COMPOSITIONS AND METHODS FOR TREATING TISSUE PRODUCTS

Abstract

Compositions and colloidal particles are provided that may be used to improve a tissue making process. The compositions and colloidal particles may include a polymer and an inorganic salt. A tissue making process carried out using the presently disclosed compositions and colloidal particles may produce a tissue product that has high tensile strength and high softness without using either softeners or debonders.

Claims

1. A method of increasing the softness and strength of a tissue product, comprising: adding a composition to a tissue making machine, wherein the composition comprises a colloidal particle, the colloidal particle comprising a polymer embedded within a colloidal aluminum hydroxide complex and/or a colloidal ferric hydroxide complex, wherein the polymer comprises a cationic charge density of about 1.0 meq/g to about 8.5 meq/g.

2. The method of claim 1, further comprising adding the composition to a tissue making process water in the tissue making machine.

3. The method of claim 2, wherein a thin stock, a thick stock, and/or a headbox comprises the tissue making process water.

4. The method of claim 1, wherein the polymer comprises a monomer selected from the group consisting of an anionic monomer, a cationic monomer, a non-ionic monomer, a zwitterionic monomer, and any combination thereof.

5. The method of claim 1, wherein the polymer comprises about 0 mol % to about 20 mol % DMAEA.MCQ, about 1 mol % to about 10 mol % of acrylic acid, and about 85 mol % to about 90 mol % of acrylamide.

6. The method of claim 1, wherein the composition is an aqueous composition comprising a pH from about 2 to about 8.5.

7. The method of claim 1, wherein the polymer comprises a carboxylic acid.

8. The method of claim 1, wherein the polymer comprises a cationic charge density of about 1.0 meq/g to about 3.0 meq/g.

9. A method of increasing the softness and strength of a tissue product, comprising: adding a polymer to a tissue making process water, adding an aluminum salt and/or a ferric salt to the tissue making process water, and forming a colloidal particle in the tissue making process water, wherein the colloidal particle comprises the polymer embedded within a colloidal aluminum hydroxide complex and/or a colloidal ferric hydroxide complex, wherein the polymer comprises a cationic charge density of about 1.0 meq/g to about 8.5 meq/g.

10. The method of claim 9, further comprising co-feeding the polymer and the aluminum salt and/or the ferric salt into the tissue making process water.

11. The method of claim 9, wherein the aluminum salt is selected from the group consisting of aluminum chloride, aluminum chloride hydrate, aluminum sulfate, alum, PAC, aluminum chlorohydrate, a compound having the formula Al.sub.nCl.sub.(3n-m)(OH).sub.m, wherein m is an integer from 0-100, n is an integer from 1-100, and m is less than 3n, and any combination thereof.

12. The method of claim 9, wherein a thin stock, a thick stock, and/or a headbox comprises the tissue making process water.

13. The method of claim 9, wherein the polymer comprises a monomer selected from the group consisting of an anionic monomer, a cationic monomer, a non-ionic monomer, a zwitterionic monomer, and any combination thereof.

14. The method of claim 9, wherein the polymer comprises a carboxylic acid.

15. The method of claim 9, wherein a composition comprises the polymer and the ferric salt and/or aluminum salt.

16. The method of claim 15, wherein the composition comprises a weight ratio of the aluminum salt and/or the ferric salt to the polymer from about 0.05:1 to 100:1.

17. The method of claim 9, wherein the polymer comprises a cationic charge density of about 1.0 meq/g to about 3.0 meq/g.

18. A composition, comprising: a colloidal particle, the colloidal particle comprising a polymer embedded within a colloidal aluminum hydroxide complex and/or a colloidal ferric hydroxide complex, wherein the polymer comprises a cationic charge density of about 1.0 meq/g to about 8.5 meq/g.

19. The composition of claim 18, wherein the polymer comprises about 0 mol % to about 20 mol % DMAEA.MCQ, about 1 mol % to about 10 mol % of acrylic acid, and about 85 mol % to about 90 mol % of acrylamide.

20. The composition of claim 18, wherein the polymer comprises a cationic charge density of about 1.0 meq/g to about 3.0 meq/g.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0011] A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:

[0012] FIG. 1 shows a schematic of an example of a tissue making process.

DETAILED DESCRIPTION

[0013] Various embodiments of the presently disclosed technology are described below. The relationship and functioning of the various elements of the embodiments may be better understood by reference to the following detailed description. However, embodiments are not limited to those explicitly described below.

[0014] The term aluminum salt as used herein refers to an inorganic compound containing an aluminum ion, which includes, but is not limited to, alum, aluminum chloride, aluminum sulfate, PAC, and aluminum chlorohydrate. An aluminum salt is the compound that contributes aluminum ions in water solutions. It may include, but is not limited to, aluminum sulfate, aluminum chloride, aluminum phosphate, aluminum nitrate, and aluminum acetate.

[0015] The term ferric salt as used herein refers to an inorganic compound containing a ferric ion, which includes, but is not limited to, ferric chloride, ferric sulfate, polyferric sulfate, and polyferric chloride. A ferric salt is the compound that contributes ferric ions in water solutions. It may include, but is not limited to, ferric sulfate, ferric chloride, ferric phosphate, ferric nitrate, and ferric acetate.

[0016] The terms co-feed, co-feeding, co-fed, and the like refer to the addition of two or more components, ingredients, chemicals, and the like, to a location, such as a reaction vessel, storage container, and/or the papermaking machine, separately but essentially/substantially at the same time and location. For example, two components, such as a polymer and an inorganic salt, may be fed into a location in the wet end of a tissue making machine, such as the furnish, through separate injection pipes. Each pipe may continuously or intermittently inject chemical at the same time to a single location in the tissue making machine or to two or more locations in the tissue making machine that are in close proximity to each other (e.g., within about 1 to about 12 inches, such as from about 1 to about 10 inches, from about 1 to about 8 inches, or from about 1 to about 6 inches).

[0017] The term degree of crosslinking refers to how many connection bonds, on average, connect one polymer chain to another polymer chain. For example, a polymer sample with an average chain length of 1000 monomer units, wherein 10 monomer units are connected to another chain has a degree of crosslinking of 1%.

[0018] A tissue product as described herein encompass all types of fiber webs that contain virgin or recycle fibers, alternative fibers including bamboo, wheat straw, miscanthus, switchgrass, sorghum, bagasse, rice straw, flax straw, hemp, kenaf, natural and/or synthetic fibers, including cellulosic fibers, wood fibers, cotton fibers, fibers derived from recycled paper, rayon, nylon, fiberglass, and polyolefin fibers, for example.

[0019] The term weight average molecular weight refers to the molecular weight average of polymer determined by static light scattering measurement, specifically by Size-Exclusion-Chromatography/Multi-Angle-Laser-Light-Scattering (SEC/MALLS) technique. The polymer of the present disclosure has a weight average molecular weight of from about 10,000 to about 10,000,000 Daltons.

[0020] The term average particle size refers to the average size of particles determined by a dynamic light scattering particle size analyzer when particles are less than 10 microns and by a laser diffraction size analyzer when the particle size is between 1 and 10 microns. The particle of the present disclosure has an average particle size of from about 0.01 to about 10 microns.

[0021] The term pulp furnish or furnish means a mixture comprising a liquid medium, such as water, within which solids, such as fibers (e.g., cellulose fibers) and optionally fillers, are dispersed or suspended such that between about >99% to about 45% by mass of the furnish is liquid medium. The portion of the tissue making process prior to the press section (or prior to the through air dryers if working on a TAD machine) where a liquid medium, such as water, comprises more than about 45% of the mass of the substrate is referred to as the wet end. When working with a TAD machine, through air dryers will dry the sheet from approximately 20% consistency to about 65-90% consistency prior to the Yankee dryer. The term dry end refers to that portion of the tissue making process including and subsequent to the press section (or through air dryers) where a liquid medium, such as water, typically comprises less than about 45% of the mass of the substrate. The compositions and methods disclosed herein can be incorporated into or carried out in the wet end and/or dry end of the tissue making process.

[0022] The pulp furnish, and thus a sheet formed from the furnish, may comprise, for example, a natural fiber, a synthetic fiber, a chemical pulp, a mechanical pulp, a vegetable fiber, a virgin fiber, an alternative fiber, a recycled fiber, a filler, or any combination thereof.

[0023] The present disclosure provides compositions, particles and methods of using the compositions and particles in tissue making processes and/or towel making processes. When the present disclosure refers to a tissue product or a tissue making process, those terms are intended to encompass not only tissue and tissue making but also a towel product or a towel making process.

[0024] In some embodiments, the compositions and particles are used in methods for increasing softness and/or the strength, such as the dry strength, of a tissue product. The compositions, which may be aqueous compositions, may include a colloidal particle, which may be interchangeably referred to as a particle throughout the present disclosure. The particle comprises a polymer embedded within a colloidal aluminum hydroxide complex and/or a colloidal ferric hydroxide complex.

[0025] In some embodiments, the particle of the present disclosure is formed by mixing a trivalent ion, such as an aluminum salt and/or a ferric salt, with a polymer and the resulting mixture is added to a tissue making machine. In a typical tissue making process, however, if a trivalent ion, such as a polyaluminum chloride, is to be added to the process water, it is added alone as a charge scavenger. One of ordinary skill in the art would not attempt to combine it with other compounds, such as the polymer of the present disclosure, before addition to the tissue making machine because it would be expected that the polymer would interfere with the charge scavenger and destroy its intended function.

[0026] The polymer of the present disclosure is chemically and/or physically entangled and/or embedded in the colloidal aluminum hydroxide and/or colloidal ferric hydroxide complex. The polymer may include one or more anionic monomers, one or more cationic monomers, one or more non-ionic monomers, one or more zwitterionic monomers, or any combination of these monomers.

[0027] In some embodiments, the polymer has a net negative charge and in other embodiments, the polymer has a net positive charge or a neutral charge at neutral pH. In certain embodiments, the polymer is water-soluble. In some embodiments, the polymer comprises a carboxylic acid group.

[0028] For example, the polymer may comprise from about 0.1 mol % to about 50 mol % of the carboxylic acid, such as about 1 mol % to about 40 mol %, about 1 mol % to about 30 mol %, about 1 mol % to about 20 mol %, about 1 mol % to about 10 mol %, about 10 mol % to about 50 mol %, about 20 mol % to about 50 mol %, about 30 mol % to about 50 mol % or about 40 mol % to about 50 mol %.

[0029] In some embodiments, the polymer comprises from about 1 mol % to about 8 mol %, from about 1 mol % to about 7 mol %, from about 1 mol % to about 6 mol %, from about 1 mol % to about 5 mol %, from about 1 mol % to about 4 mol %, from about 1 mol % to about 3 mol %, or from about 1 mol % to about 2 mol % of the carboxylic acid, such as about 1 mol %, about 2 mol %, about 3 mol %, about 4 mol %, about 5 mol %, about 6 mol %, about 7 mol %, or about 8 mol % of the carboxylic acid.

[0030] Illustrative, non-limiting examples of non-ionic monomers that may be included in the polymer may be selected from acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-vinylformamide, N-vinylmethylacetamide, N-vinyl pyrrolidone, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-tert-butylacrylamide, N-methylolacrylamide, diallylamine, allylamine, and the like.

[0031] Illustrative, non-limiting examples of anionic monomers include acrylic acid, and its salts, including, but not limited to sodium acrylate, and ammonium acrylate, methacrylic acid, and its salts, including, but not limited to sodium methacrylate, and ammonium methacrylate, AMPS, the sodium salt of AMPS, sodium vinyl sulfonate, styrene sulfonate, maleic acid, and its salts, including, but not limited to the sodium salt, and ammonium salt, sulfonate itaconate, sulfopropyl acrylate or methacrylate or other water-soluble forms of these or other polymerizable carboxylic or sulphonic acids, sulfomethylated acrylamide, allyl sulfonate, sodium vinyl sulfonate, itaconic acid, acrylamidomethylbutanoic acid, fumaric acid, vinylphosphonic acid, vinylsulfonic acid, allylphosphonic acid, sulfomethylated acrylamide, phosphonomethylated acrylamide, and the like.

[0032] Illustrative, non-limiting examples of cationic monomers include dialkylaminoalkyl acrylates and methacrylates and their quaternary 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 sulfuric acid salt, dimethylaminoethyl acrylate hydrochloric acid salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfuric acid salt, dimethylaminoethyl methacrylate hydrochloric acid salt, dialkylaminoalkylacrylamides or methacrylamides and their quaternary or acid salts, such as acrylamidopropyltrimethylammonium chloride, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, methacrylarnidopropyl trimethylammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl acrylamide hydrochloric acid salt, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt, diethylaminoethylacrylate, diethylaminoethylmethacrylate, diallyldiethylammonium chloride, diallyldimethylammonium chloride, and the like.

[0033] Illustrative, non-limiting examples of zwitterionic monomers include N,N-dimethyl-N-acryloyloxyethyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(3-sulfopropyl)-ammonium betaine, N,N-dimethyl-N-acrylamidopropyl-N-(2-carboxymethyl)-ammonium betaine, 2-(methylthio)ethyl methacryloyl-S-(sulfopropyl)-sulfonium betaine, 2-[(2-acryloylethyl)dimethylammonio]ethyl 2-methyl phosphate, 2-(acryloyloxyethyl)-2-(trimethylammonium)ethyl phosphate, [(2-acryloylethyl)dimethylammonio]methyl phosphonic acid, 2-methacryloyloxyethyl phosphorylcholine (MPC), 2-[(3-acrylamidopropyl)dimethylammonio]ethyl 2-isopropyl phosphate (AAPI), 1-vinyl-3-(3-sulfopropyl) imidazolium hydroxide, (2-acryloxyethyl) carboxymethyl methylsulfonium chloride, 1-(3-sulfopropyl)-2-vinylpyridinium betaine, N-(4-sulfobutyl)-N-methyl-N, N-diallylamine ammonium betaine (MDABS), N,N-diallyl-N-methyl-N-(2-sulfoethyl) ammonium betaine, and the like.

[0034] In some embodiments, the polymer comprises a monomer selected from the group consisting of acrylamide, methacrylamide, 2-(dimethylamino)ethyl acrylate (DMAEA), 2-(dimethylamino)ethyl methacrylate (DMAEM), 3-(dimethylamino) propyl methacrylamide (DMAPMA), 3-(dimethylamino) propyl acrylamide (DMAPA), 3-methacrylamidopropyl-trimethyl-ammonium chloride (MAPTAC), 3-acrylamidopropyl-trimethyl-ammonium chloride (APTAC), N-vinyl pyrrolidone (NVP), diallyldimethylammonium chloride (DADMAC), diallylamine, 2-(acryloyloxy)-N,N, N-trimethylethanaminium chloride (DMAEA.MCQ), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (DMAEM.MCQ), N,N-dimethylaminoethyl acrylate benzyl chloride (DMAEA.BCQ), N, N-dimethylaminoethyl methacrylate benzyl chloride (DMAEM.BCQ), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), 2-acrylamido-2-methylbutane sulfonic acid (AMBS), acrylamide tertbutylsulfonate (ATBS), [2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid, acrylic acid, methacrylic acid, maleic acid, itaconic acid, a salt of any of the foregoing monomer units, and any combination thereof.

[0035] In some embodiments, the polymer comprises a glyoxalated polyacrylamide (GPAM), a polyvinylamine (PVAM), a polyethylenimine (PEI), a polyamidoamine epichlorohydrin (PAE), or any combination thereof.

[0036] Additional examples of polymers can be found in Table 1.

TABLE-US-00001 TABLE 1 MW Sample polymer chemistry (SEC/MALLS) Comment Polymer AcAm/AA/DMAEAMCQ >1 mil dalton latex 1 48/2/50 (mol %) Polymer AcAm/AA/DMAEAMCQ >1 mil dalton latex 2 45/5/50 (mol %) Polymer DADMAC/AA 90/10 (mol %) 500-1000 kd solution 3 polymer Polymer DADMAC/AA 95/5 (mol %) 500-1000 kd solution 4 polymer Polymer AcAm/AA/DMAEAMCQ 300-500 kd solution 5 40/30/30 (mol %) polymer Polymer AcAm/AA 95/5 mol % 100 kd solution 6 polymer Polymer AcAm/AA 99/1 mol % 100 kd solution 7 polymer Polymer AcAm/DMAEAMCQ 90/10 480 kd solution 8 (mol %) polymer Polymer AcAm/DMAEAMCQ 90/10 830 kd solution 9 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA/ 500 kd solution 10 DAAM 85.5/8/4/2.5 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA/ 920 kd solution 11 DAAM 85.5/8/4/2.5 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA/ 1300 kd solution 12 DAAM 80.5/8/4/7.5 (mol %) polymer Polymer AcAm/DMAEAMCQ/AAEM 550 kd solution 13 90/5/5 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 510 kd solution 14 88/8/4 (mol %) polymer Polymer AcAm/APTAC 90/10 (mol %) 490 kd solution 15 polymer Polymer AcAm/DMAEAMCQ/AA = 540 kd solution 16 90/8/2 (mole %) polymer Polymer AcAm/DMAEAMCQ/ATBS = 510 kd solution 17 90/8/2 (mole %) polymer Polymer AcAm/AA = 96/4 (mol) 530 kd solution 18 polymer Polymer AcAm/DMAEAMCQ/AA 210 kd solution 19 88/8/4 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 240 kd MBA 20 88/8/4 (mol %) crosslinked Polymer AcAm/DMAEAMCQ/AA 310 kd MBA 21 88/8/4 (mol %) crosslinked Polymer AcAm/DMAEAMCQ/AA 470 kd solution 22 86/8/6 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 500 kd solution 23 84/8/8 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 520 kd solution 24 92/4/4 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 860 kd solution 25 88/8/4 (mol %) polymer Polymer AcAm/DMAEAMCQ/ATBS 540 kd solution 26 88/8/4 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 530 kd MBA 27 88/8/4 (mol %) crosslinked Polymer AcAm/DMAEAMCQ/AA 760 kd MBA 28 88/8/4 (mol %) crosslinked Polymer AcAm/DMAEAMCQ/AA 200 kd solution 29 86/8/6 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 210 kd solution 30 84/8/8 (mol %) polymer Polymer AcAm/ATBS = 88.3/11.7 720 kd solution 31 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 260 kd solution 32 90/4/6 (mol %) polymer Polymer AcAm/DMAEAMCQ/AA 590 kd solution 33 91/8/1 (mol %) polymer Polymer AcAm/DMAEAMCQ/MAA = ~1,000 kd dry 34 90/9.8/0.2 (mole %) powder Polymer AcAm/DMAEAMCQ/AA ~1,000 kd dry 35 88/8/4 (mol %) powder Polymer AcAm/DMAEAMCQ/AA ~1,000 kd dry 36 83/15/2 (mol %) powder Polymer AcAm/DMAEAMCQ/MAA = ~500 kd dry 37 90/9.5/0.5(mole %) powder Polymer AcAm/DMAEAMCQ/MAA = ~2,000 kd dry 38 90/9.9/0.1 (mole %) powder Polymer AcAm/MAA = 100 (mole %) ~1,000 kd dry 39 powder Polymer homopolyacrylamide 570 kd solution 40 polymer Polymer AcAm/DMAEAMCQ/AA 1500 kd solution 41 88/8/4 (mol %) polymer Polymer AcAm/DMAEA/AA 88/8/4 530 kd Solution 42 (mol %) polymer

[0037] In Table 1, DAAM refers to diacetone acrylamide, AAEM refers to acetoacetoxyethyl methacrylate, and MAA refers to methacrylic acid. In some embodiments, the polymer comprises about 90 mol % acrylamide, about 8 mol % DMAEA.MCQ and about 2 mol % itaconic acid.

[0038] The mole percentage of each monomer in the polymer is not particularly limited. In some embodiments, the polymer comprises from about 1 mol % to about 99 mol % of the cationic monomer. For example, the polymer may comprise from about 1 mol % to about 90 mol %, from about 1 mol % to about 80 mol %, from about 1 mol % to about 70 mol %, from about 1 mol % to about 60 mol %, from about 1 mol % to about 50 mol %, from about 1 mol % to about 40 mol %, from about 1 mol % to about 30 mol %, from about 1 mol % to about 20 mol %, from about 1 mol % to about 10 mol %, from about 10 mol % to about 99 mol %, from about 20 mol % to about 99 mol %, from about 30 mol % to about 99 mol %, from about 40 mol % to about 99 mol %, from about 50 mol % to about 99 mol %, from about 60 mol % to about 99 mol %, from about 70 mol % to about 99 mol %, from about 80 mol % to about 99 mol %, or from about 90 mol % to about 99 mol % of a cationic monomer.

[0039] In some embodiments, the polymer comprises from about 1 mol % to about 99 mol % of the anionic monomer. For example, the polymer may comprise from about 1 mol % to about 90 mol %, from about 1 mol % to about 80 mol %, from about 1 mol % to about 70 mol %, from about 1 mol % to about 60 mol %, from about 1 mol % to about 50 mol %, from about 1 mol % to about 40 mol %, from about 1 mol % to about 30 mol %, from about 1 mol % to about 20 mol %, from about 1 mol % to about 10 mol %, from about 10 mol % to about 99 mol %, from about 20 mol % to about 99 mol %, from about 30 mol % to about 99 mol %, from about 40 mol % to about 99 mol %, from about 50 mol % to about 99 mol %, from about 60 mol % to about 99 mol %, from about 70 mol % to about 99 mol %, from about 80 mol % to about 99 mol %, or from about 90 mol % to about 99 mol % of an anionic monomer.

[0040] In some embodiments, the polymer comprises from about 1 mol % to about 99 mol % of a non-ionic monomer. For example, the polymer may comprise from about 1 mol % to about 90 mol %, from about 1 mol % to about 80 mol %, from about 1 mol % to about 70 mol %, from about 1 mol % to about 60 mol %, from about 1 mol % to about 50 mol %, from about 1 mol % to about 40 mol %, from about 1 mol % to about 30 mol %, from about 1 mol % to about 20 mol %, from about 1 mol % to about 10 mol %, from about 10 mol % to about 99 mol %, from about 20 mol % to about 99 mol %, from about 30 mol % to about 99 mol %, from about 40 mol % to about 99 mol %, from about 50 mol % to about 99 mol %, from about 60 mol % to about 99 mol %, from about 70 mol % to about 99 mol %, from about 80 mol % to about 99 mol %, or from about 90 mol % to about 99 mol % of a non-ionic monomer.

[0041] In some embodiments, the polymer comprises from about 1 mol % to about 99 mol % of a zwitterionic monomer. For example, the polymer may comprise from about 1 mol % to about 90 mol %, from about 1 mol % to about 80 mol %, from about 1 mol % to about 70 mol %, from about 1 mol % to about 60 mol %, from about 1 mol % to about 50 mol %, from about 1 mol % to about 40 mol %, from about 1 mol % to about 30 mol %, from about 1 mol % to about 20 mol %, from about 1 mol % to about 10 mol %, from about 10 mol % to about 99 mol %, from about 20 mol % to about 99 mol %, from about 30 mol % to about 99 mol %, from about 40 mol % to about 99 mol %, from about 50 mol % to about 99 mol %, from about 60 mol % to about 99 mol %, from about 70 mol % to about 99 mol %, from about 80 mol % to about 99 mol %, or from about 90 mol % to about 99 mol % of a zwitterionic monomer.

[0042] In certain embodiments, the polymer disclosed herein comprises from about 1 mol % to about 10 mol % of the cationic monomer and about 1 mol % to about 5 mol % of the anionic monomer. For example, the polymer may comprise from about 5 mol % to about 10 mol % of the cationic monomer, such as about 6 mol %, about 7 mol %, about 8 mol %, or about 9 mol % of the cationic monomer, and about 1 mol %, about 2 mol %, about 3 mol %, about 4 mol %, or about 5 mol % of the anionic monomer.

[0043] In some embodiments, the polymer is not a disaccharide or a polysaccharide. In certain embodiments, the polymer excludes monosaccharide monomers. In certain embodiments, the composition or particle disclosed herein excludes a polysaccharide, an anionic polysaccharide, and/or pulp fibers. In some embodiments, the polymer excludes a hydroxamic acid group, an isocyanate group, N-bromoamine and/or N-chloroamine. In certain embodiments, the polymer comprises unmodified/unreacted amide and/or amine side chains. In some embodiments, if the polymer comprises amide and/or amine side chains, less than 10% of those side chains, such as less than 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or 0%, are modified/reacted with other functional groups before the polymer is embedded within a colloidal aluminum hydroxide complex and/or a colloidal ferric hydroxide complex.

[0044] In some embodiments, a polymer of the present disclosure is a water-soluble amphoteric polymer containing a carboxylic acid group. In certain embodiments, a polymer of the present disclosure may be linear, branched, crosslinked, structured, synthetic, semi-synthetic, natural, and/or functionally modified. A polymer of the present disclosure can be in the form of a solution, a dry powder, a liquid, or a dispersion, for example.

[0045] The weight average molecular weight of the polymer is not particularly limited. In some embodiments, the polymer has a molecular weight ranging from about 10,000 Da to about 10,000,000 Da. For example, the polymer may have a molecular weight ranging from about 10,000 Da to about 5,000,000 Da, from about 10,000 Da to about 3,000,000 Da, from about 10,000 Da to about 1,000,000 Da, from about 10,000 Da to about 750,000 Da, from about 10,000 Da to about 500,000 Da, from about 10,000 Da to about 250,000 Da, from about 10,000 Da to about 100,000 Da, from about 10,000 Da to about 50,000 Da, from about 100,000 Da to about 10,000,000 Da, from about 500,000 Da to about 10,000,000 Da, from about 750,000 Da to about 10,000,000 Da, from about 1,000,000 Da to about 10,000,000 Da, from about 3,000,000 Da to about 10,000,000 Da, from about 5,000,000 Da to about 10,000,000 Da or from about 8,000,000 Da to about 10,000,000 Da.

[0046] As additional examples, the weight average molecular weight of the polymer may be from about 200,000 Da to about 1,000,000 Da, such as from about 200,000 Da to about 800,000 Da, from about 200,000 Da to about 600,000 Da, or from about 300,000 to about 500,000 Da.

[0047] In the SEC/MALLS analysis of the present disclosure, the polymer solution was diluted with an aqueous mobile phase (0.3M NaCl, 0.1M NaH.sub.2PO.sub.4, 25 ppm NaN.sub.3) to about 0.05%. About 200 L of the solution was injected into a set of TSKgel PW columns (TSKgel GMPW+GMPW+G1000PW), and the mobile phase had a flow rate of about 1.0 mL/min. Bovine serum albumin (BSA) was used as standard for multiangle light scattering detector normalization. The calibration constant of the RI detector was verified with sodium chloride (NaCl).

[0048] In some embodiments, the polymer may be crosslinked with the aluminum or iron of the aluminum hydroxide complex or the ferric hydroxide complex. In some embodiments, the polymer has a degree of crosslinking greater than 1%, greater than 2%, greater than 3%, greater than 4%, greater than 5%, greater than 6%, greater than 7%, greater than 8%, greater than 9% or greater than 10%. In certain embodiments, the polymer has a degree of crosslinking less than about 50%, less than about 40%, less than about 30% or less than about 20%. For example, the polymer may have a degree of crosslinking from about 1% to about 50%, from about 5% to about 50%, from about 10% to about 50%, from about 15% to about 50%, from about 20% to about 50%, from about 30% to about 50%, from about 2% to about 25%, from about 2% to about 20%, from about 2% to about 15%, from about 2% to about 10%, from about 3% to about 25%, from about 3% to about 20%, from about 3% to about 15%, from about 3% to about 10%, from about 4% to about 25%, from about 4% to about 20%, from about 4% to about 15% or from about 4% to about 10%.

[0049] In some embodiments, the crosslink is formed from an interaction/reaction of an anionic monomer and the iron and/or aluminum. For example, the polymer may comprise a carboxylic acid group and a crosslink may be formed from a reaction/interaction between the carboxylic acid group and the iron and/or aluminum.

[0050] The polymer of the present disclosure may have, in some embodiments, a charge density between about 1.0 meq/g to about 8.5 meq/g at neutral pH. In some embodiments, the polymer comprises a cationic charge density of greater than about 0.5 meq/g or greater than about 1.5 meq/g at neutral pH. For example, the polymer may have a cationic charge density of about 1.0 to about 8.0, about 1.0 to about 7.5, about 1.0 to about 7.0, about-1.0 to about 6.5, about 1.0 to about 6.0, about 1.0 to about 5.5, about 1.0 to about 5.0, about 1.0 to about 4.5, about 1.0 to about 4.0, about 1.0 to about 3.5, about 1.0 to about 3.0, about 1.0 to about 2.5, about 1.0 to about 2.0, about 1.0 to about 1.5, about 1.0 to about 1, about 0.5 to about 4.0, about 0.5 to about 3.0, about 0.5 to about 2.0, about 1.0 to about 4.0, about 1.0 to about 3.5, about 1.0 to about 3.0, about 1.0 to about 2.5, about 1.0 to about 2.0, about 1.0 to about 8.5, about 1.5 to about 8.5, about 2.0 to about 8.5, about 2.5 to about 8.5, about 3.0 to about 8.5, about 3.5 to about 8.5, about 4.0 to about 8.5, about 5.0 to about 8.5, about 6.0 to about 8.5, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, or about 1.9 meq/g at neutral pH (about 7).

[0051] An aqueous medium may comprise the colloidal particle (thereby forming an aqueous colloidal composition) and the aqueous medium may have a pH, for example, from about 2 to about 8.5, from about 4.5 to about 8.5, from about 5.5 to about 8.5, from about 5.5 to about 8, from about 6 to about 8 or from about 7 to about 8. In some embodiments, the aqueous medium comprises a pH from about 3.5 to about 8.5.

[0052] In some embodiments, the colloidal particle is water-insoluble.

[0053] In certain embodiments, the colloidal particle is prepared by adding a polymer disclosed herein to an aqueous solvent, such as water, and then adding an aluminum salt and/or ferric salt to the solvent. The polymer and metal salt can be added continuously, intermittently, and in any order. In some embodiments, the polymer and metal salt are co-fed into the solvent.

[0054] In some embodiments, the solvent comprises about 0.01 wt. % to about 10 wt. % of the polymer, such as from about 0.01 wt. % to about 9 wt. %, about 0.01 wt. % to about 8 wt. %, about 0.01 wt. % to about 7 wt. %, about 0.01 wt. % to about 6 wt. %, about 0.01 wt. % to about 5 wt. %, about 0.01 wt. % to about 4 wt. %, about 0.01 wt. % to about 3 wt. %, about 0.01 wt. % to about 2 wt. %, or about 0.01 wt. % to about 1 wt. % of the polymer.

[0055] In some embodiments, the solvent comprises a weight ratio of the aluminum salt and/or the ferric salt to the polymer from about 0.05:1 to 100:1. For example, the solvent may comprise a weight ratio of the aluminum salt and/or the ferric salt to the polymer from about 0.1:1, about 0.5:1, about 1:1, about 5:1, about 10:1, about 20:1, about 30:1, about 40:1, about 50:1, about 60:1, about 70:1, about 80:1, or about 90:1. In some embodiments, the solvent comprises more aluminum salt and/or ferric salt than polymer.

[0056] As an illustrative example, if a weight ratio of PAC (based on Al2O3) to the polymer was about 1:1, the aluminum ion would be about 159 mol % of the polymer. As an additional, non-limiting example, if a weight ratio of PAC to polymer was about 0.1:1, the aluminum ion would be about 15.9 mol % of the polymer.

[0057] The aqueous solvent may have a pH from, for example, about 1.0 to about 6.5 and, after at least some of the polymer and metal salt have been added, the pH may be raised to about 7.0, about 7.5, about 8.0, about 8.5, or higher. In some embodiments, the pH of the composition may be raised by adding a base, such as sodium hydroxide, diluting the composition with water, etc. In certain embodiments, the pH of the composition is raised by adding it to a tissue making process water, wherein a pH of the tissue making process water may be from, for example, about 6.5 to about 8.5. While an amount of colloidal particle may form in the composition before the pH is raised, the substantial majority or all of the colloidal particle forms after the pH is raised.

[0058] The colloidal particle has a weight ratio of aluminum hydroxide and/or ferric hydroxide to the polymer from about 0.1:99 to about 99:0.1. For example, the weight ratio may be from about 0.1:50 to about 50:0.1, from about 0.1:25 to about 25:0.1, from about 0.1:10 to about 10:0.1, from about 0.1:5 to about 5:0.1 or from about 0.1:2 to about 2:0.1. In certain embodiments, a weight ratio of the aluminum hydroxide and/or ferric hydroxide to the polymer is from about 0.1:1 to about 2:1. In some embodiments, a weight ratio of the aluminum hydroxide and/or ferric hydroxide to the polymer is from about 0.1:1 to about 0.9:1 or 0.1:1 to about 0.5:1.

[0059] The colloidal particle comprises from about 1 wt. % to about 99 wt. % of the polymer. For example, the colloidal particle may comprise form about 5 wt. % to about 99 wt. %, from about 5 wt. % to about 95 wt. %, from about 10 wt. % to about 99 wt. %, or from about 10 wt. % to about 90 wt. % of the polymer.

[0060] The colloidal particle comprises from about 1 wt. % to about 99 wt. % of the aluminum hydroxide and/or the ferric hydroxide. For example, the colloidal particle may comprise form about 5 wt. % to about 99 wt. %, from about 5 wt. % to about 95 wt. %, from about 10 wt. % to about 99 wt. %, or from about 10 wt. % to about 90 wt. % of the aluminum hydroxide and/or the ferric hydroxide.

[0061] The colloidal particle has an average particle size ranging from about 0.01 to about 10 microns. For example, the average particle size may be from about 0.05 to about 10 microns, from about 0.05 to about 8 microns, from about 0.05 to about 6 microns, from about 0.05 to about 4 microns, from about 0.05 to about 2 microns, from about 0.05 to about 1 micron, from about 0.1 to about 5 microns, from about 0.1 to about 4 microns, from about 0.1 to about 3 microns, from about 0.1 to about 2 microns, or from about 0.1 to about 1 micron.

[0062] As additional examples, the average particle size may be from about 50 nm to about 500 nm, such as from about 50 nm to about 400 nm, about 50 nm to about 300 nm, about 100 nm to about 200 nm, about 100 nm to about 300 nm, or about 100 nm to about 400 nm.

[0063] In some embodiments, an aqueous composition may comprise at least about 0.01 wt. % of the colloidal particles, based on the dosage of the particles to the aqueous slurry of cellulosic fiber, such as a tissue making furnish. In some embodiments, the composition comprises greater than 0.01 wt. % of the particles to about 10 wt. % of the particles, such as greater than about 0.02 wt. %, greater than about 0.05 wt. %, greater than about 1 wt. %, greater than about 2 wt. %, or greater than about 3 wt. % to about 5 wt. % of the particles. The percentages in this paragraph refer to the dosage of particles relative to solid fiber dispersed in the furnish.

[0064] The compositions and/or particles disclosed herein may include additional tissue making additives including, but not limited to, a dry strength agent, a wet strength agent, a temporary wet strength agent, a dry strength agent, a debonding agent, a softening agent, a dye, a filler, a retention aid, an optical brightener, a pigment, a dewatering agent, a microparticle, a coagulant, an enzyme, an absorbency aid, a flocculant, a coagulant, a humectant, an emollient, a bactericide, a buffer, a lotion, a perfume, a superabsorbent, a fungicide, a moisturizer, and any combination thereof.

[0065] The softening agent may be selected from, for example, organic quaternary salts having fatty chains of about 12 to about 22 carbon atoms, such as dialkyl imidazolinium quaternary salts, dialkyl diamidoamine quaternary salts, monoalkyl trimethylammonium quaternary salts, dialkyl dimethylammonium quaternary salts, trialkyl monomethylammonium quaternary salts, ethoxylated quaternary salts, dialkyl and trialkyl ester quaternary salts, and the like. Additional suitable additives include polysiloxanes, quaternary silicones, organoreactive polysiloxanes, amino-functional polydimethylsiloxanes, and the like.

[0066] The amount of the optional additional additive may vary depending upon the particular circumstances. For example, the composition may comprise from about 0.1 wt. % to about 20 wt. % of the additional additive, such as from about 0.1 wt. % to about 18 wt. %, about 0.1 wt. % to about 16 wt. %, about 0.1 wt. % to about 14 wt. %, about 0.1 wt. % to about 12 wt. %, about 0.1 wt. % to about 10 wt. %, about 0.1 wt. % to about 8 wt. %, about 0.1 wt. % to about 6 wt. %, about 0.1 wt. % to about 4 wt. %, about 0.1 wt. % to about 2 wt. %, or about 0.1 wt. % to about 1 wt. % of the additional additive.

[0067] The present disclosure also provides methods of using the presently disclosed compositions and particles in a tissue making process. For example, a composition and/or particle may be added to a tissue making machine, such as to the tissue making furnish or tissue making process water, in order to achieve the strength target and/or softness of the resulting tissue product through reduction in refining or substitution of long fibers by short fibers.

[0068] In some embodiments, a composition comprising the particle is added to the tissue making machine. For example, the polymer may be premixed with a trivalent ion, such as an aluminum salt and/or a ferric salt, in an aqueous medium to form the particle and the resulting mixture may be added to the tissue making machine.

[0069] In some embodiments, a composition comprises the polymer and inorganic salt, such as the aluminum salt and/or the ferric salt. This composition may optionally comprise an amount of a colloidal particle as defined herein, such as from about 0 wt. % to about 20 wt. %, about 0 wt. % to about 15 wt. %, about 0 wt. % to about 10 wt. %, about 0 wt. % to about 5 wt. %, or about 0 wt. % to about 1 wt. %.

[0070] The composition may be an aqueous composition comprising a pH from about 1 to about 14, such as from about 1 to about 10, from about 1 to about 9, from about 1 to about 8.5, from about 3 to about 14, from about 3 to about 10, from about 3 to about 8.5, from about 3.5 to about 8.5, from about 5 to about 14, from about 5 to about 10 or from about 5 to about 8. In certain embodiments, the composition comprises a pH of about 1 to about 7, such as from about 3 to about 5.

[0071] In some embodiments, the composition comprises a weight ratio of the aluminum salt and/or the ferric salt to the polymer from about 0.05:1 to 100:1. For example, the composition may comprise a weight ratio of the aluminum salt and/or the ferric salt to the polymer from about 0.1:1, about 0.5:1, about 1:1, about 5:1, about 10:1, about 20:1, about 30:1, about 40:1, about 50:1, about 60:1, about 70:1, about 80:1, or about 90:1. In some embodiments, the composition comprises more aluminum salt and/or ferric salt than polymer.

[0072] In certain embodiments, the composition comprises from about 0.01 wt. % to about 10 wt. % of the polymer. For example, the composition may comprise from about 0.01 wt. % to about 9 wt. %, from about 0.01 wt. % to about 8 wt. %, from about 0.01 wt. % to about 7 wt. %, from about 0.01 wt. % to about 6 wt. %, from about 0.01 wt. % to about 5 wt. %, from about 0.01 wt. % to about 4 wt. %, from about 0.01 wt. % to about 3 wt. %, from about 0.01 wt. % to about 2 wt. %, or from about 0.01 wt. % to about 1 wt. % of the polymer.

[0073] In some embodiments, the polymer comprises one or more anionic monomers. The pH of the aqueous composition may be adjusted such that it is greater than the lowest pKa value of a monomer of the polymer. The pKa of an anionic monomer equals the pH value while 50% anionic monomer carries an anionic charge. When the solution pH is higher than the pKa, more anionic charge sites will appear on the polymer chain that can promote its interaction with trivalent ions and their derivatives. If the aqueous composition comprising the polymer is being added separately from the inorganic salt, such as when the polymer and inorganic salt are being co-fed, the pH of the aqueous composition comprising the polymer may be adjusted as described in the foregoing paragraph.

[0074] In some embodiments, the polymer and the aluminum salt and/or ferric salt are co-fed into a location, such as into a reaction vessel, a storage tank, the tissue making machine, etc. Other components, such as retention aids, dewatering agents, strength aids, or any of the additional tissue making additives disclosed herein may also be co-fed alongside the polymer and/or inorganic salt. In some embodiments when the polymer and inorganic salt are co-fed into a location, the particle is formed in the location, such as in a reaction vessel, a storage tank, and/or a tissue making machine, such as in the furnish. In some embodiments, the tissue making process water receiving the polymer, inorganic salt, and/or colloidal particle has a near-neutral pH, such as a pH from about 5.5 to about 8.5 or from about 6 to about 8.

[0075] For example, an injection pipe may lead to a location in the tissue making furnish and the pipe may inject polymer into the furnish. An adjacent pipe may be present and it may add additional chemical(s), such as inorganic salts. Each chemical addition may be continuous or intermittent, for example. Since the injection pipes are adjacent or substantially adjacent to one another, the chemicals are fed to substantially the same location in the furnish at substantially the same time. The chemicals may interact in the furnish and form a colloidal particle.

[0076] Thus, in some embodiments, a colloidal particle is formed in the furnish or process water and optionally a colloidal particle is additionally or alternatively added to the furnish or process water. In some embodiments, a colloidal particle may form in a composition before the composition is added to the tissue furnish or process water and optionally a colloidal particle may form in the furnish or process water.

[0077] Any appropriate aluminum salt may be selected and used with the presently disclosed innovation. In some embodiments, the aluminum salt is selected from the group consisting of aluminum chloride, aluminum chloride hydrate, aluminum sulfate, alum, PAC, aluminum chlorohydrate, a compound having the formula Al.sub.nCl.sub.(3n-m)(OH).sub.m, wherein m is an integer from 0-100, n is an integer from 1-100, and m is less than 3n, and any combination thereof.

[0078] Any appropriate ferric salt may be selected and used with the presently disclosed innovation. In some embodiments, the ferric salt is selected from the group consisting of ferric chloride, ferric sulfate, a polyferric salt, and any combination thereof.

[0079] The compositions, particles, polymers, aluminum salts and/or ferric salts can be added at any location or at any time during a tissue making process. Two or more of the components may be added together and/or two or more components may be co-fed into the tissue making machine. For example, the compositions, particles, polymers, aluminum salts and/or ferric salts may be added together, separately, and/or co-fed to the thin stock, the thick stock, the headbox, before the headbox, after the headbox, before a press section, and/or any combination of the foregoing locations. The composition, salts, polymers, and/or particles can be added to a liquid medium of the tissue making process, such as the process water or furnish.

[0080] In some embodiments, the polymer is added to the tissue making process, such as to the furnish, before, after, and/or concurrently with the aluminum and/or ferric salt. The polymer and aluminum and/or ferric salt may be added at the same location and/or at different locations.

[0081] In some embodiments, a composition comprising any one or more of aluminum salt, ferric salt, polymer, and particle is added during a tissue making process, such as to a pulp slurry prior to formation of the tissue product. In some embodiments, one or more of the aluminum salt, ferric salt, polymer, and particle may be added separately into the tissue making process, such as by co-feeding. In certain embodiments, the aluminum and/or ferric salt and the polymer are premixed prior to addition to the pulp slurry.

[0082] An illustrative, non-limiting embodiment of a tissue making process/machine is shown in FIG. 1. The tissue manufacturing process can be organized into different general sections. For example, with respect to FIG. 1, a section includes the location where a pulp furnish exits a headbox and is disposed as a thin layer wet web on a forming fabric. The headbox creates turbulence to keep the fibers from clumping together and uniformly distributes the slurry across the width of the forming fabric. At this point, the sheet has about 0.1% consistency, meaning it comprises about 99.9% moisture and about 0.1% fiber in the wet web. Liquid drains through the forming fabric using, for example, gravity, centrifugal force, a vacuum, or any combination thereof.

[0083] The sheet travels from the forming fabric to the felt, which is located in the press section. The press section removes much of the remaining water via gravity and pressing against the Yankee dryer before sheet transfer. As the sheet travels around the Yankee dryer, the consistency increases, as shown in FIG. 1. The sheet is removed from the dryer by a doctor blade when the consistency is about 95%. At this point, there are various steps that can be carried out depending upon the intended use of the sheet. Finally, the dried substrate may pass through a finishing section (not shown), such as a calendaring section (see, for example, Handbook for Pulp and Paper Technologists, 3rd Edition, by Gary A. Smook, Angus Wilde Publications Inc., (2002) and The Nalco Water Handbook (3rd Edition), by Daniel Flynn, McGraw Hill (2009)).

[0084] It should be noted that the compositions and methods disclosed herein can be used with a conventional tissue making machine, but they can be used with other advanced tissue making machines as well, such as a through-air drying (TAD) machine, a new Tissue Technology (NTT) machine, energy efficiency TAD (eTAD), Quality Rush transfer (QRT), and advanced tissue molding system (ATMOS).

[0085] FIG. 1 shows examples of locations (depicted by arrows) where the composition of the present disclosure may be added. However, as described herein, the compositions, compounds, components, particles, etc., disclosed herein can additionally or alternatively be added at other locations in the papermaking process.

[0086] In some embodiments, the compositions, compounds, components, particles, etc., is added before the sheet is formed. In certain embodiments, the compositions, compounds, components, particles, etc., is added before the sheet is transferred to the felt. In some embodiments, the compositions, compounds, components, particles, etc., is not added after transferring the sheet to the felt. If the methods disclosed herein are carried out on a TAD machine, the compositions, compounds, components, particles, etc., may be added, for example, to a fabric, such as the inner or outer forming wires.

[0087] When using a TAD machine, the wet sheet is dried by means of through-air dryers, whereby hot air is passed through the sheet. This process preserves the bulk of the sheet and provides improved softness. The wet sheet is carried to the through-air dryer by means of a fabric (referred to as a TAD fabric). The TAD fabric has a 3-dimensional character and serves to mold or pattern the wet sheet so that when dry, this pattern remains in the sheet. In order for effective patterning of the sheet to occur, the wet sheet must be pulled into the fabric by a vacuum molding box. However, after the sheet is dry, it must be transferred from the TAD fabric for additional processing.

[0088] In a creped TAD process, the sheet is transferred to a Yankee dryer and creped prior to final winding on the reel. In an un-creped TAD process, the sheet is separated from the fabric and sent directly to the reel. In both processes, the sheet that has been intimately molded into the 3-dimensional TAD fabric must be separated from the TAD fabric without damaging the sheet.

[0089] The amount of polymer and aluminum and/or ferric salt added to the tissue making process is not particularly limited. In some embodiments, from about 0.1 to about 100 lb/ton of the aluminum and/or ferric salt, relative to solid fiber, is added to the tissue making process, such as to the pulp slurry. For example, from about 0.1 to about 75 lb/ton, from about 0.1 to about 50 lb/ton, from about 0.1 to about 25 lb/ton, from about 1 to about 30 lb/ton or from about 1 to about 20 lb/ton of the aluminum and/or ferric salt, relative to solid fiber, is added to the tissue making process, such as to the pulp slurry.

[0090] In some embodiments, from about 0.1 to about 100 lb/ton of the polymer, relative to solid fiber, is added to the tissue making process, such as to the pulp slurry. For example, from about 0.1 to about 75 lb/ton, from about 0.1 to about 50 lb/ton, from about 0.1 to about 25 lb/ton, from about 1 to about 30 lb/ton or from about 1 to about 20 lb/ton of the polymer, relative to solid fiber, is added to the tissue making process, such as to the pulp slurry.

[0091] The present disclosure also provides methods of improving a tissue making process that include the step of treating a component of the tissue making process with the colloidal particle disclosed herein. The term treating as used herein refers to contacting, reacting, mixing, or otherwise bringing together the colloidal particle and the component. As noted throughout the present disclosure, the colloidal particle is formed from mixing a polymer and an aluminum salt and/or ferric salt. In some embodiments, the colloidal particle is water-insoluble and has an average particle size ranging from about 0.01 to about 10 microns. In some embodiments, the colloidal particle is formed in the absence of paper/tissue fibers. For example, the colloidal particle may be formed prior to addition to the tissue making process and contact paper fibers only after formation and addition to the tissue making process.

[0092] In certain embodiments, a component of the tissue making process is treated with a colloidal particle. In certain embodiments, the component is located in the tissue making process water, such as the water of the thin stock, thick stock, furnish, pulp slurry, etc., and the particle is added to the process water to carry out the treating step. In certain embodiments, a polymer and inorganic salt, such as an aluminum salt and/or ferric salt, are added to the process water. The polymer and salt may be added together in a single composition, may be added separately in any order, and/or may be co-fed into the process water. In these embodiments, all or at least some of the colloidal particles are formed in the process water. If the polymer and salt are added together in a single composition, the composition may optionally comprise some colloidal particles.

[0093] Any component of the tissue making process may be treated with the compositions, components, compounds and/or particles disclosed herein. In some embodiments, the component to be treated is selected from the group consisting of a fiber, such as a cellulose fiber, a tissue sheet, a tissue product, a fines particle, a filler particle, a pulp, and any combination thereof.

[0094] Additionally, the treating step can be carried out at one or more locations throughout the tissue making process, such as before the headbox, in the headbox, after the headbox, before a press section, and any combination thereof.

[0095] The polymer may comprise any one or more of the polymers disclosed herein, such as a polymer comprising a monomer selected from the group consisting of an anionic monomer, a cationic monomer, a non-ionic monomer, a zwitterionic monomer, and any combination thereof.

[0096] The foregoing may be better understood by reference to the following examples, which are intended for illustrative purposes and are not intended to limit the scope of the disclosure or its application in any way.

Examples

[0097] To test for dry tensile of the tissue sheets, compositions were dosed into a bleached virgin tissue furnish at the wet end of a tissue making system (dilute suspension of fiber in water) at the indicated dosages. Sheets were then formed in a handsheets mold, pressed, and dried. The resulting sheets were allowed to equilibrate at about 23 C. and about 50% RH for about 18 hours before the dry tensile test. In addition, the disintegration of the sheets was tested for flushability.

[0098] In one study, a polyampholyte polymer comprising about 10 mol % DMAEA.MCQ, about 2 mol % AA, and about 88 mol % acrylamide) was crosslinked with PAC at a ratio of about 1:0.5 and concentration of about 0.5%. Four commercially available dry strength polymers including liquid starch, polyelectrolyte complex, and polyampholytes with different cationic charge densities were included for comparison. Liquid starch was dosed to the furnish at about 2, about 4, and about 8 lb/ton by actives. The rest of the dry strength additives were dosed to the fiber stock at about 1, about 2, and about 4 lb/ton by actives. Table 1 shows the polymer sample details. Table 2 shows the dry tensile gained upon addition of the dry strength additives. The results show that the presently claimed technology provides a significant improvement in dry tensile compared to other commercial dry strength additives.

TABLE-US-00002 TABLE 1 Summary of five dry strength additives Dry strength additives Chemistry DSA-1 Cationic liquid starch DSA-2 Polyelectrolyte complex with cationic net charge DSA-3 Polyampholyte + PAC DSA-4 Polyampholyte DSA-5 Polyampholyte

[0099] In Table 1, the polymer of DSA-2 included acrylamide/sodium acrylate (92.5/7.5) copolymer complexed with polyamine, the polymer of DSA-3 included acrylamide/sodium acrylate/DMAEA.MCQ (90/2/8) terpolymer complexed with polyaluminium chloride, and the polymer of DSA-4 and DSA-5 included acrylamide/sodium acrylate/DMAEA.MCQ terpolymer with net charge density of about 0 and 0.5 at neutral pH, respectively.

TABLE-US-00003 TABLE 2 Paper dry tensile gain from five different dry strength additives at different dosages Dosage Dry tensile index % of Dry tensile Sample ID (lb/ton) (N*m/g) 95% CI improvement Blank n/a 31.8 2.9 0.0% DSA-1 2 34.7 1.1 9.1% 4 36.0 1.4 13.4% 8 38.8 1.7 22.2% DSA-2 1 34.2 1.5 7.6% 2 33.8 1.3 6.5% 4 35.6 1.4 12.0% DSA-3 1 34.4 1.4 8.3% 2 37.8 1.5 19.0% 4 40.5 2.2 27.6% DSA-4 1 33.2 1.0 4.5% 2 33.6 1.4 5.9% 4 34.4 1.6 8.3% DSA-5 1 34.9 1.3 9.9% 2 34.6 2.2 9.0% 4 35.8 1.8 12.7%

[0100] Another study was carried out to assess the coverage of the dry strength additives on a fiber surface by zeta potential measurements. As shown in Table 3, the five dry strength additives carry different levels of cationic charges. DSA-4 and DSA-5 have the lowest cationic charge density and therefore their influence on fiber surface charge is minimal. DSA-1 and DSA-3 have comparable cationic charge densities. However, DSA-3 significantly reduces fiber anionic charge density at an equal dosage in comparison to DSA-1, suggesting that DSA-3 has better surface absorbance efficiency than DSA-1. While DSA-2 carries the highest charge density, its surface absorbency efficiency is lower than DSA-3, thus limiting its dry tensile gain.

TABLE-US-00004 TABLE 3 Zeta potential of thin stock at 0.5% consistency after dosing 5 different dry strength additives Dosage Zeta Potential Cationic charge density of DSA Sample ID (lb/ton) (mV) at neutral pH Blank n/a 13.3 n/a DSA-1 4 11.3 1.67 8 5.4 DSA-2 4 10.9 >4 DSA-3 4 4.7 1.7 DSA-4 4 15.6 ~0 DSA-5 4 12.8 0.5

[0101] Another study was carried to assess the dry strength additives on sheet disintegration. In this study, about 0.6 g of the tissue sheet was dipped into 150 ml tap water and mixed for 90 seconds. The flushability was visually evaluated by any residual fiber chunks. As shown in Table 4, no strength additives showed negative impact on sheet flushability.

TABLE-US-00005 TABLE 4 Sheet flushability with 3 different dry strength additives Dosage Sample ID (lb/ton) Sheet flushability Blank n/a Yes DSA-1 8 Yes DSA-2 4 Yes DSA-3 4 Yes

[0102] A pilot machine study was conducted to evaluate the impact of strength additives on the softness of the paper sheet. As demonstrated in Table 5, DSA-1 at a dosage of about 2 lb/ton increased the total dry tensile strength by 16.6% compared to the blank sheet without any strength additives. The hand feel (HF) softness, measured using the Tissue Softness Analyzer (TSA), was approximately 81.8. DSA-2 at the same dosage increased the total dry tensile strength by 23.5% and had an HF softness of 81.7, indicating a lesser negative impact on softness compared to DSA-1. Conversely, DSA-3 at a dosage of 1 lb/ton provided a 24.4% increase in total tensile strength with an HF softness of 82.3, suggesting that DSA-3 has a higher capability for tensile gain with a minimal negative impact on sheet softness. In other words, the paper sheet treated with DSA-3 is both stronger and softer, even at 50% of the dosage of DSA-1 and DSA-2.

TABLE-US-00006 TABLE 5 Dosage Total Dry Tensile Gain TSA- (lb/ton) (%) HF DSA-1 2 16.6 81.8 DSA-2 2 23.5 81.7 DSA-3 1 24.4 82.3

[0103] All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. In addition, unless expressly stated to the contrary, use of the term a is intended to include at least one or one or more. For example, a polymer is intended to include at least one polymer or one or more polymers.

[0104] Any ranges given either in absolute terms or in approximate terms are intended to encompass both, and any definitions used herein are intended to be clarifying and not limiting. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges (including all fractional and whole values) subsumed therein.

[0105] Any composition disclosed herein may comprise, consist of, or consist essentially of any element, component and/or ingredient disclosed herein or any combination of two or more of the elements, components or ingredients disclosed herein.

[0106] Any method disclosed herein may comprise, consist of, or consist essentially of any method step disclosed herein or any combination of two or more of the method steps disclosed herein.

[0107] The transitional phrase comprising, which is synonymous with including, containing, or characterized by, is inclusive or open-ended and does not exclude additional, un-recited elements, components, ingredients and/or method steps.

[0108] The transitional phrase consisting of excludes any element, component, ingredient, and/or method step not specified in the claim.

[0109] The transitional phrase consisting essentially of limits the scope of a claim to the specified elements, components, ingredients and/or steps, as well as those that do not materially affect the basic and novel characteristic(s) of the claimed invention.

[0110] Unless specified otherwise, all molecular weights referred to herein are weight average molecular weights and all viscosities were measured at 25 C. with neat (not diluted) polymers.

[0111] As used herein, the term about refers to the cited value being within the errors arising from the standard deviation found in their respective testing measurements, and if those errors cannot be determined, then about may refer to, for example, within 5% of the cited value.

[0112] Furthermore, the invention encompasses any and all possible combinations of some or all of the various embodiments described herein. It should also be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.