EP4623147A1 - Improved retention of engineered cellulosic additives using synergistic cationic polymer combination - Google Patents
Improved retention of engineered cellulosic additives using synergistic cationic polymer combinationInfo
- Publication number
- EP4623147A1 EP4623147A1 EP23904554.5A EP23904554A EP4623147A1 EP 4623147 A1 EP4623147 A1 EP 4623147A1 EP 23904554 A EP23904554 A EP 23904554A EP 4623147 A1 EP4623147 A1 EP 4623147A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- polymer
- cationic
- fixation
- eca
- retention
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
- D21H17/24—Polysaccharides
- D21H17/25—Cellulose
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
- D21H17/24—Polysaccharides
- D21H17/28—Starch
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
- D21H17/42—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups anionic
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/71—Mixtures of material ; Pulp or paper comprising several different materials not incorporated by special processes
- D21H17/72—Mixtures of material ; Pulp or paper comprising several different materials not incorporated by special processes of organic material
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/18—Reinforcing agents
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/18—Reinforcing agents
- D21H21/20—Wet strength agents
Definitions
- ECA engineered cellulosic additives
- CMC is more commonly used to add strength to the paper web.
- ECA is differentiated from CMC in terms of its solubility, charge density and molecular weight (Mw). CMC is fully dissolvable in water and has a Mw range from 10k to 1MDaltons.
- ECA exists as somewhat of a hybrid technology in the space between CMC and nanocellulose/microfibrillated cellulose (MFC).
- ECA is lower in charge than CMC and has portions of material existing as dissolved material and other parts ranging from 200 to 300 nm in length. Being able to retain the dissolved, colloidal fraction as well as the nano ⁇ scale fraction is important to ECA’s strength performance.
- Both ECA and CMC additives rely on cationic additives and particularly cationic polymers in order to be chemically retained in the fiber web.
- ECAs even though they are anionically charged, are difficult to retain in the papermaking furnish, even with the addition of current cationic polymer additives used to promote the retention of ECA in the fiber web.
- fixation polymer a high ⁇ charge low molecular weight quick inversion polymer
- anionic ECA product anionic ECA product
- retention polymer relatively low ⁇ charge high molecular weight quick inversion polymer
- the term “surface sizing” generally refers to the application of a solution, often containing starch, to the surface of paper, usually in order to increase surface strength, and sometimes with addition of hydrophobic polymers or other material at the paper surface.
- surfactant refers to a surface active agent usually comprised of molecules with water ⁇ loving and water ⁇ hating groups, used for wetting, emulsifying, etc.
- thick stock generally refers to mixture of papermaking pulp and other materials with a consistency of about 2 to 5%.
- the term "thin stock” generally refers to a mixture of papermaking pulp and other materials, after having been diluted with whitewater at a fan pump.
- wet strength generally refers to the strength of a sheet of paper after it has been exposed to a standard solution for a standard length of time, but often expressed as a ratio vs. the dry strength.
- wet end of a paper machine generally refers to the parts of a papermaking process between pulping (or bleaching) and wet ⁇ pressing of the paper.
- 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.
- kg/T means kilograms per metric ton.
- the present invention relates to a papermaking process that includes the separate addition of a high ⁇ charge low molecular weight quick inversion polymer for fixation, an anionic ECA product, and a relatively low ⁇ charge high molecular weight quick inversion polymer for retention, preferably with the addition sequence in this order.
- the high cationic charged quick inversion fixation polymer enhances the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers; and that the high Mw quick inversion cationic retention polymer, which is subsequently added (after the ECA), improves the retention of the ECA, fines and other colloidal particles in the web.
- the two cationic quick inversion polymers are used together in the same furnish with the ECA (but added separately), synergistic benefits are attained.
- the combined use of the two cationic quick inversion polymers in conjunction with the ECA synergistically enhance total retention of ECA, as well as fines and fiber on paper machines.
- the molecular weight of the cationic polymer is reduced to a range which is suitable to improve fixation without damaging sheet formation at elevated polymer dosage levels.
- This high charge quick inversion fixation polymer has been demonstrated to be more efficient in fixation than traditional charge fixation/control agents (CCA) such as polyacrylamide ⁇ DADMAC dispersions, polyamines, and polyDADMAC solution polymers.
- CCA charge fixation/control agents
- This polymer is generally synthesized in emulsion form, i.e., by use of inverse emulsion methods as described below.
- the temperature is desirably maintained below 50 °C, optionally using a water bath and by simultaneously cutting the SO 2 supply. Completion of polymerization is indicated when no further increase in temperature is seen even when SO 2 is continuously being fed. At this point, set the SO 2 flow rate back to the initial value and reactor temperature to 50 °C and hold for ⁇ 1.5 hours. Nitrogen is desirably continuously sparged throughout the entire process.
- Post Additives [0115] A breaker or inverse surfactant is added to the polymerizate, optionally an ethoxylated alcohol, further optionally at an addition rate of ⁇ 2.0 wt% and the admixture is permitted to mix, optionally for ⁇ 20 minutes.
- the cellulose derivative having a degree of substitution of carboxyalkyl groups up to about 0.65, preferably about 0.05 to 0.55.
- the anionic cellulose derivative have a viscosity of ⁇ 2 wt% water solution greater or equal to 100 mPa.s at 25°C, preferably greater or equal to 2500 mPa.s. The viscosity is optionally measured by Brookfield LVT viscometer at 30 rpm using #62 spindle.
- the cellulose derivative is water ⁇ soluble or at least partly water ⁇ soluble or water ⁇ dispersible, more preferably water ⁇ soluble or at least partly water ⁇ soluble.
- the cellulose derivative is ionic.
- sulphoalkyl, phosphate and phosphonate groups in which the alkyl group can be methyl, ethyl propyl and mixtures thereof, suitably methyl; suitably the cellulose derivative contains an anionic group comprising a carboxylate group, e.g. a carboxyalkyl group.
- the counter ⁇ ion of the anionic group is usually an alkali metal or alkaline earth metal, preferably sodium.
- suitable cationic groups of cellulose derivatives according to the invention include salts of amines, suitably salts of tertiary amines, and quaternary ammonium groups, preferably quaternary ammonium groups.
- the chain of atoms is an alkylene group with from 2 to 18 and suitably 2 to 8 carbon atoms, optionally interrupted or substituted by one or more heteroatoms, e.g. O or N such as alkyleneoxy group or hydroxy propylene group.
- Preferred cellulose derivatives containing cationic groups include those obtained by reacting cellulose or derivative thereof with a quaternization agent selected from 2, 3 ⁇ epoxypropyl trimethyl ammonium chloride, 3 ⁇ chloro ⁇ 2 ⁇ hydroxypropyl trimethyl ammonium chloride and mixtures thereof.
- the cellulose derivatives of this invention can contain non ⁇ ionic groups such as alkyl or hydroxy alkyl groups, e.g.
- the cellulose derivative contains both ionic groups and non ⁇ ionic groups.
- suitable cellulose derivatives according to the invention include carboxyalkyl celluloses, e.g.
- carboxymethyl cellulose carboxyethyl cellulose, carboxypropyl cellulose, sulphoethyl carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose (“CM ⁇ HEC”), carboxymethyl cellulose wherein the cellulose is substituted with one or more non ⁇ ionic substituents, preferably carboxymethyl cellulose (“CMC”).
- CMC carboxymethyl cellulose
- suitable cellulose derivatives and methods for their preparation include those disclosed in U.S. Pat. No. 4,940,785, which is hereby incorporated herein by reference.
- the terms “degree of substitution” or “DS”, as used herein, mean the number of substituted ring sites of the beta ⁇ anhydroglucose rings of the cellulose derivative.
- the cellulose derivative has a degree of substitution of carboxyalkyl groups (“DSCA”) up to about 0.65, i.e. the cellulose derivative has an average degree of carboxyalkyl substitution per glucose unit up to about 0.65.
- the carboxyalkyl groups are suitably carboxymethyl groups and then DSCA referred to herein is the same as the degree of substitution of carboxymethyl groups (“DSCM”).
- DSNI, DSNA, DSNC, and DSCA independently of each other are usually up to about 0.60, preferably up to about 0.55, whereas DSNI, DSNA, DSNC and DSCA independently of each other are usually at least 0.01, suitably at least about 0.05, preferably at least about 0.10 and more preferably at least about 0.15.
- the ranges of DSNI, DSNA, DSNC and DSCA independently of each other are usually from about 0.01 to about 0.60, preferably from about 0.05 to about 0.55.
- Cellulose derivatives that are anionic or amphoteric usually have a degree of anionic substitution (“DSA ”) in the range of from 0.01 to about 1.0 as long as DSNI and DSNA are as defined herein; suitably from about 0.05, preferably from about 0.10, and more preferably from about 0.15 and suitably up to about 0.75, preferably up to about 0.55.
- DSA degree of anionic substitution
- DSNA is 0.60.
- suitable cellulose derivatives having degrees of substitution as defined above include the water ⁇ soluble low DS carboxyalkyl cellulose derivatives.
- the water ⁇ soluble cellulose derivatives suitably has a solubility of at least 85% by weight, based on total weight of dry cellulose derivative, in an aqueous solution, preferably at least 90% by weight, more preferably at least 95% by weight, and most preferably at least 98% by weight.
- An exemplary preferred ECA is ECA 720.
- the quick inverting cationic polyacrylamide emulsions disclosed herein have been found to have excellent fixative and retentive properties in pulp and paper systems.
- the two cationic quick inversion polymers are used together in the same furnish, a synergistic effect can be seen.
- the fixation polymer is added, followed by the ECA, in turn followed by the addition of the retention polymer provides for separate and synergistic benefits including one or more of the following: 19 Docket No.: 1149704.052013
- the high charge quick inversion fixation polymer enhances the fixation of ECA to the anionic fibers without damaging paper sheet formation optionally at high polymer dosage levels
- the high charge quick inversion fixation polymer promotes the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers
- the high charge quick inversion fixation polymer more efficiently promotes fixation of ECA than traditional charge fixation/control agents (CCA) such as
- the methods and polymer/ECA combination of the current invention may be added to any process water from pulp, paper, or board production and/or to thick or thin stock used in pulp, paper, or board production.
- the stock will preferably 20 Docket No.: 1149704.052013 predominantly or entirely comprise virgin or Kraft fibers, and optionally may comprise some recycled fibers, and/or mill broke fibers.
- the fiber stock comprises at least 50%, 60%, 70%, 80%, 90% or 100% by weight of virgin or Kraft fibers, and may comprise some recycled fibers, although the preferred use of the inventive methods is for treating stock comprising virgin or Kraft fibers. In some instances such fibers may contain starch, in some instances a significant amount of starch.
- Thick stock is here understood as a fibrous stock or furnish, which has consistency of above 1% (i.e., above 10 g dry solids/L of stock) and thin stock has consistency of below 1% (i.e., below 10 g dry solids/L of stock).
- These fiber stock fractions optionally may comprise elevated amounts of low molecular weight (LMW) starch, hydrophobics, fines, filler/pigment, dye or the like.
- LMW low molecular weight
- a thick or thin stock again will preferably predominantly comprise virgin or Kraft fibers, and optionally may comprise some recycled fibers, and/or mill broke fibers, optionally originating from different sources, e.g., including recycled fiber materials and/or mill broke and/or coated broke.
- the treated fiber stock which predominantly comprises Kraft or virgin fibers, optionally may comprise some fibers originating from recycled 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.
- OCC old corrugated containerboard
- MOW mixed office waste
- OMG old magazine
- NCCS neutral sulphite semi chemical pulp
- the treated fiber stock, predominantly or entirely comprising virgin or Kraft fibers may contain variable amounts of colloidal fines, colloidal particles, filler, hydrophobic, and hydrophilic particles, depending on fiber source and paper mill processing methods. Additionally, fiber suspensions are often diluted with paper mill white water, which also contains variable amounts of colloidal fines and the like.
- Furnish or fiber stock which used in the present invention may contain low levels of fines (e.g., fines content ranging from 0.1% – 5%, more typically 0.1% – 0.2% on a mass dry fine to volume basis) or high levels of fines (e.g., fines content ranging from 5% – 15%).
- the definition of “fines” for the current application is any suspended particle smaller than 125 P filter (e.g., 0.76 micron or 200 mesh).
- the retention and fixation polymers of the present invention may employ solutions of the subject quick inversion cationic retention and fixation polymers, which may be used as pump and go products, optionally not requiring conventional polymer inverting and aging tanks.
- polyacrylamide emulsions such as cationic retention aids 21 Docket No.: 1149704.052013 having molecular mass values in the range of 10 to 20 million Dalton and SV > 4.5 mPas, do not instantly invert in water under a normal mixing speed ( ⁇ 500 RPM), and pre ⁇ diluted conventional polymer solutions should be aged for a minimum of 30 minutes prior to use.
- the retention and fixation polymers may be synthesized off site and delivered to a paper mill, and then mixed on ⁇ site. Alternatively, the retention and fixation polymers may be pre ⁇ blended off site, prior to arrival at the paper mill, then delivered as pre ⁇ blended emulsion polymers to customer sites.
- the retention and fixation quick inversion polymer solutions can be produced by injecting the emulsions into a high shear water pump, and inverting the mixture optionally via a static mixer before pumping the polymer solution onto paper machines.
- Increased synergistic effects of the inventive combination may be observed when the fixation polymer is used in combination with an optimized amount of the retention polymer, i.e., optimized ratios.
- the retention polymer has higher molecular weight than the fixative polymer and has been found to be more effective at mechanical retention; i.e., the retention polymer is better for fiber to fiber bridging.
- the fixative polymer has a lower molecular weight than the retention polymer and has been found to be more effective at fixation of the ECA to the fiber; i.e. it is a better fixative. Without being bound by theory, it can be reasoned that the combination of polymers at an optimal blend ratio provides both optimal fixation and better mechanical retention of the ECA, providing a possible mechanistic rationale for the synergistic benefits of the combination.
- Optimal ratios mass ratio of fixation/retention polymer are dependent on many variables including, but not limited to, paper mill, point of addition to the paper making process, furnish characteristics including pH, conductivity, and content of starch, fines, hydrophobics, ash, and/or dyes.
- the ratio of the retention and fixation polymers may range from ⁇ 90/10 to less than 1/99, and preferably range from 85/15 to 15/85.
- the 2 polymer solutions elicit a synergistic or additive increase in ECA retention compared to the administration of equivalent dosage levels of the retention or fixation polymer alone.
- the invention provides methods for using the retention and fixation polymers for treatment of starch ⁇ containing fiber stock and/or mill broke fibers and/or process water in the manufacture of paper or board.
- the treatment is effected prior to the use of the treated fiber stock in a papermaking process or other industrial process using cationic functional polymers or other papermaking chemicals.
- Said retention and fixation polymers may be separately injected into the process stream at several points in the manufacturing process including, but not limited to Chemical(s) addition point 1, upstream of thickening, wherein said fiber stock has consistency (i.e., percent oven dry mass in the stock) of less than approximately 10%, 5%, 2%, 1%, or 0.65% (see Figure 4).
- Addition of the inverted solution of cationic polymers to the fiber suspension before the thickening step is advantageous as the enrichment of the ECA in the water circulation is effectively prevented in most processes, and a large amount of the ECA is effectively retained on the fibers. 22 Docket No.: 1149704.052013 [0140] Said retention and fixation polymers may also be added at Chemical(s) addition point 2(see Figure 4), upstream of forming and/or pressing and/or drying, wherein said fiber stock has consistency (i.e., percent oven dry mass in the stock) of approximately 10 ⁇ 30%. Said methods of the current invention are effected to trap and retain ECA that may otherwise be lost or degraded, thereby protecting ECA for incorporation into paper or board.
- Optimal ratios are empirically pre ⁇ determined for each paper mill and fiber stock composition to elicit a synergistic or additive increase in ECA retention without over ⁇ flocculation of fibers or formation of hydrophobic substances, such as stickies or flocs, in the stock.
- Solutions of the retention and fixation polymers may also be added to the fiber suspension before washing and/or cleaning of the fiber suspension for improving ECA retention and filtration of the fiber suspension, wherein it may be achieved cleaner filtrate, and higher fines content in fiber suspension to which hydrophobics, sizing agent, fillers, dyes or the like can associate. Solutions of the retention and fixation polymers may also be separately added to fiber suspensions before a machine chest or before a mixing chest of a paper or board machine.
- Optimal dosage levels for plant applications will be dependent on paper mill, fiber and furnish characteristics, consistency, point of addition, and the ratio of the retention and fixation polymers.
- the retention and fixation polymers of the present invention provide great dosage latitude for increased ECA fixation and retention without over ⁇ flocculating or damaging sheet formation.
- a papermaking method which comprises the addition of an engineered cellulose additive (ECA), optionally to replace virgin fiber and/or starch and/or as a strength booster, wherein said papermaking method comprises the use of: (i) a high ⁇ charge quick inversion fixation copolymer which comprises 2 ⁇ (acryloyloxy)ethyl] trimethylammonium chloride (Q9) (cationic) and acrylamide monomers (“fixation polymer”); (ii) anionic ECA; and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are separately added to the papermaking system.
- ECA engineered cellulose additive
- a method for treating fiber stock and/or process water used in pulp, paper, or board production, which preferably predominantly comprises Kraft or virgin fibers comprising obtaining said fiber stock and/or process water and treating said fiber stock and/or process water with: (i) a high ⁇ charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers (“fixation polymer”); (ii) anionic ECA; and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are each separately added to the fiber stock and/or process water.
- fixation copolymer which comprises Q9 (cationic) and acrylamide monomers
- anionic ECA anionic ECA
- retention polymer a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers
- a method for manufacture of paper or board, where a fiber web is formed from an aqueous suspension of fibers comprising: ⁇ providing an aqueous fiber suspension, which preferably predominantly comprises Kraft or virgin fibers, and optionally comprises recycled fiber material and/or coated broke, ⁇ optionally diluting the aqueous fiber suspension, ⁇ delivering the aqueous fiber suspension to a headbox, draining the aqueous fiber suspension on a wire screen to form a wet fibrous web, and ⁇ pressing and drying the wet fibrous web to obtain a web of paper or board, which process includes the separate addition of (i) a high ⁇ charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers, (ii) ECA and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers wherein each of (i) (ii) and (iii) are each separately added during manufacture.
- Embodiment A, B or C wherein the high ⁇ charge quick inversion fixation copolymer (fixation polymer) promotes fixation of the ECA and optionally other colloidal particles to the anionic fibers and/or the high molecular weight quick inversion cationic polymer (retention polymer) promotes retention of ECA, and optionally fines and other colloidal particles in the fibrous web.
- the high ⁇ charge quick inversion fixation polymer comprises 30 to 40 mol% of Q9 monomers and a standard viscosity (SV) of between 1.7 to 2.0 cPs. 24 Docket No.: 1149704.052013 F.
- the high molecular weight quick inversion cationic retention copolymer comprises 20 to 30 mol% of Q9 monomers and has a standard viscosity (SV) of between 3.0 to 3.5 cPs.
- G The method of any of the previous Embodiments, wherein (i) the high charge quick inversion fixation polymer is initially added to the papermaking system; (ii) ECA is added to the papermaking system after the addition of the high charge quick inversion fixation polymer; and (iii) the high molecular weight quick inversion cationic retention polymer is added after the addition of ECA to the papermaking system.
- the method of any of the previous Embodiments, wherein the combined dosage of the retention and fixation polymer is equal to or greater than ECA.
- CCA charge fixation/control agents
- the total dosage by weight of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer ranges from about 0.8 to about 20 times the amount of the ECA, about 1.0 to about 10 times the amount of the ECA, about 1.0 to about 5.0 times the amount of the ECA, about 1.0 to about 3.0 times the amount of the ECA, about 1.0 to about 2.0 times the amount of the ECA, or is about equal to the amount of the ECA added to the papermaking system.
- weight quick inversion cationic retention polymer added to the papermaking system ranges from (i) about 1/20 to about 20/1 by weight; (ii) about 1/10 to about 10/1 by weight; (iii) about 2/10 to about 10/2 by weight; (iv) about 3/10 to about 10/3 by weight; (vi) about 3/8 to about 8/3 by weight; (vii) about 3/7 to about 7/3 by weight; (viii) about 4/6 to about 6/4 by weight; (ix) about 5.5/4.5 to about 4.5/5.5 by weight; or (x) about equal amounts by weight of the quick inversion cationic retention polymer added to the papermaking system.
- the fiber suspension comprises at least 50 weight ⁇ %, preferably at least 60 weight ⁇ %, more preferably at least 70 weight ⁇ %, or even more preferably at least 80 weight ⁇ % or 100 weight ⁇ %, of Kraft or virgin fibers;
- the polymers and ECA are separately added to a fiber suspension having consistency of above 30 g/l;
- the polymers and ECA are separately added to a fiber suspension having a consistency of below 20 g/l;
- the polymers and ECA are added to said fiber stock prior to washing and/or cleaning and/or thickening, wherein said fiber stock has consistency (i.e., percent oven dry mass in the stock) of less than approximately 4%, 2%, or 1%;
- the polymers and ECA are added to said fiber stock prior to forming and/or pressing and/or drying, wherein said fiber stock optionally has a consistency (i.e., percent oven dry mass in the stock) of approximately 15 ⁇ 35%;
- a fiber stock preferably comprising a high content of virgin or Kraft fibers, e.g., at least 50 ⁇ 60 weight ⁇ % of virgin or Kraft fibers, and optionally comprising small amounts of recycled fibers, e.g., at most 5 ⁇ 10 weight ⁇ %, and/or starch, for use in pulp, paper or board production, which comprises and/or has been treated with a composition comprising a combination of cationic polymers and ECA, optionally produced according to any of the foregoing Embodiments.
- the fiber stock of Embodiment V which comprises at least 50 weight ⁇ %, preferably at least 60 weight ⁇ %, more preferably at least 70 weight ⁇ %, or even more preferably at least 80 weight ⁇ % or 90 weight ⁇ %, of Kraft or virgin fibers.
- Polymers were prepared according to standard makedown procedures. [0151] For each measurement, an aliquot of stock was poured into the DDA stirring jar where additives were dosed in accordance with machine conditions. After mixing, the stock is drained through a paper machine wire and the filtrate is collected in a vessel. The drain time is recorded and used as a measure of drainage performance. [0152] The filtrate is then measured for turbidity using a Hach 2100Q turbidimeter. Lower turbidity values indicate better retention of fiber, fines, and colloidal and particulate materials.
- the incumbent system again utilizes a charge control agent (CCA) to fix the ECA onto the fiber.
- CCA charge control agent
- a traditional retention polymer is used in the incumbent system to retain fiber, fines and other papermaking additives.
- the same quick inversion polymers were evaluated as CCA replacement products and also as a dual component system where the higher charge fixative was used to fix the ECA to the fiber and the lower charge polymer was used as a retention aid by comparing the effects thereof on filtrate turbidity in the DDA system.
- the timing of addition was ECA @ 10 seconds, Polymer A @ 15 seconds, Polymer B @ 75 seconds.
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Abstract
The invention generally relates to a novel combination comprising 2 different cationic polymers and engineered cellulose additive (ECA) and the use thereof for promoting the retention of engineered cellulose additives (ECAs) to anionic fibers and colloids and in the fiber web during papermaking, optionally wherein the papermaking process predominantly or entirely uses Kraft or virgin fibers.
Description
Docket No.: 1149704.052013 IMPROVED RETENTION OF ENGINEERED CELLULOSIC ADDITIVES USING SYNERGISTIC CATIONIC POLYMER COMBINATION RELATED APPLICATIONS [0001] The present application claims benefit of priority to US Provisional Application No.: 63/387,298, filed on December 14, 2022, and to Finnish Application Number 20235307 filed on March 16, 2023, the contents both of which are incorporated by reference in their entireties. FIELD OF THE INVENTION [0002] The present disclosure generally relates to a novel combination of cationic polymers and engineered cellulose additive (ECA) and the use of this novel combination in papermaking, preferably in papermaking methods which use fiber stocks that predominantly or entirely comprise Kraft or virgin fibers. BACKGROUND [0003] In papermaking, strength is an important property for finished goods and can be achieved by changing the amount or the type of the fibers used or by using chemical additives to provide more bonding sites or higher bonding energy. Additives used during papermaking to enhance the strength of the final paper product include carboxymethylcellulose (CMC), and engineered cellulosic additives (ECA). [0004] Particularly, engineered cellulosic additives (ECA) have been used in papermaking to replace virgin fiber, as a starch replacement, and as a strength booster. ECAs are employed to add strength to the paper web without using expensive fiber sources by providing more sites for hydrogen bonds. ECA products are anionic and do not adhere to anionic fiber sources themselves. [0005] CMC is more commonly used to add strength to the paper web. ECA is differentiated from CMC in terms of its solubility, charge density and molecular weight (Mw). CMC is fully dissolvable in water and has a Mw range from 10k to 1MDaltons. ECA exists as somewhat of a hybrid technology in the space between CMC and nanocellulose/microfibrillated cellulose (MFC). ECA is lower in charge than CMC and has portions of material existing as dissolved material and other parts ranging from 200 to 300 nm in length. Being able to retain the dissolved, colloidal fraction as well as the nano‐scale fraction is important to ECA’s strength performance. [0006] Both ECA and CMC additives rely on cationic additives and particularly cationic polymers in order to be chemically retained in the fiber web. However, ECAs, even though they are anionically charged, are difficult to retain in the papermaking furnish, even with the addition of current cationic polymer additives used to promote the retention of ECA in the fiber web. Particularly, a substantial amount of the ECAs are “lost” during current papermaking processes because they are not effectively fixed to the anionic fibers or retained in the fiber web. Consequently these ECAs are not comprised on the eventually produced paper product. This is disadvantageous as this requires more ECA and/or cationic polymer to be added which increases the cost of the papermaking process and moreover may result in paper products of inadequate strength properties. [0007] Based on the foregoing there is a need for improved methods and polymer additives for use in the manufacturing of paper and/or board, which promote the retention of 1
Docket No.: 1149704.052013 strength additives such as ECA on anionic fibers and in the fiber web. The present invention achieves these objectives as described herein. BRIEF SUMMARY AND INVENTIVE OBJECTS [0008] It is a specific object of the invention to provide a papermaking process that includes the use of a high‐charge low molecular weight quick inversion polymer (fixation polymer), an anionic ECA product, and a relatively low‐charge high molecular weight quick inversion polymer (retention polymer), for promoting the retention of ECA to anionic fibers and in the fiber web during papermaking. [0009] It is a specific object of the invention to provide a papermaking method which comprises the addition of an engineered cellulose additive (ECA), optionally in order to replace virgin fiber and/or starch and/or as a strength booster, that comprises the addition of the following: (i) a high‐charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers (“fixation polymer”), (ii) ECA and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are separately added to the papermaking system in the order set forth above. [0010] It is a specific object of the invention to provide a method for treating fiber stock and/or process water used in pulp, paper, or board production, the method comprising obtaining said fiber stock and/or process water and treating said fiber stock and/or process water with: (i) a high‐charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers (“fixation polymer”), (ii) anionic ECA and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are separately added to the fiber stock and/or process water. [0011] It is a specific object of the invention to provide a method for manufacture of paper or board, where a fiber web is formed from an aqueous suspension of fibers, the method comprising: ‐ providing an aqueous fiber suspension, predominantly or entirely comprising virgin or Kraft fibers, and optionally further comprising some recycled fiber material and/or coated broke, ‐ optionally diluting the aqueous fiber suspension, ‐ delivering the aqueous fiber suspension to a headbox, draining the aqueous fiber suspension on a wire screen to form a wet fibrous web, and ‐ pressing and drying the wet fibrous web to obtain a web of paper or board, which process includes the separate addition of (i) a high‐charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers, (ii) ECA and (iii) a high 2
Docket No.: 1149704.052013 molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers wherein each of (i) (ii) and (iii) are each separately added during manufacture. [0012] It is a specific object of the invention to provide a method as above described wherein the high‐charge quick inversion fixation copolymer (fixation polymer) promotes fixation of the ECA and optionally other colloidal particles to the anionic fibers and/or the high molecular weight quick inversion cationic polymer (retention polymer) promotes retention of ECA, and optionally fines and other colloidal particles in the fibrous web. [0013] It is a specific object of the invention to provide a method as above described wherein the high‐charge quick inversion fixation copolymer (fixation polymer) promotes fixation of the ECA and optionally other colloidal particles to the anionic fibers and/or the high molecular weight quick inversion cationic polymer (retention polymer) promotes retention of ECA, and optionally fines and other colloidal particles in the fibrous web. [0014] It is a specific object of the invention to provide a method as above described wherein the high‐charge quick inversion fixation polymer comprises 30 to 40 mol% of Q9 monomers and a standard viscosity (SV) of between 1.7 to 2.0 cPs. [0015] It is a specific object of the invention to provide a method as above described wherein the high molecular weight quick inversion cationic retention copolymer comprises 20 to 30 mol% of Q9 monomers and has a standard viscosity (SV) of between 3.0 to 3.5 cPs. [0016] It is a specific object of the invention to provide a method as above described wherein (i) the high charge quick inversion fixation polymer is initially added to the papermaking system; (ii) ECA is added to the papermaking system after the addition of the high charge quick inversion fixation polymer; and (iii) the high molecular weight quick inversion cationic retention polymer is added after the addition of ECA to the papermaking system. [0017] It is a specific object of the invention to provide a method as above described wherein the combined dosage of the retention and fixation polymer is equal to or greater than ECA. [0018] It is a specific object of the invention to provide a method as above described wherein the dosage of the fixation polymer ranges from 0.1 to 5 kg per ton. [0019] It is a specific object of the invention to provide a method as above described wherein the dosage of the retention polymer ranges from 0.1 to 5 kg per ton. [0020] It is a specific object of the invention to provide a method as above described wherein the combined dosage of the fixation polymer and the retention polymer ranges from 0.2 to 5 kg per ton. [0021] It is a specific object of the invention to provide a method as above described wherein the dosage of the ECA ranges from 0.25 to 5 kg per ton. 3
Docket No.: 1149704.052013 [0022] It is a specific object of the invention to provide a method as above described wherein the interval between steps (i) and (ii) and (iii) is sufficient to achieve sufficient mixing, which typically is at least 3 seconds to 5 minutes depending on shear dynamics at the time of mixing, [0023] It is a specific object of the invention to provide a method as above described which includes one or more other additives typically used in papermaking, e.g., dyes, starches, biocides, other fixation or retention agents, sizing agents, and the like. [0024] It is a specific object of the invention to provide a method as above described wherein (i) the high charge quick inversion fixation polymer enhances the fixation of ECA to the anionic fibers without damaging paper sheet formation optionally at high polymer dosage levels; (ii) the high charge quick inversion fixation polymer promotes the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers; (iii) the high charge quick inversion fixation polymer more efficiently promotes fixation of ECA than traditional charge fixation/control agents (CCA) such as polyacrylamide‐DADMAC dispersion, polyamine, and polyDADMAC solution polymers; (iv) the high molecular weight quick inversion cationic retention polymer more effectively interacts with colloids and fines than linear and conventional high Mw cationic polymers (typical SV range =4.5 to 5.5 cPs); (v) the high molecular weight quick inversion cationic retention polymer enhances total retention of the ECA, fines and fiber on paper machines; (vi) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on paper machine drainage; (vii) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on total first pass retention of ECA on Engineered cellulosic additives (ECA) strengthened paper grades; (viii) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye retention; (ix) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of dye required; (x) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of required fillers; (xi) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer improves dryer efficiency; (xii) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye and/or filler retention; 4
Docket No.: 1149704.052013 (xiii) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the required amount of starch; (xiv) the combination of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer has a synergistic effect in the retention of ECA, fines and fiber on the produced paper; (xv) any combination of the foregoing. [0025] It is a specific object of the invention to provide a method as above described wherein the total dosage by weight of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer ranges from about 0.8 to about 20 times the amount of the ECA, about 1.0 to about 10 times the amount of the ECA, about 1.0 to about 5.0 times the amount of the ECA, about 1.0 to about 3.0 times the amount of the ECA, about 1.0 to about 2.0 times the amount of the ECA, or is about equal to the amount of the ECA added to the papermaking system. [0026] It is a specific object of the invention to provide a method as above described wherein the ratio of the dosage by weight of the high molecular weight quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer added to the papermaking system ranges from (i) about 1/20 to about 20/1 by weight; (ii) about 1/10 to about 10/1 by weight; (iii) about 2/10 to about 10/2 by weight; (iv) about 3/10 to about 10/3 by weight; (vi) about 3/8 to about 8/3 by weight; (vii) about 3/7 to about 7/3 by weight; (viii) about 4/6 to about 6/4 by weight; (ix) about 5.5/4.5 to about 4.5/5.5 by weight; or (x) about equal amounts by weight of the quick inversion cationic retention polymer added to the papermaking system. [0027] It is a specific object of the invention to provide a method as above described wherein the polymers and ECA are added to a fiber stock predominantly comprising Kraft or virgin fibers, e.g., which comprises at least 50 weight‐%, preferably at least 60 weight‐%, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐% or 90 weight‐%, of Kraft or virgin fibers; and optionally comprises substantially lesser amounts of recycled fibers, e.g., 5‐10 weight‐% of recycled fibers, optionally a thin or thick stock, preferably to a thick stock. [0028] It is a specific object of the invention to provide a method as above described, which comprises the use of hard water, and/or (ii) some (e.g., at most 5‐10 weight‐%) recycled fibers. 5
Docket No.: 1149704.052013 [0029] It is a specific object of the invention to provide a method as above described wherein the polymers and ECA are added to a fluid, composition or machine used in the papermaking system. [0030] It is a specific object of the invention to provide a method as above described wherein (i) the fiber suspension comprises at least 50 weight‐%, preferably at least 60 weight‐ %, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐% or 100 weight‐%, of Kraft or virgin fibers, and optionally may comprise some recycled fiber material and/or coated broke, based on dry paper or board; (ii) the polymers and ECA are separately added to a fiber suspension having consistency of above 30 g/l; (iii) the polymers and ECA are separately added to a fiber suspension having a consistency of below 20 g/l; (iv) the polymers and ECA are added to said fiber stock prior to washing and/or cleaning and/or thickening, wherein said fiber stock has consistency (i.e., percent oven dry mass in the stock) of less than approximately 4%, 2%, or 1%; (v) the polymers and ECA are added to said fiber stock prior to forming and/or pressing and/or drying, wherein said fiber stock optionally has a consistency (i.e., percent oven dry mass in the stock) of approximately 15‐35%; (vi) the polymers and ECA are separately added to added to fiber suspension having consistency of above 20 g/l, optionally wherein the ECA is added in an amount of about 0.1 to 5 kg/ton produced paper or board; (vii) the stock comprises starch; (viii) the stock comprises at most 5‐10 weight‐%, of recycled fiber stock containing low levels of fines; (ix) the stock comprises at most 5‐10 weight‐% of recycled fiber stock containing high levels of fines; (x) the stock comprises some recycled fibers, optionally at most 5‐10 weight‐%, obtained from a papermaking machine which entirely or predominantly uses recycled paper; (xi) the stock comprises some fibers, optionally at most 5‐10 weight‐%, originating from recycled 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; (xii) the stock comprises at least 50%, 60%, 70%, 80%, 90% or 100% by weight of Kraft or virgin fibers, and optionally the pretreated fiber stock may comprise some fibers obtained from a papermaking process using a paper machine that uses at least 60%, 70%, 80%, 90% or 100% by weight of recycled fibers; (xiii) the stock comprises some OCC recycled fibers, optionally at most 5‐10 weight‐%, containing approximately 5% native size press starch and starch gel that optionally may be reclaimed for use in the manufacture of paper or board; (xiv) the stock comprises starch optionally derived from recycled fibers and/or mill broke fibers in the stock and/or starch is added to the treated fiber stock; (xv) the treatment is effected prior or concomitant to the addition of other cationic functional polymers or other papermaking chemicals; or (xvi) any combination of the foregoing. 6
Docket No.: 1149704.052013 [0031] It is a specific object of the invention to provide a fiber stock, which preferably comprises at least 50%, 60%, 70%, 80%, 90% or 100% by weight of Kraft or virgin fibers, and which optionally comprises some fibers and/or mill broke fibers, and/or optionally comprises some starch, for use in pulp, paper or board production, which comprises and/or has been treated with a composition comprising a combination of cationic polymers and ECA according to any of the foregoing claims. [0032] It is a specific object of the invention to provide paper or board produced by the method of any of the foregoing claims. DESCRIPTION OF THE FIGURES [0033] Figure 1 compares the effects of different quick inversion polymers, and a conventional charge control agent (CCA) polymer on drainage time in an incumbent DDA/retention polymer system wherein ECA is added as a strength additive. The incumbent system utilizes a charge control agent (CCA), e.g., a polyacrylamide‐DADMAC emulsion to fix the ECA onto the fiber and in addition uses a traditional retention polymer to retain fiber, fines and other papermaking additives. In these experiments the effects of different dosages (kg/T) of a high charge quick inversion polymer fixative (Polymer A), a high molecular weight quick inversion retention polymer (Polymer B), the combination of Polymer A and Polymer B, and a conventional CCA polymer (polyacrylamide‐DADMAC dispersion) on drainage rates were evaluated. The results show that the combination of Polymer A (used to replace the CCA) and Polymer B (to replace the traditional retention aid), improved drain time by 32 – 35%. [0034] Figure 2 compares the effects of different quick inversion polymers, and a conventional CCA polymer on filtrate turbidity in an incumbent DDA/retention polymer system. The incumbent system again utilizes a charge control agent (CCA) to fix the ECA onto the fiber and in addition uses a traditional retention polymer to retain fiber, fines and other papermaking additives. In these experiments the effects of different dosages (kg/T) of a high charge fixative (Polymer A), a high molecular weight cationic retention polymer (Polymer B), the combination of Polymer A and Polymer B, and a conventional CCA polymer (polyacrylamide‐DADMAC dispersion) on filtrate turbidity were evaluated. The results show that the combination of Polymer A (used to replace the CCA) and Polymer B (to replace the traditional retention aid), promoted the retention of ECA (as measured by turbidity) comparably to the incumbent DDA/retention polymer system. [0035] Figure 3 compares the effects of Polymer A as a fixative for ECA and Polymer B as retention aid in a paper machine trial. In these experiments a NA paper machine running a bleached, undyed grade was using an amphoteric strength additive in conjunction with starch to achieve strength targets. In these experiments Polymer A was added within 10 seconds of ECA addition. As shown from the results in the figure the combination of the ECA, Polymer A (as a fixative) and Polymer B (as a retention aid) provided the highest strength at the lowest dose, as measured by ZDT (Z‐dimensional tensile). As shown the incumbent program required 3.6 kg/T of starch and 2.7 kg/T of the amphoteric polymer with CCA addition in order to meet the performance seen with the combination of Polymer A and Polymer B (3.6 kg/T starch, 0.9 kg/T ECA). As shown there was no observed drop‐off in performance during the machine trial. 7
Docket No.: 1149704.052013 [0036] Figure 4 provides an exemplary flow chart of one of many possible methods for using polymers A and B and ECA for treatment of fiber stock, preferably predominantly comprising virgin or Kraft fibers, and optionally comprising recycled or mill broke fibers; and/or process water in the manufacture of paper or board as described herein. DESCRIPTION [0037] This invention provides a papermaking process that provides for enhanced fixation and retention of ECA to the fibers during papermaking and retention of the ECA to the produced paper or board material which comprises the separate addition of a high‐charge low molecular weight quick inversion polymer for fixation (“fixation polymer”), an anionic ECA product, and a relatively low‐charge high molecular weight quick inversion polymer for retention (“retention polymer”), preferably with the addition sequence in this order. As previously discussed, the initially added high fixation polymer enhances the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers and the subsequently added retention polymer improves the retention of the ECA, fines and other colloidal particles in the web. [0038] Also, surprisingly, when the two cationic quick inversion polymers are used together in the same furnish with the ECA, a synergistic effect is discovered. Particularly, combined use of the two cationic quick inversion polymers in conjunction with ECA results in a synergistic enhancement on drainage rates, ECA retention to the fiber web, and the retention of the ECA, fines and fiber on paper produced using this synergistic combination. As shown in the examples, paper machine trials have confirmed the synergistic effect of using the two cationic quick inversion polymers on drainage rates and the retention of the ECA, fines and fiber on paper. [0039] The high‐charge quick inversion fixation polymer is a Q9 (cationic) and acrylamide copolymer comprising 30 to 40 mol% of Q9 monomers. This copolymer has a standard viscosity (SV) of between 1.7 to 2.0 cPs. [0040] The extra low SV value range and 3‐D structure of the polyacrylamides of this copolymer are in exemplary embodiments achieved using sodium hypophosphite as a chain transfer agent and methylene bis‐acrylamide as a crosslinking agent. The molecular weight of the cationic polymer is thereby reduced to a range which is suitable to improve fixation without damaging sheet formation at elevated polymer dosage levels. [0041] The high Mw quick inversion cationic retention polymer is a Q9 (cationic) and acrylamide copolymer comprising 20 to 30 mol% of Q9 monomers. This copolymer has a standard viscosity (SV) of between 3.0 to 3.5 cPs. The optimal Mw range and 3‐D polymer structure of this cationic polymer are found to more effectively interact with colloids and fines than linear and conventional high Mw cationic polymers (typical SV range =4.5 to 5.5 cPs) and ultimately enhance total retention of the ECA, fines and fiber on paper machines. [0042] The combination of these two polymers is found to create a synergistic effect on paper machine drainage and total first pass retention of ECA on ECA‐strengthened paper grades. Additionally, this combination of copolymers provides for additional benefits including reduced dye and filler use and improved dryer efficiency. [0043] The advantages of the invention and exemplary embodiments are disclosed in further detail infra. 8
Docket No.: 1149704.052013 DETAILED DESCRIPTION OF THE INVENTION [0044] Before describing the invention in detail, 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 [0045] 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. [0046] 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.” [0047] 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. [0048] As used herein acrylamide or “AM” refers to a neutral monomer of molecular formula: C3H5NO and a molecular weight of 71.08 g/mol. [0049] As used herein, the term “amphoteric polymer” refers to polymers containing both anionic and cationic groups on the macromolecular chain. These polymers exhibit both attraction and repulsion in their electrostatic intermolecular interactions (resulting in anti‐ polyelectrolyte association called “Amphoteric Effect”) and they exhibit excellent salt tolerance, especially in high Ca+2 aqueous compositions. [0050] As used herein, the term "anionic monomers" may refer to either anionic monomers that are substantially anionic in whole or (in equilibrium) in part, at a pH in the range of about 4.0 to about 9.0. "Anionic monomers" may be neutral at low pH (from a pH of about 2 to about 6), and anionic at low pH. Non‐limiting representative anionic monomers include acrylic acid, sodium acrylate, ammonium acrylate, methacrylic acid, 2‐acrylamido‐2‐ methylpropanesulfonic acid (AMPS), vinyl sulfonic acid, styrene sulfonic acid, maleic acid, sulfopropyl acrylate or methacrylate or other water‐soluble forms of these or other polymerizable carboxylic or sulphonic acids, sulfomethylated acrylamide, allyl sulfonate, itaconic acid, acrylamidomethylbutanoic acid, fumaric acid, vinylphosphonic acid, allylphosphonic acid, phosphonomethylated acrylamide, methacrylate, itaconate, 2‐ acrylamido 2‐methyl propane sulphonate, sulfoalkyl(meth)acrylic acids, sulfonated styrenes, unsaturated dicarboxylic acids, sulfoalkyl(meth)acrylamides, vinyl acetate, n‐ vinylformamide, n‐vinylacetamide, n‐vinylcaprolactam, n‐vinylimidazole, n‐vinylpyridine, n‐ vinylpyrolidone, acrylamidopropyltrimonium chloride, salts of said acids and the like, or another anionic ethylenically unsaturated compound. [0051] As used herein the term "breaking length" refers to a measure of the tensile strength of paper; in theory, the maximum length of a strip of paper that can support itself without tensile failure. [0052] As used herein the term "break of the web" generally refers to breaks of the paper during papermaking. "Dry‐End Breaks" can result from (a) weak points or holes in the paper, 9
Docket No.: 1149704.052013 (b) insufficient ability to stretch, relative to the draw applied to the paper, (c) air‐handling and fluttering issues, or (d) adhesion of the paper web to tacky surfaces. "Size‐Press Breaks" can result from holes or weak areas in the sheet, but they also are often related to internal sizing issues. "Wet‐End Breaks" are breaks of the wet web of paper after the couch roll or in the wet‐press section of the papermaking machine. This may result from et‐web mechanical properties such as wet‐web tensile strength and stretch. The ability of a wet web to resist breakage is a function of both tensile strength and stretch, and both of these variables are affected by moisture content. A common way to increase wet‐web tensile strength is to increase the softwood content of the furnish. Surfactants and other materials that tend to lubricate the contacts between fibers tend to weaken the wet web. Other factors that may cause wet‐end breaks include deposition of tacky materials onto press felts and transfer rolls in the wet‐press section which can result in excessive adhesion of the paper in these areas. [0053] 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. [0054] As used herein, “a chain transfer agent” is a compound used during polymerization which acts to control the molecular weight of the polymer. Examples of chain transfer agents which may be used In the production of an acrylic acid‐based polymer include sodium phosphite, sodium hypophosphite, sodium bisulfite, mercaptoacetic acid, mercaptopropionic acid, 2‐propanethiol, 2‐mercaptoethanol, thiophenol, isopropyl alcohol, and the like, preferably sodium hypophosphite or isopropyl alcohol. [0055] As used herein a "closed water system" refers to a papermaking process in which the amount of liquid effluent has been decreased, sometimes to zero (totally closed). [0056] As used herein the term "DCS" generally refers to dissolved and colloidal substances usually derived from wood and usually having a negative charge, tending to interfere with retention aids and other papermaking additives. [0057] As used herein the term "dry strength" generally refers to the force or energy required to break a paper sample, by one of various procedures, after equilibration in a standard atmosphere. [0058] As used herein, the terms “dispersion” or “aqueous dispersion” generally refer to a heterogeneous mixture of a fluid (e.g., water) that contains solid particles, wherein the solid particles forms a phase separated mixture in which one substance of macroscopically or microscopically dispersed insoluble or soluble particles is suspended throughout another substance, typically a liquid substance. A dispersion has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension) that arise by phase separation. Macroscopic particles typically separate and settle quickly, while colloids typically do not completely settle or take a long time to settle completely into two separated layers. [0059] 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. 10
Docket No.: 1149704.052013 [0060] As used herein the term "fixative" generally refers to an additive having the tendency to help retain dye or other materials onto fiber surfaces, usually because of a strong positive charge. This includes in particular cationic polymers. [0061] As used herein the term "furnish" generally refers to a mixture of cellulosic fibers, optional fillers, and water from which paper is made. [0062] 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. [0063] As used herein the term "internal sizing" generally refers to treatment of the fiber slurry so that the paper will resist fluids. [0064] 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. [0065] As used herein “Kraft fibers” refers to cellulose fibers obtained by the Kraft process (also known as Kraft pulping or sulfate process) which converts wood into wood pulp, which consists of almost pure cellulose fibers, the main component of paper. [0066] 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. As mentioned previously, lignocellulosic substrate containing stocks used in the invention will preferably predominantly or entirely comprise virgin or Kraft fibers. [0067] 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 11
Docket No.: 1149704.052013 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. [0068] As used herein, the term "monomer" generally refers to nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, betaine monomers, and amphoteric ion pair monomers. [0069] As used herein the term "nonionic monomer" generally refers to a monomer that possesses a neutral charge. Non‐limiting examples of nonionic monomers include, acrylamide, N‐alkylacrylamides, N,N‐dialkylacrylamides, methacrylamide, N‐ vinylmethylacetamide or formamide, vinyl acetate, vinyl pyrrolidone, alkyl methacrylates, acrylonitrile, N‐vinylpyrrolidone other acrylic (or other ethylenically unsaturated) ester or other water insoluble vinyl monomers such as styrene or acrylonitrile. Herein a nonionic monomer" generally refers to acrylamide. [0070] As used herein the term "OCC" refers to old corrugated cardboard boxes. Corrugated refers to those boxes where the materials is 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. [0071] 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. In some instances, papermaking processes and applications may comprise the use of one or more polymer solutions, wherein said polymer solutions may comprise one or more DPAMs, one or more CDPAMs, one or more ADPAMs, and/or one or more PAE resins, for example as paper strengthening agents and/or wet‐strength agents. [0072] As used herein, the terms "papermaking system" generally refers to all of the equipment used to convert pulp into paper, paperboard or market pulp, including the stock storage and preparation systems, the paper or paperboard machines, and the paper machine white water system, broke recovery systems, and the systems involved in calendering, drying, on‐machine coating, slitting, winding and cutting the fluids, and materials and fluids used therein such as additives, polymers, fiber materials, one or more polymer solutions, wherein said polymer solutions may comprise one or more DPAMs, one or more CDPAMs, one or more ADPAMs, and/or one or more PAE resins, for example as paper strengthening agents and/or wet‐strength agents and the like. [0073] 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 comprising acrylamide moieties, e.g., one or more acrylamide (co)polymers. In some instances, PAMs may comprise anionic PAMs (APAMs), cationic PAMs (CPAMs), and/or sulfonated PAMs (SPAMs). [0074] As used herein, the terms "polymer," "polymers," "polymeric," and similar terms are used in their ordinary sense as understood by one skilled In the art, and thus may be used 12
Docket No.: 1149704.052013 herein to refer to or describe a large molecule (or group of such molecules) that 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 various methods e.g., by 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, e.g., 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" that may comprise polymers that may comprise three or more different recurring units. The term "polymer" as used herein is intended to include both the acid form of the polymer as well as its various salts. In particular the term “Polymers” includes amphoteric polymers, i.e., polymers containing both anionic and cationic substituents, generally in different molar proportions. [0075] As used herein the term “polymerization initiator” includes compounds and compositions which promote polymerization, e.g., during acrylamide polymerization. Examples of polymerization initiator include 2,3‐Dimethyl‐2,3‐diphenylbutane, tert‐Butyl hydroperoxide, tert‐Amyl hydroperoxide, Cumyl hydroperoxide, 1,1,3,3‐Tetramethylbutyl hydroperoxide, hydroperoxide, Isopropylcumyl hydroperoxide, 2,5‐Dimethyl‐2,5‐di(tert‐ butylperoxy)hexyne‐3, 3,6,9‐Triethyl‐3,6,9‐trimethyl‐1,4,7‐triperoxonane, Di(tert‐ butyl)peroxide, 2,5‐Dimethyl‐2,5‐di(tert‐butylperoxy)hexane, Di(tert‐butylperoxy‐ isopropyl)benzene, tert‐Butyl cumyl peroxide, Di‐(tert‐amyl)‐peroxide, Dicumyl peroxide, Butyl 4,4‐di(tert‐butylperoxy)valerate, tert‐Butylperoxybenzoate, 2,2‐Di(tert‐ butylperoxy)butane, tert‐Amyl peroxy‐benzoate, tert‐Butylperoxy‐acetate, tert‐Butylperoxy‐ (2‐ethylhexyl)carbonate, tert‐Butylperoxy isopropyl carbonate, tert‐Butyl peroxy‐3,5,5‐ trimethyl‐hexanoate, 1,1‐Di(tert‐butylperoxy)cyclohexane, tert‐Amyl peroxyacetate, tert‐ Amylperoxy‐(2‐ethylhexyl)carbonate, 1,1‐Di(tert‐butylperoxy)‐3,5,5‐trimethylcyclohexane, 1,1‐Di(tert‐amylperoxy)cyclohexane, tert‐Butyl‐monoperoxy‐maleate, 1,1’‐ Azodi(hexahydrobenzonitrile), tert‐Butyl peroxy‐isobutyrate, tert‐Butyl peroxydiethylacetate, tert‐Butyl peroxy‐2‐ethylhexanoate, Dibenzoyl peroxide, tert‐Amyl peroxy‐2‐ethylhexanoate, Di(4‐methylbenzoyl)peroxide, 1,1,3,3‐Tetramethylbutyl peroxy‐2‐ ethylhexanoate, Ammoniumperoxodisulfate, 2,5‐Dimethyl‐2,5‐di(2‐ ethylhexanoylperoxy)hexane, 2,2’‐Azodi(2‐methylbutyronitrile), 2,2’‐Azodi(isobutyronitrile), Didecanoyl peroxide, Dilauroyl peroxide, Di(3,5,5‐trimethylhexanoyl) peroxide, tert‐Amyl peroxypivalate, tert‐Butyl peroxyneoheptanoate, 1,1,3,3‐Tetramethylbutyl peroxypivalate, tert‐Butyl peroxypivalate, Dicetyl peroxydicarbonate, Dimyristyl peroxydicarbonate, Di(2‐ ethylhexyl) peroxydicarbonate, Di(4‐tert‐butylcyclohexyl) peroxydicarbonate, Diisopropyl peroxydicarbonate, tert‐Butyl peroxyneodecanoate, Di‐sec‐butyl peroxydicarbonate, tert‐ Amyl peroxyneodecanoate, Cumyl peroxyneoheptanoate, Di(3‐methoxybutyl) peroxydicarbonate, 1,1,3,3‐Tetramethylbutyl peroxyneodecanoate, Cumyl peroxyneodecanoate, and Diisobutyryl peroxide. In the exemplified polymerization methods tert‐butyl hydroperoxide is used as the initiator. [0076] As used herein “Q9 monomer” refers to 2‐(acryloyloxy)ethyl] trimethylammonium chloride (Q9) which has a molecular formula of C8H16ClNO2 and a molecular weight of 193.67 g/mol. 13
Docket No.: 1149704.052013 [0077] As used herein, the term "recycled fibers" includes by way of example postconsumer reclaimed material and pre‐consumer reclaimed material. Post‐consumer reclaimed material includes material that is reclaimed from a consumer or commercial product that has been used for its intended purpose by individuals, households or by commercial, industrial and institutional facilities in their role as end‐users of the product. Pre‐consumer reclaimed material includes material that is reclaimed from a process of secondary manufacture or further downstream industry, in which the material has not been intentionally produced, is unfit for end use and not capable of being re‐used on‐site in the same manufacturing process that generated it. 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. Also, the term "recycled fibers" includes the fiber fraction or broke of a paper machine, e.g., a paper machine which produces paper partially or entirely from recycled fibers, and the actual post‐consumer waste paper and board. In some instances the recycled fibers may have recycled numerous times, e.g., 2, 3, 4, 5, 6, 7 or more times. [0078] As used herein the term “rheology modifier” refer to any substance that can alter the rheological properties (e.g., resistance to deformation and flow) of a material. They are added to formulations to increase or decrease viscosity and to control a finished the properties and characteristics of a liquid composition in a desired manner. [0079] As used herein the term “standard viscosity” or “SV” is used to indicate the molecular weight for polymers having relatively high molecular weight. Standard viscosity (SV) is measured using a Brookfield LVT type viscosimeter equipped with a UL adapter of which the spindle rotates at 60 rpm (0.1% by weight of polymer in a 1 M saline solution of sodium chloride). SV values are given for the inversion polymers disclosed herein as the term “Mw” expressed in conventional molecular weight, such as in g/mole is generally not accurate for high weight emulsion polymers. [0080] As used herein the term "stickies" refers to sticky materials often comprised in recycled papermaking pulp, often involving pressure‐sensitive labels. Because they are deformable, they cannot be completely excluded by pressure screens. The main culprit in stickies is the polyvinylacetate (PVA) and other binders in the "pressure‐sensitive" labels that have become so common in mail and packages which can cling together and tend to build up into globs or strings, adhere to papermaking equipment, fill felts, and/or make spots in paper products. [0081] As used herein the term "surface sizing " generally refers to the application of a solution, often containing starch, to the surface of paper, usually in order to increase surface strength, and sometimes with addition of hydrophobic polymers or other material at the paper surface. [0082] As used herein the term "surfactant" refers to a surface active agent usually comprised of molecules with water‐loving and water‐hating groups, used for wetting, emulsifying, etc. [0083] As used herein the term "thick stock" generally refers to mixture of papermaking pulp and other materials with a consistency of about 2 to 5%. 14
Docket No.: 1149704.052013 [0084] As used herein the term "thin stock" generally refers to a mixture of papermaking pulp and other materials, after having been diluted with whitewater at a fan pump. [0085] As used herein the term "wet strength" generally refers to the strength of a sheet of paper after it has been exposed to a standard solution for a standard length of time, but often expressed as a ratio vs. the dry strength. [0086] As used herein the term "wet end of a paper machine " generally refers to the parts of a papermaking process between pulping (or bleaching) and wet‐pressing of the paper. [0087] 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. [0088] As used herein the term kg/T means kilograms per metric ton. Detailed Description [0089] The present invention relates to a papermaking process that includes the separate addition of a high‐charge low molecular weight quick inversion polymer for fixation, an anionic ECA product, and a relatively low‐charge high molecular weight quick inversion polymer for retention, preferably with the addition sequence in this order. [0090] It is hypothesized that the high cationic charged quick inversion fixation polymer enhances the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers; and that the high Mw quick inversion cationic retention polymer, which is subsequently added (after the ECA), improves the retention of the ECA, fines and other colloidal particles in the web. [0091] As earlier disclosed when the two cationic quick inversion polymers are used together in the same furnish with the ECA (but added separately), synergistic benefits are attained. In particular the combined use of the two cationic quick inversion polymers in conjunction with the ECA synergistically enhance total retention of ECA, as well as fines and fiber on paper machines. [0092] Also, the combination of these two polymers elicits a synergistic effect on improving paper machine drainage and also on total first pass retention of ECA on ECA‐strengthened paper grades. [0093] Yet additionally, the combination of these two polymers permits the use of reduced amounts of dyes and other fillers. [0094] Further, the combination of these two polymers synergistically improves dryer efficiency. [0095] In fact, as disclosed infra, paper machine trials have confirmed the synergistic effect of using the two cationic quick inversion polymers in the retention of the ECA, fines and fiber on paper. [0096] The materials, methods of making, and methods of use thereof in the inventive methods are further described below. [0097] INVENTIVE FIXATION POLYMER [0098] The high‐charge quick inversion fixation polymer used in the inventive methods is a Q9 (cationic) and acrylamide copolymer with 30 to 40 mol% of Q9 monomer. This 15
Docket No.: 1149704.052013 copolymer has a standard viscosity (SV) of between 1.7 to 2.0 cPs. The extra low SV value range and 3‐D structure of polyacrylamides in this copolymer are achieved in exemplary embodiments (as described in the inverse emulsion methods below) using sodium hypophosphite as a chain transfer agent and methylene bis‐acrylamide as a crosslinking agent. The molecular weight of the cationic polymer is reduced to a range which is suitable to improve fixation without damaging sheet formation at elevated polymer dosage levels. [0099] This high charge quick inversion fixation polymer has been demonstrated to be more efficient in fixation than traditional charge fixation/control agents (CCA) such as polyacrylamide‐DADMAC dispersions, polyamines, and polyDADMAC solution polymers. This polymer is generally synthesized in emulsion form, i.e., by use of inverse emulsion methods as described below. [0100] INVENTIVE RETENTION POLYMER [0101] The high Mw quick inversion cationic retention polymer used in the inventive methods is a Q9 (cationic) and acrylamide copolymer with 20 to 30 mol% of Q9 monomer. This copolymer has a standard viscosity (SV) of between 3.0 to 3.5 cPs. The optimal Mw range and 3‐D polymer structure of this cationic polymer are found to more effectively interact with colloids and fines than linear and conventional high Mw cationic polymers (typical SV range =4.5 to 5.5 cPs) and to thereby enhance total retention of the ECA, fines and fiber on paper machines. This polymer is generally synthesized in emulsion form, i.e., by use of inverse emulsion methods, in exemplary embodiments as disclosed below. [0102] SYNTHESIS OF INVENTIVE QUICK INVERSION RETENTION AND FIXATION POLYMERS [0103] The subject retention and fixation polymers of the invention in exemplary embodiments are synthesized in emulsion form by the use of inverse emulsion methods as generally described below. [0104] Preparation of Monomer Phase: [0105] For fixation polymer: acrylamide/Q9 mole ratio at 70/30, methylene bis‐acrylamide as a crosslinker at 5‐15 ppm, sodium hypophosphite as a chain transfer agent at 300‐400 ppm, than add 4‐5% citric acid solution and 0.08% diethylene triamine pentaacetic acid, and adjust the monomer phase pH between 3.3‐3.7 with sodium hydroxide. During these processes, the temperature of the reactants is desirably maintained below 30 °C, optionally by the use of an ice bath. [0106] For retention polymer: acrylamide/Q9 mole ratio at 80/20, methylene bis‐acrylamide as a crosslinker at 2‐10ppm, sodium hypophosphite as a chain transfer agent at 50‐80 ppm, than add 4‐5% citric acid solution and 0.08% diethylene triamine pentaacetic acid, and adjust the monomer phase pH between 3.3‐3.7 with sodium hydroxide. During these processes, the temperature of the reactants is desirably maintained below 30 °C, optionally by the use of an ice bath. [0107] Preparation of Oil Phase: (same for the two emulsion polymers) [0108] To a container, optionally a tared 1000 mL steel jug, add 20‐22 wt% petroleum solvents and stir, optionally using an overhead mixer. To this, add a hydrophobic solvent, optionally a 2‐3 wt% ethoxylated alcohols (C10‐C16, C12‐C16, C12‐C14) or a vegetable or other naturally occurring oil if the paper is to be produced using “green” methods. Allow to mix, optionally for at least 10 minutes. 16
Docket No.: 1149704.052013 [0109] Addition of Monomer Phase to Oil Phase: [0110] a) Slowly add the monomer solution to the oil phase, optionally over a period of 30 seconds, and allow the admixture to mix, optionally for ~20 minutes. Record the viscosity and homogenize the mixture. Record the viscosity again after homogenizing. Pour this mixture into the polymerization reactor and record the initial temperature. [0111] b) Sparge the contents of the reactor with nitrogen, optionally for ~1 hour and continuously stir. [0112] Polymerization: [0113] Add a polymerization initiator, optionally tert‐butyl hydroperoxide, further optionally at 20‐40 ppm to the mixture after 1 hour of sparging and allow the admixture to mix, optionally for ~10 minutes. Introduce SO2 gas (0.4%), optionally at 18 SCCM and monitor the temperature as the reaction proceeds. An exotherm is observed (indicated by an increase in temperature), signaling polymerization. Control the flow rate of SO2 such that the increase in temperature is gradual (optionally ~1.5 °C/minute or ~1 °C/minute). To obtain a polymer of the desired molecular weight, the temperature is desirably maintained below 50 °C, optionally using a water bath and by simultaneously cutting the SO2 supply. Completion of polymerization is indicated when no further increase in temperature is seen even when SO2 is continuously being fed. At this point, set the SO2 flow rate back to the initial value and reactor temperature to 50 °C and hold for ~1.5 hours. Nitrogen is desirably continuously sparged throughout the entire process. [0114] Post Additives: [0115] A breaker or inverse surfactant is added to the polymerizate, optionally an ethoxylated alcohol, further optionally at an addition rate of ~2.0 wt% and the admixture is permitted to mix, optionally for ~20 minutes. The reactor is then permitted to cool to < 30 °C before transferring the polymer to an appropriate container. [0116] EXEMPLARY ENGINEERED CELLULOSE ADDITIVES WHICH MAY BE USED IN THE INVENTION [0117] An engineered cellulose derivative or additive according to the invention refers to an anionic cellulose derivative having a degree of substitution of net ionic groups up to about 0.65, preferably about 0.05 to 0.55. The cellulose derivative contains anionic groups selected from the group consisting of carboxylate, carboxyalkyl, sulphonate, sulphoalkyl, phosphate and phosphonate groups and mixtures thereof. More specifically, the cellulose derivative having a degree of substitution of carboxyalkyl groups up to about 0.65, preferably about 0.05 to 0.55. The anionic cellulose derivative have a viscosity of ~2 wt% water solution greater or equal to 100 mPa.s at 25°C, preferably greater or equal to 2500 mPa.s. The viscosity is optionally measured by Brookfield LVT viscometer at 30 rpm using #62 spindle. [0118] It is preferred that the cellulose derivative is water‐soluble or at least partly water‐ soluble or water‐dispersible, more preferably water‐soluble or at least partly water‐soluble. Preferably, the cellulose derivative is ionic. The cellulose derivative can be anionic, cationic or amphoteric, preferably anionic or amphoteric. Examples of suitable cellulose derivatives include cellulose ethers, e.g. anionic and amphoteric cellulose ethers, preferably 17
Docket No.: 1149704.052013 anionic cellulose ethers. The cellulose derivative preferably has ionic or charged groups, or substituents. Examples of suitable ionic groups include anionic and cationic groups. Examples of suitable anionic groups include carboxylate, e.g. carboxyalkyl, sulphonate, e.g. sulphoalkyl, phosphate and phosphonate groups in which the alkyl group can be methyl, ethyl propyl and mixtures thereof, suitably methyl; suitably the cellulose derivative contains an anionic group comprising a carboxylate group, e.g. a carboxyalkyl group. The counter‐ion of the anionic group is usually an alkali metal or alkaline earth metal, preferably sodium. [0119] Examples of suitable cationic groups of cellulose derivatives according to the invention include salts of amines, suitably salts of tertiary amines, and quaternary ammonium groups, preferably quaternary ammonium groups. The substituents attached to the nitrogen atom of amines and quaternary ammonium groups can be same or different and can be selected from alkyl, cycloalkyl, and alkoxyalkyl, groups, and one, two or more of the substituents together with the nitrogen atom can form a heterocyclic ring. The substituents independently of each other usually comprise from 1 to about 24 carbon atoms, preferably from 1 to about 8 carbon atoms. The nitrogen of the cationic group can be attached to the cellulose or derivative thereof by means of a chain of atoms which suitably comprises carbon and hydrogen atoms, and optionally O and/or N atoms. Usually the chain of atoms is an alkylene group with from 2 to 18 and suitably 2 to 8 carbon atoms, optionally interrupted or substituted by one or more heteroatoms, e.g. O or N such as alkyleneoxy group or hydroxy propylene group. Preferred cellulose derivatives containing cationic groups include those obtained by reacting cellulose or derivative thereof with a quaternization agent selected from 2, 3‐epoxypropyl trimethyl ammonium chloride, 3‐ chloro‐2‐hydroxypropyl trimethyl ammonium chloride and mixtures thereof. [0120] The cellulose derivatives of this invention can contain non‐ionic groups such as alkyl or hydroxy alkyl groups, e.g. hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxylbutyl and mixtures thereof, e.g. hydroxyethyl methyl, hydroxypropyl methyl, hydroxybutyl methyl, hydroxyethyl ethyl, hydroxypropyl and the like. In a preferred embodiment of the invention, the cellulose derivative contains both ionic groups and non‐ionic groups. [0121] Examples of suitable cellulose derivatives according to the invention include carboxyalkyl celluloses, e.g. carboxymethyl cellulose, carboxyethyl cellulose, carboxypropyl cellulose, sulphoethyl carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose (“CM‐HEC”), carboxymethyl cellulose wherein the cellulose is substituted with one or more non‐ionic substituents, preferably carboxymethyl cellulose (“CMC”). Examples of suitable cellulose derivatives and methods for their preparation include those disclosed in U.S. Pat. No. 4,940,785, which is hereby incorporated herein by reference. [0122] The terms “degree of substitution” or “DS”, as used herein, mean the number of substituted ring sites of the beta‐anhydroglucose rings of the cellulose derivative. Since there are three hydroxyl groups on each anhydroglucose ring of the cellulose that are available for substitution, the maximum value of DS is 3.0. According to one preferred embodiment of the invention, the cellulose derivative has a degree of substitution of net ionic groups (“DSNI”) up to about 0.65, i.e., the cellulose derivative has an average degree of net ionic substitution per glucose unit up to about 0.65. The net ionic substitution can be net anionic, net cationic or net neutral. When the net ionic substitution is net anionic, there is a net excess of anionic groups (net anionic groups=the average number of anionic groups minus the average number of cationic groups, if any, per glucose unit) and DSNI is the same 18
Docket No.: 1149704.052013 as the degree of substitution of net anionic groups (“DSNA”). When the net ionic substitution is net cationic, there is a net excess of cationic groups (net cationic groups=the average number of cationic groups minus the average number of anionic groups, if any, per glucose unit) and DSNI is the same as the degree of substitution of net cationic groups (“DSNC”). When the net ionic substitution is net neutral, the average number of anionic and cationic groups, if any, per glucose unit is the same, and DSNI as well as DSNA and DSNC are 0. According to another preferred embodiment of the invention, the cellulose derivative has a degree of substitution of carboxyalkyl groups (“DSCA”) up to about 0.65, i.e. the cellulose derivative has an average degree of carboxyalkyl substitution per glucose unit up to about 0.65. The carboxyalkyl groups are suitably carboxymethyl groups and then DSCA referred to herein is the same as the degree of substitution of carboxymethyl groups (“DSCM”). According to these embodiments of the invention, DSNI, DSNA, DSNC, and DSCA independently of each other are usually up to about 0.60, preferably up to about 0.55, whereas DSNI, DSNA, DSNC and DSCA independently of each other are usually at least 0.01, suitably at least about 0.05, preferably at least about 0.10 and more preferably at least about 0.15. The ranges of DSNI, DSNA, DSNC and DSCA independently of each other are usually from about 0.01 to about 0.60, preferably from about 0.05 to about 0.55. [0123] Cellulose derivatives that are anionic or amphoteric usually have a degree of anionic substitution (“DSA ”) in the range of from 0.01 to about 1.0 as long as DSNI and DSNA are as defined herein; suitably from about 0.05, preferably from about 0.10, and more preferably from about 0.15 and suitably up to about 0.75, preferably up to about 0.55. Cellulose derivatives that are cationic or amphoteric can have a degree of cationic substitution (“DSC ”) in the range of from 0.01 to about 1.0 as long as DSNI and DSNC are as defined herein; suitably from about 0.02, preferably from about 0.03, and more preferably from about 0.05 and suitably up to about 0.75, preferably up to about 0.55. The cationic groups are suitably quaternary ammonium groups and then DSC referred to herein is the same as the degree of substitution of quaternary ammonium groups (“DSQN”). For amphoteric cellulose derivatives of this invention DSA or DSC can of course be higher than 0.65 as long as DSNA and DSNC, respectively, are as defined herein. For example, if DSA is 0.75 and DSC is 0.15, then DSNA is 0.60. [0124] Examples of suitable cellulose derivatives having degrees of substitution as defined above include the water‐soluble low DS carboxyalkyl cellulose derivatives. The water‐ soluble cellulose derivatives suitably has a solubility of at least 85% by weight, based on total weight of dry cellulose derivative, in an aqueous solution, preferably at least 90% by weight, more preferably at least 95% by weight, and most preferably at least 98% by weight. An exemplary preferred ECA is ECA 720. [0125] The quick inverting cationic polyacrylamide emulsions disclosed herein have been found to have excellent fixative and retentive properties in pulp and paper systems. When the two cationic quick inversion polymers are used together in the same furnish, a synergistic effect can be seen. [0126] As shown in the examples which follow the use of the two cationic quick inversion polymers in conjunction with ECA during papermaking, wherein each are separately added to the papermaking system, i.e., the fixation polymer is added, followed by the ECA, in turn followed by the addition of the retention polymer provides for separate and synergistic benefits including one or more of the following: 19
Docket No.: 1149704.052013 (i) the high charge quick inversion fixation polymer enhances the fixation of ECA to the anionic fibers without damaging paper sheet formation optionally at high polymer dosage levels; (ii) the high charge quick inversion fixation polymer promotes the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers; (iii) the high charge quick inversion fixation polymer more efficiently promotes fixation of ECA than traditional charge fixation/control agents (CCA) such as a polyacrylamide‐DADMAC dispersion, polyamine, and polyDADMAC solution polymers; (iv) the high molecular weight quick inversion cationic retention polymer more effectively interacts with colloids and fines than linear and conventional high Mw cationic polymers (typical SV range =4.5 to 5.5 cPs); (v) the high molecular weight quick inversion cationic retention polymer enhances total retention of the ECA, fines and fiber on paper machines; (vi) the combination of the high charge quick inversion cationic fixation retention polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on paper machine drainage; (vii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on total first pass retention of ECA on Engineered cellulosic additives (ECA) strengthened paper grades; (viii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye retention during papermaking; (ix) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of dye required during papermaking; (x) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of required fillers during papermaking; (xi) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer improves dryer efficiency; (xii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye and/or filler retention; (xiii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the required amount of starch; (xiv) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer has a synergistic effect in the retention of ECA, fines and fiber on the produced paper; or (xv) any combination of the foregoing. [0127] In some embodiments the methods and polymer/ECA combination of the current invention may be added to any process water from pulp, paper, or board production and/or to thick or thin stock used in pulp, paper, or board production. The stock will preferably 20
Docket No.: 1149704.052013 predominantly or entirely comprise virgin or Kraft fibers, and optionally may comprise some recycled fibers, and/or mill broke fibers. [0128] In exemplary embodiments, the fiber stock comprises at least 50%, 60%, 70%, 80%, 90% or 100% by weight of virgin or Kraft fibers, and may comprise some recycled fibers, although the preferred use of the inventive methods is for treating stock comprising virgin or Kraft fibers. In some instances such fibers may contain starch, in some instances a significant amount of starch. [0129] In some embodiments, the treated fiber stock may comprise some OCC recycled fiber which may contain approximately 5% native size press starch and starch gel that may be reclaimed for use in the manufacture of paper or board, said starch being derived from the recycled fibers and/or mill broke fibers in the stock and/or added to the treated fiber stock. Typically, recycled fiber material comprises low molecular weight starch, which originates from the surface sizing of the paper or board and retains poorly on fibers, as it typically uncharged or has slightly anionic charge. [0130] Wet end applications of the current invention comprise the addition of the fixation polymer, ECA, and the retention polymer to thick stock and/or to thin stock. Thick stock is here understood as a fibrous stock or furnish, which has consistency of above 1% (i.e., above 10 g dry solids/L of stock) and thin stock has consistency of below 1% (i.e., below 10 g dry solids/L of stock). [0131] These fiber stock fractions optionally may comprise elevated amounts of low molecular weight (LMW) starch, hydrophobics, fines, filler/pigment, dye or the like. A thick or thin stock again will preferably predominantly comprise virgin or Kraft fibers, and optionally may comprise some recycled fibers, and/or mill broke fibers, optionally originating from different sources, e.g., including recycled fiber materials and/or mill broke and/or coated broke. [0132] According to some embodiments of the present invention, the treated fiber stock which predominantly comprises Kraft or virgin fibers, optionally may comprise some fibers originating from recycled 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. [0133] The treated fiber stock, predominantly or entirely comprising virgin or Kraft fibers, may contain variable amounts of colloidal fines, colloidal particles, filler, hydrophobic, and hydrophilic particles, depending on fiber source and paper mill processing methods. Additionally, fiber suspensions are often diluted with paper mill white water, which also contains variable amounts of colloidal fines and the like. Furnish or fiber stock which used in the present invention may contain low levels of fines (e.g., fines content ranging from 0.1% – 5%, more typically 0.1% – 0.2% on a mass dry fine to volume basis) or high levels of fines (e.g., fines content ranging from 5% – 15%). The definition of “fines” for the current application is any suspended particle smaller than 125 P filter (e.g., 0.76 micron or 200 mesh). [0134] The retention and fixation polymers of the present invention may employ solutions of the subject quick inversion cationic retention and fixation polymers, which may be used as pump and go products, optionally not requiring conventional polymer inverting and aging tanks. By contrast, conventional polyacrylamide emulsions, such as cationic retention aids 21
Docket No.: 1149704.052013 having molecular mass values in the range of 10 to 20 million Dalton and SV > 4.5 mPas, do not instantly invert in water under a normal mixing speed (<500 RPM), and pre‐diluted conventional polymer solutions should be aged for a minimum of 30 minutes prior to use. [0135] The retention and fixation polymers may be synthesized off site and delivered to a paper mill, and then mixed on‐site. Alternatively, the retention and fixation polymers may be pre‐blended off site, prior to arrival at the paper mill, then delivered as pre‐blended emulsion polymers to customer sites. Mixing on site is flexible, allowing for easy customization of blend ratios to meet specific process water and other requirements of plants. In some embodiments, the retention and fixation quick inversion polymer solutions can be produced by injecting the emulsions into a high shear water pump, and inverting the mixture optionally via a static mixer before pumping the polymer solution onto paper machines. [0136] Increased synergistic effects of the inventive combination may be observed when the fixation polymer is used in combination with an optimized amount of the retention polymer, i.e., optimized ratios. The retention polymer has higher molecular weight than the fixative polymer and has been found to be more effective at mechanical retention; i.e., the retention polymer is better for fiber to fiber bridging. The fixative polymer has a lower molecular weight than the retention polymer and has been found to be more effective at fixation of the ECA to the fiber; i.e. it is a better fixative. Without being bound by theory, it can be reasoned that the combination of polymers at an optimal blend ratio provides both optimal fixation and better mechanical retention of the ECA, providing a possible mechanistic rationale for the synergistic benefits of the combination. [0137] Optimal ratios (mass ratio of fixation/retention polymer) are dependent on many variables including, but not limited to, paper mill, point of addition to the paper making process, furnish characteristics including pH, conductivity, and content of starch, fines, hydrophobics, ash, and/or dyes. Optimal ratios are determined empirically by preliminary studies at each specific mill on a furnish by furnish basis. In exemplary embodiments, the ratio of the retention and fixation polymers may range from ~90/10 to less than 1/99, and preferably range from 85/15 to 15/85. At optimal ratios, the 2 polymer solutions elicit a synergistic or additive increase in ECA retention compared to the administration of equivalent dosage levels of the retention or fixation polymer alone. [0138] In some exemplary embodiments the invention provides methods for using the retention and fixation polymers for treatment of starch‐containing fiber stock and/or mill broke fibers and/or process water in the manufacture of paper or board. In preferred embodiments, the treatment is effected prior to the use of the treated fiber stock in a papermaking process or other industrial process using cationic functional polymers or other papermaking chemicals. [0139] Said retention and fixation polymers may be separately injected into the process stream at several points in the manufacturing process including, but not limited to Chemical(s) addition point 1, upstream of thickening, wherein said fiber stock has consistency (i.e., percent oven dry mass in the stock) of less than approximately 10%, 5%, 2%, 1%, or 0.65% (see Figure 4). Addition of the inverted solution of cationic polymers to the fiber suspension before the thickening step is advantageous as the enrichment of the ECA in the water circulation is effectively prevented in most processes, and a large amount of the ECA is effectively retained on the fibers. 22
Docket No.: 1149704.052013 [0140] Said retention and fixation polymers may also be added at Chemical(s) addition point 2(see Figure 4), upstream of forming and/or pressing and/or drying, wherein said fiber stock has consistency (i.e., percent oven dry mass in the stock) of approximately 10‐30%. Said methods of the current invention are effected to trap and retain ECA that may otherwise be lost or degraded, thereby protecting ECA for incorporation into paper or board. Optimal ratios are empirically pre‐determined for each paper mill and fiber stock composition to elicit a synergistic or additive increase in ECA retention without over‐flocculation of fibers or formation of hydrophobic substances, such as stickies or flocs, in the stock. [0141] Solutions of the retention and fixation polymers may also be added to the fiber suspension before washing and/or cleaning of the fiber suspension for improving ECA retention and filtration of the fiber suspension, wherein it may be achieved cleaner filtrate, and higher fines content in fiber suspension to which hydrophobics, sizing agent, fillers, dyes or the like can associate. Solutions of the retention and fixation polymers may also be separately added to fiber suspensions before a machine chest or before a mixing chest of a paper or board machine. [0142] Because of high polymer molecular weights of the conventional retention aid polymers, dosage level of them is typically limited below 0.45 kg/ton (where kg/ton denotes mass of dry polymer per ton of process slurry), and often limited to below 0.3 kg/ton, in order not to over‐flocculate fiber stock in the wet end. By contrast, for the present invention, solutions of the quick inversion retention and fixation polymers, they may be added to fiber stock and/or mill broke fibers and/or process water in the manufacture of paper or board at dosage levels ranging from 0.25 – 5kg/ton, preferably from 0.3 – 1.0 kg/ton, and more preferably from 0.5‐0.7 kg/ton. Optimal dosage levels for plant applications will be dependent on paper mill, fiber and furnish characteristics, consistency, point of addition, and the ratio of the retention and fixation polymers. The retention and fixation polymers of the present invention provide great dosage latitude for increased ECA fixation and retention without over‐flocculating or damaging sheet formation. [0143] A preferred embodiment of the present invention provides a fiber stock comprising a high content of virgin or Kraft fibers, preferably at least 50 weight‐%, preferably at least 60 weight‐%, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐ % or 100 weight‐%, of Kraft or virgin fibers, optionally containing a much smaller amount of recycled fibers and/or mill broke fibers, e.g., at most 5‐10 weight‐%, optionally a starch‐ containing thick fiber stock, optionally starch‐containing process water from pulp, paper or board production, which comprises and/or has been treated with the retention and fixation polymers and ECA according to any of the foregoing. [0144] Paper to be manufactured by the method according to the present invention may be any kind of paper or board, and optionally may comprise some recycled fiber material and/or mill broke and/or coated broke, e.g., at most 5‐10 weight‐%. [0145] EXEMPLARY EMBODIMENTS 23
Docket No.: 1149704.052013 A. A papermaking method which comprises the addition of an engineered cellulose additive (ECA), optionally to replace virgin fiber and/or starch and/or as a strength booster, wherein said papermaking method comprises the use of: (i) a high‐charge quick inversion fixation copolymer which comprises 2‐ (acryloyloxy)ethyl] trimethylammonium chloride (Q9) (cationic) and acrylamide monomers (“fixation polymer”); (ii) anionic ECA; and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are separately added to the papermaking system. B. A method for treating fiber stock and/or process water used in pulp, paper, or board production, which preferably predominantly comprises Kraft or virgin fibers, the method comprising obtaining said fiber stock and/or process water and treating said fiber stock and/or process water with: (i) a high‐charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers (“fixation polymer”); (ii) anionic ECA; and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are each separately added to the fiber stock and/or process water. C. A method for manufacture of paper or board, where a fiber web is formed from an aqueous suspension of fibers, the method comprising: ‐ providing an aqueous fiber suspension, which preferably predominantly comprises Kraft or virgin fibers, and optionally comprises recycled fiber material and/or coated broke, ‐ optionally diluting the aqueous fiber suspension, ‐ delivering the aqueous fiber suspension to a headbox, draining the aqueous fiber suspension on a wire screen to form a wet fibrous web, and ‐ pressing and drying the wet fibrous web to obtain a web of paper or board, which process includes the separate addition of (i) a high‐charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers, (ii) ECA and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers wherein each of (i) (ii) and (iii) are each separately added during manufacture. D. The method of Embodiment A, B or C, wherein the high‐charge quick inversion fixation copolymer (fixation polymer) promotes fixation of the ECA and optionally other colloidal particles to the anionic fibers and/or the high molecular weight quick inversion cationic polymer (retention polymer) promotes retention of ECA, and optionally fines and other colloidal particles in the fibrous web. E. The method of any of the previous Embodiments, wherein the high‐charge quick inversion fixation polymer comprises 30 to 40 mol% of Q9 monomers and a standard viscosity (SV) of between 1.7 to 2.0 cPs. 24
Docket No.: 1149704.052013 F. The method of any of the previous Embodiments, wherein the high molecular weight quick inversion cationic retention copolymer comprises 20 to 30 mol% of Q9 monomers and has a standard viscosity (SV) of between 3.0 to 3.5 cPs. G. The method of any of the previous Embodiments, wherein (i) the high charge quick inversion fixation polymer is initially added to the papermaking system; (ii) ECA is added to the papermaking system after the addition of the high charge quick inversion fixation polymer; and (iii) the high molecular weight quick inversion cationic retention polymer is added after the addition of ECA to the papermaking system. H. The method of any of the previous Embodiments, wherein the combined dosage of the retention and fixation polymer is equal to or greater than ECA. I. The method of any of the previous Embodiments wherein the dosage of the retention polymer ranges from 0.1 to 5 kg per ton. J. The method of any of the previous Embodiments wherein the dosage of the fixation polymer ranges from 0.1 to 5 kg per ton. K. The method of any of the previous Embodiments wherein the combined dosage of the fixation polymer and the retention polymer ranges from 0.2 to 5 kg per ton. L. The method of any of the previous Embodiments wherein the dosage of the ECA ranges from 0.2 to 5 kg per ton. M. The method of any of the previous Embodiments wherein (i) the interval between steps (i) and (ii) and (iii) is sufficient to achieve sufficient mixing, which typically is at least 3 seconds to 5 minutes depending on shear dynamics at the time of mixing. N. The method of any of the previous Embodiments which includes one or more other additives typically used in papermaking, e.g., dyes, starches, biocides, other fixation or retention agents, sizing agents, and the like. O. The method of any of the previous Embodiments wherein (i) the high charge quick inversion fixation polymer enhances the fixation of ECA to the anionic fibers without damaging paper sheet formation optionally at high polymer dosage levels; (ii) the high charge quick inversion fixation polymer promotes the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers; (iii) the high charge quick inversion fixation polymer more efficiently promotes fixation of ECA than traditional charge fixation/control agents (CCA) such as CC610 25
Docket No.: 1149704.052013 (polyacrylamide‐DADMAC dispersion), polyamine, and polyDADMAC solution polymers; (iv) the high molecular weight quick inversion cationic retention polymer more effectively interacts with colloids and fines than linear and conventional high Mw cationic polymers (typical SV range =4.5 to 5.5 cPs); (v) the high molecular weight quick inversion cationic retention polymer enhances total retention of the ECA, fines and fiber on paper machines; (vi) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on paper machine drainage; (vii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on total first pass retention of ECA on Engineered cellulosic additives (ECA) strengthened paper grades; (viii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye retention; (ix) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of dye required; (x) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of required fillers; (xi) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer improves dryer efficiency; (xii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye and/or filler retention; (xiii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the required amount of starch; (xiv) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer has a synergistic effect in the retention of ECA, fines and fiber on the produced paper; or (xv) any combination of the foregoing. P. The method of any of the previous Embodiments wherein the total dosage by weight of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer ranges from about 0.8 to about 20 times the amount of the ECA, about 1.0 to about 10 times the amount of the ECA, about 1.0 to about 5.0 times the amount of the ECA, about 1.0 to about 3.0 times the amount of the ECA, about 1.0 to about 2.0 times the amount of the ECA, or is about equal to the amount of the ECA added to the papermaking system. Q. The method of any of the previous Embodiments wherein the ratio of the dosage by weight of the high charge quick inversion cationic fixation polymer and the high molecular 26
Docket No.: 1149704.052013 weight quick inversion cationic retention polymer added to the papermaking system ranges from (i) about 1/20 to about 20/1 by weight; (ii) about 1/10 to about 10/1 by weight; (iii) about 2/10 to about 10/2 by weight; (iv) about 3/10 to about 10/3 by weight; (vi) about 3/8 to about 8/3 by weight; (vii) about 3/7 to about 7/3 by weight; (viii) about 4/6 to about 6/4 by weight; (ix) about 5.5/4.5 to about 4.5/5.5 by weight; or (x) about equal amounts by weight of the quick inversion cationic retention polymer added to the papermaking system. R. The method of any of the previous Embodiments wherein the polymers and ECA are added to a fiber stock comprising recycled fibers, optionally a thin or thick stock, preferably to a thick stock. S. The method of any of the previous Embodiments which comprises the use of hard water, and/or recycled fibers. T. The method of any of the previous Embodiments wherein the polymers and ECA are added to a fluid, composition or machine used in the papermaking system. U. The method of any of the previous Embodiments wherein (i) the fiber suspension comprises at least 50 weight‐%, preferably at least 60 weight‐ %, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐% or 100 weight‐%, of Kraft or virgin fibers; (ii) the polymers and ECA are separately added to a fiber suspension having consistency of above 30 g/l; (iii) the polymers and ECA are separately added to a fiber suspension having a consistency of below 20 g/l; (iv) the polymers and ECA are added to said fiber stock prior to washing and/or cleaning and/or thickening, wherein said fiber stock has consistency (i.e., percent oven dry mass in the stock) of less than approximately 4%, 2%, or 1%; (v) the polymers and ECA are added to said fiber stock prior to forming and/or pressing and/or drying, wherein said fiber stock optionally has a consistency (i.e., percent oven dry mass in the stock) of approximately 15‐35%; (vi) the polymers and ECA are separately added to added to fiber suspension having consistency of above 20 g/l; (vii) the stock comprises starch; (viii) the stock comprises at least 50 weight‐%, preferably at least 60 weight‐%, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐% or 90 weight‐%, of Kraft or virgin fibers and a small amount of recycled fibers, optionally about 10 weight to about 20 weight‐ % and optionally comprises low levels of fines; (ix) the stock comprises at least 50 weight‐%, preferably at least 60 weight‐%, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐% or 90 weight‐%, of Kraft or virgin fibers and a small amount of recycled fibers, 27
Docket No.: 1149704.052013 optionally about 10 weight to about 20 weight‐ %, further optionally containing high levels of fines; (x) the stock comprises some fibers, e.g., at most 5‐10 weight‐%, obtained from a papermaking machine which entirely or predominantly uses recycled paper; (xi) the stock comprises some fibers originating from recycled 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; (xii) the stock comprises at least 50 weight‐%, preferably at least 60 weight‐%, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐% or 90 weight‐%, or 100% Kraft or virgin fibers and optionally comprises some recycled fibers obtained from a papermaking process using a paper machine that uses at least 60%, 70%, 80%, 90% or 100% recycled fibers; (xiii) the stock comprises some, optionally at most 5‐10 weight‐% of OCC recycled fibers containing approximately 5% native size press starch and starch gel that may be reclaimed for use in the manufacture of paper or board; (xiv) the stock comprises starch optionally derived from recycled fibers and/or mill broke fibers in the stock and/or starch is added to the treated fiber stock; (xv) the treatment is effected prior or concomitant to the addition of other cationic functional polymers or other papermaking chemicals; or (xvi) any combination of the foregoing. V. A fiber stock, preferably comprising a high content of virgin or Kraft fibers, e.g., at least 50‐60 weight‐% of virgin or Kraft fibers, and optionally comprising small amounts of recycled fibers, e.g., at most 5‐10 weight‐%, and/or starch, for use in pulp, paper or board production, which comprises and/or has been treated with a composition comprising a combination of cationic polymers and ECA, optionally produced according to any of the foregoing Embodiments. W. The fiber stock of Embodiment V, which comprises at least 50 weight‐%, preferably at least 60 weight‐%, more preferably at least 70 weight‐%, or even more preferably at least 80 weight‐% or 90 weight‐%, of Kraft or virgin fibers. X. Paper or board produced by the method of any of the foregoing Embodiments. [0146] Having described the invention in detail the invention is further described in the following examples. While the invention has been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations and substitutions may be applied to the compositions and/or methods described herein without departing from the concept, spirit and scope of the disclosure. Examples [0147] MATERIALS AND METHODS USED IN THE EXAMPLES [0148] Polymers Used in the Examples 28
Docket No.: 1149704.052013 [0149] The polymers used in the examples, i.e., a conventional cationic polymer used to retain, inventive high charge low Mw cationic polymer (fixation polymer) and the high molecular weight quick inversion polymer (retention polymer) are compared in the Table below: Polymer SV, cPs Cationic Charge, at GPC Mw pH 4
DDA Procedure: [0150] A dynamic drainage analyzer (DDA) was used to evaluate the polymer effect on drainage. An additive timing sequence was used to mimic the timing of additives on the machine. Polymers were prepared according to standard makedown procedures. [0151] For each measurement, an aliquot of stock was poured into the DDA stirring jar where additives were dosed in accordance with machine conditions. After mixing, the stock is drained through a paper machine wire and the filtrate is collected in a vessel. The drain time is recorded and used as a measure of drainage performance. [0152] The filtrate is then measured for turbidity using a Hach 2100Q turbidimeter. Lower turbidity values indicate better retention of fiber, fines, and colloidal and particulate materials. ZDT Procedure: The Z‐directional tensile (ZDT) is defined as the maximum tensile stress in the thickness direction when a test strip can withstand before it breaks when it is loaded perpendicular to the plan in a tensile apparatus. The ZDT test used in the examples follows TAPPI Test Method 541 om‐10, Internal Bond Strength of Paperboard (Z‐Direction Tensile). This test is intended for paperboards and some papers which have internal fiber bond strength (cohesive strength) lower than the adhesive bond strength of the tape to the specimen and/or test platens. 29
Docket No.: 1149704.052013 [0153] The following examples are provided for illustrative purposes only and are non‐ limiting. Example 1: Evaluation of Quick Inversion Polymers on Drainage Time when used as CCA replacement in EcoFill Lite System [0154] This example relates to the experiments, the results of which are contained in Figure 1. In these experiments a NA paper machine making bleached board with a target basis weight of 110 g/m2 is using engineered cellulosic additives (ECA) to add strength to the sheet to achieve ZDT targets. ECA adds additional anionic charge to the furnish so retention aids are needed to retain the ECA in order to meet strength targets. The incumbent system utilizes a charge control agent (CCA) to fix the ECA onto the fiber. In addition to the CCA, a traditional retention polymer is used to retain fiber, fines and other papermaking additives. [0155] In this example, different quick inversion polymers were evaluated as CCA replacement products and also as a dual component system where the higher charge fixative was used to fix the ECA to the fiber and the high molecular weight polymer was used as a retention aid. This combination provided the best drainage performance in DDA testing and gave very good retention benefits. Timing of addition was ECA @ 10 seconds, Polymer A @ 15 seconds, Polymer B @ 75 seconds. [0156] The results of these experiments demonstrate that Polymer A, when used as a CCA replacement, performs better for drainage than a conventional CCA product, as shown from the results in Figure 1. Particularly, the drainage results demonstrate that when Polymer A is used to replace the CCA and Polymer B is used to replace an exemplary traditional retention aid, drainage time improves by 32 – 35%. Example 2: Evaluation of Quick Inversion Polymers on Filtrate Turbidity when used as CCA replacement in EcoFill Lite System [0157] This example relates to the experiments the results of which are contained in Figure 2. In these experiments a NA paper machine making bleached board with a target basis weight of 110 g/m2 using engineered cellulosic additives (ECA) to add strength to the sheet to achieve ZDT targets was again used. As discussed previously, ECA adds additional anionic charge to the furnish so retention aids are needed to retain the ECA in order to meet strength targets. The incumbent system again utilizes a charge control agent (CCA) to fix the ECA onto the fiber. In addition to the CCA, a traditional retention polymer is used in the incumbent system to retain fiber, fines and other papermaking additives. [0158] In the experiments, the same quick inversion polymers were evaluated as CCA replacement products and also as a dual component system where the higher charge fixative was used to fix the ECA to the fiber and the lower charge polymer was used as a retention aid by comparing the effects thereof on filtrate turbidity in the DDA system. The timing of addition was ECA @ 10 seconds, Polymer A @ 15 seconds, Polymer B @ 75 seconds. [0159] The results of these experiments demonstrate that the combination of Polymer A and Polymer B functioned comparably to the conventional CCA polymer retention system, i.e., it provided for competitive retention (as measured by turbidity) to the incumbent DDA/retention polymer system. 30
Docket No.: 1149704.052013 Example 3: Machine trial Comparing the Effects of Polymer A (as fixative for ECA) and Polymer B (as retention aid) [0160] This example relates to the experiments, the results of which are contained in Figure 3. In these experiments, a NA paper machine running bleached, undyed grade board was using an amphoteric strength additive in conjunction with starch to achieve strength targets was used. [0161] In these experiments the combination of the ECA, Polymer A (used as a fixative for the ECA) and Polymer B (as a retention aid) were shown to provide the highest strength at the lowest dose, as measured by ZDT. ZDT (Z‐dimensional tensile) measures the strength in the perpendicular direction, also known as internal strength. Paper samples are affixed to two‐sided tape and the prepared sample is then affixed to the ZDT measurement head of the tensile tester. Controlled force is then applied to the upper surface of the taped paper sample under a timed hold. The measurement heads are then pulled apart under constant stress until the paper sample fails in the Z‐direction. The force required to break the sample is recorded as the ZDT measurement and is reported in lb f/in2. [0162] The results in Figure 3 revealed that whereas the incumbent program required 4 kg/T of starch and 3 kg/T of the amphoteric polymer with CCA addition in order to meet the performance seen with the Polymer A/Polymer B combination (4 kg/T starch, 1 kg/T ECA and Polymer A/B combination). In these experiments Polymer A was added within 10 seconds of ECA addition. As shown in Figure 3 there was no observed drop‐off in performance during the machine trial. Example 4: Machine trial Evaluating the Effects of Polymer A and Polymer B with ECA [0163] In this example experiments were conducted to assess the effects of Polymer A and Polymer B when used with ECA additives under papermaking machine conditions. [0164] In these experiments a machine trial was performed on a 61.5# bleached, folding board grade. The incumbent system used ECA with a charge control additive (CCA) in addition to starch for retention. During the trial the effects of the inventive combination (Polymer A / ECA / Polymer B) were evaluated on machine performance. In the experiments Polymer A was added within 10‐15 seconds of the ECA. The results of these trials revealed that the paper machine was able to make significant improvements to processes. [0165] Mill control process data (parameters taken directly from machine process data) was evaluated and these results (not shown) were compared to conventional CCA methods. The results demonstrated that inventive combination provided at least the following process improvements: i) 6% lower thick stock flow for the sale brown stock washer (BSW) and consistency; ii) Lower dye usage while also increasing ground calcium carbonate (GCC) (10 kg/T) and precipitated calcium carbonate (PCC) (20 kg/T) usage. Normal filler loading is just 10 kg/T PCC; iii) Improved cleaning of the whitewater loop; and iv) lower drying energy (steam pressure went from 462 kPa to 317 kPa) 31
Docket No.: 1149704.052013 [0166] CONCLUSIONS [0167] The results of the experiments disclosed in Examples 1‐4 and shown in Figures 1‐3 demonstrate that the inventive combination (Polymer A / ECA / Polymer B) provides for improved retention of ECA to the fiber web as evidenced by improved drainage and filtrate turbidity compared to a conventional (incumbent) DDA/retention polymer system. [0168] Further the results demonstrate that the inventive combination (Polymer A / ECA / Polymer B) when compared to an incumbent program required 4.0 kg/T of starch and 3.0 kg/T of a conventional amphoteric polymer with CCA addition in order to meet the performance attained with the Polymer A/Polymer B combination (4.0 kg/T starch, 1.0 kg/T ECA and Polymer A/B combination). [0169] Also, the results demonstrate that the inventive combination (Polymer A / ECA / Polymer B) provides for improved machine performance when used to promote ECA retention under industrial papermaking conditions. [0170] Having described the inventive combination (Polymer A / ECA / Polymer B) and methods of use thereof in terms of preferred embodiments, the invention is further defined by the claims which follow: 32
Claims
Docket No.: 1149704.052013 CLAIMS We claim: 1. A papermaking method which comprises the addition of an engineered cellulose additive (ECA), optionally to replace virgin fiber and/or starch and/or as a strength booster, wherein said papermaking method comprises the use of: (i) a high‐charge quick inversion fixation copolymer which comprises 2‐ (acryloyloxy)ethyl] trimethylammonium chloride (Q9) (cationic) and acrylamide monomers (“fixation polymer”); (ii) anionic ECA; and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are separately added to the papermaking system. 2. A method for treating fiber stock and/or process water used in pulp, paper, or board production, which preferably predominantly comprises Kraft or virgin fibers, the method comprising obtaining said fiber stock and/or process water and treating said fiber stock and/or process water with: (i) a high‐charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers (“fixation polymer”); (ii) anionic ECA; and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers (“retention polymer”); wherein each are each separately added to the fiber stock and/or process water. 3. A method for manufacture of paper or board, where a fiber web is formed from an aqueous suspension of fibers, the method comprising: ‐ providing an aqueous fiber suspension, which preferably predominantly comprises Kraft or virgin fibers, and optionally comprises recycled fiber material and/or coated broke, ‐ optionally diluting the aqueous fiber suspension, ‐ delivering the aqueous fiber suspension to a headbox, draining the aqueous fiber suspension on a wire screen to form a wet fibrous web, and ‐ pressing and drying the wet fibrous web to obtain a web of paper or board, which process includes the separate addition of (i) a high‐charge quick inversion fixation copolymer which comprises Q9 (cationic) and acrylamide monomers, (ii) ECA and (iii) a high molecular weight quick inversion cationic retention polymer which comprises Q9 (cationic) and acrylamide monomers wherein each of (i) (ii) and (iii) are each separately added during manufacture. 4. The method of claim 1, 2 or 3, wherein the high‐charge quick inversion fixation copolymer (fixation polymer) promotes fixation of the ECA and optionally other colloidal particles to the anionic fibers and/or the high molecular weight quick inversion cationic polymer (retention polymer) promotes retention of ECA, and optionally fines and other colloidal particles in the fibrous web. 33
Docket No.: 1149704.052013 5. The method of any of the previous claims, wherein (i) the high‐charge quick inversion fixation polymer comprises 30 to 40 mol% of Q9 monomers and a standard viscosity (SV) of between 1.7 to 2.0 cPs; and/or the high molecular weight quick inversion cationic retention copolymer comprises 20 to 30 mol% of Q9 monomers and has a standard viscosity (SV) of between 3.0 to 3.5 cPs. 6. The method of any of the previous claims wherein (i) the high charge quick inversion fixation polymer is initially added to the papermaking system; (ii) ECA is added to the papermaking system after the addition of the high charge quick inversion fixation polymer; and (iii) the high molecular weight quick inversion cationic retention polymer is added after the addition of ECA to the papermaking system. 7. The method of any of the previous claims wherein the combined dosage of the retention and fixation polymer is equal to or greater than ECA. 8. The method of any of the previous claims wherein the dosage of the retention polymer ranges from 0.1 to 5 kg per ton; and/or the dosage of the fixation polymer ranges from 0.1 to 5 kg per ton. 9. The method of any of the previous claims wherein the combined dosage of the fixation polymer and the retention polymer ranges from 0.2 to 5 kg per ton. 10. The method of any of the previous claims wherein the dosage of the ECA ranges from 0.2 to 5 kg per ton. 11. The method of any of the previous claims wherein (i) the interval between steps (i) and (ii) and (iii) is sufficient to achieve sufficient mixing, which typically is at least 3 seconds to 5 minutes depending on shear dynamics at the time of mixing. 12. The method of any of the previous claims which includes one or more other additives typically used in papermaking, e.g., dyes, starches, biocides, other fixation or retention agents, sizing agents, and the like. 13. The method of any of the previous claims wherein (i) the high charge quick inversion fixation polymer enhances the fixation of ECA to the anionic fibers without damaging paper sheet formation optionally at high polymer dosage levels; (ii) the high charge quick inversion fixation polymer promotes the fixation of the anionic ECA product and other anionic colloidal particles onto the anionic fibers; (iii) the high charge quick inversion fixation polymer more efficiently promotes fixation of ECA than traditional charge fixation/control agents (CCA) such as CC610 34
Docket No.: 1149704.052013 (polyacrylamide‐DADMAC dispersion), polyamine, and polyDADMAC solution polymers; (iv) the high molecular weight quick inversion cationic retention polymer more effectively interacts with colloids and fines than linear and conventional high Mw cationic polymers (typical SV range =4.5 to 5.5 cPs); (v) the high molecular weight quick inversion cationic retention polymer enhances total retention of the ECA, fines and fiber on paper machines; (vi) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on paper machine drainage; (vii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer elicits a synergistic effect on total first pass retention of ECA on Engineered cellulosic additives (ECA) strengthened paper grades; (viii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye retention; (ix) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of dye required; (x) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the amount of required fillers; (xi) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer improves dryer efficiency; (xii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer promotes dye and/or filler retention; (xiii) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer reduces the required amount of starch; (xiv) the combination of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer has a synergistic effect in the retention of ECA, fines and fiber on the produced paper; or (xv) any combination of the foregoing. 14. The method of any of the previous claims wherein the total dosage by weight of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer ranges from about 0.8 to about 20 times the amount of the ECA, about 1.0 to about 10 times the amount of the ECA, about 1.0 to about 5.0 times the amount of the ECA, about 1.0 to about 3.0 times the amount of the ECA, about 1.0 to about 2.0 times the amount of the ECA, or is about equal to the amount of the ECA added to the papermaking system. 35
Docket No.: 1149704.052013 15. The method of any of the previous claims wherein the ratio of the dosage by weight of the high charge quick inversion cationic fixation polymer and the high molecular weight quick inversion cationic retention polymer added to the papermaking system ranges from (i) about 1/20 to about 20/1 by weight; (ii) about 1/10 to about 10/1 by weight; (iii) about 2/10 to about 10/2 by weight; (iv) about 3/10 to about 10/3 by weight; (vi) about 3/8 to about 8/3 by weight; (vii) about 3/7 to about 7/3 by weight; (viii) about 4/6 to about 6/4 by weight; (ix) about 5.5/4.5 to about 4.5/5.5 by weight; or (x) about equal amounts by weight of the quick inversion cationic retention polymer added to the papermaking system. 36
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
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| US202263387298P | 2022-12-14 | 2022-12-14 | |
| FI20235307 | 2023-03-16 | ||
| PCT/US2023/083948 WO2024129932A1 (en) | 2022-12-14 | 2023-12-14 | Improved retention of engineered cellulosic additives using synergistic cationic polymer combination |
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| EP (1) | EP4623147A1 (en) |
| KR (1) | KR20250120293A (en) |
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| WO2011113119A1 (en) * | 2010-03-19 | 2011-09-22 | Fibria Celulose S/A | Process for the treatment of cellulose pulps, cellulose pulp thus obtained and use of biopolymer for treating cellulose pulps |
| FI20116163L (en) * | 2011-11-23 | 2013-05-24 | Upm Kymmene Corp | Method and system for making cellulosic material |
| FI125714B (en) * | 2012-11-12 | 2016-01-15 | Kemira Oyj | Process for the treatment of fiber pulp for the manufacture of paper, cardboard or the like and product |
| FI127284B (en) * | 2015-12-15 | 2018-03-15 | Kemira Oyj | Process for making paper, cardboard or equivalent |
| US10954633B2 (en) * | 2016-09-30 | 2021-03-23 | Kemira Oyj | Process for making paper, paperboard or the like |
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- 2023-12-14 EP EP23904554.5A patent/EP4623147A1/en active Pending
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