WO2025072390A1 - Use of quick inversion cationic emulsion polymers with polyvinylamines as retention and drainage aids - Google Patents

Abstract

The present invention generally relates to methods and compositions for manufacture of tissue, paper, or board and for enhancing retention and drainage thereof. In particular, the disclosure provides methods for enhancing retention and drainage by addition of a retention and drainage aid comprising quick inversion cationic emulsion polyacrylamides (QIC-EPAMS) and polyvinylamine (PVAm) polymers Preparation of paper sheets under these conditions provides improved retention, gravimetric drainage rates, and DDA drainage time, without over-flocculation and allowed for significant decrease in PVAm dosage.

Description

USE OF QUICK INVERSION CATIONIC EMULSION POLYMERS WITH POLYVINYLAMINES AS RETENTION AND DRAINAGE AIDS

FIELD OF THE INVENTION

[0001] The present invention generally relates to methods and compositions for manufacture of tissue, paper, or board and for enhancing retention and drainage thereof. In particular, the disclosure provides methods for enhancing retention and drainage by addition of a retention and drainage aid comprising a quick inversion cationic emulsion polymers and polyvinyl amine polymers. Preparation of paper sheets under these conditions provides improved retention, gravimetric drainage rates, and DDA drainage time, without over-flocculation.

BACKGROUND OF THE INVENTION

[0002] Recycled fiber materials, such as old corrugated containerboard (OCC), mixed office waste (MOW), and Old Magazines(OMG) are commonly used as raw material for paper and board, such as recycled liner grades. Pulp quality from recycled papers is poor in fiber strength, and recycled fibers have a high level of fines and mineral fillers, which negatively impact retention, drainage, and dryer steam consumption during recycled liner making processes.

[0003] During the production of paper or paperboard, a dilute aqueous composition known as "furnish" or "stock" is sprayed onto a moving mesh known as a "wire" or "wire screen". Solid components of this composition, such as cellulosic fibers, fines, and inorganic particulate mineral fillers captured or filtered by the wire to form a sheet. The percentage of solid material retained on the wire is known as the "retention" of the papermaking process. Retention aids are used to improve the capture efficiency of the solid components onto the mesh, thereby reducing the total suspended solids in the filtrate.

[0004] During sheet formation, the liquid components (i.e., filtrate) are removed by gravity drainage through the mesh. The sheet is then subjected to additional dewatering steps, such as vacuum dewatering, followed by press dewatering. "Drainage" relates to the rate of removal of water from the furnish as the paper sheet is formed. Drainage usually refers to water removal which takes place in the "drainage zone" (e.g., gravity and vacuum drainage sections) of the paper machine primarily before any pressing of the wet paper web.

Drainage aids are used to improve the overall efficiency of dewatering in the production of paper or paperboard.

[0005] After dewatering, the sheet is subjected to a drying process to remove residual water. Commonly used dryer sections include steam cylinders and air dyers. Efficient dewatering during the preceding steps, such as by use of drainage aids, allows for the reduction of steam and energy consumption during drying processes.

[0006] Retention and drainage aids for papermaking are generally added to the furnish or stock prior to addition to the headbox of the paper machine with the goal of providing enhanced on-machine retention and drainage while also providing additional benefits, such as improved paper strength and wet pressability. These requirements are especially challenging for papermaking operations in mills with high recycled content. Typical retention and drainage aids include high molecular weight cationic polymers or CPAM/silica retention programs. When added to recycled fibers, these additives create large flocs (i.e., over-flocculation) of recycled pulp, making recycled paper less uniform and causing poor formation. A poorly formed sheet containing large fiber flocs will exhibit a high gravimetric drainage rate and will drain quickly in the initial hydrofoil section of a paper machine. However, this over-flocculated sheet will respond poorly to vacuum in later parts of the forming section, resulting in a reduction of vacuum drainage (press dewatering) rate. Because of increased captured water in the large flocs, the sheet will also require an increase of dryer steam consumption.

[0007] Considerable effort has been directed toward developing improved retention and drainage aids. PCT/US99/29135 discloses a polyampholyte coagulant, which is used as a retention/drainage/formation aid in a papermaking process. However, commercially available retention and drainage aids remain inadequate for manufacture of paper and board with a high percentage of recycled fiber content.

[0008] Polyvinylamine (PVAM) polymers are widely used to improve vacuum drainage rate, press dewatering rate and reduce dryer steam consumption without deteriorating sheet formation for recycled paper machines. PVAm comprises high cationic charge density and low molecular weight and is an effective coagulant for trapping anionically charged fibers, fines, and fillers. PVAm polymers usually create small fiber-flocs and do not increase fiber floc size as the PVAm polymer dosage increases. Therefore, PVAm polymers have been widely used to improve vacuum drainage rate, press dewatering rate, and to reduce dryer steam consumption without deteriorating sheet formation for recycled paper machines. However, PVAm polymers are very expensive and many recycled liner board paper mills cannot afford to use PVAm as a drainage agent.

[0009] Based on the foregoing there is a need for improved additives for providing retention and drainage enhancement without over-flocculation of fibers, when used in the manufacturing of paper, tissue, towel, and/or board from recycled materials. There is also a need for retention and drainage aids that allow for significant reduction in the use of PVAm in recycled furnish. Therefore, it is an object of the present invention to provide methods and compositions for enhancing retention and drainage (i.e., retention and drainage aids) to provide improved retention and drainage time while avoiding over-flocculation and reducing the amount of added PVAm. The present invention achieves these objectives as described herein by use of a retention and drainage aid program comprising a quick inversion cationic polymer (QIC-EPAM) and PVAm.

SUMMARY OF THE INVENTION

[0010] The present invention generally relates to methods and compositions for manufacture of tissue, paper, or board and for enhancing retention and drainage thereof. In particular, the disclosure provides methods for enhancing retention and drainage by addition of a retention and drainage aid comprising quick inversion cationic emulsion polyacrylamides (QIC-EPAMS) and polyvinylamine (PVAm) polymers Preparation of paper sheets under these conditions provides improved retention, gravimetric drainage rates, and DDA drainage time, without over-flocculation and allowed for significant decrease in PVAm dosage.

[0011] In one aspect, the present invention provides a method for manufacture of tissue, paper, or board, the method comprising:

[0012] (a) forming or providing a thick stock comprising an aqueous suspension of cellulosic fibers, optionally comprising 40-100%, 60-100%, or 80-100% by weight recycled cellulosic fibers;

[0013] (b) optionally diluting the thick stock to form a thin stock;

[0014] (c) introducing the thick stock and/or the thin stock into a headbox of a paper machine and then draining on a wire screen, thereby removing sufficient water to form a wet fibrous web; and

[0015] (d) pressing and drying the wet fibrous web to obtain a tissue, paper, or board;

[0016] wherein the method comprises, prior to step (c), treating the thick stock and/or the thin stock with a retention and drainage aid comprising:

[0017] (i) one or more polyvinylamine (PVAm) polymers; and

[0018] (ii) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising acrylamide (AM) monomers and cationic acryloyloxyethyltrimethyl ammonium chloride (Q9).

[0019] In some exemplary embodiments of the method said one or more PVAm polymers and said one or more QIC-EPAMs are:

[0020] (a) premixed prior to addition to the thick stock;

[0021] (b) premixed prior to addition to the thin stock;

[0022] (c) added separately to the thick stock;

[0023] (d) added separately to the thin stock;

[0024] (e) added separately, wherein the one or more PVAm polymers are added to the thick stock and the one or more QIC-EPAMs are added to the thin stock; or

[0025] (f) added separately, wherein the one or more PVAm polymers are added to the thin stock and the one or more QIC-EPAMs are added to the thick stock;

[0026] wherein steps (a)-(f) are optionally followed by a mixing time ranging from 0.01-10 min, 0.1-5 min, or 1-2 min.

[0027] In some exemplary embodiments of the method said one or more PVAm polymers: [0028] (a) comprise a weight average molecular weight ranging from 50-3000 kDa, 100-2000 kDa, 200-2000 kDa, or 400-800 kDa;

[0029] (b) comprise a cationic charge density ranging from below 5.0 mEq/g, 0.5-5.0 mEq/g, 1.0-4.0 mEq/g, or 1.5-2.5 mEq/g as dry solids at pH 7;

[0030] (c) comprise a polymer synthesized by Hofmann degradation of a base polymer comprising (i) acrylamide; (ii) methacrylamide; (iii) a copolymer of acrylamide and cationic monomers selected from the group consisting of dimethylaminoethyl acrylate (DMAEA), quaternized dimethylaminoethyl methacrylate (DMAEMA), dimethyldiallylammonium chloride (DADMAC), acrylamidopropyltrimethylammonium chloride (APTAC), and methacrylamidopropyltrimethylammonium chloride (MAPTAC); or (iv) a copolymer of acrylamide and DADMAC;

[0031] (d) comprise a polymer synthesized by total or partial hydrolysis of one or more poly(N-vinylformamide) homopolymers or copolymers, wherein said one or more poly(N- vinylformamide) homopolymers or copolymers are optionally synthesized by radical polymerization of N-vinylformamide or by radical polymerization of N-vinylformamide and one or more additional monomers and further comprising a degree of hydrolysis ranging from 1-100 mol%, 20-100 mol%, 40-100 mol%, 60-100 mol%, or 80-100 mol%;

[0032] (e) comprise a polymer synthesized by partial hydrolysis of one or more poly(N- vinylformamide) homopolymers and further comprising a degree of hydrolysis ranging from 30-50 mol%, 35-45 mol%, or about 40 mol%;

[0033] (f) are formulated optionally as a dry powder or as an aqueous composition comprising a PVAm solids % by mass ranging from about 0.5% to about 30%, optionally from greater than 2% to about 25%, further optionally from about greater than 10% to about 22%; or

[0034] (g) any combination of (a)-(f).

[0035] In some exemplary embodiments of the method said one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs):

[0036] (a) comprise an acrylamide (AM) monomer content ranging from 60-85 wt%, 65-85 wt%, 70-85 wt%, or 70-80 wt%;

[0037] (b) comprise a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from <40 wt%, 15-40 wt%, 15-35 wt%, 15-30 wt%, or 20-30 wt%; or

[0038] (c) comprise an inverse phase emulsion, a dry polymer, or an aqueous polymer solution, preferably an inverse phase emulsion;

[0039] (d) comprise a polymer standard viscosity (SV) ranging from less than or equal to 3.5 cPs, 2.0- 3.5, 2.5-3.5 cPs, or 3.0-3.5 cPs; or

[0040] (e) any combination of the foregoing. [0041] In some exemplary embodiments of the method said retention and drainage aid optionally further comprises one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles, wherein:

[0042] (a) said more cationic dry polyacrylamides (DPAM) comprise acrylamide (AM) monomers and one or more cationic monomers, wherein said one or one or more cationic monomers are selected from the group consisting of acryloyloxyethyltrimethyl ammonium chloride ("AETAC"), methacryloyloxyethyltrimethylammonium chloride ("MAETAC"), methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), acrylamidopropyltrimethylammonium chloride ("APTAC"), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride ("DADMAC"); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary or acid salts, including but not limited to, dimethylaminoethyl acrylate ("DMAEA"), dimethylaminoethyl methacrylate ("DMAEA"), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfuric acid salt, dimethylaminoethyl acrylate hydrochloric acid salt, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfuric acid salt, dimethylaminoethyl methacrylate hydrochloric acid salt, dimethylaminoethyl methacryloyl hydrochloric acid salt; dialkylaminoalkylacrylamides and methacrylamides and their quaternary or acid salts, including but not limited to, acryloylamidopropyltrimethylammonium chloride, dimethylaminopropyl acrylamide, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl acrylamide hydrochloric acid salt, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt, diethylaminoethylacrylate, diethylaminoethylmethacrylate; and diallyldialkylammonium halides, including but not limited to, diallyldiethylammonium chloride and diallyldimethylammonium chloride ("DADMAC"), and any combination thereof; and

[0043] (b) said one or more inorganic microparticles are selected from the group of microparticles and nanoparticles consisting of silica microparticles; colloidal silica; aluminum phyllosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite, and montmorillonite.

[0044] In some exemplary embodiments the method comprises one or more of the following:

[0045] (a)said one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprise an acrylamide (AM) monomer content ranging from 70-80 wt% and a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; comprises an inverse phase emulsion; and comprises a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs;

[0046] (b) said one or more PVAm polymers comprise a weight average molecular weight ranging from 400-800 kDa; or

[0047] (c) said one or more inorganic microparticles comprise bentonite, sodium bentonite, or calcium bentonite.

[0048] In some exemplary embodiments of the method, when added to the thick stock and/or the thin stock:

[0049] (a) said retention and drainage aid comprises a ratio of said one or more QIC-EPAMs to said one or more PVAms ranging from 1:60 to 1:1; 1:30-1:1; 1:6 to 1:1; or 1:3 to 1:1;

[0050] (b) said one or more PVAm polymers are added at a dosage ranging from 0.2-12 kg/t, 0.2-10 kg/t, 0.2-8 kg/t, 0.2-6 kg/t, 0.2-2 kg/t, or 0.2-0.6 kg/t;

[0051] (c) said one or more QIC-EPAMs are added at a dosage ranging from 0.1-1 kg/t, 0.1- 0.5 kg/t, or 0.1-0.2 kg/t;

[0052] (d) said one or more DPAMs are added at a dosage ranging from 0.1-lkg/t, 0.1-0.5 kg/t, or 0.2-0.4 kg/t;

[0053] (e) said one or more inorganic microparticles are added at a dosage ranging from 0.1- 4 kg/t, 1-4 kg/t, or 2-4 kg/t; or

[0054] (f) any combination of (a)-(e).

[0055] In some exemplary embodiments the method comprises one or more of the following:

[0056] (a) the thick stock comprises a consistency ranging from 1-5%, 1-3%, or 1-1.5%, wherein consistency refers to % by weight of total suspended solids in the aqueous slurry;

[0057] (b) the thin stock comprises a consistency ranging from 0.3-1%, 0.4-1%, 0.5-1%, or 0.5-0.7%;

[0058] (c) the thick stock is diluted to form the thin stock by addition of water, chemical water, synthetic water, white water, and/or process water; or

[0059] (d) the thick stock and or the thin stock optionally further comprise one or more additives relating to papermaking, including but not limited to, starches, dyes, bleaching agents, sizing agents, wet strength agents, dry strength agents, or detackifiers; or

[0060] (e) any combination of (a)-(c).

[0061] In some exemplary embodiments of the method said aqueous suspension of cellulosic fibers comprises a pH ranging from 4-8, 4-7.5, 4-7, 4.5-7, or 5-7 and further comprises:

[0062] (a) a percentage of recycled cellulosic fibers ranging from 40-100%, 50-100%, 60- 100%, 80-100%, or 90-100% by weight recycled cellulosic fibers, [0063] (b) a combination of one or more recycled fibers optionally obtained from sources, including but not limited to, old corrugated cardboard (OCC), mixed office waste (MOW), mixed office paper, old newspaper pulp (ONP), old magazines (OMG), mill broke fibers, or coated broke,

[0064] (c) optionally softwood fiber, hardwood fiber, refined fiber, non-wood fibers, including but not limited to straw and wheat pulp, and a mixture of any of the foregoing;

[0065] (d) optionally pulp selected from Kraft pulp, unbleached Kraft pulp, bleached pulp, unbleached pulp, process water from pulp, paper, and/or board production, neutral sulfite semi chemical (NSSC) pulp, mechanical pulp, non-wood pulp, and a mixture of any of the foregoing; or

[0066] (e) an amount of pulp fines and/or an amount of mineral fillers ranging from 5-30% by mass of total solids in the aqueous suspension, wherein the amount of pulp fines pulp fines comprises pulp particles small enough to pass through a 76 pm diameter hole and said amount of mineral fillers comprise calcium carbonate, clays, kaolinite, aluminum silicates, talc, and/or gypsum; or

[0067] (f) and combination of (a)-(e).

[0068] In some exemplary embodiments of the method, when used for manufacture of tissue, paper, or board, the method results in:

[0069] (a) an increased retention of cellulosic fibers;

[0070] (b) an increase in retention of pulp fines and/or mineral fillers;

[0071] (c) a faster drainage rate on the wire screen;

[0072] (d) an increased press dewatering rate;

[0073] (e) a reduction in dryer steam usage;

[0074] (f) an improved tissue, paper, or board quality as determined by decreased permeability;

[0075] (g) a reduction in PVAm dosage;

[0076] (h) a synergistic increase in paper machine drainage rate resulting from the combination of QIC-EPAM and PVAm;

[0077] (i) a synergistic increase in Canadian Standard Freeness (CSF) resulting from the combination of QIC-EPAM and PVAm; or

[0078] (j) any combination of (a)-(i); compared to an identical method performed in the absence of (i) addition of said one or more PVAms or (ii) addition of said one or more QIC-EPAMs.

[0079] In another aspect, the present invention provides a method for manufacture of tissue, paper, linerboard, or board, the method comprising: [0080] (a) forming or providing a thick stock comprising an aqueous suspension of cellulosic fibers, optionally comprising 40-100%, 60-100%, or 80-100% by weight recycled cellulosic fibers;

[0081] (b) optionally diluting the thick stock to form a thin stock;

[0082] (c) introducing the thick stock and/or the thin stock into a headbox of a paper machine and then draining on a wire screen, thereby removing sufficient water to form a wet fibrous web; and

[0083] (d) pressing and drying the wet fibrous web to obtain a tissue, paper, or board;

[0084] wherein the method comprises, prior to step (c), treating the thick stock and/or the thin stock with a retention and drainage aid comprising:

[0085] (i) one or more polyvinylamine (PVAm) polymers;

[0086] (ii) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

[0087] (iii) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite.

[0088] In some exemplary embodiments of the method said one or more PVAm polymers and said one or more QIC-EPAMs are:

[0089] (a) premixed prior to addition to the thick stock;

[0090] (b) premixed prior to addition to the thin stock;

[0091] (c) added separately to the thick stock;

[0092] (d) added separately to the thin stock;

[0093] (e) added separately, wherein the one or more PVAm polymers are added to the thick stock and the one or more QIC-EPAMs are added to the thin stock; or

[0094] (f) added separately, wherein the one or more PVAm polymers are added to the thin stock and the one or more QIC-EPAMs are added to the thick stock.

[0095] In another aspect, the present invention provides a thick stock comprising an aqueous suspension comprising a consistency ranging from 1-5%, 1-3%, or 1-1.5%; a recycled cellulosic fiber content ranging from 40-100%; and a retention and drainage aid comprising:

[0096] (a) one or more polyvinylamine (PVAm) polymers;

[0097] (b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

[0098] (c) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite;

[0099] wherein

[0100] (i) said retention and drainage aid comprises a ratio of said one or more QIC-EPAMs to said one or more PVAms ranging from 1:60 to 1:1; 1:30-1:1; 1:6 to 1:1; or 1:3 to 1:1;

[0101] (ii) said one or more PVAm polymers and said one or more QIC-EPAMs are premixed prior to addition to the thick stock;

[0102] (iii) said one or more PVAm polymers and said one or more QIC-EPAMs are added separately to the thick stock.

[0103] In another aspect, the present invention provides a thin stock comprising an aqueous suspension comprising a consistency ranging from 0.3-1%, 0.4-1%, 0.5-1%, or 0.5-0.7%; a recycled cellulosic fiber content ranging from 40-100%; and a retention and drainage aid comprising:

[0104] (a) one or more polyvinylamine (PVAm) polymers;

[0105] (b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

[0106] (c) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite;

[0107] wherein

[0108] (i) said one or more PVAm polymers and said one or more QIC-EPAMs are premixed prior to addition to the thin stock;

[0109] (ii) said one or more PVAm polymers and said one or more QIC-EPAMs are added separately to the thin stock.

[0110] In another aspect, the present invention provides a composition for use as a retention and drainage aid in manufacture of tissue, paper, or board, the composition comprising:

[0111] (a) one or more polyvinylamine (PVAm) polymers;

[0112] (b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and [0113] (c) optionally one or more anionic organic or inorganic microparticles selected from the group of microparticles and nanoparticles consisting of silica microparticles; colloidal silica; aluminum phyllosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite, and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamides.

BRIEF DESCRIPTION OF THE DRAWINGS

[0114] The invention will be described in more detail with reference to appended drawings, described in detail below.

[0115] FIG 1 provides an exemplary graph showing DDA drainage time % gain over blank and DDA permeability % gain over blank for recycled liners prepared from OCC furnish treated with PVAms and QIC-EPAM according to Example 2.

[0116] FIG 2 provides an exemplary graph showing DDA drainage time % gain over blank and DDA filtrate turbidity (NTU) for recycled liners prepared from OCC furnish treated with PVAms and QIC-EPAM according to Example 3.

[0117] FIG 3 provides an exemplary graph showing gravimetric water retention determined by Canadian Standard Freeness (CSF) testing for recycled liners prepared from 100% OCC furnish treated with PVAms and QIC-EPAM according to Example 4.

[0118] FIG 4 provides an exemplary graph showing DDA drainage time for recycled liners prepared from OCC furnish treated with PVAms and QIC-EPAM according to Example 4.

DETAILED DESCRIPTION OF THE INVENTION

[0119] Before describing the invention, the following definitions are provided. Unless stated otherwise all terms are to be construed as they would be by a person skilled in the art.

DEFINITIONS

[0120] As used herein the singular forms "a", "and", and "the" include plural referents unless the context clearly dictates otherwise.

[0121] As used herein, the singular forms "a," "an," and "the" may mean "one" but also include plural referents such as "one or more" and "at least one" unless the context clearly dictates otherwise. All technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs unless clearly indicated otherwise.

[0122] As used herein, the term "or" in the claims is used to mean "and/or" unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and "and/or."

[0123] As used herein the term "or combinations thereof" as used herein refers to all permutations and combinations of the listed items preceding the term unless stated otherwise. [0124] PAPERMAKING

[0125] As used herein, the term "paper" includes products comprising a cellulosic sheet material including paper sheet, paperboard, and the like.

[0126] As used herein, the terms "papermaking process" and "papermaking application" generally refers to any process in which any form of paper and/or paperboard product may be produced. For example, such processes include making paper products from pulp, such as methods comprising forming an aqueous cellulosic papermaking furnish, draining the furnish to form a sheet, and drying the sheet. The steps of forming the papermaking furnish, draining and drying may be carried out in any conventional manner generally known in the art.

[0127] As used herein, the terms "wet end of a paper machine" or "wet end" generally refer to the parts of a papermaking process between pulping (or bleaching) and wet-pressing of the paper.

[0128] As used herein, the term "fiber" refers to the basic structural unit of paper or board.

[0129] As used herein, the terms "recycled fiber" and "recovered fiber", refer to paper, paperboard, and fibrous wastes from retail stores, office buildings, homes, manufacturing plants, and so forth, after they have passed through their end-usage as a consumer item. Manufacturing wastes include: dry paper and paperboard waste generated after completion of the papermaking process including by way of example: envelope cuttings, bindery trimmings, and other paper and paperboard waste resulting from printing, cutting, forming, and other converting operations; bag, box, and carton manufacturing wastes; mill wrappers, and rejected unused stock; and repulped finished paper and paperboard from obsolete inventories of paper and paperboard manufacturers, merchants, wholesalers, dealers, printers, converters, or others. In particular the term "recycled fibers" includes recycled fibers derived by processing of paper and other consumer cellulosic materials, e.g., paper, old corrugated containerboard (OCC), mixed office waste (MOW), old magazine (OMG), unbleached kraft pulp, neutral sulphite semi chemical (NCCS) pulp and/or mechanical pulp. Source materials for recycled fibers may be selected from old corrugated containerboard, mixed office waste, old newsprint, old magazines, double liner kraft, and any mixtures thereof. Mixed waste (MXW) denotes recycled mixture of recycled board, such as OCC, white lined chipboard and/or folding boxboard, and recycled paper, such as old newsprint, old magazines and/or office waste papers. Mixed office waste denotes recycled fiber material mainly containing copying papers, printer papers and offset papers. Double lined kraft denotes recycled fiber material comprising clean sorted unprinted corrugated cardboard cartons, boxes, sheet or trimmings, e.g., of kraft or jute liner. White lined chipboard (WLC) denotes multiply board comprising deinked fiber material and/or undeinked recycled fiber material originating e.g., from OCC, mixed office waste or old newspapers (ONP) in or more of the layers. Presence of any of these recycled fiber materials in the fiber suspension usually decreases drainage and paper strength and provides a substantial load of starch, hydrophobic, and colloidal substances to the process. [0130] As used herein, the term "OCC" refers to old corrugated cardboard and/or containerboard. Corrugated refers to those boxes where the materials are made from three separate layers of paper, two liners and a corrugated, or wavy, layer sandwiched between them. Brown paper bags are commonly accepted with OCC for recycling. The term OCC denotes recycled fiber material which have liners of test liner, jute or kraft, and may cover also double sorted corrugated containerboard (DS OCC).

[0131] As used herein, the terms "broke" or "mill broke" refer to paper, which during the paper making process becomes suitable only for repulping e.g., trimmings or paper that is out of specification. Broke is re-used material which never left the mill is not regarded as recycled or recovered. Broke is a valuable source of fiber and is recycled internally at the mill.

[0132] As used herein, the term "coated broke" refers to broke that contains coatings that are applied to the base sheet of paper as it is being manufactured. When the broke contains these coatings, it presents special problems in recycling to recover fiber values because the coatings introduce materials which would not normally be present in the original stock of fiber used to manufacture the base paper sheet. The coated broke may also contain dyes and/or other additives. In the present application coated broke includes surface-sized, dyed, and/or creped broke.

[0133] As used herein, the term "recycled fiber composition" generally refers to a composition comprising recycled cellulosic fibers, typically a composition wherein most or all are recycled fibers, e.g., at least 20, 40, 50, 60, 70, 80, 90 or 100%.

[0134] As used herein, the term "fiber suspension" is understood as an aqueous suspension, which comprises fibers, preferably recycled fibers, and optionally fillers. For example, the fiber suspension may comprise at least 5 %, preferably 10-30 %, more preferably 11 - 19 % of mineral filler. Mineral filler may be any filler conventionally used in paper and board manufacturing, such as ground calcium carbonate, precipitated calcium carbonate, clay, talc, gypsum, titanium dioxide, synthetic silicate, aluminum trihydrate, barium sulphate, magnesium oxide or their any of mixtures.

[0135] As used herein the term "headbox" refers a receptacle in a papermaking machine that holds suspended aqueous cellulosic solids and which regulates the flow thereof onto a wire or screen that provides for the draining of water therefrom.

[0136] As used herein the term "lignocellulosic substrate" refers to a paper and/or paperboard product formed from plant dry matter from any source, virgin or recycled, which may be coated, printed, and/or formed into a packaging product. For example, such substrates include paper products made from pulp, such as by methods comprising forming an aqueous cellulosic papermaking furnish, draining the furnish to form a sheet, and drying the sheet. The steps of forming the papermaking furnish, draining and drying may be carried out in any conventional manner generally known in the art. The substrates may contain polymeric strengthening agents, such as wet strength and dry strength agents. [0137] As used herein, the term "slurry" generally refers to a mixture of water, dissolved paper pulp, and optionally other soluble or insoluble components produced or added during the stock preparation phase of papermaking.

[0138] As used herein, the terms "furnish" or "papermaking furnish" generally refers to a mixture of cellulosic fibers, pulp, optional fillers, dyes, and water from which paper or board is made.

[0139] As used herein, the term "thick stock" generally refers to mixture of papermaking pulp and other materials with a consistency of about 1 to 5%.

[0140] As used herein, the term "thin stock" generally refers to a mixture of papermaking pulp and other materials, after having been diluted to a consistency below 1% with whitewater or other process water at a fan pump.

[0141] As used herein, the term "white water" generally refers to process water within a paper machine system, especially referring to water that is drained from paper as the sheet is being formed.

[0142] As used herein, the terms "fixation", "fixing" and "fix" means that a substance is associated or attached onto the fibers at least temporarily or permanently.

[0143] As used herein, the term "flocculation" generally refers to the tendency for fibers to collect together in bunches in the presence of flow, and especially in the presence of retention aids; the same word also refers to the action of high-mass polymers in forming bridges between suspended colloidal particles, causing strong, relatively irreversible agglomeration.

[0144] The term "flocculant" may generally refer to a reagent that may bridge neutralized or facilitate coagulation of particles into larger agglomerates, typically resulting in more efficient settling. Flocculation process generally involves addition of a flocculant followed by mixing to facilitate collisions between particles, allowing for the destabilized particles to agglomerate into larger particles that can be removed by gravity through sedimentation or by other means, e.g., centrifugation, filtration.

[0145] As used herein "molecular weight, MW" of a polymer refers to the sum of the atomic weights of individual atoms that comprise a polymeric molecule. It indicates the average length of the bulk resin's polymer chains. Not all polymer molecules of a particular grade have the exact same molecular weight. There is a range or distribution of molecular weights. Molecular weights may be measured by various methods known to persons of skill in the art. For example, weight average molecular weight may be measured using gel permeation chromatography (GPC). Additionally, polymer molecular weights may be measured by GPC/Light Scattering/Viscometry also known as Triple Detection GPC which employs Refractive Index Detector (with or without UV Detector), Dilute Solution Viscometry and Light Scattering all in series to determine molecular weights, distribution, and related solution parameters.

[0146] RETENTION AND DRAINAGE AIDS [0147] As used herein, the terms "polymer" or "polymeric additives" and similar terms are used in their ordinary sense as understood by one skilled in the art, and thus may be used herein to refer to or describe a large molecule (or group of such molecules) that may comprise recurring units. Polymers may be formed in various ways, including by polymerizing monomers and/or by chemically modifying one or more recurring units of a precursor polymer. Unless otherwise specified, a polymer may comprise a "homopolymer" that may comprise substantially identical recurring units that may be formed by, for example, polymerizing a particular monomer. Unless otherwise specified, a polymer may also comprise a "copolymer" that may comprise two or more different recurring units that may be formed by, for example, copolymerizing, two or more different monomers, and/or by chemically modifying one or more recurring units of a precursor polymer. Unless otherwise specified, a polymer or copolymer may also comprise a "terpolymer" or a "tetra polymer" which generally refer to polymers that comprise three, four, or more different recurring monomer units. The term "polymer" as used herein is intended to include both the acid form of the polymer as well as its various salts. Polymers may be amphoteric in nature, that is, containing both anionic and cationic substituents, although not necessarily in the same proportions.

[0148] As used herein, the terms "polyacrylamide" or "PAM" generally refer to polymers and co-polymers comprising acrylamide moieties, and the terms encompass any polymers or copolymers, including terpolymers, comprising acrylamide moieties, e.g., one or more acrylamide (co)polymers of acrylamide and additional monomers capable of copolymerizing with acrylamide. Furthermore, PAMs may comprise any of the polymers or copolymers discussed herein. Additionally, the PAMs described herein, e.g., one or more acrylamide (co)polymers, may be produced in one of various forms, including, for example, dry (powder ) form (e.g., DPAM), emulsion polyacrylamide (EPAM), or liquid polyacrylamide. Amphoteric polyacrylamides (AmPAM) may be formulated in dry (powder ) form (e.g., AmDPAM), or emulsion form (AmEPAM) .

[0149] As used herein, the term "emulsion polymer" generally refers to inverse emulsions (water-in-oil) in which water droplets containing the polymer are suspended in an oil phase, also termed a hydrophobic phase.

[0150] As used herein, the term "inverse phase emulsion" refers to a liquid polymer composition of polymer dissolved in an aqueous solution which is dispersed into an oil phase (e.g., hydrophobic liquid) to form an oil-continuous phase, which is then mixed with an aqueous solution so that the dispersed polymer phase of the liquid polymer composition becomes a substantially aqueous-continuous phase, and the hydrophobic liquid phase becomes a dispersed, discontinuous phase. The inversion point can be characterized as the point at which the viscosity of the inverted polymer solution has substantially reached its maximum under a given set of conditions. In practice, this may be determined for example by measuring viscosity of the composition periodically over time and when three consecutive measurements are within the standard of error for the measurement, then the solution is considered inverted. [0151] As used herein, the term "liquid polymer" refers to a combination of at least one polymer and a liquid, typically an aqueous liquid. The polymer in a may be thoroughly dissolved or may be a partially dissolved suspension, dispersion, or slurry. An "aqueous polymer mixture" or "hydrated polymer composition" refers to a combination of at least one polymer and an aqueous liquid. When a dry polymer is combined with an aqueous liquid, the polymer is initially partially hydrated at the polymer-water interface. Polymers do not dissolve instantaneously in aqueous or non-aqueous solvents. Dissolution is controlled by either the disentanglement of the polymer chains or by the diffusion of the chains through a boundary layer adjacent to the polymer-solvent interface. After thorough mixing, the polymer may become fully hydrated, at which point the wetting process is complete and the polymer may be either partially dissolved or fully dissolved, depending on the nature and composition of the polymer and solvent.

[0152] The term "water-soluble polymer" generally refers to any polymer that may dissolve and/or disperse in water. Said polymers may modify the physical properties of aqueous systems undergoing gelation, thickening, viscosification, or emulsification/stabilization. Said polymers may perform a variety of functions, including but not limited to use as dispersing and suspending agents, stabilizers, thickeners, viscosifiers, gellants, flocculants and coagulants, film-formers, humectants, binders, and lubricants.

[0153] As used herein, the term "monomer" generally refers to nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, betaine monomers, and amphoteric ion pair monomers.

[0154] As used here "Q9 monomer" refers to 2-(acryloyloxy)ethyl] trimethylammonium chloride (Q9) which has a molecular formula of C8H16CINO2 and a molecular weight of 193.67 g/mol.

[0155] As used herein acrylamide or "AM" refers to a neutral monomer of molecular formula: C3H5NO and a molecular weight of 71.08 g/mol.

[0156] As used herein, the term "cationic monomer" generally refers to a monomer that possesses a positive charge. Examples thereof include acryloyloxy ethyl trimethylammonium chloride (Q9) monomers. Cationic monomers may also be selected from acryloyloxyethyltrimethyl ammonium chloride ("AETAC"), methacryloyloxyethyltrimethylammonium chloride ("MAETAC"), methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), acrylamidopropyltrimethylammonium chloride ("APTAC"), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride ("DADMAC"); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary or acid salts, including but not limited to, dimethylaminoethyl acrylate ("DMAEA"), dimethylaminoethyl methacrylate ("DMAEA"), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfuric acid salt, dimethylaminoethyl acrylate hydrochloric acid salt, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfuric acid salt, dimethylaminoethyl methacrylate hydrochloric acid salt, dimethylaminoethyl methacryloyl hydrochloric acid salt; dialkylaminoalkylacrylamides and methacrylamides and their quaternary or acid salts, including but not limited to, acryloylamidopropyltrimethylammonium chloride, dimethylaminopropyl acrylamide, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl acrylamide hydrochloric acid salt, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt, diethylaminoethylacrylate, diethylaminoethylmethacrylate; and diallyldialkylammonium halides, including but not limited to, diallyldiethylammonium chloride and diallyldimethylammonium chloride ("DADMAC"), and any combination thereof.

[0157] As used herein, the terms "PVAm", "polyvinylamine", "vinyl amine polymer", and refer to any polymer having vinyl amine units (i.e., 1-aminoethylene units or N- ethenylamine units). PVAms are highly cationica I ly charged at typical operating pH for papermaking applications. PVAm adsorbs spontaneously and irreversibly on cellulosic fiber surfaces in water, thereby generating cationic surface properties on the fiber. PVAm polymers, typically having high cationic charge density and low molecular weight, function in papermaking as coagulants to form small fiber-flocs and do not increase fiber floc size as the PVAm polymer dosage increases. For this reason, PVAm polymers have been widely used to improve vacuum drainage rate, press dewatering rate and reduce dryer steam consumption without deteriorating sheet formation for recycled paper machines. PVAms are also widely used in papermaking as strengthening agents. One significant drawback is that PVAm polymers are very expensive. Many paper mills, especially those producing recycled liner board, cannot afford to use PVAm as a drainage agent.

[0158] PVAm may be prepared by free radical polymerization of N-vinyl formamide to form poly-N-vinylformamide (PNVF) and subsequent hydrolysis of formamide groups to amines, thereby forming PVAm. Such hydrolysis may be base catalyzed, such as by hydroxide ion, or acid catalyzed. Hydrolysis of PNVF initially forms copolymers comprising PNVF and PVAm (PNVF-co-PVAm), which may be completely hydrolyzed to form PVAm with little to no residual PNVF.

[0159] In some embodiments, the one or more PVAm polymers may comprise vinyl amine polymers and PNVF-co-PVAm copolymers, which contain other cationic, anionic, and/or nonionic monomers, including but not limited to, acrylamide, acrylic acid, acrylate, N-butyl acrylate, and polyethylenimine (i.e., polyaziridine) monomer units. In some embodiments, PVAm may have a cationic charge density ranging from 1 to 2 m Eq per gram. In some embodiments, PVAm may have a weight average molecular weight ranging from 0.5 to 2.5 million Da. [0160] In some embodiments, the one or more PVAm polymers comprise a polymer synthesized by Hofmann degradation of a base polymer comprising (i) acrylamide; (ii) methacrylamide; (iii) a copolymer of acrylamide and cationic monomers selected from the group consisting of dimethylaminoethyl acrylate (DMAEA), quaternized dimethylaminoethyl methacrylate (DMAEMA), dimethyldiallylammonium chloride (DADMAC), acrylamidopropyltrimethylammonium chloride (APTAC), and methacrylamidopropyltrimethylammonium chloride (MAPTAC); or (iv) a copolymer of acrylamide and DADMAC.

[0161] In some embodiments, the one or more PVAm polymers comprise a polymer synthesized by total or partial hydrolysis of one or more poly(N-vinylformamide) homopolymers or copolymers, wherein said one or more poly(N-vinylformamide) homopolymers or copolymers are optionally synthesized by radical polymerization of N- vinylformamide or by radical polymerization of N-vinylformamide and one or more additional monomers and further comprising a degree of hydrolysis ranging from 1-100 mol%, 20-100 mol%, 40-100 mol%, 60-100 mol%, or 80-100 mol%.

[0162] In some embodiments, the one or more PVAm polymers comprise a polymer synthesized by partial hydrolysis of one or more poly(N-vinylformamide) homopolymers and further comprising a degree of hydrolysis ranging from 30-50 mol%, 35-45 mol%, or about 40 mol%.

[0163] The "degree of hydrolysis" of a PVAm polymer refers to the mole % of PNVF units that have been hydrolyzed to vinyl amine units. For example, a PNVF-co-PVAm polymer with a degree of hydrolysis of 50 mol% comprises a 1:1 mol ratio of N-vinyl formamide and vinylamine units. A PVAm with a degree of hydrolysis of 100 mol% comprises vinylamine units and no residual N-vinyl formamide units. In some embodiments, the one or more PVAm polymers may comprise a degree of hydrolysis ranging from 30-100 mol%, 40-100 mol%, 60-100 mol%, or 80-100 mol%.

[0164] As used herein, the term "quick inversion cationic emulsion polyacrylamides" or "QIC- EPAMs" refer to high MW quick inversion cationic retention polymers comprising a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) and acrylamide copolymer with 20 to 30 mol% of Q9 monomer. This copolymer has a standard viscosity (SV) of between 2.5 to 3.5 cPs. The optimal MW range, low SV value range, and optimized 3-D structure of QIC-EPAMs are achieved by skillfully using sodium hypophosphite as a chain transfer agent and methylene bis-acrylamide as a crosslinking agent. The molecular weight of QIC-EPAM is reduced to the low-mid range which is suitable to improve the retention, drainage, and fixation of fiber, fines, and fillers without damaging sheet formations at elevated polymer dosage levels. The 3-D polymer structures in the quick inversion emulsion are found to enhance colloidal and fines retention more effectively than conventional linear cationic polymers with high MW (typical SV range =4.5 to 5.5 cPs). The combination of low SV and high cationic charge is found to make small and tight fiber flocs like PVAm and improve the effects of vacuum drainage/press dewatering for 100% recycled paper grades. Combination of the QIC-EPAMS with PVAm as an additive for reparation of recycled liners provides 1 improved retention, gravimetric drainage rates, and DDA drainage time, without overflocculation and allows for significant decrease in PVAm usage. The QIC-EPAM polymers of the present invention are described in US patent application entitled Improved Retention Of Engineered Cellulosic Additives Using Synergistic Cationic Polymer Combination (U.S. Prov. Appl. No. 63/387,298), which is hereby incorporated by reference.

[0165] As used herein, the term "added separately" refers to addition of two or more additives (e.g., process aid components, chemicals, polymers, etc.) sequentially in any order or simultaneously to an aqueous suspension of cellulosic fibers.

[0166] As used herein, the term "co-mixed" refers to mixing of two or more chemical additives by any means known in the art prior to addition of the co-mixed additives to a papermaking process (e.g., to a furnish, thick stock, think stock, or to a paper machine). In certain embodiments, retention and drainage aids comprising PVAm and QIC-EPAM are comixed in a separate location or on site. In some embodiments the co-mixed PVAm and QIC- EPAM are agitated by stirring, agitated in a pipe, or otherwise thoroughly mixed, prior to addition to a papermaking process.

[0167] TERMS AND UNITS

[0168] As used herein, the term "aqueous solution" or "solution" generally refers to a mixture of water and a water-soluble solute or solutes which are completely dissolved with little to no residual undissolved polymer gel. The solution may be homogenous. When mixed with excess of water, the polymer product is preferably fully dissolved and the obtained polymer solution is preferably free from discrete polymer particles or granules or residual gel.

[0169] As used herein, the term "aqueous suspension", "aqueous slurry", or "slurry" generally referto a heterogeneous mixture of a fluid that contains insoluble or sparingly soluble solid particles sufficiently large for sedimentation. Suspensions and slurries of the present invention may also comprise some amount of solid particles, often termed colloidal particles, which do not completely settle or take a long time to settle completely.

[0170] As used herein, the term "consistency" generally refers to percent oven dry mass in the stock, slurry, or furnish (i.e., 100% * oven dry mass/total mass).

[0171] The terms, "total solids" or "total suspended solids" are used interchangeably herein and generally refer the total amount or weight of suspended solids contained in oil sands or other sands comprising dispersion. "Total solids" or "total suspended solids" generally does not include dissolved solids.

[0172] As used herein, the term "ppm" refers to parts per million on the basis of milligrams of solute per liter of aqueous solution or slurry (e.g., mg/L).

[0173] As used herein, the terms "Ibs/ton" or "#/T" denote pounds of dry mass of added material (e.g., additive, solute, and/or particle) per ton of suspended solids (e.g., weight of AKD per total dry ton of suspended solids). [0174] As used herein, the terms "kg/T" or "kg/ton" denote kilograms of dry mass (additive, solute, and/or particle) per ton of slurry, stock, and/or furnish.

[0175] As used herein, the phrases "% by wt." denotes pounds of dry mass of additive per dry mass of solids in the formulation, solution, or slurry, multiplied by 100%.

[0176] As used herein, the terms "CSF" is a measure of water drainage rates from fibers and is often used to characterize the degree of fiber fibrillation in pulp and paper science. The freeness has been shown to be related to the surface conditions and swelling of the fibers (TAPPI 1999b). CSF is obtained by gravimetric water retention methods.

DESCRIPTION OF THE INVENTION

[0177] A recently discovered synergy between a novel QIC-EPAM and PVAms in paper furnish containing high amounts of recycled content shows unexpected performance efficiency for retention and drainage without over-flocculation of the fibers and allows for significant reduction in PVAm dosage. In mills with high recycled content with higher levels of calcium ions and high conductivity, North American paper manufacturers are looking for effective chemistry that will provide on-machine retention and drainage without overflocculation.

[0178] Retention is a function of different mechanisms, such as filtration by mechanical entrainment, electrostatic attraction, and bridging between the fibers and the fillers in the furnish. Because both the cellulosic fibers and many common filler materials are negatively charged, they are mutually repellent. Generally, the only factor tending to enhance retention is mechanical entrainment. Therefore, a retention aid is generally used to improve retention of the fibers and fillers on the wire.

[0179] Recycled fiber material is commonly used as raw material for paper or board. The recycled fiber material comprises in addition to the fibers a high level of fines and fillers. Greater retention of fines and fillers is highly desired and permits a reduction in the content of cellulosic fiber. As pulps of inferior quality are employed to reduce papermaking costs, the retention aspect of papermaking becomes even more important. This is due to the higher level of fines found in lower quality pulps, such as recycled fiber and coated broke. Greater retention of fines, fillers, and other slurry components also reduces the amount of such substances lost to the white water. This reduces the amount of material wastes, the cost of waste disposal, and the adverse environmental effects therefrom.

[0180] Retention and drainage aids for papermaking are generally added to the furnish or stock prior to addition to the headbox of the paper machine with the goal of providing enhanced on-machine retention and drainage while also providing additional benefits, such as improved paper strength and wet pressability. These requirements are especially challenging for papermaking operations in mills with high recycled content. Typical retention and drainage aids include high molecular weight cationic polymers or CPAM/silica retention programs. When added to recycled fibers, these additives create large flocs (i.e., over-flocculation) of recycled pulp, making recycled paper less uniform and causing poor formation. A poorly formed sheet containing large fiber flocs will exhibit a high gravimetric drainage rate and will drain quickly in the initial hydrofoil section of a paper machine. However, this over-flocculated sheet will respond poorly to vacuum in later parts of the forming section, resulting in a reduction of vacuum drainage (press dewatering) rate. Because of increased captured water in the large flocs, the sheet will also require an increase of dryer steam consumption.

[0181] The present invention provides a process for using a novel QIC-EPAM with PVAm as a drainage/retention aid program in making recycled OCC liners. A synergic effect between PVAms and the novel QIC-EPAM has been surprisingly observed in industrial settings on paper machines. The synergic effect allows for a significant reduction of expensive PVAm dosage levels and achieves equal or better retention and drainage results without overflocculation.

[0182] Retention and drainage aids of the present invention comprising QIC-EPAM + PVAm provide several advantages over the conventional PVAm only drainage/retention program: 1) QIC-EPAM + PVAm can be used as pump and go products without conventional emulsion polymer inverting and aging tanks; 2) QIC-EPAM + PVAm provides small tight fiber flocs like PVAm and improves the effects of vacuum drainage/press dewatering for 100% recycled paper grades; 3) 20-40% PVAm dosage reduction has been observed on paper machines by combining PVAm with 0.25-1.2 Kg/ton of QIC-EPAM; 4) the combination of PVAm and QIC- EPAM can be added onto a paper machine by the following addition processes: (a) premixed prior to addition to the thick stock; ( b) premixed prior to addition to the thin stock; (c)added separately to the thick stock; (d) added separately to the thin stock; (e) added separately, wherein the one or more PVAm polymers are added to the thick stock and the one or more QIC-EPAMs are added to the thin stock; or (f) added separately, wherein the one or more PVAm polymers are added to the thin stock and the one or more QIC-EPAMs are added to the thick stock.

[0183] The present invention generally relates to methods and compositions for manufacture of tissue, paper, or board and for enhancing retention and drainage thereof. In particular, the disclosure provides methods for enhancing retention and drainage by addition of a retention and drainage aid comprising quick inversion cationic emulsion polyacrylamides (QIC-EPAMS) and polyvinylamine (PVAm) polymers Preparation of paper sheets under these conditions provides improved retention, gravimetric drainage rates, and DDA drainage time, without over-flocculation and allowed for significant decrease in PVAm usage.

[0184] In one aspect, the present invention provides a method for manufacture of tissue, paper, or board, the method comprising:

[0185] (a) forming or providing a thick stock comprising an aqueous suspension of cellulosic fibers, optionally comprising 40-100%, 60-100%, or 80-100% by weight recycled cellulosic fibers;

[0186] (b) optionally diluting the thick stock to form a thin stock; [0187] (c) introducing the thick stock and/or the thin stock into a headbox of a paper machine and then draining on a wire screen, thereby removing sufficient water to form a wet fibrous web; and

[0188] (d) pressing and drying the wet fibrous web to obtain a tissue, paper, or board;

[0189] wherein the method comprises, prior to step (c), treating the thick stock and/or the thin stock with a retention and drainage aid comprising:

[0190] (i) one or more polyvinylamine (PVAm) polymers; and

[0191] (ii) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising acrylamide (AM) monomers and cationic acryloyloxyethyltrimethyl ammonium chloride (Q9).

[0192] In some exemplary embodiments of the method said one or more PVAm polymers and said one or more QIC-EPAMs are:

[0193] (a) premixed prior to addition to the thick stock;

[0194] (b) premixed prior to addition to the thin stock;

[0195] (c) added separately to the thick stock;

[0196] (d) added separately to the thin stock;

[0197] (e) added separately, wherein the one or more PVAm polymers are added to the thick stock and the one or more QIC-EPAMs are added to the thin stock; or

[0198] (f) added separately, wherein the one or more PVAm polymers are added to the thin stock and the one or more QIC-EPAMs are added to the thick stock;

[0199] wherein steps (a)-(f) are optionally followed by a mixing time ranging from 0.01-10 min, 0.1-5 min, or 1-2 min.

[0200] In some exemplary embodiments of the method said one or more PVAm polymers:

[0201] (a) comprise a weight average molecular weight ranging from 50-3000 kDa, 100-2000 kDa, 200-2000 kDa, or 400-800 kDa ;

[0202] (b) comprise a cationic charge density ranging from below 5.0 mEq/g, 0.5-5.0 mEq/g, 1.0-4.0 mEq/g, or 1.5-2.5 mEq/g as dry solids at pH 7;

[0203] (c) comprise a polymer synthesized by Hofmann degradation of a base polymer comprising (i) acrylamide; (ii) methacrylamide; (iii) a copolymer of acrylamide and cationic monomers selected from the group consisting of dimethylaminoethyl acrylate (DMAEA), quaternized dimethylaminoethyl methacrylate (DMAEMA), dimethyldiallylammonium chloride (DADMAC), acrylamidopropyltrimethylammonium chloride (APTAC), and methacrylamidopropyltrimethylammonium chloride (MAPTAC); or (iv) a copolymer of acrylamide and DADMAC;

[0204] (d) comprise a polymer synthesized by total or partial hydrolysis of one or more poly(N-vinylformamide) homopolymers or copolymers, wherein said one or more poly(N- vinylformamide) homopolymers or copolymers are optionally synthesized by radical polymerization of N-vinylformamide or by radical polymerization of N-vinylformamide and one or more additional monomers and further comprising a degree of hydrolysis ranging from 1-100 mol%, 20-100 mol%, 40-100 mol%, 60-100 mol%, or 80-100 mol%;

[0205] (e) comprise a polymer synthesized by partial hydrolysis of one or more poly(N- vinylformamide) homopolymers and further comprising a degree of hydrolysis ranging from 30-50 mol%, 35-45 mol%, or about 40 mol%;

[0206] (f) are formulated optionally as a dry powder or as an aqueous composition comprising a PVAm solids % by mass ranging from about 0.5% to about 30%, optionally from greater than 2% to about 25%, further optionally from about greater than 10% to about 22%; or

[0207] (g) any combination of (a)-(f).

[0208] In some exemplary embodiments of the method said one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs):

[0209] (a) comprise an acrylamide (AM) monomer content ranging from 60-85 wt%, 65-85 wt%, 70-85 wt%, or 70-80 wt%;

[0210] (b) comprise a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from <40 wt%, 15-40 wt%, 15-35 wt%, 15-30 wt%, or 20-30 wt%; or

[0211] (c) comprise an inverse phase emulsion, a dry polymer, or an aqueous polymer solution, preferably an inverse phase emulsion;

[0212] (d) comprise a polymer standard viscosity (SV) ranging from less than or equal to 3.5 cPs, 2.0- 3.5, 2.5-3.5 cPs, or 3.0-3.5 cPs; or

[0213] (e) any combination of the foregoing.

[0214] In some exemplary embodiments of the method said retention and drainage aid optionally further comprises one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles, wherein:

[0215] (a) said more cationic dry polyacrylamides (DPAM) comprise acrylamide (AM) monomers and one or more cationic monomers, wherein said one or one or more cationic monomers are selected from the group consisting of acryloyloxyethyltrimethyl ammonium chloride ("AETAC"), methacryloyloxyethyltrimethylammonium chloride ("MAETAC"), methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), acrylamidopropyltrimethylammonium chloride ("APTAC"), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride ("DADMAC"); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary or acid salts, including but not limited to, dimethylaminoethyl acrylate ("DMAEA"), dimethylaminoethyl methacrylate ("DMAEA"), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfuric acid salt, dimethylaminoethyl acrylate hydrochloric acid salt, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfuric acid salt, dimethylaminoethyl methacrylate hydrochloric acid salt, dimethylaminoethyl methacryloyl hydrochloric acid salt; dialkylaminoalkylacrylamides and methacrylamides and their quaternary or acid salts, including but not limited to, acryloylamidopropyltrimethylammonium chloride, dimethylaminopropyl acrylamide, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl acrylamide hydrochloric acid salt, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt, diethylaminoethylacrylate, diethylaminoethylmethacrylate; and diallyldialkylammonium halides, including but not limited to, diallyldiethylammonium chloride and diallyldimethylammonium chloride ("DADMAC"), and any combination thereof; and

[0216] (b) said one or more inorganic microparticles are selected from the group of microparticles and nanoparticles consisting of silica microparticles; colloidal silica; aluminum phyllosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite, and montmorillonite.

[0217] In some exemplary embodiments the method comprises one or more of the following:

[0218] (a)said one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprise an acrylamide (AM) monomer content ranging from 70-80 wt% and a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; comprises an inverse phase emulsion; and comprises a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs;

[0219] (b) said one or more PVAm polymers comprise a weight average molecular weight ranging from 400-800 kDa; or

[0220] (c) said one or more inorganic microparticles comprise bentonite, sodium bentonite, or calcium bentonite.

[0221] In some exemplary embodiments of the method, when added to the thick stock and/orthe thin stock:

[0222] (a) said retention and drainage aid comprises a ratio of said one or more QIC-EPAMs to said one or more PVAms ranging from 1:60 to 1:1; 1:30-1:1; 1:6 to 1:1; or 1:3 to 1:1;

[0223] (b) said one or more PVAm polymers are added at a dosage ranging from 0.2-12 kg/t, 0.2-10 kg/t, 0.2-8 kg/t, 0.2-6 kg/t, 0.2-2 kg/t, or 0.2-0.6 kg/t;

[0224] (c) said one or more QIC-EPAMs are added at a dosage ranging from 0.1-1 kg/t, 0.1- 0.5 kg/t, or 0.1-0.2 kg/t; [0225] (d) said one or more DPAMs are added at a dosage ranging from 0.1-lkg/t, 0.1-0.5 kg/t, or 0.2-0.4 kg/t;

[0226] (e) said one or more inorganic microparticles are added at a dosage ranging from 0.1- 4 kg/t, 1-4 kg/t, or 2-4 kg/t; or

[0227] (f) any combination of (a)-(e).

[0228] In some exemplary embodiments the method comprises one or more of the following:

[0229] (a) the thick stock comprises a consistency ranging from 1-5%, 1-3%, or 1-1.5%, wherein consistency refers to % by weight of total suspended solids in the aqueous slurry;

[0230] (b) the thin stock comprises a consistency ranging from 0.3-1%, 0.4-1%, 0.5-1%, or 0.5-0.7%;

[0231] (c) the thick stock is diluted to form the thin stock by addition of water, chemical water, synthetic water, white water, and/or process water; or

[0232] (d) the thick stock and or the thin stock optionally further comprise one or more additives relating to papermaking, including but not limited to, starches, dyes, bleaching agents, sizing agents, wet strength agents, dry strength agents, or detackifiers; or

[0233] (e) any combination of (a)-(c).

[0234] In some exemplary embodiments of the method said aqueous suspension of cellulosic fibers comprises a pH ranging from 4-8, 4-7.5, 4-7, 4.5-7, or 5-7 and further comprises:

[0235] (a) a percentage of recycled cellulosic fibers ranging from 40-100%, 50-100%, 60- 100%, 80-100%, or 90-100% by weight recycled cellulosic fibers,

[0236] (b) a combination of one or more recycled fibers optionally obtained from sources, including but not limited to, old corrugated cardboard (OCC), mixed office waste (MOW), mixed office paper, old newspaper pulp (ONP), old magazines (OMG), mill broke fibers, or coated broke,

[0237] (c) optionally softwood fiber, hardwood fiber, refined fiber, non-wood fibers, including but not limited to straw and wheat pulp, and a mixture of any of the foregoing;

[0238] (d) optionally pulp selected from Kraft pulp, unbleached Kraft pulp, bleached pulp, unbleached pulp, process water from pulp, paper, and/or board production, neutral sulfite semi chemical (NSSC) pulp, mechanical pulp, non-wood pulp, and a mixture of any of the foregoing; or

[0239] (e) an amount of pulp fines and/or an amount of mineral fillers ranging from 5-30% by mass of total solids in the aqueous suspension, wherein the amount of pulp fines pulp fines comprises pulp particles small enough to pass through a 76 pm diameter hole and said amount of mineral fillers comprise calcium carbonate, clays, kaolinite, aluminum silicates, talc, and/or gypsum; or [0240] (f) and combination of (a)-(e).

[0241] In some exemplary embodiments of the method, when used for manufacture of tissue, paper, or board, the method results in:

[0242] (a) an increased retention of cellulosic fibers;

[0243] (b) an increase in retention of pulp fines and/or mineral fillers;

[0244] (c) a faster drainage rate on the wire screen;

[0245] (d) an increased press dewatering rate;

[0246] (e) a reduction in dryer steam usage;

[0247] (f) an improved tissue, paper, or board quality as determined by decreased permeability;

[0248] (g) a reduction in PVAm dosage;

[0249] (h) a synergistic increase in paper machine drainage rate resulting from the combination of QIC-EPAM and PVAm;

[0250] (i) a synergistic increase in Canadian Standard Freeness (CSF) resulting from the combination of QIC-EPAM and PVAm; or

[0251] (j) any combination of (a)-(i); compared to an identical method performed in the absence of (i) addition of said one or more PVAms or (ii) addition of said one or more QIC-EPAMs.

[0252] In another aspect, the present invention provides a method for manufacture of tissue, paper, linerboard, or board, the method comprising:

[0253] (a) forming or providing a thick stock comprising an aqueous suspension of cellulosic fibers, optionally comprising 40-100%, 60-100%, or 80-100% by weight recycled cellulosic fibers;

[0254] (b) optionally diluting the thick stock to form a thin stock;

[0255] (c) introducing the thick stock and/or the thin stock into a headbox of a paper machine and then draining on a wire screen, thereby removing sufficient water to form a wet fibrous web; and

[0256] (d) pressing and drying the wet fibrous web to obtain a tissue, paper, or board;

[0257] wherein the method comprises, prior to step (c), treating the thick stock and/or the thin stock with a retention and drainage aid comprising:

[0258] (i) one or more polyvinylamine (PVAm) polymers;

[0259] (ii) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

[0260] (iii) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite.

[0261] In some exemplary embodiments of the method said one or more PVAm polymers and said one or more QIC-EPAMs are:

[0262] (a) premixed prior to addition to the thick stock;

[0263] (b) premixed prior to addition to the thin stock;

[0264] (c) added separately to the thick stock;

[0265] (d) added separately to the thin stock;

[0266] (e) added separately, wherein the one or more PVAm polymers are added to the thick stock and the one or more QIC-EPAMs are added to the thin stock; or

[0267] (f) added separately, wherein the one or more PVAm polymers are added to the thin stock and the one or more QIC-EPAMs are added to the thick stock.

[0268] In another aspect, the present invention provides a thick stock comprising an aqueous suspension comprising a consistency ranging from 1-5%, 1-3%, or 1-1.5%; a recycled cellulosic fiber content ranging from 40-100%; and a retention and drainage aid comprising:

[0269] (a) one or more polyvinylamine (PVAm) polymers;

[0270] (b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

[0271] (c) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite;

[0272] wherein

[0273] (i) said retention and drainage aid comprises a ratio of said one or more QIC-EPAMs to said one or more PVAms ranging from 1:60 to 1:1; 1:30-1:1; 1:6 to 1:1; or 1:3 to 1:1;

[0274] (ii) said one or more PVAm polymers and said one or more QIC-EPAMs are premixed prior to addition to the thick stock;

[0275] (iii) said one or more PVAm polymers and said one or more QIC-EPAMs are added separately to the thick stock.

[0276] In another aspect, the present invention provides a thin stock comprising an aqueous suspension comprising a consistency ranging from 0.3-1%, 0.4-1%, 0.5-1%, or 0.5-0.7%; a recycled cellulosic fiber content ranging from 40-100%; and a retention and drainage aid comprising: [0277] (a) one or more polyvinylamine (PVAm) polymers;

[0278] (b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

[0279] (c) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite;

[0280] wherein

[0281] (i) said one or more PVAm polymers and said one or more QIC-EPAMs are premixed prior to addition to the thin stock;

[0282] (ii) said one or more PVAm polymers and said one or more QIC-EPAMs are added separately to the thin stock.

[0283] In another aspect, the present invention provides a composition for use as a retention and drainage aid in manufacture of tissue, paper, or board, the composition comprising:

[0284] (a) one or more polyvinylamine (PVAm) polymers;

[0285] (b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

[0286] (c) optionally one or more anionic organic or inorganic microparticles selected from the group of microparticles and nanoparticles consisting of silica microparticles; colloidal silica; aluminum phyllosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite, and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamides.

[0287] The methods and compositions illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein and/or any element specifically disclosed herein. Exemplary embodiments of the invention and its advantages are further disclosed in the following examples.

EXAMPLES

[0288] The examples provided herein are for illustrative purposes so that the invention may be more fully understood. These examples should not be construed as limiting the invention in any way.

Example 1: Experimental procedures and chemical additives

[0289] Determination of DDA drainage time [0290] Cellulosic fibrous webs were prepared and drainage times were analyzed by dynamic drainage analyzer (DDA) testing according to the following. An aliquot of cellulosic stock (500-700 mL) with a consistency of 0.5 to 0.7% by wt (Total Suspended solids, TSS) was mixed with chemical additives. Chemicals were added in a time sequence that simulates where the chemicals are added on the paper machine. Blank samples contained no added chemical. After mixing, the flocculated stock was drained through a 60 mesh screen under vacuum (250 mBar). Drainage time was determined by measuring the time until vacuum break (i.e., a rapid increase in vacuum pressure). Shorter drainage times indicates better drainage. DDA Drainage % Gain was determined by calculating the % decrease in drainage time compared to the blank (no chemical additive). For the present examples, higher DDA Drainage % Gain above the drainage lower limit line indicated on FIGS 1-2 is preferred. DDA filtrates were used for turbidity testing as set forth below.

[0291] Determination of DDA permeability

[0292] Permeability of fiber pads from DDA drainage testing was determined by tracking the air flow time in the pressed fiber pad during the DDA drainage tests. Permeability % Gain was determined by calculating the % increase in permeability compared to the blank (no chemical additive). The percentage of sheet permeability gain by using polymers is preferably below the permeability upper limit line indicated on FIGS 1-2. Percent permeability gains over the permeability upper limit line indicate over-flocculation of cellulosic fibers, which leads to larger flocs and causes poor sheet formation.

[0293] Determination of filtrate turbidity

[0294] Turbidity testing was performed on the filtrates from DDA screening as an indication of retention. Turbidity of treated filtrates was performed using a Hach 2100Q turbidimeter. The Model 2100Q Portable Turbidimeter operates on the nephelometric principle of turbidity measurement. The optical system includes a tungsten-filament lamp, a 90° detector to monitor scattered light and a transmitted light detector. The instrument's microprocessor calculates the ratio of the signals from the 90° and transmitted light detectors, which corrects for interferences from color and/or light-absorbing materials. The instrument range is 0 to 1000 NTU. A lower turbidity level generally trends with an increase in retention of filler, fines, and/or contaminants in the furnish in the fiber mat.

[0295] Gravimetric Water Retention

[0296] A Canadian Standard Freeness Tester was used to determine the rate of drainage of dilute pulp suspension, reported in units of Canadian Standard Freeness (CSF). CSF testing was used to measure the rate of free water drainage of a diluted pulp suspension with a consistency of 3 g of pulp per 1 L of water. CSF is a measure of water drainage rates from fibers and is often used to characterize the degree of fiber fibrillation in pulp and paper science. The freeness of a stock is generally related to the surface conditions and swelling of the fibers (TAPPI 1999b). In this study, higher gravimetric drainage rates (i.e., higher CSF) is preferred and indicates that the added retention polymers positively affect the fiber surface conditions and swelling of the fibers. [0297] Chemical Additives

[0298] Chemical additives shown in Table 1 were evaluated as retention and drainage aids in Examples 2-4 and include polyvinylamines (PVAml-3) and a quick inversion cationic emulsion polyacrylamide (QIC-EPAM) comprising cationic [2- (Acryloyloxy)ethyl]trimethylammonium chloride monomers (Q9) and acrylamide monomers. Where indicated, conventional additives (e.g., DPAM and bentonite) were also added to the fiber stocks.

[0299] Table 1: Chemical additives tested as retention and drainage aids in Examples 2-4.

*PAM = Polyacrylamide

NVF = N-vinylformamide

PNVF = poly-N-vinylformamide

DH = degree of hydrolysis (mol%)of NVF to vinylamine

Q9 = [2-(Acryloyloxy)ethyl]trimethylammonium chloride

SV = Specific Viscosity

Example 2: Evaluation of QIC-EPAM with PVAms as retention and drainage aids for improving DDA drainage and permeability in recycled OCC furnish

[0300] Polyvinylamines (PVAms 1-3) and quick inversion cationic EPAM (QIC-EPAM) (see Table 1) were evaluated alone and in combination as retention and drainage aids for recycled linerboard prepared from 100% recycled old corrugated cardboard (OCC) and wastepaper fiber stock from a North American paper plant.

[0301] The OCC fiber stock was diluted to form a thin stock with a consistency of 0.5-0.7% by wt (Total Suspended solids, TSS). Preparation of sheets, determination of DDA drainage time, and determination of DDA permeability was performed according to Example 1. [0302] PVAml was evaluated alone at dosages ranging from 2-10 kg/t. PVAm2 was evaluated alone at dosages ranging from 2-12 kg/t. PVAm3 was evaluated alone at dosages ranging from 0.2-1 kg/t. For these experiments, PVAms were added directly to the thin stock.

[0303] Combinations of QIC-EPAM and PVAmsl-3 were also evaluated for potential synergistic improvements in drainage and permeability. QIC-EPAM (dosage = 0.1-0.2 kg/t) and one of PVAml (dosage = 6 kg/t), PVAm2 (dosage = 6 kg/t), or PVAm3 (dosage = 0.6 kg/t), were co-mixed and then added to the thin stock.

[0304] Results are shown in FIG 1. For the present examples, higher DDA Drainage % Gain above the drainage lower limit line indicated on FIG 1 was preferred. The percentage of sheet permeability gain below the permeability upper limit line indicated on FIG 1 was preferred. Percent permeability gains over the limit line (i.e., over-permeabilization) indicate over-flocculation of cellulosic fibers, which leads to larger flocs and causes poor sheet formation. Permeability is a property of porous materials that is an indication of the ability for fluids (gas or liquid) to flow through them. Fluids can more easily flow through a material with high permeability than one with low permeability. The permeability of a medium is related to the porosity, but also to the shapes of the pores in the medium and their level of connectedness. Increased fiber pad permeability was caused by chemical flocculation of fibers.

[0305] These results indicate that the inventive retention and drainage aids (e.g., PVAm with QIC-EPAM) significantly improve the drainage (i.e., shorter drainage times, with drainage gains above lower limit) without over-permeabilizing (i.e., permeability gains at or below upper limit) sheets prepared from a 100% recycled furnish over PVAm alone. The inventive retention and drainage aids improved drainage in a dose dependent manner as the QIC- EPAM dosage increased.

[0306] It was surprisingly found that the inventive retention and drainage aids (e.g., PVAm with QIC-EPAM) allowed for a significant reduction of PVAm dosage, while providing improved DDA drainage without over-permeabilizing the liner sheets. A 20-40% PVAm dosage reduction was observed on the customer paper machines by using 0.1-0.2 Kg/ton of QIC-EPAM. The best results were achieved with QIC-EPAM + PVAml, which allowed for reduction of PVAml from 8-10 kg/t to 6 kg/t. The greatest enhancement was observed with QIC-EPAM + PVAm3 using 0.6 kg/t of PVAm3.

[0307] Without being bound to theory, it can be rationalized that the combination of QIC- EPAM and PVAm avoids over flocculation of the fiber stock by allowing smaller fiber flocs to form, most likely by binding to PVAm, and then effectively retaining the smaller flocs without over-flocculation by association with the highly cationica I ly charged 3-D structure of the QIC-EPAM. The 3-D structure of QIC-EPAM is controlled using sodium hypophosphite as a chain transfer agent and methylene bis-acrylamide as a crosslinking agent and has been found to effectively enhance colloidal and fines retention compared to linear cationic polymers. [0308] Additionally, and without being bound to theory, it can be rationalized that there is an advantage to combining the higher molecular weight QIC-EPAM (MW = 2-3 million Da) with the lower MW PVAm (MW = less than 2 million Da, preferably 500,000 Da). The QIC- EPAM is a cationic quaternary co-polyacrylamide having a standard viscosity (SV) of 2.5-3.5 cPs and 20-30 mol% Q9 cationic monomer content. The molecular weight of QIC-EPAM is suitable to improve retention, drainage and fixation without damaging sheet formations at elevated polymer dosage levels. The combination of high cationic charge, higher MW QIC- EPAM with lower MW PVAm is likely to make small and tight fiber flocs to compensate for the lack of high MW in PVAM, thereby making PVAm more efficient and improving the effects of vacuum drainage and press dewatering for 100% recycled paper grades.

[0309] These results provide proof of concept that the inventive retention and drainage aids (e.g., QIC-EPAM + PVAm) provide enhancements in drainage over PVAm alone without overflocculating. Addition of QIC-EPAM + PVAm to recycled fiber stock provides faster drainage, reduction in dryer steam usage, improved liner quality (i.e., uniformity and permeability), and significant reduction in overall PVAm dosage in an industrial setting.

Example 3: Evaluation of QIC-EPAM with PVAms as retention and drainage aids (comixed vs. separate addition) for improving DDA drainage and retention in recycled OCC furnish

[0310] PVAms 1-3 and QIC-EPAM (see Table 1) were evaluated as retention and drainage aids for recycled linerboard prepared from 100% recycled old corrugated cardboard (OCC) fiber stock from a North American paper plant.

[0311] The OCC fiber stock was diluted to form a thin stock with a consistency of 0.5-0.7% by wt (Total Suspended solids, TSS). Recycled liners were prepared and evaluated for DDA drainage time and the resulting DDA filtrates were evaluated for turbidity according to Example 1.

[0312] PVAms 1-3 were evaluated alone at 6 kg/t for PVAm 1-2 and 0.6 kg.t for PVAm3. For these experiments, PVAms were added directly to the thin stock.

[0313] Combinations of QIC-EPAM (dosage = 0.1-0.2 kg/t) and PVAmsl-3 (dosage = 6 kg/t for PVAm 1-2 and 0.6 kg.t for PVAm3) were also evaluated (co-mixed vs. separate addition) for potential synergistic improvements in drainage and permeability. For co-mixed experiments, QIC-EPAM was co-mixed with PVAml, PVAm2, or PVAm3 prior to addition to the thin stock. For separate addition experiments, QIC-EPAM and PVAmsl-3 were added separately to the thin stock.

[0314] Results are shown in FIG 2. For the present example, lower turbidity is preferred and is an indication of better fiber retention.

[0315] These results indicate that the inventive retention and drainage aids (e.g., PVAm + QIC-EPAM) significantly improved both drainage time and fiber retention when co-mixed prior to addition and when added separately. Notably, all co-mixed experiments provided drainage gains above the lower limit line. The best results were achieved by combining QIC- EPAM and PVAml. This combination achieved the highest DDA drainage gain and lowest turbidity for both co-mixed and separate addition experiments.

[0316] These results provide initial proof of concept that the inventive retention and drainage aids (e.g., QIC-EPAM + PVAm) can be co-mixed or added separately to the stock to improve both drainage and retention (i.e., shorter drainage time and lower turbidity) of liners made from 100% recycled furnish. Addition of QIC-EPAM + PVAm to recycled fiber stock provides faster drainage, reduction in dryer steam usage, and significant improvements in fiber retention in an industrial setting.

Example 4: Evaluation of QIC-EPAM with PVAms as retention and drainage aids in recycled furnish with conventional paper additives

[0317] For the current Example, PVAm3 and QIC-EPAM (see Table 1) were evaluated as retention and drainage aids along with conventional additives (DPAM and bentonite) for recycled linerboard prepared from 100% recycled old corrugated cardboard (OCC) fiber stock from a North American paper plant.

[0318] The OCC fiber stock was diluted to form a thin stock with a consistency of 0.5-0.7% by wt (Total Suspended solids, TSS). Recycled liners were prepared and evaluated for DDA drainage time and gravimetric water retention (CSF) according to Example 1.

[0319] PVAm3 was evaluated at increasing dosages (e.g., 0.5 kg/t, 0.8 kg/t, and 1 kg/t) along with DPAM and bentonite. QIC-EPAM (0.25 kg/t and 0.5 kg/t) was evaluated alone and in combination with PVAm3 (0.5 kg/t and 0.8 kg/t).

[0320] Water retention (CSF) and DDA drainage times are shown in FIG 3 and FIG 4, respectively.

[0321] Results from FIG 3 indicate that addition of QIC-EPAM significantly improved the gravimetric drainage of PVAm3. CSF is a measure of water drainage rates from fibers and is often used to characterize the degree of fiber fibrillation in pulp and paper science. The freeness of a stock is generally related to the surface conditions and swelling of the fibers (TAPPI 1999b). In this study, higher gravimetric drainage rates (i.e., higher CSF) is preferred and indicates that the added retention polymers positively affect the fiber surface conditions and swelling of the fibers.

[0322] From FIG 3, it was surprisingly found that the inventive retention and drainage aids (e.g., PVAm with QIC-EPAM) allowed for a significant reduction of PVAm3 dosage by 50% from 1 kg/t to 0.5 kg/t while achieving better results with the same overall retention aid dosage (i.e., 1 kg/t total). Similar enhancements to DDA drainage time can be seen in FIG 4, where the addition of QIC-EPAM allowed for a 20-50% reduction in PVAm3, while achieving similar or better DDA drainage results. Rationale for enhanced performance of QIC-EPAM + PVAm3 can be found in Example 2.

[0323] These results further proof of concept that addition of the inventive retention and drainage aids (e.g., QIC-EPAM + PVAm3) to recycled fiber stock containing conventional additives (e.g., bentonite and DPAM) provides faster drainage and significant reduction in overall PVAm dosage in an industrial setting and suggests that the inventive QIC-EPAM + PVAm3 will be effective in the presence of other papermaking additives.

Claims

CLAIMS What is claimed is:

1. A method for manufacture of tissue, paper, or board, the method comprising:

(a) forming or providing a thick stock comprising an aqueous suspension of cellulosic fibers, optionally comprising 40-100%, 60-100%, or 80-100% by weight recycled cellulosic fibers;

(b) optionally diluting the thick stock to form a thin stock;

(c) introducing the thick stock and/or the thin stock into a headbox of a paper machine and then draining on a wire screen, thereby removing sufficient water to form a wet fibrous web; and

(d) pressing and drying the wet fibrous web to obtain a tissue, paper, or board; wherein the method comprises, prior to step (c), treating the thick stock and/or the thin stock with a retention and drainage aid comprising:

(i) one or more polyvinylamine (PVAm) polymers; and

(ii) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising acrylamide (AM) monomers and cationic acryloyloxyethyltrimethyl ammonium chloride (Q9).

2. The method of claim 1, wherein said one or more PVAm polymers and said one or more QIC-EPAMs are:

(a) premixed prior to addition to the thick stock;

(b) premixed prior to addition to the thin stock;

(c) added separately to the thick stock;

(d) added separately to the thin stock;

(e) added separately, wherein the one or more PVAm polymers are added to the thick stock and the one or more QIC-EPAMs are added to the thin stock; or

(f) added separately, wherein the one or more PVAm polymers are added to the thin stock and the one or more QIC-EPAMs are added to the thick stock; wherein steps (a)-(f) are optionally followed by a mixing time ranging from 0.01-10 min, 0.1-5 min, or 1-2 min.

3. The method of any of the foregoing claims, wherein said one or more PVAm polymers:

(a) comprise a weight average molecular weight ranging from 50-3000 kDa, 100- 2000 kDa, 200-2000 kDa, or 400-800 kDa;

(b) comprise a cationic charge density ranging from below 5.0 mEq/g, 0.5-5.0 mEq/g, 1.0-4.0 mEq/g, or 1.5-2.5 mEq/g as dry solids at pH 7; (c) comprise a polymer synthesized by Hofmann degradation of a base polymer comprising (i) acrylamide; (ii) methacrylamide; (iii) a copolymer of acrylamide and cationic monomers selected from the group consisting of dimethylaminoethyl acrylate (DMAEA), quaternized dimethylaminoethyl methacrylate (DMAEMA), dimethyldiallylammonium chloride (DADMAC), acrylamidopropyltrimethylammonium chloride (APTAC), and methacrylamidopropyltrimethylammonium chloride (MAPTAC); or (iv) a copolymer of acrylamide and DADMAC;

(d) comprise a polymer synthesized by total or partial hydrolysis of one or more poly(N-vinylformamide) homopolymers or copolymers, wherein said one or more poly(N-vinylformamide) homopolymers or copolymers are optionally synthesized by radical polymerization of N-vinylformamide or by radical polymerization of N- vinylformamide and one or more additional monomers and further comprising a degree of hydrolysis ranging from 1-100 mol%, 20-100 mol%, 40-100 mol%, 60- 100 mol%, or 80-100 mol%;

(e) comprise a polymer synthesized by partial hydrolysis of one or more poly(N- vinylformamide) homopolymers and further comprising a degree of hydrolysis ranging from 30-50 mol%, 35-45 mol%, or about 40 mol%;

(f) are formulated optionally as a dry powder or as an aqueous composition comprising a PVAm solids % by mass ranging from about 0.5% to about 30%, optionally from greater than 2% to about 25%, further optionally from about greater than 10% to about 22%; or

(g) any combination of (a)-(f).

4. The method of any of the foregoing claims, wherein said one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs):

(a) comprise an acrylamide (AM) monomer content ranging from 60-85 wt%, 65-85 wt%, 70-85 wt%, or 70-80 wt%;

(b) comprise a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from <40 wt%, 15-40 wt%, 15-35 wt%, 15-30 wt%, or 20-30 wt%;

(c) comprise an inverse phase emulsion, a dry polymer, or an aqueous polymer solution, preferably an inverse phase emulsion;

(d) comprise a polymer standard viscosity (SV) ranging from less than or equal to 3.5 cPs, 2.0- 3.5, 2.5-3.5 cPs, or 3.0-3.5 cPs; or

(e) any combination of the foregoing.

5. The method of claim 1, wherein said retention and drainage aid optionally further comprises one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles, wherein:

(a) said more cationic dry polyacrylamides (DPAM) comprise acrylamide (AM) monomers and one or more cationic monomers, wherein said one or one or more cationic monomers are selected from the group consisting of acryloyloxyethyltrimethyl ammonium chloride ("AETAC"), methacryloyloxyethyltrimethylammonium chloride ("MAETAC"), methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), acrylamidopropyltrimethylammonium chloride ("APTAC"), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride ("DADMAC"); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary or acid salts, including but not limited to, dimethylaminoethyl acrylate ("DMAEA"), dimethylaminoethyl methacrylate ("DMAEA"), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfuric acid salt, dimethylaminoethyl acrylate hydrochloric acid salt, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfuric acid salt, dimethylaminoethyl methacrylate hydrochloric acid salt, dimethylaminoethyl methacryloyl hydrochloric acid salt; dialkylaminoalkylacrylamides and methacrylamides and their quaternary or acid salts, including but not limited to, acryloylamidopropyltrimethylammonium chloride, dimethylaminopropyl acrylamide, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl acrylamide hydrochloric acid salt, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt, diethylaminoethylacrylate, diethylaminoethylmethacrylate; and diallyldialkylammonium halides, including but not limited to, diallyldiethylammonium chloride and diallyldimethylammonium chloride ("DADMAC"), and any combination thereof; and

(b) said one or more inorganic microparticles are selected from the group of microparticles and nanoparticles consisting of silica microparticles; colloidal silica; aluminum phyllosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite, and montmorillonite.

6. The method of any of the foregoing claims, wherein:

(a) said one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprise an acrylamide (AM) monomer content ranging from 70-80 wt% and a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; comprises an inverse phase emulsion; and comprises a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; (b) said one or more PVAm polymers comprise a weight average molecular weight ranging from 400-800 kDa; or

(c) said one or more inorganic microparticles comprise bentonite, sodium bentonite, or calcium bentonite.

7. The method of any of the foregoing claims, wherein when added to the thick stock and/or the thin stock:

(a) said retention and drainage aid comprises a ratio of said one or more QIC-EPAMs to said one or more PVAms ranging from 1:60 to 1:1; 1:30-1:1; 1:6 to 1:1; or 1:3 to 1:1;

(b) said one or more PVAm polymers are added at a dosage ranging from 0.2-12 kg/t, 0.2-10 kg/t, 0.2-8 kg/t, 0.2-6 kg/t, 0.2-2 kg/t, or 0.2-0.6 kg/t;

(c) said one or more QIC-EPAMs are added at a dosage ranging from 0.1-1 kg/t, 0.1- 0.5 kg/t, or 0.1-0.2 kg/t;

(d) said one or more DPAMs are added at a dosage ranging from 0.1-lkg/t, 0.1-0.5 kg/t, or 0.2-0.4 kg/t;

(e) said one or more inorganic microparticles are added at a dosage ranging from 0.1-4 kg/t, 1-4 kg/t, or 2-4 kg/t; or

(f) any combination of (a)-(e).

8. The method of any of the foregoing claims, wherein:

(a) the thick stock comprises a consistency ranging from 1-5%, 1-3%, or 1-1.5%, wherein consistency refers to % by weight of total suspended solids in the aqueous slurry;

(b) the thin stock comprises a consistency ranging from 0.3-1%, 0.4-1%, 0.5-1%, or 0.5-0.7%;

(c) the thick stock is diluted to form the thin stock by addition of water, chemical water, synthetic water, white water, and/or process water;

(d) the thick stock and or the thin stock optionally further comprise one or more additives relating to papermaking, including but not limited to, starches, dyes, bleaching agents, sizing agents, wet strength agents, dry strength agents, or detackifiers; or

(e) any combination of (a)-(c).

9. The method of any of the foregoing claims, wherein said aqueous suspension of cellulosic fibers comprises a pH ranging from 4-8, 4-7.5, 4-7, 4.5-7, or 5-7 and further comprises:

(a) a percentage of recycled cellulosic fibers ranging from 40-100%, 50-100%, 60- 100%, 80-100%, or 90-100% by weight recycled cellulosic fibers,

(b) a combination of one or more recycled fibers optionally obtained from sources, including but not limited to, old corrugated cardboard (OCC), mixed office waste (MOW), mixed office paper, old newspaper pulp (ONP), old magazines (OMG), mill broke fibers, or coated broke,

(c) optionally softwood fiber, hardwood fiber, refined fiber, non-wood fibers, including but not limited to straw and wheat pulp, and a mixture of any of the foregoing;

(d) optionally pulp selected from Kraft pulp, unbleached Kraft pulp, bleached pulp, unbleached pulp, process water from pulp, paper, and/or board production, neutral sulfite semi chemical (NSSC) pulp, mechanical pulp, non-wood pulp, and a mixture of any of the foregoing;

(e) an amount of pulp fines and/or an amount of mineral fillers ranging from 5-30% by mass of total solids in the aqueous suspension, wherein the amount of pulp fines pulp fines comprises pulp particles small enough to pass through a 76 pm diameter hole and said amount of mineral fillers comprise calcium carbonate, clays, kaolinite, aluminum silicates, talc, and/or gypsum; or

(f) and combination of (a)-(e).

10. The method of any of the foregoing claims, wherein when used for manufacture of tissue, paper, or board, the method results in:

(a) an increased retention of cellulosic fibers;

(b) an increase in retention of pulp fines and/or mineral fillers;

(c) a faster drainage rate on the wire screen;

(d) an increased press dewatering rate;

(e) a reduction in dryer steam usage;

(f) an improved tissue, paper, or board quality as determined by decreased permeability;

(g) a reduction in PVAm dosage;

(h) a synergistic increase in paper machine drainage rate resulting from the combination of QIC-EPAM and PVAm;

(i) a synergistic increase in Canadian Standard Freeness (CSF) resulting from the combination of QIC-EPAM and PVAm; or

(j) any combination of (a)-(i); compared to an identical method performed in the absence of (i) addition of said one or more PVAms or (ii) addition of said one or more QIC-EPAMs.

11. A method for manufacture of tissue, paper, linerboard, or board, the method comprising:

(a) forming or providing a thick stock comprising an aqueous suspension of cellulosic fibers, optionally comprising 40-100%, 60-100%, or 80-100% by weight recycled cellulosic fibers;

(b) optionally diluting the thick stock to form a thin stock;

(c) introducing the thick stock and/or the thin stock into a headbox of a paper machine and then draining on a wire screen, thereby removing sufficient water to form a wet fibrous web; and

(d) pressing and drying the wet fibrous web to obtain a tissue, paper, or board; wherein the method comprises, prior to step (c), treating the thick stock and/or the thin stock with a retention and drainage aid comprising:

(i) one or more polyvinylamine (PVAm) polymers;

(ii) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

(iii) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite.

12. The method of claim 12, wherein said one or more PVAm polymers and said one or more QIC-EPAMs are:

(a) premixed prior to addition to the thick stock;

(b) premixed prior to addition to the thin stock;

(c) added separately to the thick stock;

(d) added separately to the thin stock;

(e) added separately, wherein the one or more PVAm polymers are added to the thick stock and the one or more QIC-EPAMs are added to the thin stock; or

(f) added separately, wherein the one or more PVAm polymers are added to the thin stock and the one or more QIC-EPAMs are added to the thick stock.

13. A thick stock comprising an aqueous suspension comprising a consistency ranging from 1-5%, 1-3%, or 1-1.5%; a recycled cellulosic fiber content ranging from 40-100%; and a retention and drainage aid comprising:

(a) one or more polyvinylamine (PVAm) polymers;

(b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and (c) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite; wherein

(i) said retention and drainage aid comprises a ratio of said one or more QIC- EPAMs to said one or more PVAms ranging from 1:60 to 1:1; 1:30-1:1; 1:6 to 1:1; or 1:3 to 1:1;

(ii) said one or more PVAm polymers and said one or more QIC-EPAMs are premixed prior to addition to the thick stock;

(iii) said one or more PVAm polymers and said one or more QIC-EPAMs are added separately to the thick stock.

14. A thin stock comprising an aqueous suspension comprising a consistency ranging from 0.3-1%, 0.4-1%, 0.5-1%, or 0.5-0.7%; ; a recycled cellulosic fiber content ranging from 40- 100%; and a retention and drainage aid comprising:

(a) one or more polyvinylamine (PVAm) polymers;

(b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

(c) optionally, one or more cationic dry polyacrylamides (DPAMs) and/or one or more inorganic microparticles comprising bentonite; wherein

(i) said one or more PVAm polymers and said one or more QIC-EPAMs are premixed prior to addition to the thin stock;

(ii) said one or more PVAm polymers and said one or more QIC-EPAMs are added separately to the thin stock.

15. A composition for use as a retention and drainage aid in manufacture of tissue, paper, or board, the composition comprising:

(a) one or more polyvinylamine (PVAm) polymers;

(b) one or more quick inversion cationic emulsion polyacrylamides (QIC-EPAMs) comprising an acrylamide (AM) monomer content ranging from 70-80 wt%; a cationic acryloyloxyethyltrimethyl ammonium chloride (Q9) monomer content ranging from 20-30 wt%; wherein said QIC-EPAM comprises an inverse phase emulsion; and a polymer standard viscosity (SV) ranging from 3.0-3.5 cPs; and

(c) optionally one or more anionic organic or inorganic microparticles selected from the group of microparticles and nanoparticles consisting of silica microparticles; colloidal silica; aluminum phyllosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite, and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamides.