Use of amphoteric emulsion polymers with strength resins as retention and drainage aids

Abstract

The present invention generally relates to methods and compositions for making tissue, paper or paperboard and for enhancing their retention and draining. Specifically, the present disclosure provides methods for enhancing retention and draining by adding a retention aid comprising a reactive cationic polymer (e.g., a cationic strength resin), a water soluble amphoteric terpolymer, and optionally anionic organic or inorganic microparticles. Preparation of paper under these conditions provides improved retention, drain time, STFI, and rupture strength, as well as improved hydrophobic particle control.

Description

Related applications

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 510,759, filed June 28, 2023, and Finnish Application No. 20236130, filed October 12, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This invention generally relates to methods and compositions for preparing facial tissues, paper, or paperboard, and for enhancing their retention and drainability. Specifically, this disclosure provides methods for enhancing retention and drainability by adding retention-enhancing and filter-enhancing agents comprising reactive cationic polymers (e.g., cationic strength resins), water-soluble amphoteric terpolymers, and optionally anionic organic or inorganic microparticles. Paper preparation under these conditions provides improved retention, drain time, STFI, and burst strength, as well as improved hydrophobic particle control. Background Technology

[0003] Glyoxylated polyacrylamide (GPAM) is commonly used in various types of paper to enhance dry strength and temporary wet strength. For example, it can be used to improve the initial wet strength of many household toilet papers that come into contact with water during use. Glyoxylated polyacrylamide is also used to improve the compressive strength and dimensional stability of many paperboard products.

[0004] In the production of paper or paperboard, a diluted aqueous composition, referred to as "pulp" or "raw material," is sprayed onto a moving wire called "wire" or "wire screen." The solid components of this composition (such as cellulose fibers, fine powders, and inorganic particulate mineral fillers) are drained or filtered by the wire to form paper. The percentage of solid material retained on the wire is called the "first pass retention" in the papermaking process.

[0005] Paper and paperboard manufacturers require chemical additives that effectively provide enhanced on-machine retention and drainability, while also offering additional benefits such as improved paper strength and wet pressing properties. These requirements are particularly challenging for papermaking operations in mills with high recycling rates.

[0006] Retention rates vary depending on the mechanism (e.g., filtration via mechanical entrainment, electrostatic attraction, and bridging between fibers and fillers in the slurry). Because both cellulose fibers and many common filler materials carry a negative charge, they repel each other. Typically, the only factor that helps improve retention is mechanical entrainment. Therefore, retention aids are commonly used to improve the retention of fibers and fillers on the wire.

[0007] Draining is related to the rate at which water is removed from the pulp during paper formation. Draining generally refers to the removal of water primarily occurring in the "draining zone" (gravity and vacuum section) of the paper machine after the paper web has formed and before any pressing is performed on the wet paper web. Therefore, filter aids are used to improve the overall dewatering efficiency in the production of paper or paperboard.

[0008] For several reasons, there is a particular need to improve the retention and drainability of the final paper or paperboard sheet, with productivity being the most important. Good retention and good drainability allow paper machines to run faster and increase output.

[0009] These improvements are achieved through the use of retention and filter aids. These retention and filter aids are typically added to the pulp near the headbox of the paper machine and may include a coagulant / flocculator system used in conjunction with one or more shear stages.

[0010] Accelerators are typically low-molecular-weight cationic synthetic polymers that reduce the negative surface charge on fiber, fine powder, and / or filler particles to facilitate their aggregation. Flocculants are typically high-molecular-weight cationic, nonionic, or anionic synthetic polymers that bridge particles and / or agglomerates from one surface to another, thereby binding the particles into larger flocs. Larger flocs improve particle retention; however, when they are filtered from water onto the fiber web, the pores of the flocs are covered, thereby reducing the draining efficiency of the fiber web. Larger flocs can be broken down by shearing, which is provided by one or more stages of the papermaking process, including the cleaning, mixing, and pumping stages.

[0011] Greater retention of fines and fillers allows for a reduction in cellulose fiber content. Retention in papermaking becomes even more critical as inferior pulps are used to reduce paper production costs. This is due to the higher levels of fines found in lower-quality pulps, such as recycled fibers and coated waste paper. Greater retention of fines, fillers, and other pulp components also reduces the amount of these substances lost to white water. This reduces material waste, waste disposal costs, and the resulting adverse environmental impact.

[0012] There is a need in the art for an improved coagulant / flocculator system that replaces existing cationic coagulant / high molecular weight anionic flocculant systems, thereby significantly improving the retention and drip properties of paper pulps, as well as the physical properties of the resulting paper products, such as shape and brightness. This is particularly true for paper pulps containing recycled deinked fibers, groundwood, bleached fiber linerboard and / or coated waste paper, as well as treated or untreated fillers, higher levels of viscous substances, calcium ions, and conductivity.

[0013] Recycled fiber materials are commonly used as raw materials for paper or paperboard. Besides fibers, recycled fiber materials contain many other substances. Particulate matter is separated from the pulp in the pulper or during screening. Some substances remain naturally on the fibers and do not interfere with the process. Other substances, such as sticky substances, can be separated from the pulp during screening and are at least partially removed from the process.

[0014] The use of recycled fiber materials as raw materials is a major source of hydrophobic substances (so-called sticky substances) in paper and paperboard manufacturing. Although some, or even most, of these hydrophobic substances are removed during pulping of the recycled fiber raw materials, a significant amount remains during the paper and paperboard manufacturing process. Hydrophobic substances not removed during deinking or other recycled fiber processing stages (e.g., not captured by screens) enter the paper or paperboard machine and circulate in the process water. Due to increased environmental awareness and regulations, papermaking processes are becoming increasingly closed, and less freshwater is being used. This leads to a significant accumulation of interfering substances, including hydrophobic substances, in fiber suspensions and process water. These substances can agglomerate into larger hydrophobic particles, which can form deposits. Additionally, the accumulation of dissolved salts makes conventional CPAM less effective. Conventional CPAM does not react effectively with dissolved salts because its molecular size is too large and the polymer's cationic charge is too low.

[0015] Besides recycled fiber materials, the recycling of coated waste paper can also cause similar problems to those described above for recycled fiber materials. If left uncontrolled, the deposition of coated waste paper contaminants in the papermaking system can cause serious operational problems. In most coated advanced paper mills, coated waste paper is repulped and used as a pulping source. The most difficult problems involving recycled coated waste paper stem from binder materials, sometimes in combination with pigments or fillers, as these polymers and the materials they adhere to are sources of sticky deposits. These sticky deposits cause difficulties when recycling back to the paper machine. The deposits that form can cause web breakage, so as a precaution, the most affected surfaces (such as dryers, calenders, wire, and felt) are regularly washed and cleaned, which can lead to downtime and production losses.

[0016] Significant efforts have been devoted to developing improved retention and filter aids. PCT / US99 / 29135 discloses a polyampholyte coagulant used as a retention aid / filter aid / forming aid in papermaking processes. However, commercially available retention and filter aids remain insufficient for the preparation of paper and paperboard with a high percentage of recycled fiber content.

[0017] Added high molecular weight polymer additives and retention aids tend to retain water during the initial pass in the press section, which significantly increases draining time and reduces the wet pressing properties of the fiber web. Retention and filter aids that allow for more efficient dewatering in the press section and faster drying of the paper web in the drying section will save paper manufacturers significant amounts of steam and increase productivity.

[0018] Based on the foregoing, there is a need for improved polymer additives for preparing paper, facial tissues, paper towels, and / or paperboard from recycled materials. These improved polymer additives provide retention and drainability enhancement while also controlling hydrophobic particles and agglomerates (“sticky substances”) in the pulp. Therefore, the object of this invention is to provide methods and compositions (i.e., retention aids and filter aids) for enhancing retention and drainability, providing improved retention, drain time, paper strength, and improved control of hydrophobic particles. Summary of the Invention

[0019] This invention generally relates to methods and compositions for preparing facial tissues, paper, or paperboard, and for enhancing their retention and drainability. Specifically, this disclosure provides methods for enhancing retention and drainability by adding retention-enhancing and filter-enhancing agents comprising reactive cationic polymers (e.g., cationic strength resins), water-soluble amphoteric terpolymers, and optionally anionic organic or inorganic microparticles. Paper preparation under these conditions provides improved retention, drain time, STFI, and burst strength, as well as improved hydrophobic particle control.

[0020] On one hand, the present invention provides a method for preparing facial tissues, paper, or paperboard, the method comprising: (a) Forming or providing an aqueous suspension containing cellulose fibers; (b) Optionally dilute the aqueous suspension; (c) Floccating the aqueous suspension to form a flocculated fiber suspension; (d) Removing sufficient water from the flocculated fiber suspension to form a wet fiber web, preferably by introducing the flocculated fiber suspension into a headbox and draining the flocculated fiber suspension on a wire mesh screen; and (e) Pressing and drying the wet fiber web to obtain facial tissues, paper, or paperboard; The method further comprises treating the aqueous suspension containing cellulose fibers with a retention aid prior to step (c), the retention aid comprising: (i) one or more reactive cationic polymers; and (ii) One or more water-soluble amphoteric polymers.

[0021] In some exemplary embodiments of the method, the retention aid may optionally further comprise one or more anionic organic or inorganic microparticles.

[0022] In some exemplary embodiments of the method, (i) the one or more reactive cationic polymers, (ii) the one or more water-soluble amphoteric polymers, and optionally (iii) the one or more anionic organic or inorganic microparticles: (a) Add in any order, simultaneously, or premix before addition; or (b) Added in the order of (i), (ii) and then optionally (iii), wherein a mixing time is allowed after each addition, and the mixing time ranges from 0.01 to 10 minutes, 0.1 to 5 minutes or 1 to 2 minutes.

[0023] In some exemplary embodiments of the method, the one or more reactive cationic polymers comprise: (a) a functional group that is reactive to the surface of cellulose or lignocellulose fibers; and (b) The range of cation charge density as a dry solid at pH 7 is less than 5.0 mEq / g, 0.5–5.0 mEq / g, 1.0–4.0 mEq / g, or 1.5–2.5 mEq / g; Furthermore, the one or more reactive cationic polymers further comprise one of the following: (c) One or more cationic glyoxylated polyacrylamides (GPAM); (d) One or more cationic polyamide amine-epimercohydrin (PAE) resins; or (e) A combination of one or more cationic GPAM and one or more cationic PAE resins, the combination having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40 or 45:55, wherein the one or more cationic PAE resins and the one or more cationic GPAM are added sequentially, simultaneously or premixed before being added to the aqueous suspension containing cellulose fibers in any order.

[0024] In some exemplary embodiments of the method, the one or more cationic GPAMs: (a) Suitable for use as a dry and / or wet reinforcing agent; (b) Synthesized by reacting glyoxal with a base polymer, wherein the base polymer has a weight-average molecular weight in the range of 5-5000 kDa, 50-2500 kDa, 80-2000 kDa, or 100-1000 kDa, and comprises a nonionic monomer, a cationic monomer, and optionally an anionic monomer, wherein (i) The nonionic monomer is selected from the group consisting of monomers containing primary amides, including acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methacrylamide, N-butylacrylamide, N-ethylmethacrylamide, and any combination thereof; (ii) The cationic monomer is selected from acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate dimethyl Aminoethyl methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, methacrylamide dimethylaminoethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyl dialkylammonium halides, including but not limited to diallyl diethylammonium chloride and diallyl dimethylammonium chloride (“DADMAC”), and any combination thereof; and (iii) The optional anionic monomer contains a functional group selected from the following: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid and vinylphosphonic acid, their corresponding alkali metals, alkaline earth metals and ammonium salts, and any combination thereof; (c) Contains a glyoxal:base polymer weight ratio ranging from 0.1:99.9 to 50:50, 5:95 to 20:80, or 5:95 to 10:90; (d) The cation charge density contained as a dry solid at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g; (e) Includes a range of 3-60% by weight of cationic monomer content and a range of 0-50% by weight of anionic monomer content, wherein the remainder of the monomer content includes nonionic monomers; (f) Optionally formulated as a dry powder or as an aqueous composition, said aqueous composition comprising a percentage of GPAM solids ranging from about 0.5% to about 20%, optionally greater than about 2% to about 10%, and further optionally greater than about 4% to about 8%.

[0025] In some exemplary embodiments of the method, the one or more cationic PAE resins: (a) Suitable for use as a wet reinforcing agent; (b) is synthesized by reacting one or more polyamide amine backbones with epichlorohydrin, wherein the one or more polyamide amine backbones are synthesized by reacting a carboxylic acid and / or a carboxylic acid derivative with an amine, wherein the one or more polyamide amine backbones comprise a molar ratio of the amine to the carboxylic acid and / or the carboxylic acid derivative in the range of 1:1 to 2:1, 1.05:1 to 2:1 or 1.5:1 to 2:1; (c) The molar ratio of epichlorohydrin to the secondary amine group of the polyamidoamine backbone, ranging from about 0.15 to about 1.7.

[0026] In some exemplary embodiments of the method, the one or more water-soluble amphoteric polymers: (a) comprising an acrylamide (AM) monomer, one or more anionic monomers, and one or more cationic monomers, wherein, (i) The one or more anionic monomers contain functional groups selected from the group consisting of: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid, and vinylphosphonic acid, their corresponding alkali metals, alkaline earth metals, and ammonium salts, and any combination thereof; and (ii) The one or more cationic monomers are selected from the group consisting of: acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt Dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, and dimethylaminoethyl methacryloyl hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate; and diallyl dialkyl ammonium halides, including but not limited to diallyl diethyl ammonium chloride and diallyl dimethyl ammonium chloride (“DADMAC”), and any combination thereof; (b) Contains an inverted emulsion, a dry polymer, or an aqueous solution of a polymer, preferably an inverted emulsion; (c) Polymer standard viscosity (SV) including ranges of <3.5 cPs, 1-3.5 cPs, 2-3.5 cPs or 2.5-3.5 cPs; (d) Includes molecular weights ranging from 1.5 million to 9 million Daltons, 1.5 million to 8 million Daltons, 2 million to 8 million Daltons, 4 million to 8 million Daltons, or preferably 2 million to 5 million Daltons; (e) Contains acrylamide (AM) monomer content ranging from 77-100 wt%, 78-100 wt%, 80-100 wt%, 90-100 wt%, or 95-100 wt%; (f) Includes anionic monomer content in the range of ≤ 3wt%, ≤ 2wt%, 0.01-3wt%, 0.5-2wt%, 1-2wt%, 1.5-2wt%, or 1.8-2wt%; (g) Contains cationic monomers in the range of ≤ 20wt%, 1-20wt%, 2-16wt%, 4-12wt%, or 7-9wt%; or (h) Any combination of the foregoing terms.

[0027] In some exemplary embodiments of the method, the one or more anionic organic or inorganic microparticles are selected from the group consisting of microparticles and nanoparticles comprising: silica microparticles; colloidal silica; layered aluminosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamide.

[0028] In some exemplary implementations of the method: (a) The one or more reactive cationic polymers comprise the one or more cationic GPAMs and / or the one or more cationic PAE resins in an aqueous form; (b) The one or more cationic GPAMs comprise the base polymer, which comprises a cationic monomer selected from DADMAC, AETAC, and combinations thereof; a nonionic monomer selected from acrylamide, methacrylamide, and combinations thereof; and optionally an anionic monomer selected from acrylic acid and / or the corresponding water-soluble salt, water-dispersible alkali metal salt, alkaline earth metal salt, ammonium salt, and combinations thereof, or the base polymer comprises (i) acrylamide and DADMAC, (ii) acrylamide and AETAC, or (iii) acrylamide, DADMAC, and AETAC. (c) one or more water-soluble amphoteric polymers (i) A reverse emulsion comprising monomers of acrylamide (AM), acrylic acid (AA) and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9); (ii) Preferably, it contains no more than 2 wt% acrylic acid (AA) monomer; and (iii) Preferably, it includes an AM:AA:Q9 ratio ranging from 89:2:9 to 91:2:7; and (d) The one or more anionic organic or inorganic particles comprise colloidal silica.

[0029] In some exemplary embodiments of the method, when added to the aqueous suspension containing cellulose fibers: (a) The one or more reactive cationic polymers are added at a dose ranging from 0.1-15 g / kg, 0.5-5 g / kg or 0.5-4 g / kg; (b) The one or more water-soluble amphoteric polymers are added at a dosage ranging from 0.05-5 g / kg, 0.1-4 g / kg or 0.3-1 g / kg; (c) The one or more anionic organic or inorganic microparticles are added at a dose ranging from 0.1-1 g / kg, 0.2-0.8 g / kg or 0.4-0.6 g / kg.

[0030] In some exemplary embodiments of the method, the aqueous suspension containing cellulose fibers has a pH in the range of 4-8, 4-7.5, 4-7, 4.5-7, or 5-7, and further comprises: (a) Cellulose fibers, wherein the cellulose fibers are optionally obtained from sources selected from the following: softwood fibers, hardwood fibers, recycled fibers, recycled old corrugated cardboard (OCC), recycled mixed office waste (MOW), recycled mixed office paper, refined fibers, factory waste paper fibers, coated waste paper, non-wood fibers including but not limited to straw pulp, and mixtures of any of the foregoing. (b) Pulp, wherein the pulp is selected from the following: kraft pulp, unbleached kraft pulp, bleached pulp, unbleached pulp, process water from pulp, paper and / or paperboard production, neutral sulfite semi-chemical (NSSC) pulp, mechanical pulp, non-wood pulp, and mixtures of any of the foregoing; or (c) Raw materials, said raw materials being selected from concentrated slurry, concentrated slurry diluted with chemical water, synthetic water, white water and / or process water, thin slurry, and mixtures of any of the foregoing.

[0031] In some exemplary embodiments of the method, when used to prepare facial tissues, paper, or paperboard, the method results in the following differences compared to facial tissues, paper, or paperboard prepared by the same method without (i) the addition of the one or more reactive cationic polymers or (ii) the addition of the one or more water-soluble amphoteric polymers: (a) Improved retention of the cellulose fibers; (b) Improvement of the draining of the flocculated fiber suspension; (c) STFI and / or improved fracture strength; (d) Decreased count of hydrophobic particles and / or hydrophobic aggregates; (e) Improvement in dry tensile, immediate wet tensile, and / or soaking wet tensile strength; or Any combination of (f)(a)-(e).

[0032] On the other hand, the present invention provides a method for preparing facial tissues, paper, or paperboard, the method comprising: (a) Forming or providing an aqueous suspension containing cellulose fibers; (b) Optionally dilute the aqueous suspension; (c) Floccating the aqueous suspension to form a flocculated fiber suspension; (d) Removing sufficient water from the flocculated fiber suspension to form a wet fiber web, preferably by introducing the flocculated fiber suspension into a headbox and draining the flocculated fiber suspension on a wire mesh screen; and (e) Pressing and drying the wet fiber web to obtain facial tissues, paper, or paperboard; The method further comprises treating the aqueous suspension containing cellulose fibers with a retention aid prior to step (c), the retention aid comprising: (i) One or more reactive cationic polymers comprising functional groups reactive to the surface of cellulose or lignocellulose fibers, and having a cationic charge density as dry solids at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g, wherein the one or more reactive cationic polymers comprise one or more cationic glyoxylated polyacrylamide (GPAM); one or more cationic polyamide amine-epimercohydrin (PAE) resins; or a combination of one or more cationic GPAM and one or more cationic PAE resins having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40, or 45:55, wherein the one or more cationic PAE resins and the one or more cationic GPAM are added sequentially, simultaneously, or premixed before being added to the aqueous suspension containing cellulose fibers in any order; (ii) One or more water-soluble amphoteric polymers comprising a reverse emulsion of acrylamide (AM), acrylic acid (AA), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9) monomers; preferably comprising an acrylic acid (AA) monomer content of not more than 2 wt%; and preferably comprising an AM:AA:Q9 ratio in the range of 89:2:9 to 91:2:7; and (iii) Optionally comprising one or more anionic organic or inorganic particles containing silica.

[0033] On the other hand, the present invention provides a fiber raw material composition comprising: (a) An aqueous suspension containing cellulose fibers; and (b) A retention aid and filtration aid, wherein the retention aid and filtration aid comprises (i) One or more reactive cationic polymers; (ii) one or more water-soluble amphoteric polymers; and (iii) Optionally one or more anionic organic or inorganic particles; The fiber raw material composition can be obtained by the method according to any one of the preceding claims.

[0034] On the other hand, the present invention provides a composition for use as a retention aid and filter aid in the preparation of facial tissues, paper, or paperboard, the composition comprising: (a) One or more reactive cationic polymers, wherein the reactive cationic polymers contain a cationic charge density as a dry solid at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g, wherein the reactive cationic polymers contain (i) one or more cationic acetaldehyde-treated polyacrylamides (GPAMs), said one or more GPAMs being synthesized by reacting glyoxal with a base polymer, said base polymer having a weight-average molecular weight in the range of 5-5000 kDa, 50-2500 kDa, 80-2000 kDa or 100-1000 kDa; (i) acrylamide and DADMAC, (ii) acrylamide and AETAC, or (iii) acrylamide, DADMAC and AETAC, and further wherein said one or more GPAMs have a glyoxal:base polymer weight ratio in the range of 0.1:99.9 to 50:50, 5:95 to 20:80 or 5:95 to 10:90; and a cationic charge density as dry solids in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g or 1.5-2.5 mEq / g at pH 7; (ii) One or more cationic polyamide amine-epimercohydrin (PAE) resins; or (iii) A combination of one or more cationic GPAM and one or more cationic PAE resins, the combination having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40 or 45:55; (b) One or more water-soluble amphoteric polymers, said one or more water-soluble amphoteric polymers comprising acrylamide (AM), acrylic acid (AA), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9) monomers; wherein said one or more water-soluble amphoteric emulsion polymers preferably comprise an acrylic acid (AA) monomer content of not more than 2 wt% and an AM:AA:Q9 ratio ranging from 89:2:9 to 91:2:7, wherein said one or more water-soluble amphoteric polymers are inverse emulsions, dry polymers, aqueous solutions, preferably inverse emulsions; and (c) Optionally one or more anionic organic or inorganic microparticles, said one or more anionic organic or inorganic microparticles being selected from the group consisting of microparticles and nanoparticles of the following: silica microparticles; colloidal silica; layered aluminosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamide. Attached Figure Description

[0035] The present invention will now be described in more detail with reference to the accompanying drawings. Detailed Implementation

[0036] Before describing the present invention, the following definitions are provided. Unless otherwise stated, all terms should be interpreted in accordance with the understanding of those skilled in the art.

[0037] Figure 1 An exemplary variation diagram is provided, showing the DDA draining time (in seconds) of recycled paper towels prepared from 100% OCC pulp treated with PAE and amphoteric emulsion polymers, with or without silica, according to Example 1.

[0038] Figure 2 An exemplary variation diagram is provided, showing the filtrate turbidity (NTU) of recycled paper towels prepared from 100% OCC pulp treated with PAE and amphoteric emulsion polymers, with or without silica, according to Example 1.

[0039] Figure 3 An exemplary variation diagram is provided, showing the DDA draining time (in seconds) of recycled paper towels prepared from 100% OCC pulp treated with GPAM and amphoteric emulsion polymers, with or without silica, according to Example 1.

[0040] Figure 4 An exemplary variation diagram is provided, showing the filtrate turbidity (NTU) of recycled paper towels prepared from 100% OCC pulp treated with GPAM and amphoteric emulsion polymers, with or without silica, according to Example 1.

[0041] Figure 5 An exemplary graph is provided showing the DDA draining time (seconds) relative to the polymer dosage for packaged slurries with a conductivity of 3.84 mS / cm treated with reference cationic polyacrylamide (CPAM, solid line) + GPAM and amphoteric emulsion polyacrylamide (amPAM, dashed line) + GPAM according to Example 3.

[0042] Figure 6 An exemplary graph is provided showing the DDA draining time (seconds) relative to the polymer dosage for packaged slurries with a conductivity of 5.09 mS / cm treated with reference cationic polyacrylamide (CPAM, solid line) + GPAM and amphoteric emulsion polyacrylamide (amPAM, dashed line) + GPAM according to Example 3.

[0043] Figure 7An exemplary bar graph is provided showing the filtrate turbidity (NTU) of reference cationic polyacrylamide (CPAM) and amphoteric emulsion polyacrylamide (amPAM) for packaging padding sheets at three conductivity levels, according to Example 3, as a function of polymer dosage.

[0044] Figure 8 An exemplary graph is provided showing the strength (GM STFI) of a packaging liner sheet prepared according to Example 4 using amphoteric emulsion polyacrylamide or dry amphoteric polyacrylamide relative to the GPAM dosage.

[0045] Figure 9 An exemplary bar graph is provided showing the strength properties (STFI and bursting strength) of the handmade paper prepared according to Example 5.

[0046] Figure 10 An exemplary variation diagram is provided, showing the DDA draining time (seconds) of a tissue prepared from 100% recycled blend office paper according to Example 6.

[0047] Figure 11 An exemplary variation diagram is provided, showing the filtrate turbidity (NTU) of a tissue prepared from 100% recycled blended office paper according to Example 6.

[0048] definition As used herein, the singular forms “a”, “and”, and “the” include the plural reference unless the context clearly specifies otherwise.

[0049] As used herein, unless the context clearly indicates otherwise, 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 otherwise expressly stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0050] As used herein, the term “or” in the claims is used to mean “and / or” unless it is explicitly stated that it refers only to alternatives or that alternatives are mutually exclusive, but this disclosure supports the definition of “and / or” as referring only to alternatives.

[0051] As used herein, unless otherwise stated, the term "or combinations thereof" as used herein refers to all permutations and combinations of the items listed preceding the term.

[0052] papermaking As used herein, the term "paper" includes articles comprising cellulose sheet materials, including paper, paperboard, etc.

[0053] As used herein, the terms “papermaking process” and “papermaking application” generally refer to any process capable of producing paper and / or paperboard articles of any form. Such processes include, for example, the manufacture of paper articles from pulp, including methods comprising forming an aqueous cellulose papermaking pulp, draining the pulp to form paper, and drying the paper. The steps of forming the papermaking pulp, draining, and drying can be performed in any conventional manner known in the art.

[0054] As used herein, the term "wet end of the paper machine" or "wet end" generally refers to the portion of the papermaking process between pulping (or bleaching) and wet pressing.

[0055] As used in this article, the term "fiber" refers to the basic structural unit of paper or paperboard.

[0056] As used herein, the terms “recycled fiber” and “reclaimed fiber” refer to paper, paperboard, and fiber waste from retail stores, office buildings, residences, manufacturing plants, etc., after they have been used as consumer products. Manufacturing waste includes: dry paper and paperboard waste generated after the completion of papermaking processes, such as envelope scraps, binding scraps, and other paper and paperboard waste generated from printing, cutting, forming, and other processing operations; bag, box, and carton manufacturing waste; factory packaging paper and unused raw materials; and finished paper and paperboard repulped from obsolete stockpiles of paper and paperboard manufacturers, merchants, wholesalers, distributors, printers, processors, or other parties. Specifically, the term “recycled fiber” includes recycled fibers obtained through processing paper and other consumer cellulosic materials, such as paper, old corrugated cardboard (OCC), mixed office waste (MOW), old magazines (OMG), unbleached kraft pulp, neutral sulfite semi-chemical (NCCS) pulp, and / or mechanical pulp. Raw materials for recycled fibers can be selected from used corrugated cardboard, mixed office waste, used newsprint, used magazines, double-lined kraft paper, and any mixture thereof. Mixed waste (MXW) refers to a recycled mixture of recycled cardboard (such as OCC, white cardboard, and / or folding linerboard) and recycled paper (such as used newsprint, used magazines, and / or office waste). Mixed office waste refers to recycled fiber materials primarily consisting of copy paper, printer paper, and offset paper. Double-lined kraft paper refers to recycled fiber materials containing clean, sorted, unprinted corrugated cardboard boxes, cartons, paper, or scraps (e.g., kraft paper or jute lining). White cardboard (WLC) refers to multi-layer cardboard containing deinked fiber materials and / or undeinked recycled fiber materials in one or more layers, derived from, for example, OCC, mixed office waste, or used newspapers (ONP). The presence of any of these recycled fiber materials in the fiber suspension typically reduces the strength of the drained paper and provides significant amounts of starch, hydrophobic, and colloidal substances to the process.

[0057] As used herein, the term "OCC" refers to recycled corrugated cardboard and / or boxboard. Corrugated boxes are those made of three separate layers of paper, two layers of linerboard, and a corrugated or wave-shaped layer sandwiched between them. Brown paper bags are typically accepted for OCC for recycling. The term OCC indicates recycled fiber material with linerboards such as test linerboard, jute, or kraft paper, and may also include double-sorted corrugated boxboard (DS OCC).

[0058] As used herein, the term "waste paper" or "factory waste paper" refers to paper that becomes only suitable for repulping during the papermaking process, such as scraps or non-standard paper. Waste paper is reused material that never leaves the factory and is not considered for recycling or recovery. Waste paper is a valuable source of fiber that can be recycled within the factory.

[0059] As used herein, the term "coated waste paper" refers to waste paper containing coatings applied to the base paper during the papermaking process. When waste paper contains these coatings, particular problems arise in recycling to restore fiber value because these coatings introduce materials that are not typically present in the original fiber raw material used to manufacture the base paper. Coated waste paper may also contain dyes and / or other additives. In this application, coated waste paper includes surface-sized, dyed, and / or creased waste paper.

[0060] As used herein, the term “recycled fiber composition” generally refers to a composition comprising recycled cellulose fibers, typically a composition in which most or all of the fibers are recycled fibers, for example at least 20%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%.

[0061] As used herein, the term "fiber suspension" should be understood as an aqueous suspension comprising fibers (preferably recycled fibers) and optionally fillers. For example, a fiber suspension may contain at least 5%, preferably 10%-30%, more preferably 11%-19% mineral fillers. The mineral fillers may be any fillers conventionally used in paper and paperboard manufacturing, such as milled calcium carbonate, precipitated calcium carbonate, clay, talc, gypsum, titanium dioxide, synthetic silicates, aluminum trihydrate, barium sulfate, magnesium oxide, or any mixture thereof.

[0062] As used herein, the term "headbox" refers to a container in a paper machine that holds suspended aqueous cellulose solids and regulates their flow on wires or screens to drain them.

[0063] As used herein, the term "lignocellulose matrix" refers to paper and / or paperboard articles formed from plant dry matter (virgin or recycled) of any origin, which can be coated, printed, and / or formed into packaging articles. For example, such matrices include paper articles made from pulp, such as by methods comprising forming an aqueous cellulose pulping compound, draining the pulping compound to form sheets, and drying the sheets. The steps of forming the pulping compound, draining, and drying can be performed in any conventional manner known in the art. The matrix may contain polymeric reinforcing agents, such as wet strength agents and dry strength agents.

[0064] As used herein, the term "pulp" generally refers to a mixture of water, dissolved pulp, and optional other soluble or insoluble components that are produced or added during the raw material preparation stage of papermaking.

[0065] As used herein, the term “pulp formulation” or “paper pulp formulation” generally refers to a mixture of cellulose fibers, pulp, optional fillers, dyes and water used to make paper or paperboard.

[0066] As used herein, the term "thick pulp" generally refers to a mixture of paper pulp and other materials with a consistency of about 1% to 5%.

[0067] As used herein, the term "slurry" generally refers to a mixture of paper pulp and other materials in a sector pump after it has been diluted with white water or other process water to a consistency of less than 1%.

[0068] As used in this article, the term "white water" generally refers to the process water within a papermaking machine system, particularly the water that is drained from the paper during the papermaking process.

[0069] As used herein, the term “fixed” means that a substance is at least temporarily or permanently bound or attached to a fiber.

[0070] As used herein, the term “flocculation” generally refers to the tendency of fibers to aggregate into bundles in the presence of retention aids, especially when in motion; the term also refers to the behavior of high-quality polymers forming bridges between suspended colloidal particles, resulting in strong, relatively irreversible aggregation.

[0071] The term "flocculator" generally refers to an agent that can bridge, neutralize, or promote the agglomeration of particles into larger aggregates, typically resulting in more efficient sedimentation. Flocculation processes typically involve adding a flocculant and then mixing it to promote collisions between particles, causing unstable particles to aggregate into larger particles, which can then be removed by gravity settling or by other means such as centrifugation or filtration.

[0072] As used herein, the term "dry strength" generally refers to the force or energy required to break a paper sample through one of a variety of procedures after it has been balanced in standard atmosphere.

[0073] As used herein, the term “wet strength” generally refers to the strength of paper after exposure to a standard solution for a standard length of time, but is usually expressed as a ratio to dry strength.

[0074] Polymer molecular weight can be measured using various methods known to those skilled in the art. For example, weight-average molecular weight can be measured using gel permeation chromatography (GPC). Alternatively, polymer molecular weight can be measured using a GPC / light scattering / viscosity assay (also known as triple-detection GPC), which employs a refractive index detector (with or without a UV detector), dilute solution viscosity assay, and light scattering in series to determine molecular weight, distribution, and related solution parameters.

[0075] Retention aids and filter aids As used herein, the terms “polymer” or “polymer additive” and similar terms are used in their ordinary meaning as understood by those skilled in the art, and are therefore used herein to refer to or describe macromolecules (or groups of such molecules) that may contain repeating units. Polymers can be formed in a variety of ways, including by polymerizing monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise stated, polymers may comprise “homopolymers” that may contain substantially the same repeating units, which can be formed, for example, by polymerizing a particular monomer. Unless otherwise stated, polymers may also comprise “copolymers” that may contain two or more different repeating units, which can be formed, for example, by copolymerizing two or more different monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise stated, polymers or copolymers may also comprise “terpolymers” or “quaternary copolymers,” which generally refer to polymers containing three, four, or more different repeating monomer units. As used herein, the term “polymer” is intended to include both the acidic form of the polymer and its various salts. Polymers can be inherently amphoteric, that is, containing both anionic and cationic substituents, but not necessarily in equal proportions.

[0076] As used herein, the term "polyacrylamide" or "PAM" generally refers to polymers and copolymers containing an acrylamide moiety, and the term covers any polymer or copolymer (including terpolymers) containing an acrylamide moiety, such as one or more acrylamide polymers (copolymers) and additional monomers capable of copolymerizing with acrylamide. Furthermore, PAM may comprise any of the polymers or copolymers discussed herein. Additionally, the PAM described herein, such as one or more acrylamide polymers (copolymers), can be produced in a variety of forms, including, for example, dry (powder) forms (e.g., DPAM), emulsion polyacrylamide (EPAM), or liquid polyacrylamide. Amphoteric polyacrylamide (AmPAM) can be formulated in dry (powder) forms (e.g., AmDPAM) or emulsion forms (AmEPAM).

[0077] As used herein, the term "ampholy polymer" refers to a polymer containing both anionic and cationic groups on its macromolecular chain. These polymers exhibit both attractive and repulsive forces in their electrostatic intermolecular interactions (resulting in anti-polyelectrolyte association known as the "ampholy effect"), and they exhibit excellent salt resistance, especially in high-Ca+2 aqueous compositions.

[0078] As used herein, the term "emulsion polymer" generally refers to a reverse emulsion (water-in-oil), in which water droplets containing the polymer are suspended in an oil phase (also known as a hydrophobic phase).

[0079] As used herein, the term "inverse emulsion" refers to a liquid polymer composition in which a polymer dissolved in an aqueous solution is dispersed in an oil phase (e.g., a hydrophobic liquid) to form an oil continuous phase, and then the oil continuous phase is mixed with the aqueous solution such 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 conversion point can be characterized as the point at which the viscosity of the polymer solution substantially reaches its maximum value under a given set of conditions. In practice, this can be determined, for example, by periodically measuring the viscosity of the composition over time, and the solution is considered to have been converted when three consecutive measurements are within a criterion of measurement error.

[0080] 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 may be a completely dissolved or partially dissolved suspension, dispersion, or slurry. A "waterborne 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. The polymer does not immediately dissolve in the aqueous or non-aqueous solvent. Dissolution is controlled by the unwinding of the polymer chains or by diffusion of the chains through the boundary layer near the polymer-solvent interface. Upon thorough mixing, the polymer may become fully hydrated, at which point the wetting process is complete and the polymer may partially or completely dissolve, depending on the nature and composition of the polymer and solvent.

[0081] The term "water-soluble polymer" generally refers to any polymer that can be dissolved and / or dispersed in water. The polymer can alter the physical properties of aqueous systems undergoing gelation, thickening, viscousening, or emulsification / stabilization. The polymer can perform a variety of functions, including but not limited to use as a dispersant and suspending agent, stabilizer, thickener, viscous agent, gelling agent, flocculant and coagulant accelerator, film-forming agent, humectant, adhesive, and lubricant.

[0082] As used herein, the term "monomer" generally refers to nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, betaine monomers, and zwitterionic-pair monomers.

[0083] As used here, "Q9 monomer" refers to 2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9), which has the molecular formula C8H16ClNO2 and a molecular weight of 193.67 g / mol.

[0084] As used herein, acrylamide or "AM" refers to a neutral monomer with the molecular formula C3H5NO and a molecular weight of 71.08 g / mol.

[0085] As used herein, acrylic acid or "AA" refers to an anionic monomer with the molecular formula CH2CHCOOH and a molecular weight of 72.06 g / mol.

[0086] As used herein, the term "cationic monomer" generally refers to a monomer that has a positive charge. Examples of this include the monomer acryloyloxyethyltrimethylammonium chloride (Q9). The cationic monomer may also be selected from acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate dimethylaminoacrylate Dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, dimethylaminoethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropyl acrylamide, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfate, dimethylaminopropyl acrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfate, dimethylaminopropyl methacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyl dialkyl ammonium halides, including but not limited to diallyl diethyl ammonium chloride and diallyl dimethyl ammonium chloride (“DADMAC”), and any combination thereof.

[0087] As used herein, the term "nonionic monomer" generally refers to a monomer having a neutral charge. Exemplary nonionic monomers may comprise, but are not limited to, monomers comprising the group consisting of: acrylamide ("AMD"), methacrylamide, vinyl, allyl, ethyl, etc., all of which may be substituted with side chains selected from, for example, alkyl, aralkyl, dialkyl, ethoxy, and / or hydrophobic groups. In one exemplary embodiment, the nonionic monomer may comprise AMD. In some embodiments, the nonionic monomer may comprise, but is not limited to, vinylamides (e.g., acrylamide, methacrylamide, N-methacrylamide, N,N-dimethylacrylamide), 4-acryloylmorpholine, maleic anhydride, N-vinylpyrrolidone, vinyl acetate, N-vinylformamide, and their derivatives, such as hydroxyethyl(meth(acrylate)CH2=CR-COO-CH2CH2OH (I) and CH2=CR-CO-N(Z1)(Z2) (2) N-substituted (meth)acrylamide (II), R = H or Me; Z1 = 5-15C alkyl; 1-3C alkyl substituted with 1-3 phenyl, phenyl, or 6-12C cycloalkyl (both optionally substituted), and Z2 = H; or Z1 and Z2 are each 3-10C alkyl; (II) is N-tert-hexyl, tert-octyl, methylundecyl, cyclohexyl, benzyl, diphenylmethyl, or triphenylacrylamide. Nonionic monomers include N-isopropylacrylamide, N-vinylformamide, methacrylamide; N-alkylacrylamide, including but not limited to N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, and N-butylacrylamide; N,N-dialkylacrylamide, including but not limited to N,N-dimethylacrylamide and N,N-diethylacrylamide; N-alkylmethylacrylamide; alkyl acrylates; hydroxyalkyl acrylates and hydroxyalkyl methacrylates, including but not limited to methyl acrylate, 2-hydroxy acrylate... Ethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate; dialkyl acrylates and dialkyl methacrylates, including but not limited to 2,3-dihydroxypropyl acrylate, 3,4-dihydroxybutyl acrylate, 2,3-dihydroxypropyl methacrylate (DHPMA), and 3,4-dihydroxybutyl methacrylate; alkyl acrylates, including but not limited to methyl methacrylate; acrylonitrile; N-vinylmethylacetamide, N-vinylmethylformamide; N-vinyl acetate, glyoxylated acrylamide, and vinylpyrrolidone. For example, nonionic monomers can be combined with acrylamide to form copolymers.

[0088] As used herein, the term "anionic monomer" can refer to an anionic monomer that is substantially all or part (in equilibrium) anionic in a pH range of about 1.0 to about 10.0. Depending on the pKa value of the acidic protons contained therein, anionic monomers may be neutral at low pH levels (e.g., about 0-1, 0-2, or 0-3). Some anionic monomers are obtained in anionic form, such as alkali metal salts, alkaline earth metal salts, and ammonium salts, such as sodium acetate and sodium 2-acrylamido-2-methylpropanesulfonate (AMPS).

[0089] Examples of anionic monomers that may be used herein include, but are not limited to, anionic monomers comprising acrylic acid, methacrylic acid, maleic acid monomers, sodium acrylate, calcium diacrylate, and / or any monomer substituted with a carboxylic acid group or a salt thereof. In some embodiments, the anionic monomer may be substituted with a carboxylic acid group and includes, for example, acrylic acid and methacrylic acid. In some embodiments, the anionic monomer that may be used herein may be a (meth)acrylamide monomer, wherein the amide group has been hydrolyzed to a carboxyl group. According to other embodiments, the monomer may be a derivative or salt of a monomer. Further examples of anionic monomers include, but are not limited to, anionic monomers comprising a sulfonic acid or a sulfonic acid group or both. In some embodiments, anionic monomers that may be used herein may comprise a sulfonic acid functional group, which may comprise, for example, 2-acrylamido-2-methylpropanesulfonic acid (acrylamido-tert-butylsulfonic acid or "ATBS"). In some embodiments, the anionic monomer may comprise an organic acid. In some embodiments, the anionic monomer may comprise acrylic acid, methacrylic acid, maleic acid, itaconic acid, acrylamidomethylpropanesulfonic acid, vinylphosphonic acid, styrene sulfonic acid, and salts thereof, such as sodium, ammonium, and potassium. In other embodiments, the anionic monomer may comprise acrylic acid, methacrylic acid; sulfonic acid, phosphonic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid, vinylphosphonic acid, and their alkali metal salts, alkaline earth metal salts, and ammonium salts. The anionic monomers may be combined, for example, to form a terpolymer of acrylamide, acrylic acid, and 2-acrylamido-2-methylpropanesulfonic acid (AMPS). In an exemplary embodiment, one or more acrylamide polymers (polymers) may comprise at least one monoolefinically unsaturated monomer containing an acid group, such as a monomer containing at least one group selected from -COOH, SO3H, or -PO3H2. Examples of such monomers may include, but are not limited to, acrylic acid, methacrylic acid, vinyl sulfonic acid, allyl sulfonic acid, or 2-acrylamido-2-methylpropanesulfonic acid, particularly preferably acrylic acid and / or 2-acrylamido-2-methylpropanesulfonic acid, and most preferably acrylic acid or its salts. In one exemplary embodiment, one or more acrylamide polymers (copolymers), or each of one or more acrylamide polymers (copolymers), may contain acrylic acid and / or 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof.

[0090] Retention aids and filter aids As used herein, the term "reactive cationic polymer" refers to a polymer containing a reactive moiety (e.g., a nitrogen-containing butane ring, aldehyde, hemiacetal, etc.) that reacts with the carboxylate and -OH moiety on cellulose and lignocellulose fibers to form covalent bonds. Exemplary reactive cationic polymers, including but not limited to cationic glyoxylated polyacrylamide (GPAM) and cationic polyamide amine-epimyl (PAE) resins, are commonly used as wet strength and / or dry strength additives in papermaking. In this document, GPAM and PAE resins are used in combination with amphoteric emulsions and dry polyacrylamide as retention and filtration aids.

[0091] As used herein, the term "cationic glyoxylated polyacrylamide (GPAM)" or "GPAM" generally refers to a polymer obtained by reacting glyoxal with a polyacrylamide-based polymer. Methods for producing glyoxylated polyacrylamide are known in the art. (See, for example, U.S. Patent No. 3,556,932, which first discloses the synthesis of a GPAM composition prepared by reacting glyoxal with a cationic polyacrylamide). In some cases, the polyacrylamide backbone of GPAM can incorporate a small amount of cationic monomer, allowing the polymer to self-retain on the fiber. Generally, GPAM contains reactive polymers that can covalently bind to cellulose upon dehydration.

[0092] In some embodiments, cationic glyoxylated polyacrylamide (GPAM) refers to an aldehyde-containing polymer suitable for use as a dry reinforcing agent and / or a wet reinforcing agent, preferably cationic glyoxylated polyacrylamide (“GPAM”), wherein the cationic GPAM comprises: A.) a base polymer comprising a cationic monomer, optionally wherein the cationic monomer comprises DADMAC and / or acryloyloxyethyltrimethylammonium chloride; B.) the base polymer comprising a weight-average molecular weight of at least 5,000 Da, preferably at least 80,000 Da, more preferably 100-1000 kDa; C.) the cationic GPAM comprising a glyoxal:base polymer weight ratio of at least about 5:95, optionally about 10:90; D.) the GPAM optionally comprising a solids percentage of about 0.5% to about 20%, optionally greater than about 2% to about 10%, and further optionally greater than about 4% to about 8%.

[0093] In some embodiments, the cationic monomer may be selected from the group consisting of: acryloyloxyethyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, methacrylamidopropyltrimethylammonium chloride, acrylamidopropyltrimethylammonium chloride, methacryloyloxyethyldimethylammonium sulfate, dimethylaminoethyl acrylate, dimethylaminopropylmethacrylamide, diallyl dimethylammonium chloride (DADMAC); dialkylaminoalkyl acrylates and methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, methylaminoethyl acrylate... Dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, methacryloxyethyl methacrylate hydrochloride, dialkylaminoalkyl acrylamide or methacrylamide, and their quaternary salts or acid salts, such as acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and diallyl dialkyl ammonium halides, such as diallyl diethyl ammonium chloride and diallyl dimethyl ammonium chloride. In some embodiments, the one or more cationic monomers may comprise DADMAC. In some embodiments, the one or more cationic monomers may comprise acryloyloxyethyltrimethylammonium chloride. In some embodiments, the one or more cationic monomers may comprise DADMAC and / or acryloyloxyethyltrimethylammonium chloride. In some embodiments, the one or more cationic monomers may be selected from the group consisting of: methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, 3-(methacrylamido)propyltrimethylammonium chloride, 3-(acrylamido)propyltrimethylammonium chloride, diallyl dimethylammonium chloride, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate and dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide.

[0094] In some embodiments, the main-chain polymer may comprise one or more primary amide-containing monomers. In some embodiments, the main-chain polymer may comprise one or more monomers selected from the group consisting of: acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methacrylamide, N-butylacrylamide, N-ethylmethacrylamide, and any combination thereof. In some embodiments, the main-chain polymer may comprise one or more acrylamide monomers.

[0095] In some embodiments, the main-chain polymer may comprise one or more anionic monomers. Preferably, the anionic monomer is selected from the group consisting of monomers containing: carboxylic acid functional groups, sulfonic acid functional groups, phosphonic acid functional groups, their corresponding water-soluble or dispersible salts, and any combination thereof; preferably, the anionic monomer is selected from the group consisting of: acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid, and vinylphosphonic acid, their corresponding water-soluble or dispersible alkali metal, alkaline earth metal, and ammonium salts, and any combination thereof; more preferably, the anionic monomer is selected from acrylic acid, its water-soluble or dispersible alkali metal, alkaline earth metal, or ammonium salts, and any combination thereof.

[0096] As used herein, the term "glyoxylation percentage" refers to the percentage of acrylamide monomers that are glyoxylated in the polymer of the cationic GPAM composition (e.g., the first base polymer and / or the second base polymer).

[0097] As used herein, the terms "cationic polyamidoamine-epimercaprol (PAE) resin," "PAE resin," or "PAE" generally refer to a reactive cationic polymer typically synthesized by reacting one or more polyamidoamine backbones containing an acid value of about 35 to about 40 with epichlorohydrin. In some embodiments, the molar ratio of epichlorohydrin to the secondary amine groups of the polyamidoamine backbone can be about 0.15 to about 1.7. In some embodiments, the method may include a low-temperature holding time of less than 24 hours in a temperature range of 30-35°C at the start of the synthesis reaction. In some embodiments, the method may include the addition of a strong acid and a weak acid. In some embodiments, the method may include the addition of a weak acid to a strong acid weight ratio of about 0.25 or higher, 1.2 or higher, or 1.6 or higher, for example, wherein the strong acid comprises sulfuric acid and / or the weak acid comprises formic acid. In some embodiments, the method may further include the sequential addition of formic acid and sulfuric acid. In some embodiments, the method may include the addition of formic acid once or multiple times and / or the addition of sulfuric acid once or multiple times. In some embodiments, the method can produce a stable PAE resin comprising a solids percentage ranging from about 10-30%, 20-27%, or about 25%. In some embodiments, the method can produce a stable PAE resin comprising a final resin pH of about 2.5 to about 3.8. In some embodiments, after the synthesis of the stable PAE resin, the stable PAE resin may contain about 10,500 ppm or more, about 10,500 ppm or less, about 5,000 ppm or less, or about 1,000 ppm or less of epichlorohydrin byproducts.

[0098] Polyamide amine epichlorohydrin resin (PAE resin) has been used in papermaking for a variety of applications. For example, PAE resin is widely used as a strength additive to improve the wet strength of paper. PAE resin is also the most commonly used adhesive in creping processes for producing facial tissues and paper towel products. Conventional PAE resin is typically produced in a two-step reaction. In the first step, polyamide amine is prepared by the condensation of nearly equimolar amounts of polyamine and polycarboxylic acid or polycarboxylic acid derivatives. The resulting polyamide amine is then reacted with epichlorohydrin in an aqueous solution to produce PAE resin. Detailed synthesis is well known and documented in numerous patents, such as U.S. Patents 2,926,116 and 7,175,740.

[0099] As used herein, the terms "water-soluble amphoteric polymer" or "water-soluble amphoteric terpolymer" generally refer to polymers comprising an acrylamide (AM) monomer, one or more anionic monomers, and one or more cationic monomers. Such polymers can be used as retention and filtration aids of the present invention as amphoteric dry polymers (AmDPAM). An exemplary water-soluble amphoteric dry terpolymer (AmDPAM) is described in EP3250752B1. Water-soluble amphoteric polymers can also be used as retention and filtration aids of the present invention as amphoteric emulsion polymers (AmEPAM).

[0100] Exemplary water-soluble amphoteric polymers comprise one or more anionic monomers containing functional groups selected from the group consisting of: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid, and vinylphosphonic acid, their corresponding alkali metals, alkaline earth metals, and ammonium salts, and any combination thereof.

[0101] Exemplary water-soluble amphoteric polymers comprise one or more cationic monomers selected from the group consisting of: acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride Quaternary salts of methacrylates, including but not limited to dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, and dimethylaminoethyl methacryloyl chloride hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate; and diallyl dialkyl ammonium halides, including but not limited to diallyl diethyl ammonium chloride and diallyl dimethyl ammonium chloride (“DADMAC”), and any combination thereof.

[0102] A preferred embodiment of the water-soluble amphoteric polymer is synthesized from three different monomers: acrylamide (AM) (nonionic), acrylic acid (AA) (anionic at higher pH levels), and Q9 (cationic). In an exemplary embodiment, the emulsion amphoteric polymer of the present invention is synthesized by reverse emulsion; it comprises <2 wt% and at most 20 wt% of Q9 anionic acrylic acid monomer and >78 wt% of acrylamide (AM) monomer; in a more preferred exemplary embodiment, it comprises AM:AA:Q9 - 89:2:9; has a low SV value (<3.5 cPs) or preferably 2.5 cPs to 3.5 cPs; and has a MW of at least 1.5 million Daltons to 9 million Daltons, typically 2 million Daltons to 5 million Daltons.

[0103] As used herein, the terms “anionic microparticles,” “anionic organic or inorganic microparticles,” or “anionic additives” generally refer to anionic materials added to paper pulp as part of a filter aid process. Exemplary anionic organic or inorganic microparticles are selected from the group consisting of microparticles and nanoparticles comprising: silica microparticles; colloidal silica; layered aluminosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite, and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamide. Preferred anionic organic or inorganic microparticles may include silica or colloidal silica. The function of colloidal silica appears to involve (a) releasing water from polyelectrolyte bridges, causing the polyelectrolyte bridges to contract, and (b) acting as a connector in bridges involving macromolecules adsorbed on different fibers or fine particles. These effects create a more streamlined path for water to flow around the fibers. The tendency of microparticles to promote first-pass retention also tends to have a positive impact on the initial dewatering rate. It has been reported that paper produced through particle retention and draining processes has a more open, porous structure, although the effects may be masked by subsequent wet pressing and calendering operations.

[0104] Terms and Units As used herein, the terms "aqueous solution" or "solution" generally refer to a mixture of water and one or more water-soluble solutes, which are completely dissolved with little or no residual undissolved polymer gel. The solution may be homogeneous. When mixed with excess water, the polymer article preferably dissolves completely, and the resulting polymer solution preferably does not contain discrete polymer particles or residual gel.

[0105] As used herein, the terms "aqueous suspension," "aqueous slurry," or "slurry" generally refer to a heterogeneous mixture of fluids containing sufficiently large insoluble or slightly soluble solid particles to settle. The suspensions and slurries of the present invention may also contain a quantity of solid particles, commonly referred to as colloidal particles, which cannot settle completely or require a long time to settle completely.

[0106] As used herein, the term “consistency” typically refers to the percentage of dried mass in the raw materials, pulp, or mix (i.e., 100% * dried mass / total mass).

[0107] The terms “total solids” or “total suspended solids” are used interchangeably herein and generally refer to the total amount or weight of suspended solids contained in oil sands or other sands containing dispersions. “Total solids” or “total suspended solids” typically excludes dissolved solids.

[0108] As used herein, the term “ppm” refers to parts per million (e.g., mg / L) based on milligrams of solute per liter of aqueous solution or slurry.

[0109] As used herein, the term “lbs / ton” or “# / T” indicates the dry mass pounds of material (e.g., AKD weight per gross dry tonne of suspended solids) added per tonne of suspended solids.

[0110] As used herein, the term “kg / T” or “kg / ton” means the number of kilograms of dry mass (additives, solutes and / or particles) of tonne of slurry, raw materials and / or slurry mix.

[0111] As used herein, the phrase “wt.%” means the dry weight of additives in a formulation, solution, or slurry multiplied by 100% of the dry weight of solids.

[0112] Detailed description of the invention A recently discovered novel amphoteric emulsion polymer, in synergy with reactive resins such as PAE and GPAM in paper pulp containing high levels of recycled contents, has shown unexpected retention and draining efficiency, and may also act as a pressure enhancer. In paper mills with high recycled contents (characterized by high levels of calcium ions and high conductivity), North American paper manufacturers are seeking effective chemicals that will provide on-machine retention and draining while maintaining strength properties.

[0113] Glyoxylated polyacrylamide (GPAM) products are widely used in the paper industry, often to improve the wet and dry strength of paper. An additional benefit is increased seepage yield of fiber pulp. GPAM is typically prepared by the reaction of glyoxal with a cationic polyacrylamide base polymer. Original GPAM has been reported in U.S. Patent No. 3,556,932. The cationic polyacrylamide base polymer has a molecular weight below 25,000 Da and a molar ratio of acrylamide to diallyldimethylammonium chloride of 99:1 to 75:1.

[0114] Recent patent reports describe several methods for improving the performance efficiency of GPAM. U.S. Patents 8,222,303, 8,703,847, and 9,644,320 claim protection for novel GPAM articles prepared using cationic polyacrylamide with an average molecular weight ranging from 30 kDa to 5 million Da. The final GPAM articles have a GPAM content of less than 4%.

[0115] Polyamide amine epichlorohydrin (PAE) is a primary chemical for providing wet strength to paper products. It is commonly used in tissues, labels, and carrier board grade products to provide strength when the paper is wet. U.S. Patents 2,926,154 and 2,926,116 describe the synthesis of PAE samples.

[0116] Recently, an amphoteric polymer has been designed to improve the operability of papermaking machines. U.S. Patent 10,590,604 B2 claims a novel amphoteric polymer having a mass-average molecular weight (MW) of 1,500,000-6,000,000 g / mol and a total ionization degree of 4-15 mol-%, thereby resulting in polymer articles having a polymer content of at least 60 wt%. Even more recently, an emulsion amphoteric polymer (Patent Application No.: 1149704.048000) has been reported for improving the draining and retention rates of papermaking systems.

[0117] This invention generally relates to methods and compositions for preparing facial tissues, paper, or paperboard, and for enhancing their retention and drainability. Specifically, this disclosure provides methods for enhancing retention and drainability by adding retention-enhancing and filter-enhancing agents comprising reactive cationic polymers (e.g., cationic strength resins), water-soluble amphoteric terpolymers, and optionally anionic organic or inorganic microparticles. Paper preparation under these conditions provides improved retention, drain time, STFI, and burst strength, as well as improved hydrophobic particle control.

[0118] On one hand, the present invention provides a method for preparing facial tissues, paper, or paperboard, the method comprising: (a) Forming or providing an aqueous suspension containing cellulose fibers; (b) Optionally dilute the aqueous suspension; (c) Floccating the aqueous suspension to form a flocculated fiber suspension; (d) The flocculated fiber suspension is delivered to a headbox and drained on a wire mesh screen to form a wet fiber web; and (e) Pressing and drying the wet fiber web to obtain facial tissues, paper, or paperboard; The method further comprises treating the aqueous suspension containing cellulose fibers with a retention aid prior to step (c), the retention aid comprising: (i) one or more reactive cationic polymers; and (ii) One or more water-soluble amphoteric polymers.

[0119] In some exemplary embodiments of the method, the retention aid may optionally further comprise one or more anionic organic or inorganic microparticles.

[0120] In some exemplary embodiments of the method, (i) the one or more reactive cationic polymers, (ii) the one or more water-soluble amphoteric polymers, and optionally (iii) the one or more anionic organic or inorganic microparticles: (a) Add in any order, simultaneously, or premix before addition; or (b) Added in the order of (i), (ii) and then optionally (iii), wherein a mixing time is allowed after each addition, and the mixing time ranges from 0.01 to 10 minutes, 0.1 to 5 minutes or 1 to 2 minutes.

[0121] In some exemplary embodiments of the method, the one or more reactive cationic polymers comprise: (a) a functional group that is reactive to the surface of cellulose or lignocellulose fibers; and (b) The range of cation charge density as a dry solid at pH 7 is less than 5.0 mEq / g, 0.5–5.0 mEq / g, 1.0–4.0 mEq / g, or 1.5–2.5 mEq / g; Furthermore, the one or more reactive cationic polymers further comprise one of the following: (c) One or more cationic glyoxylated polyacrylamides (GPAM); (d) One or more cationic polyamide amine-epimercohydrin (PAE) resins; or (e) A combination of one or more cationic GPAM and one or more cationic PAE resins, the combination having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40 or 45:55, wherein the one or more cationic PAE resins and the one or more cationic GPAM are added sequentially, simultaneously or premixed before being added to the aqueous suspension containing cellulose fibers in any order.

[0122] In some exemplary embodiments of the method, the one or more cationic GPAMs: (a) Suitable for use as a dry and / or wet reinforcing agent; (b) Synthesized by reacting glyoxal with a base polymer, wherein the base polymer has a weight-average molecular weight in the range of 5-5000 kDa, 50-2500 kDa, 80-2000 kDa, or 100-1000 kDa, and comprises a nonionic monomer, a cationic monomer, and optionally an anionic monomer, wherein (i) The nonionic monomer is selected from the group consisting of monomers containing primary amides, including acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methacrylamide, N-butylacrylamide, N-ethylmethacrylamide, and any combination thereof; (ii) The cationic monomer is selected from acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate dimethyl Aminoethyl methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, methacrylamide dimethylaminoethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyl dialkylammonium halides, including but not limited to diallyl diethylammonium chloride and diallyl dimethylammonium chloride (“DADMAC”), and any combination thereof; and (iii) The optional anionic monomer contains a functional group selected from the following: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid and vinylphosphonic acid, their corresponding alkali metals, alkaline earth metals and ammonium salts, and any combination thereof; (c) Contains a glyoxal:base polymer weight ratio ranging from 0.1:99.9 to 50:50, 5:95 to 20:80, or 5:95 to 10:90; (d) The cation charge density contained as a dry solid at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g; (e) Includes a range of 3-60% by weight of cationic monomer content and a range of 0-50% by weight of anionic monomer content, wherein the remainder of the monomer content includes nonionic monomers; (f) Optionally formulated as a dry powder or as an aqueous composition, said aqueous composition comprising a percentage of GPAM solids ranging from about 0.5% to about 20%, optionally greater than about 2% to about 10%, and further optionally greater than about 4% to about 8%.

[0123] In some exemplary embodiments of the method, the one or more cationic PAE resins: (a) Suitable for use as a wet reinforcing agent; (b) is synthesized by reacting one or more polyamide amine backbones with epichlorohydrin, wherein the one or more polyamide amine backbones are synthesized by reacting a carboxylic acid and / or a carboxylic acid derivative with an amine, wherein the one or more polyamide amine backbones comprise a molar ratio of the amine to the carboxylic acid and / or the carboxylic acid derivative in the range of 1:1 to 2:1, 1.05:1 to 2:1 or 1.5:1 to 2:1; (c) The molar ratio of epichlorohydrin to the secondary amine group of the polyamidoamine backbone, ranging from about 0.15 to about 1.7.

[0124] In some exemplary embodiments of the method, the one or more water-soluble amphoteric polymers: (a) comprising an acrylamide (AM) monomer, one or more anionic monomers, and one or more cationic monomers, wherein, (i) The one or more anionic monomers contain functional groups selected from the group consisting of: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid, and vinylphosphonic acid, their corresponding alkali metals, alkaline earth metals, and ammonium salts, and any combination thereof; and (ii) The one or more cationic monomers are selected from the group consisting of: acryloyloxyethyltrimethylammonium chloride (“AETAC”), methacryloyloxyethyltrimethylammonium chloride (“MAETAC”), methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), acrylamidopropyltrimethylammonium chloride (“APTAC”), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride (“DADMAC”); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate (“DMAEA”), dimethylaminoethyl methacrylate (“DMAEA”), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt Dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, and dimethylaminoethyl methacryloyl hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate; and diallyl dialkyl ammonium halides, including but not limited to diallyl diethyl ammonium chloride and diallyl dimethyl ammonium chloride (“DADMAC”), and any combination thereof; (b) Contains an inverted emulsion, a dry polymer, or an aqueous solution of a polymer, preferably an inverted emulsion; (c) Polymer standard viscosity (SV) including ranges of <3.5 cPs, 1-3.5 cPs, 2-3.5 cPs or 2.5-3.5 cPs; (d) Includes molecular weights ranging from 1.5 million to 9 million Daltons, 1.5 million to 8 million Daltons, 2 million to 8 million Daltons, 4 million to 8 million Daltons, or preferably 2 million to 5 million Daltons; (e) Contains acrylamide (AM) monomer content ranging from 77-100 wt%, 78-100 wt%, 80-100 wt%, 90-100 wt%, or 95-100 wt%; (f) Includes anionic monomer content in the range of ≤ 3wt%, ≤ 2wt%, 0.01-3wt%, 0.5-2wt%, 1-2wt%, 1.5-2wt%, or 1.8-2wt%; (g) Contains cationic monomers in the range of ≤ 20wt%, 1-20wt%, 2-16wt%, 4-12wt%, or 7-9wt%; or (h) Any combination of the foregoing terms.

[0125] In some exemplary embodiments of the method, the one or more anionic organic or inorganic microparticles are selected from the group consisting of microparticles and nanoparticles comprising: silica microparticles; colloidal silica; layered aluminosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamide.

[0126] In some exemplary implementations of the method: (a) The one or more reactive cationic polymers comprise the one or more cationic GPAMs and / or the one or more cationic PAE resins in an aqueous form; (b) The one or more cationic GPAMs comprise the base polymer, which comprises a cationic monomer selected from DADMAC, AETAC, and combinations thereof; a nonionic monomer selected from acrylamide, methacrylamide, and combinations thereof; and optionally an anionic monomer selected from acrylic acid and / or the corresponding water-soluble salt, water-dispersible alkali metal salt, alkaline earth metal salt, ammonium salt, and combinations thereof, or the base polymer comprises (i) acrylamide and DADMAC, (ii) acrylamide and AETAC, or (iii) acrylamide, DADMAC, and AETAC. (c) one or more water-soluble amphoteric polymers (i) A reverse emulsion comprising monomers of acrylamide (AM), acrylic acid (AA) and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9); (ii) Preferably, it contains no more than 2 wt% acrylic acid (AA) monomer; and (iii) Preferably, it includes an AM:AA:Q9 ratio ranging from 89:2:9 to 91:2:7; and (d) The one or more anionic organic or inorganic particles comprise colloidal silica.

[0127] In some exemplary embodiments of the method, when added to the aqueous suspension containing cellulose fibers: (a) The one or more reactive cationic polymers are added at a dose ranging from 0.1-15 g / kg, 0.5-5 g / kg or 0.5-4 g / kg; (b) The one or more water-soluble amphoteric polymers are added at a dosage ranging from 0.05-5 g / kg, 0.1-4 g / kg or 0.3-1 g / kg; (c) The one or more anionic organic or inorganic microparticles are added at a dose ranging from 0.1-1 g / kg, 0.2-0.8 g / kg or 0.4-0.6 g / kg.

[0128] In some exemplary embodiments of the method, the aqueous suspension containing cellulose fibers has a pH in the range of 4-8, 4-7.5, 4-7, 4.5-7, or 5-7, and further comprises: (a) Cellulose fibers, wherein the cellulose fibers are optionally obtained from sources selected from the following: softwood fibers, hardwood fibers, recycled fibers, recycled old corrugated cardboard (OCC), recycled mixed office waste (MOW), recycled mixed office paper, refined fibers, factory waste paper fibers, coated waste paper, non-wood fibers including but not limited to straw pulp, and mixtures of any of the foregoing. (b) Pulp, wherein the pulp is selected from the following: kraft pulp, unbleached kraft pulp, bleached pulp, unbleached pulp, process water from pulp, paper and / or paperboard production, neutral sulfite semi-chemical (NSSC) pulp, mechanical pulp, non-wood pulp, and mixtures of any of the foregoing; or (c) Raw materials, said raw materials being selected from concentrated slurry, concentrated slurry diluted with chemical water, synthetic water, white water and / or process water, thin slurry, and mixtures of any of the foregoing.

[0129] In some exemplary embodiments of the method, when used to prepare facial tissues, paper, or paperboard, the method results in the following differences compared to facial tissues, paper, or paperboard prepared by the same method without (i) the addition of the one or more reactive cationic polymers or (ii) the addition of the one or more water-soluble amphoteric polymers: (a) Improved retention of the cellulose fibers; (b) Improvement of the draining of the flocculated fiber suspension; (c) STFI and / or improved fracture strength; (d) Decreased count of hydrophobic particles and / or hydrophobic aggregates; (e) Improvement in dry tensile, immediate wet tensile, and / or soaking wet tensile strength; or Any combination of (f)(a)-(e).

[0130] On the other hand, the present invention provides a method for preparing facial tissues, paper, or paperboard, the method comprising: (a) Forming or providing an aqueous suspension containing cellulose fibers; (b) Optionally dilute the aqueous suspension; (c) Floccating the aqueous suspension to form a flocculated fiber suspension; (d) The flocculated fiber suspension is delivered to a headbox and drained on a wire mesh screen to form a wet fiber web; and (e) Pressing and drying the wet fiber web to obtain facial tissues, paper, or paperboard; The method further comprises treating the aqueous suspension containing cellulose fibers with a retention aid prior to step (c), the retention aid comprising: (i) One or more reactive cationic polymers comprising functional groups reactive to the surface of cellulose or lignocellulose fibers, and having a cationic charge density as dry solids at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g, wherein the one or more reactive cationic polymers comprise one or more cationic glyoxylated polyacrylamide (GPAM); one or more cationic polyamide amine-epimercohydrin (PAE) resins; or a combination of one or more cationic GPAM and one or more cationic PAE resins having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40, or 45:55, wherein the one or more cationic PAE resins and the one or more cationic GPAM are added sequentially, simultaneously, or premixed before being added to the aqueous suspension containing cellulose fibers in any order; (ii) One or more water-soluble amphoteric polymers comprising a reverse emulsion of acrylamide (AM), acrylic acid (AA), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9) monomers; preferably comprising an acrylic acid (AA) monomer content of not more than 2 wt%; and preferably comprising an AM:AA:Q9 ratio in the range of 89:2:9 to 91:2:7; and (iii) Optionally comprising one or more anionic organic or inorganic particles containing silica.

[0131] On the other hand, the present invention provides a fiber raw material composition comprising: (a) An aqueous suspension containing cellulose fibers; and (b) A retention aid and filtration aid, wherein the retention aid and filtration aid comprises (i) One or more reactive cationic polymers; (ii) one or more water-soluble amphoteric polymers; and (iii) Optionally one or more anionic organic or inorganic particles; The fiber raw material composition can be obtained by the method according to any one of the preceding claims.

[0132] On the other hand, the present invention provides a composition for use as a retention aid and filter aid in the preparation of facial tissues, paper, or paperboard, the composition comprising: (a) One or more reactive cationic polymers, wherein the reactive cationic polymers contain a cationic charge density as a dry solid at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g, wherein the reactive cationic polymers contain (i) one or more cationic acetaldehyde-acidified polyacrylamides (GPAMs), said one or more GPAMs being synthesized by reacting glyoxal with a base polymer, said base polymer having a weight-average molecular weight in the range of 5-5000 kDa, 50-2500 kDa, 80-2000 kDa or 100-1000 kDa; (i) acrylamide and DADMAC, (ii) acrylamide and AETAC, or (iii) acrylamide, DADMAC and AETAC, and further wherein said one or more GPAMs have a glyoxal:base polymer weight ratio in the range of 0.1:99.0 to 50:50, 5:95 to 20:80 or 5:95 to 10:90; and a cationic charge density as dry solids at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g or 1.5-2.5 mEq / g; (ii) One or more cationic polyamide amine-epimercohydrin (PAE) resins; or (iii) A combination of one or more cationic GPAM and one or more cationic PAE resins, the combination having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40 or 45:55; (b) One or more water-soluble amphoteric polymers, said one or more water-soluble amphoteric polymers comprising acrylamide (AM), acrylic acid (AA), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9) monomers; wherein said one or more water-soluble amphoteric emulsion polymers preferably comprise an acrylic acid (AA) monomer content of not more than 2 wt% and an AM:AA:Q9 ratio ranging from 89:2:9 to 91:2:7, wherein said one or more water-soluble amphoteric polymers are inverse emulsions, dry polymers, aqueous solutions, preferably inverse emulsions; and (c) Optionally one or more anionic organic or inorganic microparticles, said one or more anionic organic or inorganic microparticles being selected from the group consisting of microparticles and nanoparticles of the following: silica microparticles; colloidal silica; layered aluminosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamide.

[0133] The methods and compositions illustratively disclosed herein may be practiced in the absence of any elements not specifically disclosed herein and / or any elements specifically disclosed herein. Exemplary embodiments of the invention and their advantages will be further disclosed in the following examples.

[0134] Example The embodiments provided herein are for illustrative purposes only, in order to provide a more complete understanding of the invention. These embodiments should not be construed as limiting the invention in any way.

[0135] Experimental Procedure Drainage time was determined by DDA screening. Cellulose fiber webs were prepared, and the draining time was analyzed using a dynamic drain analyzer (DDA) according to the following method. Aliquots of cellulose feedstock (500 mL) with a consistency of 0.4 wt% to 0.7 wt% (total suspended solids, TSS) were mixed with chemical additives for 45 seconds while stirring. After mixing, the flocculated feedstock was drained through a 60-mesh sieve under vacuum (250 mBar). The draining time was determined by measuring the time required for vacuum rupture (i.e., a rapid increase in vacuum pressure). The fiber pads and filtrate remaining on the DDA sieve were used for further testing.

[0136] Determination of filtrate turbidity Turbidity testing was performed on the filtrate from the DDA screening as an indicator of retention. The turbidity of the treated filtrate was measured using a Hach 2100Q turbidimeter. The 2100Q portable turbidimeter operates based on the principle of turbidity measurement. The optical system includes a tungsten filament lamp, a 90° detector for monitoring scattered light, and a transmitted light detector. The instrument's microprocessor calculates the ratio of signals from the 90° detector and the transmitted light detector, which corrects for interference from color and / or light-absorbing materials. The instrument range is 0 NTU to 1000 NTU. Lower turbidity levels typically increase with higher retention rates of fillers, fine powders, and / or contaminants in the slurry within the fiber pad.

[0137] Example 1: Evaluation of amphoteric emulsion polymers with reactive strength resins and silica in recycled OCC slurry as retention and filtration aids Amphoteric emulsion terpolymers with and without silica as retention and filtration aids were evaluated for use in 100% recycled old corrugated cardboard (OCC) feedstock. Table 1 shows the retention and filtration aid additives.

[0138] The NA facial tissue machine is used to form recycled paper towels using recycled OCC cellulose fiber raw materials. The raw material has a pH of approximately 7.3, and the white water has a conductivity of 1.4 mS / cm. The total white water hardness is 140 ppm (based on CaCO3), and the alkalinity is 360 ppm (based on CaCO3). The consistency is 0.60%, measured as total suspended solids (TSS).

[0139] Table 1: Chemical and polymeric additives tested as retention and filtration aids in Examples 1-7.

[0140] DDA screening was used to prepare sheets and determine the draining time. Prepare sheets (i.e., cellulose fiber mats) and analyze the draining time using a dynamic drain analyzer (DDA) according to the following: Combine aliquots of cellulose raw material (500 mL) with a reactive strength resin (GPAM or PAE, 3 kg / T, where T = metric tonnes) and mix for up to 2 minutes, followed by the addition of polymer additives (AmEPAM A, AmEPAM B, or ANMicro). If indicated, add silica last.

[0141] After stirring for 45 seconds, the flocculated material was drained through a 60-mesh sieve under vacuum (250 mBar) to form a fiber mat. The draining time was determined by measuring the time required for the vacuum to break down (i.e., a rapid increase in vacuum pressure). The filtrate was collected and used to determine its turbidity, which served as a measure of fiber retention.

[0142] Determination of filtrate turbidity Turbidity testing was performed on the filtrate from the DDA screening as an indicator of the retention rate of cellulose fiber material from the fiber raw material in the fiber mat. The turbidity of the treated filtrate was measured using a Hach 2100Q turbidimeter. The 2100Q portable turbidimeter operates based on the principle of turbidity measurement. The optical system includes a tungsten filtrate lamp, a 90° detector for monitoring scattered light, and a transmitted light detector. The instrument's microprocessor calculates the ratio of signals from the 90° detector and the transmitted light detector, which corrects for interference from color and / or light-absorbing materials. The instrument range is 0 NTU to 1000 NTU. Lower turbidity levels generally increase with higher retention rates of fillers, fine powders, and / or contaminants in the slurry within the fiber mat.

[0143] Figure 1-4 The additives, dosage, retention rate, and draining results are shown.

[0144] Results indicate that, compared with the use of GPAM or PAE alone, the retention and filtration aids of the present invention (e.g., reactive strength resins having amphoteric emulsion terpolymer properties) significantly improved the draining and retention rates (i.e., shorter draining times and lower turbidity) of sheets prepared from 100% recycled slurry. With increasing AmEPAM polymer dosage, the retention and filtration aids of the present invention improved both draining and turbidity in a dose-dependent manner.

[0145] It is known that, in the absence of PAE, GPAM, and / or AmEPAM, the addition of silica alone to cellulose fiber suspension has no effect or has a detrimental effect on both retention and drainability. The addition of silica to the retention and filtration aid of this invention provides synergistic improvements in both retention and drainability, with the shortest draining time and lowest turbidity observed in the presence of 0.5 kg / T silica.

[0146] These results provide proof of concept that the retention and filtration aids of the present invention (e.g., reactive strength resin + amphoteric polymer) offer synergistic enhancements in retention and drainability compared to using reactive strength resin alone. The optional addition of silica adds further synergistic benefits.

[0147] Example 2: Evaluation of AmEPAM and AmDPAM in recycled MOW slurry as retention and filtration aids with reactive strength resins and silica Amphoteric emulsion terpolymers and amphoteric dry polymers, with and without silica or ANMicro, were evaluated using reactive strength resins (PAEs) as retention and filtration aids for recycled mixed office waste (MOW) pulping. The retention and filtration aids of this invention were evaluated against chemical additives (polyamine and CPAM), which are known for their performance on the compressibility of wet pulp. Table 1 shows the retention and filtration aid additives.

[0148] The NA facial tissue machine is used to produce recycled white tissues using recycled MOW cellulose fiber raw materials. The pH of the headbox pulp is 6.28, and the conductivity of the white water is measured to be 1.5 mS / cm. The total hardness of the white water is 600 ppm (calculated as CaCO3), and the alkalinity is 360 ppm (calculated as CaCO3). The consistency is 0.63%, measured as total suspended solids (TSS).

[0149] Paper towel fiber pads were prepared, and the draining time was evaluated using DDA screening. The turbidity of the resulting filtrate was assessed according to Example 1. Aliquots of cellulose raw material (500 mL) were combined with reactive strength resin (PAE) or control resin (CPAM2) and mixed for up to 2 minutes, followed by the addition of an amphoteric polymer additive (AmEPAM or AmDPAM) or control polymer (CPAM1 or polyamine). If indicated, an anionic additive (silica or ANMicro) was added last. Additionally, the hydrophobic particle (HP) count and HP agglomerate count were determined.

[0150] Table 2 summarizes the conditions, dosage, and results.

[0151] Table 2: Additives and Results for Recycled Paper Towels These results indicate that, compared to commonly used additives (CPAM1 or polyamine) and anionic additives, the retention and filtration aids of the present invention (e.g., amphoteric polymer + PAE) significantly improve the draining and retention rates (i.e., shorter draining times and lower turbidity) of recycled MOW pulp. The optional addition of anionic additives (e.g., silica or ANMicro) provides further benefits to draining and retention rates.

[0152] The results also indicated that both amphoteric emulsion polymers (AmEPAM) and amphoteric dry polymers (AmDPAM) significantly improved draining and retention rates when used with PAE or cationic polyacrylamide (CPAM2) and anionic additives.

[0153] These results provide further proof of concept that the retention and filtration aids of the present invention (e.g., amphoteric polymer + PAE + anionic additive) provide synergistic enhancements in retention and drainability compared to polymer additive + anionic additive.

[0154] Example 3: Evaluation of AmEPAM as a retention and filtration aid compared to CPAM and GPAM in packaging pulp formulation At different conductivity levels, the amphoteric emulsion terpolymer (AmEPAM) + GPAM was evaluated as a retention aid and filtration aid, as well as a common additive (e.g., rosin and alum) in commercial packaging formulations.

[0155] NA packaging liner sheets were prepared, and the draining time was evaluated by DDA screening. The turbidity of the resulting filtrate was evaluated according to Example 1.

[0156] The liner sheet was prepared using a pulp formulation containing 69% unbleached kraft paper and 31% recycled OCC. Thick pulp was collected from the paper machine pulp tank before any papermaking additives were introduced. Tray water was collected and used to dilute the thick pulp to headbox consistency (0.6%), measured as total suspended solids (TSS). The resulting thin pulp formulation had the following characteristics: pH 6.02, conductivity 3.84 µS / cm, alkalinity 320 mg / L (based on CaCO3), and total hardness 800 mg / L (based on CaCO3). A portion of the feedstock was also treated with a 10% CaCl2 solution and a 10% Na2SO4 solution to improve the system's conductivity. Total conductivity was measured at three different levels: 3.84 mS / cm, 5.09 mS / cm, and 8.01 mS / cm.

[0157] The order and dosage of commercial chemical additives are followed, with the polymer being the independent variable. The order comprises 1.5 kg / ton GPAM, 0.1 kg / ton rosin, 5 kg / ton alum, and the polymer, wherein the polymer is cationic polyacrylamide (CPAM) or the amphoteric polyacrylamide (AmEPAM) of the present invention, at a dosage ranging from 0.1 to 0.3 kg / ton.

[0158] Figure 5-6 The results for the conditions, dosage, and draining time for the two conductivity levels are shown in the figure. Figure 7 The results show the conditions, dosage, and filtrate turbidity for three conductivity levels.

[0159] From Figure 5 The results indicate that, when treated with AmEPAM, the packaging pulp mix at a conductivity of 3.84 mS / cm provides significantly better draining time compared to CPAM. (Source: [Original Source Name]) Figure 6The results indicate that AmEPAM continues to outperform CPAM as a filter aid for packaging slurries with a conductivity of 5.09 mS / cm. Figure 7 The results indicate that, at all dosages, AmEPAM outperformed CPAM in filtrate turbidity tests at all three conductivity levels.

[0160] These results provide proof of concept that the retention and filtration aid system of the present invention (AmEPAM + GPAM) outperforms conventional combinations (CPAM + GPAM) in packaged slurries containing rosin and alum at several conductivity levels and polymer dosages.

[0161] Example 4: Evaluation of the strength of packaging liner sheets made with AmEPAM relative to AmDPAM and GPAM According to Example 3, NA packaging liner sheets were prepared using amphoteric emulsion terpolymer (AmEPAM) or amphoteric dry polymer (AmDPAM) at several GPAM dosages (1.5-4.5 kg / T). The resulting sheets were evaluated using standard strength tests (e.g., short span compression test (STFI)). Figure 8 The geometric mean STFI results are shown in the figure.

[0162] These results indicate that both AmEPAM and AmDPAM provide strength benefits superior to GPAM alone when used with GPAM. These results also indicate that the amphoteric emulsion polymer (AmEPAM) provides strength benefits superior to the amphoteric dry polymer (AmDPAM) when used with GPAM.

[0163] Example 5: Strength evaluation of handmade paper made with AmEPAM relative to CPAM and with GPAM and silica as retention and filtration aids in recycled OCC pulping. According to Example 1, NA handmade paper was prepared using a retention aid and filter aid composed of amphoteric emulsion terpolymer (AmEPAM) + GPAM + silica or cationic polyacrylamide (CPAM) + GPAM + silica.

[0164] This embodiment uses 100% recycled OCC. Thick pulp is collected from the paper machine pulp tank before any papermaking additives are introduced. Pallet water is collected and used to dilute the thick pulp to headbox consistency (0.6%), measured as total suspended solids (TSS). The resulting thinned pulp formulation has the following characteristics: pH 6.3, conductivity 2.9 mS / cm, alkalinity 300 mg / L (based on CaCO3), and total hardness 900 mg / L (based on CaCO3).

[0165] GPAM was added at 4 kg / ton. AmEPAM or CPAM was added at 0.125 kg / ton as an active polymer. Silica was added at 0.125 kg / ton. NA handmade paper was prepared, and its strength was tested using standard STFI and burst strength tests. Figure 9 The STFI and fracture strength results are shown in the figure.

[0166] These results indicate that amphoteric emulsion polymers (AmEPAM) offer superior strength benefits compared to CPAM when used with GPAM and silica. Without being bound by theory, it is reasonable to assume that, when used with silica, the amphoteric polymer exhibits better retention of GPAM-treated fine powder than CPAM. This results in better paper strength properties.

[0167] These results further provide proof of concept that the retention and filtration aid system of the present invention (AmEPAM + GPAM) is superior to the conventional combination (CPAM + GPAM).

[0168] Example 6: Evaluation of amphoteric emulsion polymers, reactive strength resins, and silica as retention and filtration aids in recycled tissue paper OCC pulp formulation. Amphoteric emulsion terpolymers (EPAMs) were evaluated as retention and filter aids in 100% recycled tissue OCC raw materials, with or without silica, compared to other commonly used polymers (ANMicro or CPAM) and reactive strength resins (PAE or GPAM). Table 1 shows the retention and filter aid additives. The main chain MW of GPAM A is 10-50 kDa, and the main chain MW of GPAM B is 100-200 kDa.

[0169] This embodiment uses 100% OCC for brown tissue paper. Thick pulp is collected from the pulp tank of the paper machine before any papermaking additives are introduced. Tray water is collected and used to dilute the thick pulp to headbox consistency (0.5% TSS). The resulting diluted pulp has the following characteristics: pH 6.45, conductivity 1.9 mS / cm, and total hardness 600 mg / L (based on CaCO3).

[0170] Paper towel fiber pads were prepared, and the draining time was evaluated by DDA screening. The turbidity of the resulting filtrate was evaluated according to Example 1. Figure 10-11 The conditions, dosage, and results are shown in the diagram.

[0171] These results indicate that combinations of GPAM A or GPAM B with or without silica, and amphoteric PAM, exhibit better draining and retention rates than combinations of GPAM with or without silica, and anionic polymers (ANMicro) or cationic polymers (CPAM). The combination of GPAM B with silica and amphoteric PAM shows the best retention and draining rates.

[0172] These results further provide proof of concept that the retention and filtration aids of the present invention, composed of reactive strength resins (GPAM or PAE) and amphoteric PAM, provide synergistic enhancements in retention and drainability relative to individual polymers (e.g., amphoteric PAM or ANMicro) and relative to individual reactive strength resins (GPAM or PAE). Optionally, the addition of silica provides further synergistic enhancements to the retention and filtration aids.

[0173] Without being bound by theory, it is reasonable to assume that the observed synergistic effect may be caused by the following mechanisms, in which (i) the cationic and highly reactive reactive strength resins (GPAM, PAE) are effectively bound to the anionic cellulose fibers and fine powder, which will otherwise be lost, thereby providing better retention, because (ii) the co-existence of amphoteric PAM (a terpolymer containing anionic and cationic monomers (see Table 1)) induces flocculation and causes the reactive strength resin to react with the anionic monomers of the amphoteric terpolymer, thereby forming large and stable flocs comprising fibers, fine powder, amphoteric PAM and strength resin, and causing a synergistic improvement in retention and drainability; and (iii) the optional addition of silica causes the flocs to shrink by breaking the bond between the strength resin and the polymer and squeezing out water, thereby forming a higher density floc structure, which allows for an additional synergistic improvement in retention, faster drainability and possibly better wet pressing properties.

[0174] In summary, the results of Examples 1-6 indicate that a synergistic improvement in retention and drainability has the potential to significantly enhance retention, drainability, and the incorporation of hydrophobic particles / agglomerates into sheets formed from recycled fiber sheets. These results also demonstrate that the optional addition of silica provides additional drainability and retention benefits.

[0175] Example 7: Evaluation of amphoteric emulsion polymers with reactive strength resins (PAE and DPAM) and silica in recycled office paper pulp as retention and filtration aids A combination of amphoteric emulsion terpolymers (amphoteric PAM) with reactive strength resins (PAE and GPAM) was evaluated as a retention and filtration aid for 100% recycled office paper raw materials, with or without silica.

[0176] In this embodiment, 100% recycled blended office paper was used to manufacture recycled white tissues. The pulp was diluted with white water to a consistency of 0.83%. Tissue fiber pads were prepared, and the draining time was evaluated by DDA screening, and the turbidity of the resulting filtrate was evaluated according to Example 1. The conditions, dosages, and results are shown in Table 3.

[0177] Table 3: Additives, Dosage, and Results for Recycled Paper Towels These results indicate a synergistic effect between amphoteric polyacrylamide and the combination of both PAE and GPAM (containing silica). Optimal results were achieved by adding both GPAM and PAE. These results provide proof of concept that GPAM and PAE can be added together to the retention and filtration aids of this invention to enhance draining time and turbidity.

Claims

1. A method for preparing facial tissues, paper, or paperboard, the method comprising: (a) Forming or providing an aqueous suspension containing cellulose fibers; (b) Optionally dilute the aqueous suspension; (c) Floccating the aqueous suspension to form a flocculated fiber suspension; (d) Remove sufficient water from the flocculated fiber suspension to form a wet fiber web, preferably by introducing the flocculated fiber suspension into a headbox and draining the flocculated fiber suspension on a wire mesh screen; as well as (e) Pressing and drying the wet fiber web to obtain facial tissues, paper, or paperboard; The method further comprises treating the aqueous suspension containing cellulose fibers with a retention aid prior to step (c), the retention aid comprising: (i) one or more reactive cationic polymers; and (ii) One or more water-soluble amphoteric polymers.

2. The method according to claim 1, wherein the retention aid or filter aid optionally further comprises one or more anionic organic or inorganic microparticles.

3. The method according to claim 1 or 2, wherein (i) the one or more reactive cationic polymers, (ii) the one or more water-soluble amphoteric polymers, and optionally (iii) the one or more anionic organic or inorganic microparticles: (a) Add in any order, simultaneously, or premix before addition; or (b) Added in the order of (i), (ii) and then optionally (iii), wherein a mixing time is allowed after each addition, and the mixing time ranges from 0.01 to 10 minutes, 0.1 to 5 minutes or 1 to 2 minutes.

4. The method according to any one of the preceding claims, wherein the one or more reactive cationic polymers comprises: (a) a functional group that is reactive to the surface of cellulose or lignocellulose fibers; and (b) The range of cation charge density as a dry solid at pH 7 is less than 5.0 mEq / g, 0.5–5.0 mEq / g, 1.0–4.0 mEq / g, or 1.5–2.5 mEq / g; Furthermore, the one or more reactive cationic polymers further comprise one of the following: (c) One or more cationic glyoxylated polyacrylamides (GPAM); (d) One or more cationic polyamide amine-epimercohydrin (PAE) resins; or (e) A combination of one or more cationic GPAM and one or more cationic PAE resins, the combination having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40 or 45:55, wherein the one or more cationic PAE resins and the one or more cationic GPAM are added sequentially, simultaneously or premixed before being added to the aqueous suspension containing cellulose fibers in any order.

5. The method according to claim 4, wherein the one or more cationic GPAMs are: (a) Suitable for use as a dry and / or wet reinforcing agent; (b) Synthesized by reacting glyoxal with a base polymer, wherein the base polymer has a weight-average molecular weight in the range of 5-5000 kDa, 50-2500 kDa, 80-2000 kDa, or 100-1000 kDa, and comprises a nonionic monomer, a cationic monomer, and optionally an anionic monomer, wherein (i) The nonionic monomer is selected from the group consisting of monomers containing primary amides, including acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methacrylamide, N-butylacrylamide, N-ethylmethacrylamide, and any combination thereof; (ii) The cationic monomer is selected from acryloyloxyethyltrimethylammonium chloride ("AETAC"), methacryloyloxyethyltrimethylammonium chloride ("MAETAC"), methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), acrylamidopropyltrimethylammonium chloride ("APTAC"), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride ("DADMAC"); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate ("DMAEA"), dimethylaminoethyl methacrylate ("DMAEA"), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate dimethyl Aminoethyl methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, methacrylamide dimethylaminoethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; and diallyl dialkyl ammonium halides, including but not limited to diallyl diethyl ammonium chloride and diallyl dimethyl ammonium chloride ("DADMAC"), and any combination thereof; and (iii) The optional anionic monomer contains a functional group selected from the following: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid and vinylphosphonic acid, their corresponding alkali metals, alkaline earth metals and ammonium salts, and any combination thereof; (c) Contains a glyoxal:base polymer weight ratio ranging from 0.1:99.9 to 50:50, 5:95 to 20:80, or 5:95 to 10:90; (d) The cation charge density contained as a dry solid at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g; (e) Includes a range of 3-60% by weight of cationic monomer content and a range of 0-50% by weight of anionic monomer content, wherein the remainder of the monomer content includes nonionic monomers; (f) Optionally formulated as a dry powder or as an aqueous composition, said aqueous composition comprising a percentage of GPAM solids ranging from about 0.5% to about 20%, optionally greater than about 2% to about 10%, and further optionally greater than about 4% to about 8%.

6. The method according to claim 4, wherein the one or more cationic PAE resins: (a) Suitable for use as a wet reinforcing agent; (b) is synthesized by reacting one or more polyamide amine backbones with epichlorohydrin, wherein the one or more polyamide amine backbones are synthesized by reacting a carboxylic acid and / or a carboxylic acid derivative with an amine, wherein the one or more polyamide amine backbones comprise a molar ratio of the amine to the carboxylic acid and / or the carboxylic acid derivative in the range of 1:1 to 2:1, 1.05:1 to 2:1 or 1.5:1 to 2:1; (c) The molar ratio of epichlorohydrin to the secondary amine group of the polyamidoamine backbone, ranging from about 0.15 to about 1.

7.

7. The method according to any one of the preceding claims, wherein the one or more water-soluble amphoteric polymers: (a) comprising an acrylamide (AM) monomer, one or more anionic monomers, and one or more cationic monomers, wherein, (i) The one or more anionic monomers contain functional groups selected from the group consisting of: carboxylic acids, sulfonic acids, phosphonic acids, their corresponding water-soluble salts, their corresponding water-dispersible salts, and any combination thereof, including but not limited to acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, 2-hydroxy-3-acrylamidopropanesulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid, and vinylphosphonic acid, their corresponding alkali metals, alkaline earth metals, and ammonium salts, and any combination thereof; and (ii) The one or more cationic monomers are selected from the group consisting of: acryloyloxyethyltrimethylammonium chloride ("AETAC"), methacryloyloxyethyltrimethylammonium chloride ("MAETAC"), methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), acrylamidopropyltrimethylammonium chloride ("APTAC"), methacryloyloxyethyldimethylammonium sulfate, diallyldimethylammonium chloride ("DADMAC"); dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates and their quaternary salts or acid salts, including but not limited to dimethylaminoethyl acrylate ("DMAEA"), dimethylaminoethyl methacrylate ("DMAEA"), dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfate, dimethylaminoethyl acrylate hydrochloride, diethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt Dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, and dimethylaminoethyl methacrylate hydrochloride; dialkylaminoalkyl acrylamides and methacrylamides and their quaternary salts or acid salts, including but not limited to acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl sulfate quaternary salt, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide, dimethylaminopropylmethacrylamide methyl sulfate quaternary salt, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate; and diallyl dialkyl ammonium halides, including but not limited to diallyl diethyl ammonium chloride and diallyl dimethyl ammonium chloride ("DADMAC"), and any combination thereof; (b) Contains an inverted emulsion, a dry polymer, or an aqueous solution of a polymer, preferably an inverted emulsion; (c) The scope includes < Polymer standard viscosity (SV) of 3.5 cPs, 1-3.5 cPs, 2-3.5 cPs or 2.5-3.5 cPs; (d) Includes molecular weights ranging from 1.5 million to 9 million Daltons, 1.5 million to 8 million Daltons, 2 million to 8 million Daltons, 4 million to 8 million Daltons, or preferably 2 million to 5 million Daltons; (e) Contains acrylamide (AM) monomer content ranging from 77-100 wt%, 78-100 wt%, 80-100 wt%, 90-100 wt%, or 95-100 wt%; (f) Includes anionic monomer content in the range of ≤ 3wt%, ≤ 2wt%, 0.01-3wt%, 0.5-2wt%, 1-2wt%, 1.5-2wt%, or 1.8-2wt%; (g) Contains cationic monomers in the range of ≤ 20wt%, 1-20wt%, 2-16wt%, 4-12wt%, or 7-9wt%; or (h) Any combination of the foregoing terms.

8. The method according to any one of claims 2 to 7, wherein the one or more anionic organic or inorganic microparticles are selected from the group consisting of microparticles and nanoparticles comprising: silica microparticles; colloidal silica; layered aluminosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamide.

9. The method according to any one of the preceding claims, wherein (a) The one or more reactive cationic polymers comprise the one or more cationic GPAMs and / or the one or more cationic PAE resins in an aqueous form; (b) The one or more cationic GPAMs comprise the base polymer, which comprises a cationic monomer selected from DADMAC, AETAC, and combinations thereof; a nonionic monomer selected from acrylamide, methacrylamide, and combinations thereof; and optionally an anionic monomer selected from acrylic acid and / or the corresponding water-soluble salt, water-dispersible alkali metal salt, alkaline earth metal salt, ammonium salt, and combinations thereof, or the base polymer comprises (i) acrylamide and DADMAC, (ii) acrylamide and AETAC, or (iii) acrylamide, DADMAC, and AETAC. (c) one or more water-soluble amphoteric polymers (i) A reverse emulsion comprising monomers of acrylamide (AM), acrylic acid (AA) and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9); (ii) Preferably, it contains no more than 2 wt% acrylic acid (AA) monomer; and (iii) Preferably, it includes an AM:AA:Q9 ratio ranging from 89:2:9 to 91:2:7; and (d) The one or more anionic organic or inorganic particles comprise colloidal silica.

10. The method according to any one of the preceding claims, wherein when added to the aqueous suspension containing cellulose fibers: (a) The one or more reactive cationic polymers are added at a dose ranging from 0.1-15 g / kg, 0.5-5 g / kg or 0.5-4 g / kg; (b) The one or more water-soluble amphoteric polymers are added at a dosage ranging from 0.05-5 g / kg, 0.1-4 g / kg or 0.3-1 g / kg; (c) The one or more anionic organic or inorganic microparticles are added at a dose ranging from 0.1-1 g / kg, 0.2-0.8 g / kg or 0.4-0.6 g / kg.

11. The method according to any one of the preceding claims, wherein the aqueous suspension containing cellulose fibers has a pH in the range of 4-8, 4-7.5, 4-7, 4.5-7, or 5-7, and further comprises: (a) Cellulose fibers, wherein the cellulose fibers are optionally obtained from sources selected from: softwood fibers, hardwood fibers, recycled fibers, recycled old corrugated cardboard (OCC), recycled mixed office waste (MOW), recycled mixed office paper, refined fibers, factory waste paper fibers, coated waste paper, non-wood fibers including but not limited to straw pulp, and mixtures of any of the foregoing. (b) Pulp, wherein the pulp is selected from the following: kraft pulp, unbleached kraft pulp, bleached pulp, unbleached pulp, process water from pulp, paper and / or paperboard production, neutral sulfite semi-chemical (NSSC) pulp, mechanical pulp, non-wood pulp, and mixtures of any of the foregoing; or (c) Raw materials, said raw materials being selected from concentrated slurry, concentrated slurry diluted with chemical water, synthetic water, white water and / or process water, thin slurry, and mixtures of any of the foregoing.

12. The method according to any one of the preceding claims, wherein when used to prepare facial tissues, paper, or paperboard, compared with facial tissues, paper, or paperboard prepared by the same method in the absence of (i) the addition of said one or more reactive cationic polymers or (ii) the addition of said one or more water-soluble amphoteric polymers, said method results in: (a) Improved retention of the cellulose fibers; (b) Improvement of the draining of the flocculated fiber suspension; (c) STFI and / or improved fracture strength; (d) Decreased count of hydrophobic particles and / or hydrophobic aggregates; (e) Improvement in dry tensile, immediate wet tensile, and / or soaking wet tensile strength; or Any combination of (f)(a)-(e).

13. A method for preparing facial tissues, paper, or paperboard, the method comprising: (a) Forming or providing an aqueous suspension containing cellulose fibers; (b) Optionally dilute the aqueous suspension; (c) Floccating the aqueous suspension to form a flocculated fiber suspension; (d) The flocculated fiber suspension is delivered to a headbox and drained on a wire mesh screen to form a wet fiber web; and (e) Pressing and drying the wet fiber web to obtain facial tissues, paper, or paperboard; The method further comprises treating the aqueous suspension containing cellulose fibers with a retention aid prior to step (c), the retention aid comprising: (i) One or more reactive cationic polymers comprising functional groups reactive to the surface of cellulose or lignocellulose fibers, and having a cationic charge density as dry solids at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g, wherein the one or more reactive cationic polymers comprise one or more cationic glyoxylated polyacrylamide (GPAM); one or more cationic polyamide amine-epimercohydrin (PAE) resins; or a combination of one or more cationic GPAM and one or more cationic PAE resins having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40, or 45:55, wherein the one or more cationic PAE resins and the one or more cationic GPAM are added sequentially, simultaneously, or premixed before being added to the aqueous suspension containing cellulose fibers in any order; (ii) One or more water-soluble amphoteric polymers comprising a reverse emulsion of acrylamide (AM), acrylic acid (AA), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9) monomers; preferably comprising an acrylic acid (AA) monomer content of not more than 2 wt%; and preferably comprising an AM:AA:Q9 ratio in the range of 89:2:9 to 91:2:7; and (iii) Optionally comprising one or more anionic organic or inorganic particles containing silica.

14. A fiber raw material composition, said fiber raw material composition comprising: (a) An aqueous suspension containing cellulose fibers; and (b) A retention aid and filtration aid, wherein the retention aid and filtration aid comprises (i) One or more reactive cationic polymers; (ii) one or more water-soluble amphoteric polymers; and (iii) Optionally one or more anionic organic or inorganic particles; The fiber raw material composition can be obtained by the method according to any one of the preceding claims.

15. A composition for use as a retention aid and filter aid in the preparation of facial tissues, paper, or paperboard, said composition comprising: (a) One or more reactive cationic polymers, wherein the reactive cationic polymers contain a cationic charge density as a dry solid at pH 7 in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g, or 1.5-2.5 mEq / g, wherein the reactive cationic polymers contain (i) one or more cationic acetaldehyde-treated polyacrylamides (GPAMs), said one or more GPAMs being synthesized by reacting glyoxal with a base polymer, said base polymer having a weight-average molecular weight in the range of 5-5000 kDa, 50-2500 kDa, 80-2000 kDa or 100-1000 kDa; (i) acrylamide and DADMAC, (ii) acrylamide and AETAC, or (iii) acrylamide, DADMAC and AETAC, and further wherein said one or more GPAMs have a glyoxal:base polymer weight ratio in the range of 0.1:99.9 to 50:50, 5:95 to 20:80 or 5:95 to 10:90; and a cationic charge density as dry solids in the range of less than 5.0 mEq / g, 0.5-5.0 mEq / g, 1.0-4.0 mEq / g or 1.5-2.5 mEq / g at pH 7; (ii) One or more cationic polyamide amine-epimercohydrin (PAE) resins; or (iii) A combination of one or more cationic GPAM and one or more cationic PAE resins, the combination having a PAE to GPAM ratio in the range of 1:99 to 99:1, 20:80 to 80:20, 40:60 to 60:40 or 45:55; (b) One or more water-soluble amphoteric polymers, said one or more water-soluble amphoteric polymers comprising acrylamide (AM), acrylic acid (AA), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (Q9) monomers; wherein said one or more water-soluble amphoteric emulsion polymers preferably comprise an acrylic acid (AA) monomer content of not more than 2 wt% and an AM:AA:Q9 ratio ranging from 89:2:9 to 91:2:7, wherein said one or more water-soluble amphoteric polymers are inverse emulsions, dry polymers, aqueous solutions, preferably inverse emulsions; and (c) Optionally, one or more anionic organic or inorganic microparticles, said one or more anionic organic or inorganic microparticles being selected from the group consisting of microparticles and nanoparticles comprising: silica microparticles; colloidal silica; layered aluminosilicate mineral particles, including but not limited to bentonite, sodium bentonite, calcium bentonite and montmorillonite; and anionic polymer microparticles, including but not limited to highly structured anionic polyacrylamide; optionally, said one or more anionic organic or inorganic microparticles can be obtained by the method according to any one of the preceding claims.

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