COMPOSITION AND METHOD FOR INCREASING THE WET AND DRY STRENGTH OF PAPER

Abstract

A composition for increasing paper strength includes a dialdehyde-modified polyacrylamide reinforcing agent, a water-soluble compound that is soluble in approximately 5% by weight or more in water at approximately 25°C, and water. The water-soluble compound is typically present in a greater amount by weight than the reinforcing agent. The composition is formed by combining the reinforcing agent and the water-soluble compound in aqueous media, wherein, on a dry basis, the water-soluble compound is typically present in a greater amount than the reinforcing agent; drying the composition to form a powder or paste having a water content of less than approximately 10% by weight and that is stable after storage at approximately room temperature for approximately six months; and reconstituting the powder or paste by adding water thereto.The reconstituted composition can then be used to manufacture paper.

Description

COMPOSITION AND METHOD FOR INCREASING THE WET AND DRY STRENGTH OF PAPER CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Application No. 16 / 288,477, filed on February 28, 2019. FIELD OF INVENTION This disclosure relates generally to a composition and a method for increasing the wet and dry strength of paper. More specifically, this disclosure relates to the formation of the composition, drying the composition to ensure its stability during storage, reconstituting the composition, and subsequently using the reconstituted composition to manufacture paper. BACKGROUND OF THE INVENTION Glyoxal polyacrylamide (GPAM) resins have been widely used in the paper industry in aqueous solutions. These GPAM resins are commonly added at the wet end of papermaking processes and improve both the papermaking process and the paper's properties. The performance of these The properties of GPAM resins can be improved by increasing the molecular weight, which alters the polymer structure, and / or by controlling the level of glyoxal reactive functionality. However, the low solids content, sensitivity to temperature and pH, and relatively short shelf life of GPAM resins are significant commercial concerns. A GPAM resin with a longer shelf life, stability during transport, and high concentration during transport would be desirable. However, to date, this problem remains unresolved. Several options for improving the stability of GPAM resins are known in the art. These options include the use of stabilizing agents (US 2011 / 0146925 Al), the use of low-molecular-weight acrylamide-based polymers for glyoxalation (US 4,605,702), or the use of microparticles of a glyoxalized polyacrylamide prepared by reverse emulsion polymerization techniques (US 4,954,538). More recently, BASF (US 8703847 B2, US 9879381 B2) disclosed the conveying of high-solids polyacrylamide solutions and the performance of glyoxalation reactions at the milling sites. This process requires precise control of pH and temperature to produce reproducible materials. However, none of these methods solves the problem at hand. GPAM resins, when left to dry on their own, cannot be re-dissolved in water, and the aldehyde functionality is no longer available to impart strength properties to the paper. Furthermore, highly concentrated GPAM solutions have an even shorter shelf life than less concentrated solutions. Products used in industry typically contain only about 10% solids when stored and sold. Therefore, there remains an opportunity for improvement and development of a composition and method that meet current industry needs. Furthermore, other desirable features and characteristics of this disclosure will become apparent from the subsequent detailed description of the disclosure and the accompanying claims, taken in conjunction with the accompanying drawings and this disclosure background. ML / t / ZUZ I / UO lU10 BRIEF DESCRIPTION OF THE INVENTION This disclosure provides a composition for increasing paper strength. The composition includes a dialdehyde-modified polyacrylamide reinforcing agent, a water-soluble compound comprising one or more hydroxyl or amide portions and soluble in approximately 5% by weight or more in water at approximately 25°C, and water. Furthermore, the water-soluble compound is typically present in a weight amount greater than the weight amount of the dialdehyde-modified polyacrylamide reinforcing agent. This disclosure also provides a method for forming the composition. The method includes the steps of combining the dialdehyde-modified polyacrylamide reinforcing agent and the water-soluble compound in aqueous media to form the composition, wherein, on a dry basis, the water-soluble compound is typically present in a greater amount than the dialdehyde-modified polyacrylamide reinforcing agent. The method also includes the step of drying the composition to form a powder or paste having a water content of less than approximately 10 percent by weight and that is stable after storage at approximately room temperature for approximately six months, and the step of reconstituting the powder or paste by adding water thereto. This disclosure further provides a method for increasing the wet and / or dry strength of paper. This method includes the step of combining the dialdehyde-modified polyacrylamide reinforcing agent and the water-soluble compound in aqueous media to form the The composition, wherein, on a dry basis, the water-soluble compound is present in a greater amount than the dialdehyde-modified polyacrylamide reinforcing agent. The method also includes the step of drying the composition to form a powder or paste having a water content of less than approximately 10 percent by weight and that is stable after storage at room temperature for approximately six months, reconstituting the powder or paste by adding water thereto, providing an aqueous suspension of cellulosic fibers, combining the reconstituted composition and the aqueous suspension of cellulosic fibers, and forming paper from the combination of the reconstituted composition and the aqueous suspension of cellulosic fibers, wherein the paper has increased wet and / or dry strength compared to paper formed without the reconstituted composition. DETAILED DESCRIPTION OF THE INVENTION The following detailed description is merely illustrative and is not intended to limit the composition for increasing paper strength. Furthermore, there is no intention of being constrained by any theory presented in the preceding background or in the following description. ΜΛ / t / ZUZ I / UO / U IO detailed. The methods described herein generally pertain to compositions for increasing paper strength and methods for forming them. For the sake of brevity, conventional techniques related to the manufacture of such compositions may not be described in detail herein. Furthermore, the various tasks and process steps described herein may be incorporated into a more complete procedure or process that has additional steps or functionalities not described in detail herein. In particular, several steps in the formation of such compositions may be well known, and thus, for the sake of brevity, many conventional steps will only be mentioned briefly herein or omitted entirely without providing details of the well-known process. As used herein and unless otherwise indicated: (1) all percentages, parts, ratios, etc., are expressed by weight; (2) when a quantity, concentration, or other value or parameter is given as a list of upper preferred values ​​and lower preferred values, it is understood that all intervals formed from any pair of an upper typical value and a lower typical value are specifically disclosed, regardless of whether the intervals are ML / I / UO / UIO disclose separately; (3) the term total solids refers to the solids remaining after the volatiles (e.g. solvents) have been removed; (4) the term active solids refers to at least a portion of the GPAM resin of the total solids remaining after subtracting the water-soluble compound used in the feed. Composition This disclosure provides a composition for increasing paper strength. The composition may be a liquid, a powder, or a paste. Alternatively, the composition may change from a liquid to a powder and / or a paste, or from a powder to a paste, or vice versa, at various points during a manufacturing method and / or use. Paper strength is typically measured based on dry strength or wet strength. In several embodiments, the composition in this disclosure provides an increase of at least approximately 80, 85, 90, 95, or more percent in the dry strength of paper formed using this composition compared to paper formed without this composition. In other embodiments, the composition in this disclosure provides an increase of at least 80, 85, 90, 95, or more percent in the wet strength of paper formed ML / t / ZUZ I / UO / U IO using this composition compared to a paper formed without the present composition. Typically, wet strength is determined using TAPPI Method T456 using a Finch cup. Typically, dry strength is determined using TAPPI Test Method T494. In other embodiments, this composition provides a wet and / or dry paper strength that is approximately 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or even 100% of the wet and / or dry strength of paper formed using GPAM alone that is not dried and then reconstituted. In fact, in other embodiments, this composition provides a wet and / or dry paper strength that is approximately 5, 10, 15, 20, or even a higher percentage improvement over the wet and / or dry strength of paper formed using GPAM alone that is not dried and then reconstituted. This performance is important because it allows the compositions in this disclosure to be transported without water and to be stable in storage. This drastically reduces transportation costs and complexities and resolves the aforementioned problems. In another modality, the above compositions impart wet strength and / or temporary wet strength and / or dry strength to the formed or treated paper. ML / I / UO / UIO with the reconstituted compositions. For example, in one embodiment, the composition is in powder form and has a shelf life of at least six months, such that the wet strength and / or dry strength paper yield after six months is at least approximately 80% of the wet strength and / or dry strength paper yield measured within one month of the composition's manufacture. In other embodiments, the wet strength and / or dry strength paper yield after six months is at least approximately 85, 90, 95, or greater, % of the wet strength and / or dry strength paper yield measured within one month of the composition's manufacture. In various embodiments, the composition includes, essentially consists of, or comprises, a dialdehyde-modified polyacrylamide reinforcing agent, a water-soluble compound including one or more hydroxyl or amide portions and soluble in approximately 5% by weight or more in water at approximately 25°C, and water. In various embodiments, this composition may include, or be free of, one or more of the additives or other compounds described below. In several forms, the composition has a solids content of less than approximately 5, 10, 15, 20, 25, or 30% by weight. In other forms, the composition MA / / UO / U IO has a solids content of approximately 10% to approximately 30% by weight. In still other formulations, the composition has a solids content of more than approximately 30% by weight. The solids content is typically formed from any non-volatile compounds remaining after the extraction of water-soluble compounds. In other formulations, the composition is soluble as a solution of approximately 1% by weight in water at approximately 25°C. In other formulations, the composition is soluble as a solution of approximately 1 to 5% by weight in water at approximately 25°C. The composition itself may be completely soluble in water, for example, have a solubility of up to approximately 100%. However, this differs from the amount of the composition actually used. The composition may be used, for example, in an amount of up to approximately 5% by weight in water. In one formulation, the composition imparts both wet strength and improved chemical retention during the papermaking process. Chemical retention can describe the retention of fines and other similar particles, as understood by experts in the field. Dialdehyde-Modified Polyacrylamide Reinforcing Agent ML / I / UO / U IO The reinforcing agent for dialdehyde-modified polyacrylamide is not particularly limited and can be any dialdehyde-modified polyacrylamide in the art. For example, dialdehyde-modified polyacrylamide can be further defined as a glyoxal polyacrylamide that includes an aldehyde group, also known as a GPAM or GPAM resin. Other non-limiting examples of suitable dialdehyde-modified polyacrylamides include cationic polyacrylamides, acrylamide-DADMAC (polydiallyldimethylammonium chloride) copolymers, and the like, and combinations thereof. In other embodiments, the dialdehyde-modified polyacrylamide reinforcing agent may be cationic and be a copolymer that is or includes the reaction product of an acrylamide monomer and a cationic monomer. Examples of suitable cationic monomers include polydiallyldimethylammonium chloride monomers and the like, as would be understood by those skilled in the art. In additional embodiments, the dialdehyde-modified polyacrylamide reinforcing agent is further defined as a polyacrylamide resin with aldehyde-based reactive groups. In another embodiment, a prepolymer is used to form a GPAM resin, wherein the prepolymer can be cationic, anionic, or amphoteric in nature. The various ionic monomers that can be incorporated into the The GPAM prepolymer, and thus the GPAM resin, is not particularly limited and can be chosen by someone skilled in the art. In various forms, monomers such as diallyldimethylammonium chloride or acrylamide-methylpropane sulfonic acid can be used. In other embodiments, the dialdehyde-modified polyacrylamide reinforcing agent is the reaction product of glyoxal and a prepolymer that is the reaction product of a polyacrylamide monomer and a diallyldimethylammonium chloride monomer, wherein the molar ratio of acrylamide to diallyldimethylammonium chloride is approximately 99:1 to approximately 50:50, respectively, and wherein approximately 40 mol% of the acrylamide groups of the polyacrylamide monomer have been reacted and approximately 15 mol% of the acrylamide groups have active aldehyde functionality. The dialdehyde-modified polyacrylamide reinforcing agent is not particularly limited in quantity in this composition. In several embodiments, the amount of the dialdehyde-modified polyacrylamide reinforcing agent is stated as a ratio to the water-soluble compound, described in more detail below. For example, the water-soluble compound may be present in a dry weight ratio to the dialdehyde-modified polyacrylamide reinforcing agent that is greater than approximately 1:1, approximately 1.5:1, approximately 2:1, approximately 2.5:1, approximately 3:1, approximately 3.5:1, approximately 4:1, approximately 4.5:1, or approximately 5:1, or even greater, respectively. Typically, the water-soluble compound is present in a weight amount that is greater than the weight amount of the dialdehyde-modified polyacrylamide reinforcing agent.With respect to weight percentage, the dialdehyde-modified polyacrylamide reinforcing agent may be present in an amount of approximately 1 to approximately 20, approximately 2 to approximately 10, approximately 2 to approximately 8, approximately 5 to approximately 10, or approximately 5 to approximately 8 pounds (lb) per ton of dry paper. In other embodiments, the dialdehyde-modified polyacrylamide reinforcing agent may be present in an amount of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc., up to 20 pounds (lb) per ton of dry paper. In various non-limiting embodiments, all values ​​and ranges of values ​​included and between those stated above are expressly contemplated herein for use. In several embodiments, the dialdehyde-modified polyacrylamide reinforcing agent is formed using a vinylamide polymer and a reactive agent, as follows ML / I / UO / UIO is described below. Mainframe vinylamide polymers, which can be subsequently glyoxalized, can be synthesized by free-radical polymerization or redox catalysis of a vinylamide monomer, and optionally one or more ionic or non-ionic comonomers. Crosslinking agents with multiple polymerizable vinyl functionalities can also be included to impart structure to the mainframe polymer. A chain-transfer agent, such as sodium hypophosphite, can be used to control the molecular weight of the polymer molecules, as well as to introduce branching. Vinylamide polymers can be formed by any suitable polymerization process. They can be prepared by solution polymerization, water-in-oil suspension polymerization, or water-in-oil emulsion polymerization. Polymers can be produced as beads by suspension polymerization or as a water-in-oil emulsion or dispersion by water-in-oil emulsion polymerization. Alternatively, vinylamide polymers can be provided as a dispersion in an aqueous medium. This could be, for example, a dispersion of vinylamide particles of at least 20 microns in an aqueous medium containing a equilibrating agent.This may also include, for example, aqueous dispersions of vinylamide particles prepared by polymerizing aqueous monomers in the presence of an aqueous medium containing dissolved polymers of low intrinsic viscosity, such as polydiallyl dimethyl chloride and, optionally, other dissolved materials, for example, electrolytes and / or multihydroxy compounds, for example, polyalkylene glycols. Vinylamide polymers that can be glyoxalized can have any molecular weight obtainable by polymer synthesis methods known to those skilled in the art. The vinylamide polymer can be nonionic, cationic, anionic, or amphoteric. It can also be crosslinked or structured. The average molecular weight of a vinylamide polymer can range from 500 to approximately 5,000,000 or even 10,000,000 Daltons. The starting vinylamide polymer typically has an average molecular weight of at least 500, but more typically from at least approximately 10,000 to approximately 5,000,000. For example, ranges of 50,000 to 2,000,000 and 70,000 to 1,000,000 are anticipated. In several non-limiting embodiments, the disclosure process allows the glyoxalation of vinylamide polymers of approximately 50,000 or more, approximately 70,000 or more, and even approximately 85,000 or 100,000 or more. Typical average molecular weight ranges are, for example, between 5,000 to approximately 150,000, 10,000 to approximately 150,000 or 25,000 to approximately 150,000. Suitable vinylamide monomers include (meth)acrylamide and C1-C4 monosubstituted (meth)acrylamides such as N-methyl(meth)acrylamide and N-ethyl(meth)acrylamide. The most typical vinyl monomers are acrylamide and methacrylamide. The term (meth)acrylamides encompasses both acrylamide and methacrylamide.The vinylamide content provides the binding sites for the reactive agent or glyoxal substituents. The minimum proportion of vinylamide units present may be sufficient to make the glyoxal polymer thermostable, such that the glyoxal polymer forms a water-insoluble film when deposited from an aqueous solution onto a glass plate and heated for 5 minutes at approximately 105 °C. In this way, the vinylamide polymer (before glyoxalation) can be formed from at least approximately 10 wt% vinylamide monomers. Typically, the vinylamide polymer is formed from at least approximately 20 to approximately 100 wt% vinylamide monomers. For example, the vinylamide polymer is made up of at least approximately 20 to approximately 99% by weight, and at least approximately 25 to approximately 90% by weight of vinylamide monomers, MA / / UO l U10 or at least approximately 50% by weight and more typically at least approximately 70% by weight of vinylamide monomers. The weight percent is based on the weight of the total weight of the charged monomers used to form the vinylamide polymer. Once the monomers are polymerized, they become incorporated units in the polymer. Thus, there may be units in the polymers of this disclosure that can confer ionic properties to the polymer, or those that act as diluents or spacers, or that confer special properties, for example, enhanced or decreased water solubility. Ionic comonomers, which can be used in conjunction with vinylamide monomers, can be cationic, potentially cationic, anionic, potentially anionic, or amphoteric. When cationic comonomers are used, one or more cationic monomers can be employed, and the total amount of cationic monomer can be such that a glyoxal adduct of the vinylamide copolymer is self-substantial to the cellulose fibers in aqueous suspension. Cationic comonomers can also be used. Suitable cationic monomers or potentially cationic monomers include diallyl dialkyl amines, 2-vinylpyridine, 2-(dialkylamino)alkyl(meth)acrylates, dialkylaminoalkyl(meth)acrylamides, including acidic and quaternary ammonium addition salts thereof. Specific examples of such cationic monomers or potentially cationic monomers are diallyldimethylammonium chloride, (meth)acryloyloxyethyltrimethylammonium chloride (quaternary salt of ML / t / ZUZ I / UO lU10 methyl chloride and dimethylaminoethyl(meth)acrylate), 2-vinyl-N-methylpyridinium chloride, (p-vinylphenyl)trimethylammonium chloride, (meth)acrylate 2-ethyltrimethylammonium chloride, 1-methacryloyl-4-methylpiperazine, Mannich polyacrylamides, i.e., polyacrylamide reacted with dimethylamine-formaldehyde adduct to give N-(dimethylaminomethyl)(meth)acrylamidopropyltrimethylammonium chloride. Potentially cationic monomers can be, for example, monomers that give a cationic charge under acidic conditions, such as when an amide functional group is protonated in the potentially cationic monomer. The amount of cationic comonomer can be from approximately 0% to approximately 90% by weight, from approximately 0.1% to approximately 50% by weight, from approximately 0.1% to approximately 40%, from approximately 0.1% to approximately 30%, from approximately 0.1% to approximately 25% by weight, or from approximately 0.1% to approximately 15% or approximately 10% by weight. The weight percent is based on the total weight of charged monomer(s) used to form the vinylamide polymer. Suitable anionic monomers can be selected from vinylic acid materials such as acrylic acid, methacrylic acid, maleic acid, allylsulfonic acid, vinylsulfonic acid, itaconic acid, fumaric acid, potentially anionic monomers such as maleic anhydride and itaconic anhydride and their alkali metal and ammonium salts, 2-acrylamido-2-methylpropanesulfonic acid and its salts, sodium styrene sulfonate, and the like. Alternatively, if the starting vinylamide polymer is polyacrylamide, it can be partially hydrolyzed to achieve some anionic character and then functionalized with the reactive agent. Potentially anionic monomers can be, for example, acrylamide, which, when partially hydrolyzed, forms an acid that can impart anionic character to the polymer under basic conditions.Alternatively, potentially anionic monomers can be, for example, an anhydride monomer, such as maleic anhydride or itaconic anhydride, which can be hydrolyzed to form the corresponding acid. Vinylamide polymers can be amphoteric; that is, they can include both anionic and cationic functionalities. Amphoteric vinylamide polymers can be composed of anionic, cationic, or zwitterionic monomers. The various monomers (anionic, cationic, and / or zwitterionic) can be reacted in any weight ratio to form the amphoteric vinylamide polymer. It is preferable that the predominant charge in the resulting amphoteric vinylamide polymer be cationic. In this way, the mole percent of cationic monomer dominates over the mole percent of anionic monomer incorporated into the amphoteric vinylamide polymer. Suitable non-ionic monomers other than vinylamide can be selected from the group consisting of (meth)acrylic esters such as octadecyl (meth)acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, hydroxyethyl (meth)acrylate and 2-ethylhexyl acrylate; N-alkylacrylamides, noctyl(meth)acrylamide, N-tert-butylacrylamide, N-vinylpyrrolidone, N,N-dialkyl(meth)acrylamides such as N,N'-dimethylacrylamide; styrene, vinyl acetate, hydroxyalkyl acrylates and methacrylate such as 2-hydroxyethyl acrylate and acrylonitrile. The starting vinylamide polymer or the vinylamide polymer adduct formed may be crosslinked, branched, otherwise structured, or linear. For example, the starting vinylamide polymer or the vinylamide polymer adduct formed may be linear, crosslinked, chain-transferred, or crosslinked and chain-transferred (structured). Crosslinking agents are typically agents Polyethylene unsaturated crosslinking systems (ML / I / UO / UIO) are used. Examples include methylene-bis(meth)acrylamide, trialylammonium chloride, tetraallylammonium chloride, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, N-vinyl acrylamide, divinylbenzene, tetra(ethylene glycol) diacrylate, dimethylallylaminoethyl acrylate ammonium chloride, diallyloxyacetic acid, sodium salt, diallylocylamide, ethoxylated trimethylpropane triacrylate, N-allylacrylamide, N-methylallylacrylamide, pentaerythritol triacrylate, and combinations thereof. Other crosslinking systems may be used instead of or in addition to these. For example, covalent crosslinking through substituted groups can be achieved, for example, by using ethylenically unsaturated epoxy or silane monomers, or by using polyfunctional crosslinking agents such as silanes, epoxides, polyvalent metal compounds, or other known crosslinking systems. Chain transfer agents can be used to synthesize the starting vinylamide polymer. Suitable chain transfer agents include 2-mercaptoethanol; low molecular weight organic acids such as lactic acid, formic acid, malic acid, or butyric acid; isopropyl alcohol; thioacids; and hypophosphites. Referring now to the reactive agent, the reactive agent typically includes more than one aldehyde portion. The reactive agents can be selected from the group consisting of glyoxal, glutaraldehyde, furan dialdehyde, 2-hydroxyadipaldehyde, succinaldehyde, starch dialdehyde, diepoxy compounds, and combinations thereof. Glyoxal is the typical reactive agent. The molar ratio of amide (in the vinylamide polymer) to the reactive agent typically varies from approximately 12:1 to approximately 2:1, for example, from approximately 10:1 to approximately 2.5:1, from approximately 6:1 to approximately 2.5:1, and from approximately 6:1 to approximately 3:1. The molar content of amide in the vinylamide polymer can be determined experimentally using methods well known in the art or calculated from the known monomer composition. Adding bases or changing the pH above 7 is the most common method for catalyzing the glyoxalation reaction. Typically, a pH range of 7 to 13 is generally considered a catalytic environment for the reaction. For example, a pH range of 8 to 12 is particularly suitable. Alternatively, a concentrated pH buffer solution can be added to maintain the pH. Water-Soluble Compound Referring now to the water-soluble compound, this compound is soluble in approximately 5% by weight or ML / t / ZUZ I / UO lU10 polysaccharide and combinations thereof. As such, the water-soluble compound can be chosen from monosaccharides, disaccharides, polysaccharides, and combinations thereof. In several embodiments, the water-soluble compound is maltodextrin. However, any saccharide may be used. In other formulations, the water-soluble compound is a polymer containing acrylamide. Suitable, but not limited, examples include amphoteric polyacrylamides, copolymers of amphoteric polyacrylamide with water-soluble monomers, and combinations thereof. The choice of water-soluble compound can be made by a skilled professional depending on whether the desired improvement is dry or wet strength. In one modality, the water-soluble compound is a small molecule, or a macromolecule derived from natural material, or prepared by modification of natural material, or chemically synthesized. In one embodiment, the water-soluble compound includes or is a small molecule, an oligomer, or a polymer. In one embodiment, the water-soluble compound has three or more hydroxyl groups, or the oligomer or polymer has three or more hydroxyl groups per repeating unit. In one embodiment, the water-soluble compound is a carbohydrate. In one embodiment, the water-soluble compound ML / t / ZUZ I / UO / U IO includes a polymeric oligosaccharide or saccharide. In one embodiment, the water-soluble compound is glycerol. In one embodiment, the water-soluble compound includes a polymer with repeating acrylamide units. In one embodiment, the acrylamide is polymerized with monomers containing cationic functionality, anionic functionality, or a combination of both. In one embodiment, the acrylamide-containing polymer can be functionalized. In one embodiment, the water-soluble compound is further defined as a copolymer formed from the reaction of organic monomers. The monomers are not particularly restricted and may be chosen from acrylamide monomers, saccharides, hydroxyl-containing monomers, amide-containing monomers, carboxyl-containing monomers, aldehyde-containing monomers, and the like, and combinations thereof. Alternatively, the monomer may be any polar or hydrophilic monomer, as recognized by someone skilled in the art. When the dialdehyde-modified polyacrylamide reinforcing agent and the water-soluble compound are combined, the dialdehyde-modified polyacrylamide reinforcing agent typically reacts with the water-soluble compound in such a way that most of the available aldehyde groups (hemiacetals) of the dialdehyde-modified polyacrylamide reinforcing agent react with the hydroxyl groups of the water-soluble compound. In one modality, there is an excess of hydroxyl groups compared to the reactive aldehyde groups. For example, there may be 1.5, 2, 3, or even more times the number of hydroxyl groups compared to the reactive aldehyde groups. In one embodiment, the disclosure provides a composition that includes a glyoxal polyacrylamide resin blended at the molecular level with a water-soluble compound. The complete mixture of GPAM and water-soluble compound is not present as an aqueous solution, and the GPAM mixture, when placed in water, will generate a solution containing the GPAM such that the GPAM can impart wet and / or dry strength properties to the paper. In one embodiment, a final reactive GPAM resin is produced by reconstituting the aldehyde groups by dissolving the above composition in water. In another embodiment, the hydroxyl groups are replaced by other chemical groups that form a reversible bond upon reaction with the reactive aldehyde groups of a GPAM resin. As described above, the water-soluble compound may be present in a dry weight ratio with the dialdehyde-modified polyacrylamide reinforcing agent greater than approximately 1:1, approximately 1.5:1, approximately 2:1, approximately 2.5:1, approximately 3:1, approximately 3.5:1, approximately 4:1, approximately 4.5:1, or approximately 5:1, or even greater, respectively. Typically, the water-soluble compound is present in a weight amount greater than the weight amount of the dialdehyde-modified polyacrylamide reinforcing agent.In terms of weight percentage, the water-soluble compound may be present in an amount of approximately 1 to approximately 100 pounds (lbs) per ton of dry paper, or any weight percentage corresponding to the aforementioned weight percentages and ratios of the water-soluble compound and the dialdehyde-modified polyacrylamide reinforcing agent. The water-soluble compound is typically present in a weight amount greater than that of the dialdehyde-modified polyacrylamide reinforcing agent. However, based on molar ratios, the water-soluble compound and the dialdehyde-modified polyacrylamide reinforcing agent are typically present in molar amounts such that there are more hydroxyl groups present than aldehyde groups. The molar ratio of hydroxyl groups to aldehyde groups may be, for example, greater than approximately 1:1.5:1, approximately 2:1, approximately 2.5:1, approximately 3:1, approximately 3.5:1, approximately 4:1, approximately 4.5:1, or approximately 5:1, or even greater, respectively. It is contemplated that, in some embodiments, even if the molar quantity of hydroxyl groups is greater than the molar quantity of aldehyde groups, the weight of the compounds containing the aldehyde groups, i.e., the dialdehyde-modified polyacrylamide reinforcing agent, may be greater than the weight of the compound containing the hydroxyl groups, i.e., the water-soluble compound. Consequently, it is not always the case that the water-soluble compound is present in a weight quantity greater than the weight quantity of the dialdehyde-modified polyacrylamide reinforcing agent, provided that the molar quantity of hydroxyl groups is equal to or greater than the molar quantity of aldehyde groups.In several non-limiting modalities, all values ​​and ranges of values, including and between those set out above, are expressly contemplated in this document for use. Water The composition also includes water. Water can be present in almost any quantity. Typically, water is present in an amount of at least approximately 95, 95.5, 95, 96.5, 97, 97.5, 98, 98.5, 99. 99.5, etc. percent by weight based on the total weight of the composition. Typically, the remaining amount, such that the total weight totals 100 percent by weight, is the combination of the dialdehyde-modified polyacrylamide reinforcing agent and the water-soluble compound. In various non-limiting embodiments, all values ​​and ranges of values, including and between those stated above, are expressly contemplated herein for use. Additional Options In several embodiments, the disclosure provides a method for producing a dry aldehyde-crosslinked polyacrylamide to improve the papermaking process and paper strength properties. The method includes: a) mixing an aldehyde-functionalized polyacrylamide resin with water and certain water-soluble compounds; b) removing the water by air or vacuum drying; c) storing and transporting the composition; and d) reconstituting or redissolving the composition in water to restore the effectiveness of the GPAM resin as a strength additive for paper. The disclosure results in GPAM resins with low or essentially zero water content that can be transported in dry form with little or no degradation of strength performance and that can be redissolved in water and used in a papermaking process. ML / I / UO / UIO papermaking or paper treatment. In this way, the method of the present disclosure further improves the product's shelf life, reduces transportation costs, and ease of handling. In another embodiment, the disclosure provides a method for producing a soluble, dry GPAM that is stable, can be transported with a high solids content, is made without pH or temperature treatment, and is used to improve papermaking processes and paper strength properties. In one embodiment, the disclosure is a composition that includes a glyoxal polyacrylamide resin that is reacted with a compound having multiple hydroxyl groups where most of the aldehyde (hemiacetal) groups of the glyoxal resin are reacted with the hydroxyl groups or the hydroxyl compound and such a composition is formed by mixing the GPAM with the hydroxyl compound and the mixture is then dried. In one embodiment, the starting GPAM resin is water-soluble. In another, the starting hydroxyl compound is water-soluble. In yet another, both compounds are water-soluble, and the resulting mixture is in the form of an aqueous solution before drying. In one embodiment, the above composition is formed by the reaction of the aldehyde and hydroxyl groups after drying the composition. Method for Forming the Composition to Increase Paper Strength: This disclosure also provides a method for forming the composition. The method includes the steps of combining the dialdehyde-modified polyacrylamide reinforcing agent and the water-soluble compound in aqueous media to form the composition. The dialdehyde-modified polyacrylamide reinforcing agent can be added to the water-soluble compound, or vice versa, to form the composition. Furthermore, water can be added to the dialdehyde-modified polyacrylamide reinforcing agent, the water-soluble compound, and / or the combination thereof, in any order and amount. In other words, all possible orders of addition of the aforementioned components are covered herein. Without wishing to be limited by theory, in some embodiments the hydroxyl groups of the water-soluble compound react with the aldehyde groups of the dialdehyde-modified polyacrylamide reinforcing agent to form reversible covalent bonds. Also without wishing to be limited by theory, the hydroxyl, amide, or other similar groups of the water-soluble compound can, during drying, form hemiacetal bonds with the glyoxal-based functionality of the dialdehyde-modified polyacrylamide reinforcing agent. Also, without being ML / I / UO / UIO, limited by theory, hydroxyl, amide, or other water-soluble groups of the water-soluble compound can form associations with the dialdehyde-modified polyacrylamide reinforcing agent to prevent the composition from self-crosslinking to the point of no longer being water-soluble. In one embodiment, excess hydroxyl groups may be part of the composition. The method also includes the step of drying the composition to form a powder or paste having a water content of less than approximately 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, or 0.5 percent by weight, and which is stable after storage at approximately room temperature for approximately six months. The powder is not particularly restricted and may include particles of the composition of any size. It is also contemplated that the powder may be further treated, sieved, or pulverized to form a powder with a particular average size profile. The terminology stable after storage refers to the fact that the product maintains its performance after shelf storage, for example, at the percentages that have been described in detail above. The mixture dries to form a powder or paste. ML / I / UO / UIO because the composition, in a relatively dry form, no longer substantially self-crosslinks, such that the composition can be redissolved or reconstituted by dissolving it in water and where it can then be added during papermaking to impart paper strength. The drying step may be chosen by a person skilled in the art. For example, drying may include, or be free of, the application of heat, airflow, vacuum, turning, agitation, etc. In other words, any drying apparatus may be chosen, including, but not limited to, an oven, flash dryer, column dryer, freeze dryer, spray dryer, fluid bed dryer, ring dryer, rotary dryer, air dryer, vacuum dryer, and combinations thereof. In one embodiment, the composition is dried at room temperature. In another embodiment, the composition is dried at a temperature below approximately 50 °C. In another embodiment, the composition is dried at a temperature between approximately 50 °C and approximately 100 °C. In a further embodiment, the composition is dried at a temperature above approximately 100 °C. This step can also be described as drying to remove most of the water, so that the composition can no longer react with itself for a period of time that would prevent it from being stored for 3 months and then redissolved or reconstituted to form a functional GPAM solution for use in papermaking. The method further includes reconstituting the powder or paste by adding water to it. The reconstitution step can be further described as adding water to the powder or paste in such a way as to form an aqueous composition. The aqueous composition can be a solution, an emulsion, or a dispersion of particles of the composition in water. All the compositions, processes, and articles described above may be based on compositions that also include, or are free from, other materials commonly used in papermaking or in the preparation of aqueous solutions. The compositions may include, or be free from, additives such as antifoaming agents, biocides, pigments, and fillers. Various methods of preparing solutions, as known in the art, may be used. Various means of pumping, drying, redissolving, and reconstituting materials, as known in the art, may be used. Paper tests for dry and wet strength may be carried out in accordance with methods known in the paper industry. MA / t / ZUZ I / UO / U IO EXAMPLES Example 1 A GPAM resin was prepared from a combination of poly(acrylamide-diallyldimethylammonium chloride) and glyoxal with a molar ratio of 95:5. The level of glyoxalation was such that 40% of the acrylamide groups of the poly(acrylamide-diallyldimethylammonium chloride) reacted and 15% remained with active aldehyde functionality. The GPAM resin (as the dialdehyde-modified polyacrylamide reinforcing agent) was thoroughly mixed with a 30 wt% solution of maltodextrin (as the water-soluble compound). More specifically, the GPAM resin was a 10 wt% solution in water and was mixed with an equal amount of a 30% aqueous maltodextrin solution to form a 3:1 wt mixture. A first sample of the mixture was air-dried to form Inventive Composition 1. A second sample of the mixture was dried at 50 °C to form Inventive Composition 2. The materials could, if desired, be ground into a powder but were not in these Examples. After several days, each of Inventive Composition 1 and Inventive Composition 2 was redissolved / reconstituted in water to form a 5% by weight solution. MA / / UO l U10 Samples of Inventive Compositions 1 and 2 were used in the manufacture of hand-pressed paper sheets and were compared with hand-pressed paper sheets manufactured using the original GPAM resin without the water-soluble compound, i.e., maltodextrin, to determine paper strength. The original GPAM without the water-soluble compound is Comparative Composition 1. The pulp used to form the handmade sheets of paper was a 50:50 mixture of hardwood and softwood by weight. The paper was manufactured at a pH of approximately 6 using tap water. To evaluate Comparative Composition 1, 0.3% by weight of the comparative composition on the paper on a dry basis yielded wet strength values ​​with water soaking times of 3 seconds, 30 seconds, and 30 minutes of 10.34, 8.68, and 6.28 Newtons / inch of width, respectively. This is treated as a comparative example. To evaluate Inventive Composition 1, 0.3% by weight of Inventive Composition 1 was used to manufacture the paper and obtained wet strength values ​​with water soaking times of 3 seconds, 30 seconds and 30 minutes of 3.58, 2.82 and 2.34 Newtons / inch of width, respectively. To evaluate Inventive Composition 2, 0.3% of Inventive Composition 2 was used to manufacture paper and obtained wet strength values ​​with times of ML / t / ZUZ I / UO / U IO water soaking of 3 seconds, 30 seconds and 30 minutes of 3.36, 2.84 and 2.38 Newtons / inch, respectively. The paper formed with Inventive Compositions 1 and 2 contained only approximately 25% of the amount of GPAM present compared to the paper formed using Comparative Composition 1, but still exhibited significant wet strength. These results reveal that the aldehydic functionality of GPAM was regenerated when the solid compositions were reconstituted with water. Example 2 Inventive Composition 2, which includes the aforementioned mixture dried at 50 °C, was used to create additional hand-held sheets of paper that were evaluated for temporary wet strength. More specifically, 0.3 wt% GPAM solutions were compared with 0.6 wt% and 1.2 wt% solutions of the Inventive Compositions, such that 0.15 wt% and 0.3 wt% GPAM were added when used. The results for temporary wet strength are presented in Table 1 below. MA / / U0 / U IO TABLE 1 % of GPAM in paper 3 s wet strength 30 s wet strength Comparative composition 1 0.3 3.83 3.64 Comparative Composition 1 0.3 3.83 3.64 Inventive Composition 2 0.15 2.62 2.40 Inventive Composition 2 0.3 3.60 3.43 ML / t / ZUZ I / UO / U IO Based on the level of GPAM added to the paper, and considering the aforementioned results, it is clear that the Inventive Composition performs almost as well as Comparative Composition 1. These results should be further considered in light of the surprising and unexpected benefits associated with the Inventive Compositions, namely, their ability to be dried and stored. When the aforementioned results are considered in conjunction with these unexpected benefits, those skilled in the art appreciate the uniqueness of the present invention. Additional Examples The following examples further demonstrate that the performance of glyoxal polyacrylamide can be maintained after drying and dissolution in aqueous media. In these examples, the reconstituted compositions helped improve paper properties when the solutions were used during the papermaking process. The examples in Table 2 below were formed by mixing a solution of several water-soluble compounds in a GPAM solution at the dry weight ratios indicated below. The resulting mixtures were then air-dried overnight. The solubility of the air-dried compositions was tested by preparing a 1% solution in aqueous media. In some cases, the solubility of the material can be increased by raising the pH of the solution. TABLE 2 ML / t / ZUZ I / UO / U IO Example GPAM Water-Soluble Compound GPAM Dry Weight Ratio: Water-Soluble Compound Water Solubility after Drying Control 1-1 GPAM 1 None N / A Insoluble 1-2 GPAM 1 Maltodextrin 1:3 Soluble 1-3 GPAM 2 Maltodextrin 1:3 Soluble 1-4 GPAM 2 Maltodextrin 3:1 Soluble after pH adjustment to approximately 8-9. 1-5 GPAM 1 ACM-DADMAC Copolymer (95:5) 1:3 Soluble 1-6 GPAM 1 Amphoteric Polymer 1:3 Soluble 1-7 GPAM 3 Amphoteric Polymer 1:3 Partially Soluble 1-8 GPAM 3 ACM-DADMAC Copolymer (90:10) 1:3 Soluble GPAM 1 is a glyoxal polyacrylamide made from a polymer of 95:5 mol% acrylamide and DADMAC with approximately 8 mol% of glyoxalation reactive aldehyde. GPAM 2 is a glyoxal polyacrylamide made from a polymer of 95:5 mol% acrylamide and DADMAC with approximately 15 mol% glyoxalation reactive aldehyde. GPAM 3 is a glyoxal polyacrylamide made from a polymer of 90:10 mol% acrylamide and DADMAC with approximately 15 mol% glyoxal reactive aldehyde. Amphoteric Polymer is an amphoteric polyacrylamide formed from the monomers of Acrylamide / Acrylic Acid / Itaconic Acid and Dimethylaminoethyl methacrylate. The term "insoluble" means that solubility was assessed visually at 25 °C and that significant amounts of the compound did not dissolve in water. For example, less than 10% by weight of the compound dissolved in water. The term "soluble" means that the solubility was visually assessed at 25 °C and none of the compound was visible, indicating that a clear solution was produced and that complete or nearly complete solubility was achieved. For example, more than 95% by weight of the compound dissolved. Partially soluble terminology means ML / I / UO / UIO that the solubility was visually assessed at 25 °C and that some of the compound was visible, thus indicating that a cloudy solution was produced. For example, from approximately 10 to approximately 95% by weight of the compound dissolved. The ACM-DADMAC (95:5) copolymer is a cationic polyacrylamide with a molar ratio of 95:5 of DADMAC to polyacrylamide. The ACM-DADMAC (90:10) copolymer is a cationic polyacrylamide with a molar ratio of 90:10 of DADMAC to polyacrylamide. Additional Examples: Further examples demonstrate an improvement in the dry strength properties of hand paper sheets made from a 100% recycled medium with 50 ppm hardness, 25 ppm alkalinity, 2.5% GPC D15F oxidized starch and 2000 pS / cm conductivity. The system pH was 7.0 and the pulp drainage rate was 35–420 in accordance with the Canadian Standard Drainage Rate (CSF). Hand sheets of paper with a basis weight of 100 lb / 3000 sq ft were manufactured on a Noble and Wood hand sheet machine. Several compositions, identical to those described above, were added as dry strength agents after being redissolved at a level of 0.4% by weight of the composition on an active basis versus dry paper pulp. Hand-pressed sheets were wet-pressed and dried in a drum dryer at 115.56 °C (240 °F) for 1 minute, yielding a moisture content of 3% to 5%. Subsequently, dry tensile strength (TAPPI Test Method T494, om-01), ring compression index (TAPPI Test Method T822 om-02), and Mullen burst strength (TAPPI Test Method T403) were determined. The results are presented in Table 3 below. TABLE 3 ML / t / ¿U¿ I / UO / U IO Example Composition Dry Mullen Ring Crushing Dry Tensile Strength Comparison 2-1 None 100 100 100 2-2 GPAM 1 108 116.2 114.1 2-3 1-2 111.2 114.1 100.3 2-4 GPAM 2 104.7 109.4 100 2-5 1-3 109.3 113.5 110.5 2-6 1-5 104.4 105.6 108.3 2-7 1-6 115.6 110.2 102.6 2-8 1-8 103 107.1 97.1 These data demonstrate that even after reconstitution, GPAM maintains its performance in relation to its previous physical properties. Although at least one example embodiment has been presented in the preceding detailed description, it should be appreciated that a large number of variations exist. It should also be appreciated that the example embodiment(s) are merely examples and are not intended to limit the scope, applicability, or configuration in any way. Rather, the preceding detailed description will provide those skilled in the art with convenient guidance for implementing an example embodiment. It is understood that various changes may be made to the function and arrangement of the elements described in an example embodiment without departing from the scope set forth in the appended claims.

Claims

1. A composition for increasing the strength of paper, said composition comprising: A. a dialdehyde-modified polyacrylamide reinforcing agent; and B. a water-soluble compound comprising one or more hydroxyl or amide portions and being soluble in approximately 5% by weight or more in water at 25°C, and C. water, wherein said water-soluble compound is present in an amount by weight that is greater than an amount by weight of said dialdehyde-modified polyacrylamide reinforcing agent.

2. The composition of claim 1, wherein said dialdehyde-modified polyacrylamide reinforcing agent is a glyoxal polyacrylamide comprising an aldehyde group.

3. The composition of claim 1, wherein said water-soluble compound is selected from a carbohydrate, a polyvinyl alcohol, a polymer containing acrylamide, or combinations thereof.

4. The composition of claim 1, wherein said dialdehyde-modified polyacrylamide reinforcing agent is cationic and is a copolymer comprising the reaction product of an acrylamide monomer and a cationic monomer. ML / I / UO / UIO 5. The composition of any of claims 1 to 4, wherein said water-soluble compound is present in a dry weight ratio with said dialdehyde-modified polyacrylamide reinforcing agent that is greater than approximately 1:1, preferably greater than approximately 3:1, respectively.

6. The composition of claim 1, wherein said water-soluble compound is further defined as a copolymer formed from the reaction of organic monomers.

7. The composition of claim 1, wherein said water-soluble compound is selected from monosaccharides, disaccharides, polysaccharides and combinations thereof; a polymer containing acrylamide having a cationic or anionic charge; or an amphoteric polyacrylamide.

8. The composition of claim 1, wherein said dialdehyde-modified polyacrylamide reinforcing agent is the reaction product of glyoxal; and a prepolymer that is the reaction product of a polyacrylamide monomer and a diallyldimethylammonium chloride monomer, wherein the molar ratio of acrylamide to diallyldimethylammonium chloride is approximately 99:1 to approximately 50:50, respectively, and wherein approximately 40 mol% of the acrylamide groups of said polyacrylamide monomer have been reacted and approximately 15 mol% of the acrylamide groups have active aldehyde functionality.

9. A method for forming a composition for increasing the strength of paper, said method comprising the steps of: combining a dialdehyde-modified polyacrylamide reinforcing agent and a water-soluble compound in aqueous media to form the composition, wherein, on a dry basis, said water-soluble compound is present in a greater amount than the dialdehyde-modified polyacrylamide reinforcing agent, drying the composition to form a powder or paste having a water content of less than approximately 10 percent by weight and stable after storage at approximately room temperature for approximately six months, and reconstituting the powder or paste by adding water thereto, wherein the water-soluble compound comprises one or more hydroxyl or amide functionalities, or combinations thereof, and is soluble in approximately 5 percent by weight or more in water at 25 °C.

10. A method for increasing the wet and / or dry strength of paper, said method comprising the steps of: combining a dialdehyde-modified polyacrylamide reinforcing agent and a water-soluble compound in aqueous media to form the composition, wherein, on a dry basis, said water-soluble compound is present in a greater amount than the dialdehyde-modified polyacrylamide reinforcing agent; drying the composition to form a powder or paste having a water content of less than approximately 10 percent by weight and stable after storage at approximately room temperature for approximately six months; and reconstituting the powder or paste by adding water thereto, wherein the water-soluble compound comprises one or more hydroxyl or amide functionalities, or combinations thereof, and is soluble in approximately 5 percent by weight or more in water at 25 °C.to provide an aqueous suspension of cellulosic fibers; to combine the reconstituted composition and the aqueous suspension of cellulosic fibers; and to form paper from the combination of the reconstituted composition and the aqueous suspension of cellulosic fibers, wherein the paper has greater wet and / or dry strength compared to paper formed without the reconstituted composition.