 0.05 lb / ton to about 20 lb / ton on a dry fiber basis of an aqueous composition, the aqueous composition comprising: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution, thereby initiating a cross-linking reaction to produce GPAM; (b) quenching the reaction of step (a) once the target viscosity of the GPAM is achieved by adjusting the pH of the reaction to a value in the range of about 2 to about 6 (or about 4 to about 6), and monitoring the progress of GPAM formation by measuring the viscosity of the reaction solution via a feedback loop from an online viscometer; (c) combining the GPAM of step (b) with a fiber slurry or applying the GPAM to a flat sheet; The present invention relates to a method for preparing a compound comprising the steps of:

[0138] In certain embodiments, the disclosure provides a method of making an aldehyde-functionalized polymer (such as a GPAM) composition for treating flat sheet strength and press section dewatering. The composition includes one or more aldehyde-functionalized polymers (such as a GPAM) prepared according to the method. In some embodiments, the GPAM has a weight average molecular weight of about 10,000 g / mole to 10,000,000 g / mole. In further embodiments, the aldehyde-functionalized polymer (such as a GPAM) has a glyoxal to acrylamide (G / A ratio) of about 0.4:1 to about 20:1, or 0.4:1 to 20:1, or 0.4:1, or 0.8:1.

[0139] In another embodiment, the disclosure provides a method for enhancing sheet strength and press section drainage on a paper machine, comprising adding to the sheet from about 0.05 lb / ton to about 20 lb / ton based on dry fiber a composition comprising a GPAM comprising amino groups, amide groups, or a combination thereof, wherein (i) at least about 15 mole percent of the amino groups, amide groups, or both the amino groups or amide groups are functionalized with glyoxal, (ii) the amino groups, amide groups, or both the amino groups or amide groups are mono-reacted and di-reacted in a ratio of at least about 1.5:1, and (iii) the GPAM has a weight average molecular weight of from about 10,000 g / mole to about 10,000,000 g / mole.

[0140] The amount of GPAM added to the flat is not limited. In certain embodiments, the composition comprising one or more aldehyde-functionalized polymers is added to the flat at about 0.05 lb / ton to about 20 lb / ton based on dry fiber. Thus, in certain embodiments, the composition comprising GPAM is added at about 0.05 lb / ton to about 20 lb / ton, about 0.05 lb / ton to about 18 lb / ton, about 0.05 lb / ton to about 15 lb / ton, about 0.05 lb / ton to about 12 lb / ton, about 0.05 lb / ton to about 10 lb / ton, about 0.05 lb / ton to about 8 lb / ton, about 0.05 lb / ton to about 6 lb / ton, about 0.05 lb / ton to about 4 lb / ton, about 0.05 lb / ton to about 3 lb / ton. ton, about 0.15 lb / ton to about 2 lb / ton, about 1 lb / ton to about 20 lb / ton, about 1 lb / ton to about 18 lb / ton, about 1 lb / ton to about 15 lb / ton, about 2 lb / ton to about 20 lb / ton, about 2 lb / ton to about 18 lb / ton, about 2 lb / ton to about 15 lb / ton, about 5 lb / ton to about 15 lb / ton, about 1 lb / ton to about 10 lb / ton, about 1 lb / ton to about 5 lb / ton, or about 5 lb / ton to about 10 lb / ton. In a specific embodiment, the composition comprising GPAM is added to the flat plate at about 0.05 lb / ton to about 3 lb / ton.

[0141] The GPAM of the present invention may be added to the papermaking system in any form, such as a solution containing unreacted aldehyde (glyoxal). The solution containing the GPAM may contain any suitable amount of unreacted aldehyde (glyoxal). In certain embodiments, the solution containing the GPAM of the present invention contains unreacted glyoxal in an amount of about 40% to about 95%, about 40% to about 90%, about 40% to about 85%, about 40% to about 80%, about 40% to about 75%, about 40% to about 70%, about 40% to about 65%, about 40% to about 60%, about 45% to about 95%, about 50% to about 95%, about 55% to about 95%, about 60% to about 95%, about 65% to about 95%, about 70% to about 95%, about 75% to about 95%, or about 80% to about 95%. In certain embodiments, the solution containing GPAM contains unreacted glyoxal in an amount of about 60% to about 95%.

[0142] In certain embodiments, the present disclosure provides a flat sheet produced according to one of the aforementioned methods.

[0143] In certain embodiments, the GPAM is added to the papermaking system as an aqueous solution. In certain embodiments, the GPAM is added to the papermaking system as a solution in a water-miscible co-solvent. In certain embodiments, the GPAM is sprayed onto the flat prior to press dewatering.

[0144] The compositions and methods of the present disclosure can be used in any papermaking process, including a method for making paper products from pulp, which includes forming an aqueous cellulosic papermaking furnish, draining the furnish to form a sheet, and drying the sheet. The steps of forming, draining, and drying the papermaking furnish can be performed in any conventional manner generally known to those skilled in the art. Conventional fines, alum, cationic starch, or combinations thereof may be utilized as adjuvants with the polymer treatment of the present disclosure, although it must be emphasized that an adjuvant is not required for effective dewatering activity.

[0145] The GPAM of the present disclosure may be added at traditional wet-end locations used for conventional wet-end additives. These include thin or thick stock. The actual wet-end location is not considered critical. Since the GPAM is believed to act as a press aid, it is not essential to add it to the wet-end, and the option of adding it just before the press section after the formation of the flat can also be implemented. For example, the GPAM may be sprayed (e.g., using a shower bar) onto the wet web before entering the press section, which may be a preferred method of addition to reduce the amount or effect of possible interference at the wet-end. Other conventional wet-end additives may be used in conjunction with the aldehyde-functionalized polymer. These include retention aids, strength additives such as starch, sizing agents, and the like.

[0146] When using GPAMs described herein that have a net anionic charge, a method of anchoring the polymer to the fiber may be required. This anchoring can be achieved by using a cationic material along with the polymer. Such cationic materials can include coagulants that are either inorganic (e.g., alum, polyaluminum chloride, ferric chloride or sulfate, and any other cationic hydrolyzed salts) or organic (e.g., p-DADMAC, EPI / DMA, PEL, modified PEL, or any other high charge density low to medium molecular weight polymers). Additionally, cationic materials added for other purposes, such as starch, wet strength, or retention aids, can also help anchor the anionic polymer. Generally, no additional additives are required to anchor the cationic aldehyde-functionalized polymer to the filler.

[0147] GPAM can be used to dewater all grades of paper and paperboard. In certain embodiments, GPAM is used to prepare recycled paperboard grades using OCC (old corrugated containers) with or without mixed waste. In certain other embodiments, GPAM is used to prepare white, recycled, mechanical, chemical, bleached, or unbleached paper.

[0148] In certain embodiments, the composition comprising GPAM further comprises a cationic starch.

[0149] Embodiment A non-limiting list of embodiments is provided below: 1. A method for making a GPAM comprising the steps of: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 to obtain the GPAM; Including, A method wherein the progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscometer. 2. The method of embodiment 1, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol. 3. The method of embodiment 1 or 2, wherein the GPAm has a glyoxal to acrylamide (G / A ratio) of about 0.05:1 to about 20:1 or 0.1:1 to about 20:1. 4. The method of embodiment 1, wherein the progress of the reaction is monitored by continuously measuring the viscosity of the reaction solution, optionally with feedback control. 5. The method according to any one of the first to fourth embodiments, wherein the online viscosity meter is (a) a transducer assembly, (i) at least one flow tube inserted into the pipe, the flow tube having a lumen for conducting the reaction solution, the flow tube being clamped at an inlet end and an outlet end so as to be vibrable; (ii) Electromechanical excitation equipment; and (iii) sensor equipment; a transducer assembly including: (b) meter electronics; and A method comprising: 6. The method of any of the preceding embodiments, wherein the reaction is quenched when the viscosity of the reaction solution increases by more than 100% compared to its initial viscosity. 7. The method of any of the preceding claims, wherein the pH of the reaction in step (a) is maintained in the range of about 8 to about 9 by adding a caustic solution, which is optionally further diluted with water. 8. The method of any one of the preceding embodiments, wherein in step (b), the quenching comprises adding an organic acid, such as citric acid. 9. The method of any one of the preceding embodiments, wherein the GPAm has a glyoxal to acrylamide (G / A ratio) of about 0.4:1 to about 20:1. 10. The method of any one of the preceding claims, wherein at least one of steps (a)-(b) is carried out at a paper production site. 11. The method of any one of the preceding embodiments, wherein GPAM is prepared on-site in a semi-batch or full batch. 12. The method of any one of the preceding embodiments, wherein the method is carried out as a batch or semi-batch process. 13. The method of any one of the preceding claims, wherein the polyacrylamide is an acrylamide / DADMAC copolymer. 14. The method of embodiment 13, wherein the copolymer is about 1-30 mol % DADMAC and about 70-99 mol % acrylamide. 15. The method of embodiment 1, wherein the viscometer is an open flow tube viscometer. 16. The method of embodiment 1, wherein the viscosity meter comprises: - a measuring system with at least one measuring tube, which is filled with a reaction solution during the measuring operation or through which the reaction solution flows and which has at least one tube section which can be excited to perform oscillations; an excitation system for exciting at least two desired vibration modes of different frequencies, in which at least one of the tube sections is excited to carry out a vibration, in particular a resonant vibration; a sensing system embodied for determining, for the desired vibration modes excited during the measurement operation, the frequency and damping, in particular the frequency, amplitude and damping, of the resulting vibration of at least one pipe section excited to perform a vibration of one of the desired vibration modes in each case; and An evaluation system embodied to determine a shear rate value and a viscosity measurement value each time based on the excitation determined frequency and damping, in particular frequency, amplitude and damping, of the resulting vibrations based on calibration data stored in a memory for each desired vibration mode excited during the measurement operation, wherein the viscosity measurement value corresponds to the dynamic viscosity of the GPAM at a static shear rate corresponding to the shear rate value. 17. A method for enhancing paper strength and press section drainage of flat sheets on a paper machine, comprising adding to the flat sheets from about 0.05 lb / ton to about 20 lb / ton based on dry fiber of an aqueous composition prepared by the method of any one of embodiments 1-16. 18. A method for making an aldehyde-functionalized polymer, comprising: (a) combining at least one polymer containing at least one amide or amino group with an aldehyde to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain the aldehyde-functionalized polymer; Including, A method wherein the progress of the reaction is monitored by measuring the viscosity of the reaction solution from an online viscometer. 19. The method of embodiment 18, wherein the aldehyde is selected from formaldehyde, paraformaldehyde, and glutaraldehyde. 20. The method of embodiment 18, further comprising contacting the GPAM prepared according to any one of embodiments 1 to 19 with a fiber slurry or flat. 21. A flat sheet produced according to the method of embodiment 17 or embodiment 20. 22. A method for enhancing paper strength and press section drainage of a flat sheet on a papermaking machine, comprising adding to the flat sheet from about 0.05 lb / ton to about 20 lb / ton of an aqueous composition prepared by the method of embodiment 18 or embodiment 19 based on dry fiber. 23. The method of embodiment 18, further comprising contacting the GPAM with a fiber slurry or flat. 24. A flat-sheet produced according to the method of embodiment 22 or 23. 25. A method according to any one of the preceding embodiments, wherein the progress of the preparation of GPAM is monitored by measuring the viscosity of the reaction solution via a feedback loop from an online viscometer. 26. The method of any of the preceding embodiments, wherein the reaction is quenched when the viscosity of the reaction solution is at least 3 cP. 27. The method of any one of the preceding embodiments, wherein the reaction is quenched when the viscosity of the reaction solution is in the range of about 20 cP to about 1,000 cP. 28. A GPAM composition comprising a GPAM prepared according to the method of any one of embodiments 1 to 27, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol, and the GPAM has a glyoxal to acrylamide (G / A ratio) in the range of about 0.4:1 to about 20:1. 29. A method for producing a GPAM, comprising: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain GPAM; Including, The progress of the reaction is monitored by measuring the viscosity of the reaction solution via a feedback loop from an online viscometer; the polyacrylamide has a weight average molecular weight of about 7,000 to 50,000 daltons; The reaction is quenched when the reaction solution has a viscosity in the range of about 12 cP to about 40 cP. 30. A method for making a GPAM, comprising: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain GPAM; Including, The progress of the reaction is monitored by measuring the viscosity of the reaction solution via a feedback loop from an online viscometer; the polyacrylamide has a weight average molecular weight of about 50,000 to 200,000 daltons; The method wherein the reaction is quenched when the reaction solution has a viscosity in the range of about 20 cP to about 1,000 cP (the viscosity measurement is based on measurements at ambient temperature and the reaction solution has a concentration / solids of 8-10%). 31. A method for producing a GPAM, comprising: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 (or about 4 to about 6) to obtain GPAM; Including, The progress of the reaction is monitored by measuring the viscosity of the reaction solution via a feedback loop from an online viscometer; the polyacrylamide has a weight average molecular weight of about 15,000 daltons; The method wherein the reaction is quenched when the reaction solution has a viscosity in the range of about 10 cP to about 100 cP (the viscosity measurement is based on measurements at ambient temperature and the reaction solution has a concentration / solids content of 6-15%). 32. The polyacrylamide has a weight average molecular weight of 7,000 to 50,000 daltons; 2. The method of embodiment 1, wherein the reaction is quenched at a viscosity in the range of about 10 cP to about 40 cP. 33. The polyacrylamide has a weight average molecular weight of 50,000 to 200,000 daltons; 2. The method of embodiment 1, wherein the reaction is quenched at a viscosity in the range of about 20 cP to about 1,000 cP. 34. The polyacrylamide has a weight average molecular weight of 15,000 to about 20,000 daltons, and the reaction solution has an initial viscosity of about 2 to 4 cP; 2. The method of embodiment 1, wherein the reaction is quenched at a viscosity in the range of about 10-15 cP. 35. The polyacrylamide has a weight average molecular weight of 30,000 to about 50,000 daltons, and the reaction solution has an initial viscosity of about 5 to 8 cP; 2. The method of embodiment 1, wherein the reaction is quenched at a viscosity in the range of about 25 cP to about 40 cP (or 30 cP to about 40 cP). 36. The method of embodiment 1, wherein the reaction solution has an initial viscosity of about 2-10 cP. 37. The method of embodiment 1, 18, or 29-31, wherein the reaction is quenched when the viscosity of the reaction solution increases by more than 100% compared to its initial viscosity. 38. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution increases by 300-400% compared to its initial viscosity. 39. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution increases by 300-400% compared to its initial viscosity. 40. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution has increased by at least 50% compared to its initial viscosity. 41. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution has increased by at least 100% compared to its initial viscosity. 42. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution increases by about 300 to about 500% compared to its initial viscosity. 43. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution increases by about 300 to about 400% compared to its initial viscosity. 44. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution increases by about 400% compared to its initial viscosity. 45. The method of embodiment 1, 18, or 29-31, wherein the reaction of step (a) is quenched when the viscosity of the reaction solution increases by about 350% compared to its initial viscosity. 46. ​​The method of any one of embodiments 1, 18, or 29-31, wherein the polyacrylamide is an acrylamide / DADMAC copolymer. 47. The method of embodiment 1, 18, or 29-31, wherein the copolymer is about 1-30 mol % DADMAC and 70-99 mol % acrylamide. 48. The method of embodiment 46, wherein the copolymer is a 95 / 5 mole % acrylamide / DADMAC copolymer. 49. The method of embodiment 46, wherein the copolymer is an 80 / 20 mol % acrylamide / DADMAC copolymer. 50. The polyacrylamide has a weight average molecular weight of 50,000 to 200,000 daltons; 2. The method of embodiment 1, wherein the reaction is quenched at a viscosity in the range of about 20 cP to about 1,000 cP. 51. The method of embodiment 1, wherein step (a) comprises: mixing the polyacrylamide with water to obtain a mixture; adding the glyoxal to the mixture to obtain the reaction solution; A method comprising: 52. The method of embodiment 1, wherein step (a) comprises: combining the glyoxal with water to obtain a mixture; and adding the polyacrylamide to the mixture to obtain the reaction solution; A method comprising: 53. The method of embodiment 1, wherein step (a) includes adjusting the temperature to about 65-85°F. 54. The method of embodiment 1, wherein step (a) includes adjusting the temperature to about 60-80°F. 55. The method of embodiment 1, wherein step (a) comprises adjusting the temperature to about 70 to about 75°F. 56. The method of embodiment 1, wherein step (a) includes adjusting the temperature to about 75°F. 57. The method of embodiment 1, wherein step (a) followed by step (b) is repeated at least twice. 58. The method of embodiment 1, wherein the pH is monitored in real time. 59. The method of embodiment 1, wherein the pH is measured using at least one pH meter. 60. The method of embodiment 1, wherein the pH is measured using at least two pH meters. 61. A GPAM composition comprising a GPAM prepared according to the method of any one of embodiments 1 to 60, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol, and the GPAM has a glyoxal to acrylamide (G / A ratio) in the range of about 0.1:1 to about 20:1. 62. The method of any of the preceding embodiments, wherein the pH of the reaction solution is adjusted to a value in the range of about 4 to about 6. EXAMPLES

[0150] The above will be better understood with reference to the following examples, which are presented for illustrative purposes and are not intended to limit the scope of the invention.

[0151] Example 1 Preparation of 95 / 5 mole % acrylamide / DADMAC copolymer To a 1500 mL reaction flask equipped with a mechanical stirrer, thermocouple, condenser, nitrogen purge tube, and addition port, add 116.4 g deionized or softened water, 26.3 g phosphoric acid, 63.8 g of a 62% aqueous solution of diallyldimethylammonium chloride (Nalco Company, Naperville, IL), 7.6 g sodium formate, and 0.09 g of tetrasodium salt of ethylenediaminetetraacetic acid. The reaction mixture is stirred at 400 rpm and the pH is adjusted to 4.7-4.9 using 17.3 g of a 50% aqueous solution of sodium hydroxide. The resulting mixture is heated to 100 °C and purged with nitrogen at 50 mL / min. Once at 100 °C, add 17.6 g of a 25.0% aqueous solution of ammonium persulfate to the reaction mixture over 135 minutes. Five minutes after the addition of ammonium persulfate begins, add 750.9 g of a 49.5% aqueous solution of acrylamide to the reaction mixture over 120 minutes. After the ammonium persulfate is added, the reaction is held at 100°C for 180 minutes. The reaction mixture is then cooled to ambient temperature and the pH is adjusted to 5.2-5.8 using 50% aqueous sodium hydroxide or concentrated sulfuric acid. The product is a viscous clear to amber solution. The product has a molecular weight of approximately 20,000 g / mol.

[0152] Example 2 In situ preparation of GPAM A set of 35 GPAM samples was produced using the in situ procedure (see, for example, Figure 2). The samples were analyzed for polymer composition using NMR. All samples showed similar compositions to the commercial GPAM product, BP612. One example (GPAM-1) is shown in Table 1; the structures of the in situ samples were observed to be very similar to the commercially produced BP612 GPAM.

[0153] [Table 2]

[0154] Paper strength performance testing was performed using samples of GPAM (GPAM-2) produced using the method according to the present disclosure. Three samples were tested in the handsheet study using three conditions. One sample was used within 1 hour of synthesis, one was used after aging at room temperature for 3 hours, and another sample was used after aging at 35°C for 3 hours. The performance of these samples was evaluated using the commercially available GPAM BP612 as a benchmark. The handsheets used in this study were prepared according to TAPPI method T205 and tested for tensile strength (TAPPI method T494), burst strength (TAPPI method T403), short span compressive strength (SCT, TAPPI method T826), and ring crush strength (RCT, TAPPI method T822). The results are summarized in Table 2 and Figure 3. The results showed that the strength performance of all three GPAM samples was equal to or better than the commercially available BP612 GPAM material.

[0155] [Table 3] Average strength improvement of GPAM-2 samples produced using the in situ manufacturing process and commercial BP612 GPAM material (see Figure 3).

[0156] All references cited in this specification, including publications, patent applications, and patents, are herein incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.

[0157] The embodiments of the present disclosure are described herein and include the best mode known to the inventors for carrying out the invention. Variations of these embodiments may become apparent to those skilled in the art after reading the foregoing description. The inventors anticipate that such variations will be employed by those skilled in the art as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Also, any combination of the above-described elements in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein or clearly contradicted by context.

[0158] The present invention may be embodied in many different forms, and certain preferred embodiments of the present invention are described in detail herein. The present disclosure is an exemplification of the principles of the present invention, and is not intended to limit the present invention to the specific embodiments illustrated. All patents, patent applications, academic papers, and any other referenced materials mentioned herein are incorporated herein by reference in their entirety. Furthermore, the present invention encompasses any possible combination of some or all of the various embodiments mentioned herein, described herein, and / or incorporated herein. In addition, the present invention encompasses any possible combination that also specifically excludes any one or some of the various embodiments mentioned herein, described herein, and / or incorporated herein.

[0159] Any information in any material incorporated by reference herein (e.g., U.S. patents, U.S. patent applications, books, articles, etc.) is incorporated by reference only to the extent that there is no conflict between such information and other descriptions and drawings set forth herein. In the event of such a conflict (including a conflict that would invalidate any claim herein), any such conflicting information in such material incorporated by reference is not specifically incorporated by reference herein.

[0160] The above disclosure is intended to be illustrative and not restrictive. This specification will suggest many variations and modifications to those skilled in the art. All such variations and modifications are intended to be included within the scope of the claims, where the term "including" means "including but not limited to." Those skilled in the art may recognize other equivalents to the specific embodiments described herein, which equivalents are also intended to be included within the scope of the claims.

[0161] All ranges and parameters disclosed herein are understood to encompass any and all subranges contained within the range, as well as all numbers between the endpoints. For example, a stated range of "1-10" should be considered to include any and all subranges between (and including) the minimum value of 1 and the maximum value of 10, i.e., all subranges beginning at or above the minimum value of 1 (e.g., 1-6.1) and ending at or below the maximum value of 10 (e.g., 2.3-9.4, 3-8, 4-7), and finally each of the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range. Unless otherwise indicated, all percentages and ratios herein are by weight. G / A (glyoxal to amide) ratios disclosed herein are based on molar ratios. Additionally, NMR results disclosed herein are based on molar ratios.

[0162] This completes the description of the preferred and modified embodiments of the present invention. Those skilled in the art may recognize other equivalents to the specific embodiments described herein which equivalents are intended to be encompassed by the claims.

Claims

1. 1. A method of making a GPAM, said method comprising: (a) combining at least polyacrylamide and glyoxal to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 to obtain the GPAM; Including, The process wherein the progress of the reaction is monitored by measuring the viscosity of the reaction solution using an online viscosity meter.

2. 10. The method of claim 1, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol.

3. 3. The method of claim 1 or 2, wherein the GPAM has a glyoxal to acrylamide (G / A ratio) of about 0.05:1 to about 20:

1.

4. 3. The method of claim 1 or 2, wherein the progress of the reaction is monitored by continuously measuring the viscosity of the reaction solution, optionally with feedback control.

5. 3. The method according to claim 1 or 2, wherein the online viscosity meter comprises: (a) a transducer assembly comprising: (i) at least one flow tube inserted into the pipe, the flow tube having a lumen for conducting the reaction solution, the flow tube being clamped at its inlet and outlet ends so as to be vibrable; (ii) electromechanical excitation equipment; and (iii) sensor equipment; a transducer assembly including: (b) meter electronics; and A method comprising:

6. 3. The method of claim 1 or 2, wherein the reaction is quenched when the viscosity of the reaction solution increases by more than 100% compared to its initial viscosity.

7. 10. The method of claim 1, wherein the pH of the reaction in step (a) is maintained in the range of about 8 to about 9 by adding a caustic solution, which is optionally further diluted with water.

8. 10. The method of claim 1, wherein in step (b), the quenching comprises adding an organic acid to the reaction solution.

9. 3. The method of claim 1 or 2, wherein the GPAM has a glyoxal to acrylamide (G / A ratio) of about 0.4:1 to about 20:

1.

10. 10. The method of claim 1, wherein the polyacrylamide is a copolymer of acrylamide / DADMAC.

11. 11. The method of claim 10, wherein the copolymer is about 1 to 30 mole percent DADMAC and about 70 to 99 mole percent acrylamide.

12. 3. The method of claim 1 or 2, wherein the viscometer is an open-flow tube viscometer.

13. 10. The method of claim 1, wherein the viscosity meter comprises: a measuring system having at least one measuring tube, which is filled with a reaction solution during the measuring operation or through which the reaction solution flows and which has at least one tube section that can be excited to perform oscillations; an excitation system for exciting at least two desired vibration modes of different frequencies, in each of which at least one of the pipe sections is excited to carry out a vibration, in particular a resonant vibration; a sensing system configured to determine, for each desired vibration mode excited during the measurement operation, the frequency and damping, in particular the frequency, amplitude and damping, of the resulting vibration of at least one pipe section excited to perform one of the desired vibration modes; and an evaluation system configured to determine a shear rate value and a viscosity measurement value each time based on the excitation determined frequency and damping, in particular frequency, amplitude, and damping, of the resulting vibrations based on calibration data stored in memory for each desired vibration mode excited during the measurement operation, wherein the viscosity measurement value corresponds to the dynamic viscosity of the GPAM at a static shear rate corresponding to the shear rate value.

14. 1. A method of making an aldehyde-functionalized polymer, said method comprising: (a) combining at least one polymer containing at least one amide or amino group with an aldehyde to obtain a reaction solution; (b) quenching the reaction by adjusting the pH of the reaction solution to a value in the range of about 2 to about 6 to obtain the aldehyde-functionalized polymer; Including, The process wherein the progress of the reaction is monitored by measuring the viscosity of the reaction solution using an online viscosity meter.

15. 15. The method of claim 14, wherein the aldehyde is selected from formaldehyde, paraformaldehyde, and glutaraldehyde.

16. 16. The method of claim 15, wherein the method further comprises contacting the aldehyde-functionalized polymer with a fiber slurry or flat.

17. 3. A GPAM composition comprising GPAM prepared according to the method of claim 1 or 2, wherein the GPAM has a weight average molecular weight of about 10,000 g / mol to 10,000,000 g / mol, and the GPAM has a glyoxal to acrylamide (G / A ratio) ranging from about 0.05:1 to about 20:1.

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