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US-12618197-B2 - Additive compositions for papermaking

US12618197B2US 12618197 B2US12618197 B2US 12618197B2US-12618197-B2

Abstract

A drainage-optimized additive composition for papermaking is disclosed. The composition comprises an aqueous media and a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa. The composition comprises from about 1.95 to about 2.45 wt. % of the gPAM resin. A method of preparing the composition is also disclosed, and comprises preparing a cationic acrylamide (cAM) prepolymer having at least one predetermined property, and selectively glyoxalating the cAM prepolymer by controlling the concentration of the cAM prepolymer in the aqueous media during glyoxalation in relation to the predetermined property. The method may be carried out in situ during a papermaking process (i.e., as an on-site method). A process of forming paper with the composition also disclosed, and comprises combining the composition with the aqueous suspension of cellulosic fibers, forming the cellulosic fibers into a sheet, and drying the sheet to produce a paper.

Inventors

  • Anthony Joseph Petty, II
  • Sachin Borkar
  • Suboh Abdallah
  • Matthew Wright

Assignees

  • SOLENIS TECHNOLOGIES, L.P.

Dates

Publication Date
20260505
Application Date
20230119

Claims (20)

  1. 1 . An additive composition for papermaking, comprising: an aqueous media; and a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa, wherein the gPAM resin is present in an amount of from about 1.2 to about 6% solids, based on the aqueous media.
  2. 2 . The additive composition of claim 1 , wherein the gPAM resin has: (i) a zeta potential of from about 10 to about 30 mV, at pH 7; (ii) a radius of gyration (Rg) of at least about 100 nm; (iii) a charge density of from about 0.2 to about 3 mEq./g, at pH 7; or (iv) any combination of (i)-(iii).
  3. 3 . The additive composition of claim 1 , wherein the glyoxalated polyacrylamide resin comprises the reaction product of (A) a cationic acrylamide (cAM) prepolymer and (B) glyoxal in an aqueous media, and wherein: (i) the cAM prepolymer (A) is present in the aqueous media at an initial concentration of from about 0.9 to about 5.7%; (ii) the cAM prepolymer (A) and the glyoxal (B) are reacted in a dry weight (w/w) ratio of from about 75:25 to about 95:5 (A): (B); or (iii) both (i) and (ii).
  4. 4 . The additive composition of claim 3 , wherein the cAM prepolymer (A) has: (i) a reduced solution viscosity (RSV) of from about 0.5 to about 1.8 dL/g; (ii) a zeta potential of from about 10 to about 30 mV, at pH 7; (iii) a charge density of from about 0.2 to about 3 mEq./g, at pH 7; or (iv) any combination of (i)-(iii).
  5. 5 . The additive composition of claim 3 , wherein the gPAM resin has a zeta potential within about 10% of the zeta potential of the cAM prepolymer (A).
  6. 6 . The additive composition of claim 3 , wherein the gPAM resin has a charge density within about 10% of the charge density of the cAM prepolymer (A).
  7. 7 . The additive composition of claim 3 , wherein the cAM prepolymer (A) comprises the reaction product of: (A1) an acrylamide (AM) monomer; (A2) a cationic monomer; and optionally, (A3) one or more additional ethylenically unsaturated monomer(s); wherein the cAM prepolymer (A) comprises from about 2 to about 30 mol % of cationic monomer units derived from the cationic monomer (A2).
  8. 8 . The additive composition of claim 7 , wherein the AM monomer (A1), the cationic monomer (A2), and optionally the additional ethylenically unsaturated monomer(s) (A3) are reacted in the presence of a chain transfer agent.
  9. 9 . The additive composition of claim 7 , wherein: (i) the AM monomer (A1) comprises acrylamide; (ii) the cationic monomer (A2) comprises diallyldimethylammonium chloride (DADMAC); (iii) the one or more additional ethylenically unsaturated monomer(s) (A3), when present, are selected from styrenes, alkyl acrylates, and vinyl acetates; or (iv) any combination of (i)-(iii).
  10. 10 . The additive composition of claim 1 , wherein the gPAM resin has: (i) a zeta potential of from about 10 to about 30 mV, at pH 7; (ii) a radius of gyration (Rg) of at least about 100 nm; (iii) a charge density of from about 0.2 to about 3 mEq./g, at pH 7; or (iv) any combination of (i)-(iii); wherein the gPAM resin comprises the reaction product of (A) a cationic acrylamide (cAM) prepolymer and (B) glyoxal in an aqueous media, wherein: (i) the cAM prepolymer (A) is present in the aqueous media at an initial concentration of from about 0.9 to about 5.7%; (ii) the cAM prepolymer (A) and the glyoxal (B) are reacted in a dry weight (w/w) ratio of from about 75:25 to about 95:5 (A):(B); or (iii) both (i) and (ii); wherein the cAM prepolymer (A) has: (i) a reduced solution viscosity (RSV) of from about 0.5 to about 1.8 dL/g; (ii) a zeta potential of from about 10 to about 30 mV, at pH 7; (iii) a charge density of from about 0.2 to about 3 mEq./g, at pH 7; or (iv) any combination of (i)-(iii). wherein the cAM prepolymer (A) comprises the reaction product of: (A1) an acrylamide (AM) monomer comprising acrylamide; (A2) a cationic monomer comprising diallyldimethylammonium chloride (DADMAC); and optionally, (A3) one or more additional ethylenically unsaturated monomer(s) chosen from styrenes, alkyl acrylates, and vinyl acetates; and wherein the cAM prepolymer (A) comprises from about 2 to about 30 mol % of cationic monomer units derived from diallyldimethylammonium chloride (DADMAC).
  11. 11 . A method of preparing a drainage-optimized additive composition for papermaking, comprising: I) preparing a cationic acrylamide (cAM) prepolymer having at least one predetermined physical property selected from cationic monomer content, reduced solution viscosity (RSV), charge density, and zeta potential; and II) selectively glyoxalating the cAM prepolymer by controlling the concentration of the cAM prepolymer in an aqueous media during glyoxalation to give a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa, thereby preparing the additive composition, wherein (II) selectively glyoxalating the cAM prep comprises reacting the cAM prepolymer (A) and the glyoxal (B) in an aqueous media and wherein: (i) the cAM prepolymer (A) is present in the aqueous media at an initial concentration of from about 0.9 to about 5.7%; (ii) the cAM prepolymer (A) and the glyoxal (B) are reacted in a dry weight (w/w) ratio of from about 75:25 to about 95:5 (A):(B); or (iii) both (i) and (ii), and wherein selectively glyoxalating the CAM prepolymer gives the glyoxalated polyacrylamide (gPAM) resin in the aqueous media at a solids content (%) of about X+0.3, where X is the initial concentration of the cAM. polymer (A) in the aqu cous media.
  12. 12 . The method of claim 11 , wherein the at least one predetermined physical property of the cAM prepolymer (A) is selected from: (i) a cationic monomer content of from 2 to about 30 mol %; (ii) a reduced solution viscosity (RSV) of from about 0.5 to about 1.8 dL/g; (iii) a charge density of from about 0.2 to about 3 mEq./g, at pH 7; (iv) a zeta potential of from about 10 to about 30 mV, at pH 7; or (v) any combination of (i)-(iv).
  13. 13 . The method of claim 11 , further comprising preparing the cAM prepolymer (A), wherein preparing the cAM prepolymer (A) comprises reacting (A1) an acrylamide (AM) monomer, (A2) a cationic monomer, and optionally (A3) one or more additional ethylenically unsaturated monomer(s) in the presence of a chain transfer agent.
  14. 14 . The method of claim 13 , wherein the cAM prepolymer (A) comprises from about 2 to about 30 mol % of cationic monomer units derived from the cationic monomer (A2).
  15. 15 . The method of claim 13 , wherein: (i) the AM monomer (A1) comprises acrylamide; (ii) the cationic monomer (A2) comprises diallyldimethylammonium chloride (DADMAC); (iii) the one or more additional ethylenically unsaturated monomer(s) (A3), when present, are selected from styrenes, alkyl acrylates, and vinyl acetates; or (iv) any combination of (i)-(iii).
  16. 16 . A process of forming paper, said process comprising: (1) providing an aqueous suspension of cellulosic fibers; (2) combining an additive composition comprising a glyoxalated polyacrylamide (gPAM) resin prepared in-situ with the aqueous suspension, wherein the additive composition is the additive composition of claim 1 ; (3) forming the cellulosic fibers into a sheet; and (4) drying the sheet to produce a paper.
  17. 17 . The process of claim 16 , wherein the gPAM resin is prepared in-situ within about 5 hours of combining the additive composition with the aqueous suspension.
  18. 18 . The process of claim 16 , wherein a drainage rate exhibited during forming the cellulosic fibers into the sheet and/or drying the sheet to produce the paper is reduced by at least about 20%, compared to a substantially similar process that is substantially free from the additive composition.
  19. 19 . A method of preparing a drainage-optimized additive composition for papermaking, comprising: I) preparing a cationic acrylamide (cAM) prepolymer having at least one predetermined physical property selected from cationic monomer content, reduced solution viscosity (RSV), charge density, and zeta potential; and II) selectively glyoxalating the cAM prepolymer by controlling the concentration of the cAM prepolymer in an aqueous media during glyoxalation to give a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa, thereby preparing the additive composition, wherein: (i) the gPAM resin has a zeta potential within about 10% of the zeta potential of the cAM prepolymer (A); (ii) the gPAM resin has a charge density within about 10 of the charge density of the cAM prepolymer (A); or (iii) both (i) and (ii).
  20. 20 . A method of preparing a drainage-optimized additive composition for papermaking, comprising: I) preparing a cationic acrylamide (cAM) prepolymer having at least one predetermined physical property selected from cationic monomer content, reduced solution viscosity (RSV), charge density, and zeta potential; and II) selectively glyoxalating the cAM prepolymer by controlling the concentration of the cAM prepolymer in an aqueous media during glyoxalation to give a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa, thereby preparing the additive composition, wherein the gPAM resin is present in an amount of from about 1.2 to about 6% solids, based on the aqueous media.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and all benefits of U.S. Provisional Application No. 63/301,996, filed Jan. 21, 2022, the content of which is incorporated herein by reference. FIELD OF THE DISCLOSURE The present disclosure relates generally to additive compounds and compositions for papermaking and, more specifically, to high-charge high-molecular weight glyoxalated polyacrylamide (gPAM) resins and methods of making and using the same. BACKGROUND Papermaking is a complex process in which paper is prepared from pulp (e.g. wood), water, filler, and various chemicals. Paper manufacturing is among the most water intensive industries, as the processes include numerous stages reliant on substantial amounts of water and aqueous solutions being added to the cellulosic fibers (i.e., the “inflow stream”) to give a furnish, and eventually separated from the furnish (i.e., the “effluent stream”) to give the final product. In the course of a typical papermaking process, a relatively concentrated aqueous slurry of cellulosic material (i.e., “thick stock”) is diluted by addition of water to give a relatively diluted slurry of cellulosic material (i.e., “thin stock”), which is used to prepare a paper web that must be dewatered to give the final product. Throughout the papermaking process, various chemical additives are employed to improve particular properties of the process (i.e., “process aids”) and/or the final product being prepared (i.e., “functional aids”). Examples of processes aids include defoamers and antifoams, retention aids, biocides, drainage aids, formation aids, etc. Examples of functional additives include strength aids, e.g. for imparting temporary wet-strength (TWS), wet-strength (WS), and/or dry-strength (DS) to the final product. In view of the number and complexity of required stages in a given papermaking process, and the number and amounts of additives utilized in each stage, there is increasing demand for additives that provide both process and functional improvements to a given processes. Unfortunately, however, achieving some sought after improvements may lead to a decrease in other performance factors. For example, achieving high retention, which can lead to improvements in the strength of the final product, can lead to reduced drainage and formation. Using conventional high molecular weight drainage aids can dive excellent drainage and retention, but offer little to no strength benefits, and in some instances even result in a reduced strength due to over-flocculation. Certain DS aids like polyamidoepichlorohydrins (PAE) can give excellent dry strength, but offer little to no drainage benefits and have limited repulpability. Complicating matters further, the efficiency of any given solution is strongly furnish dependent, with some of the best known dry strength and/or drainage aids failing under desired conditions, e.g. due to fines content, lignin content, and/or conductivity of the furnish system. As such, while there are programs to address these furnish derived performance reductions, there is a still present need for additives that provide exceptional dewatering and good dry strength in even the most challenging furnish systems. One category of chemicals being increasingly explored for multi-use additive application includes glyoxalated polyacrylamide (gPAM) resins, which have been utilized in the paper industry for many years as processes aids, e.g. for improving water drainage during the papermaking process, and also as functional additives, e.g. for imparting temporary wet-strength (TWS), wet-strength (WS), and dry-strength (DS) to the final paper(s) being prepared. Typical gPAM resins are prepared by glyoxalating polyacrylamides (PAM), i.e., by reacting glyoxal with a PAM or PAM copolymer, such as those prepared from acrylamide (AM) and various anionic or cationic monomers. As but one example, diallyldimethylammonium chloride (DADMAC) is a cationic monomer utilized to prepare poly(AM/DADMAC) copolymers, which may be used as a prepolymer in a glyoxalation reaction to give the corresponding gPAM resins (i.e., glyoxalated poly(AM/DADMAC)). Unfortunately, conventional gPAM resins suffer from numerous drawbacks associated with production, storage, and use. For example, while many commercial gPAM resins are known to perform as exceptional strength aids, such resins typically underperform in difficult furnishes, especially with respect to dewatering and drainage. BRIEF SUMMARY A drainage-optimized additive composition for papermaking is provided. The additive composition comprises an aqueous media and a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa. The additive composition comprises from about 1.95 to about 2.45 wt. % of the gPAM resin, and may be prepared in situ during a papermaking process (i.e., as an on-site gPAM resin). A method of preparing the additive composition (the “preparati