Odor Control Pulp Composition

Abstract

To provide fluff pulps with improved odor control and methods of producing such fluff pulps.SOLUTION: A fluff pulp is provided that includes a bleached kraft fiber and a copper ion content from about 0.2 wt.ppm to about 50 wt.ppm of the bleached kraft fiber. The bleached kraft fiber includes: a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of more than about 3.5 meq / 100 grams; an ISO brightness of at least 80; and a viscosity from about 2 cps to about 9 cps.SELECTED DRAWING: None

Description

[Technical field]

[0001]

[0001] The present technology relates generally to fluff pulp with improved odor control and methods for making such fluff pulp. Summary of the Invention

[0002] In one embodiment, a fluff pulp is provided that includes bleached kraft fiber and a copper ion content of about 0.2 ppm to about 50 ppm by weight of the bleached kraft fiber, the bleached kraft fiber having a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of greater than about 3.5 meq / 100 grams, an ISO brightness of at least 80, and a viscosity of about 2 cps to about 9 cps, and the fluff pulp has a copper ion content of about 0.2 ppm to about 50 ppm by weight of the bleached kraft fiber.

[0003] In a related aspect, a method for preparing fluff pulp is provided. The method includes treating the lignocellulosic material by adding about 50 ppm to about 200 ppm by weight of the lignocellulosic material of a catalyst consisting of a combination of copper and iron or salts thereof in the presence of about 0.5% to about 5% by weight of the lignocellulosic material of an oxidizing agent to produce a treated lignocellulosic material. In the method, the weight ratio of iron and iron salts to copper and copper salts is up to about 10:1. The treated lignocellulosic material has a viscosity of about 2 cps to about 6 cps and has at least 50% greater inhibition effect against ammonia formation than a second treated lignocellulosic material formed by a similar method without copper. The lignocellulosic material may be a lignocellulosic kraft pulp, such as a chlorine dioxide bleached lignocellulosic kraft pulp.

[0004]

[0004] In any embodiment herein, the method may include a step of treating lignocellulosic kraft pulp by adding about 50 ppm to about 200 ppm by weight of the lignocellulosic kraft pulp in the presence of about 0.5% to about 5% by weight of the lignocellulosic kraft pulp of an oxidizing agent at an acidic pH to produce a treated lignocellulosic material.

[0005]

[0005] In any embodiment herein, the method may include treating lignocellulosic kraft pulp by adding about 50 ppm to about 150 (or about 200) ppm by weight of the lignocellulosic kraft pulp in the presence of about 0.5% to about 5% by weight of the lignocellulosic kraft pulp of an oxidizing agent at a pH of about 2.5 to about 5 to produce a treated lignocellulosic material, wherein the lignocellulosic kraft pulp is present in an aqueous solution of about 8 wt% to about 12 wt% lignocellulosic kraft pulp based on the water in the solution, the weight ratio of iron and iron salts to copper and copper salts is about 8:1 to about 1:8, and the treated lignocellulosic material has a viscosity of about 3 cps to about 5 cps.

[0006] In a further related aspect, a method for improving odor control properties of fluff pulp is provided, comprising treating a first lignocellulosic material by adding about 3.5 ppm to about 200 ppm of a copper salt and about 25 ppm to about 175 (or about 196.5) ppm of an iron salt at a pH of about 1 to about 9 to form a second lignocellulosic material, wherein the weight ratio of the iron salt to the copper salt is about 8:1 to about 1:1, and the dried second lignocellulosic material has an inhibitory effect against ammonia formation that is at least 50% greater than the dried first lignocellulosic material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] I. Definition The following terms are used throughout as defined below:

[0008] As used herein and in the appended claims, singular forms such as "a," "an," and "the" and similar referents in the context of describing elements (particularly in the context of the claims below) are interpreted to include both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The description of ranges of values ​​herein is intended to be used merely as a shorthand method to refer individually to each separate value within the range, and each separate value is incorporated herein as if it were individually described herein, unless otherwise indicated herein or clearly contradicted by context. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language provided herein (e.g., "etc.") is intended merely to make the embodiments more clear, and does not assert limitations in the claims unless otherwise expressly stated. No language herein should be interpreted to imply any non-claimed element in its nature.

[0008]

[0009] As used herein, "about" will be understood by a person of ordinary skill in the art and will vary to some extent depending on the context in which it is used. If there are uses of the term that are not clear to a person of ordinary skill in the art, "about" will mean up to plus or minus 10% of the particular term, taking into account the context in which it is used.

[0009]

[0010] As will be understood by those skilled in the art, for any and all purposes, and in the sense of providing a specifically written description, all ranges disclosed herein inclusively include any and all possible subranges and combinations of those subranges. Any recited range can be readily recognized as fully descriptive and allowing the same range to be divided into at least two, three, four, five, ten, etc. As a non-limiting example, each range discussed herein can be readily divided into a lower third, a middle third, and an upper third, etc. As will be understood by those skilled in the art, all words such as "up to," "at least," "greater than," "less than," etc. refer to a range that includes the recited number and can be subsequently divided into the subranges discussed above. Finally, as will be understood by those skilled in the art, a range includes each individual element. Thus, for example, a group having 1-3 atoms refers to a group having 1, 2, or 3 atoms. Similarly, a group having 1-5 atoms refers to a group having 1, 2, 3, 4, or 5 atoms, etc.

[0010]

[0011] As used herein, the term "halide" refers to bromide, chloride, fluoride, or iodide. II.This technology

[0012] Cellulose pulp has been used in various personal care or medical absorbent products, such as diaper fluff or incontinence articles. However, odor caused by bodily fluids is a significant problem, such as the ammonia odor from urine in the case of diaper fluff. In other applications, odor problems may be caused by other nitrogen- or sulfur-containing substances.

[0011]

[0013] The present technology is directed to fluff pulp exhibiting improved odor control, and methods for producing such advantageous fluff pulp. The fluff pulp exhibits significantly improved odor control, at least in part, through the use of surprisingly small amounts of copper. The present technology is particularly suited to diaper fluff and incontinence articles, but also applies to any situation in which odor control is beneficial and / or advantageous.

[0012]

[0014] Thus, in one embodiment, there is provided a fluff pulp comprising bleached kraft fiber and a copper ion content of about 0.2 ppm to about 50 ppm by weight of the bleached kraft fiber. The bleached kraft fiber comprises a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of more than about 3.5 meq / 100 grams, an ISO brightness of at least 80, and a viscosity of about 2 cps to about 9 cps. The fluff pulp may or may not include a superabsorbent polymer (SAP), such as sodium polyacrylate polymers and copolymers. The kraft fiber may be derived from softwood fiber, hardwood fiber, or a mixture thereof, as such fibers are described in more detail herein.

[0013]

[0015] As described further herein, in addition to other characteristics of fluff pulp, it has been surprisingly found that the inclusion of copper ion content of about 0.2 ppm to about 50 ppm by weight of copper bleached kraft fiber significantly improves odor control properties compared to copper-free fluff pulp.Indeed, such significant odor control properties from the inclusion of such low copper ion content were not expected by those skilled in the art.

[0014]

[0016] The fluff pulp may have an inhibitory effect on ammonia formation that is at least 50% higher than a second fluff pulp having the same characteristics but not containing copper, i.e., a fluff pulp of the same composition except that copper ions are not contained in the fluff pulp. "Inhibitory effect on ammonia formation" refers to a fluff pulp that exhibits less gaseous ammonia as determined by the tests of Example 1 (no SAP present) and / or Example 2 (SAP present) compared to a fluff pulp of the same composition except that copper ions are not contained in the fluff pulp. Without being bound by theory, this inhibitory effect is believed to be due to the NH 3 Increased absorption of nitrogen-containing compounds, such as NH 3 or a combination of both. The inhibitory effect may be at least about 50% higher, at least about 55% higher, at least about 60% higher, at least about 65% higher, at least about 70% higher, at least about 75% higher, at least about 80% higher, at least about 85% higher, at least about 90% higher, at least about 92% higher, at least about 94% higher, at least about 96% higher, at least about 98% higher, at least about 99% higher, about 100% higher, or any range including and / or between any two of these values.

[0015]

[0017] The copper ions of the copper ion content may be associated with the bleached kraft fiber and / or may be in the form of copper(I) salts, copper(II) salts, hydrates thereof, or any combination of two or more thereof. Copper(I) salts include, but are not limited to, copper(I) chloride, copper(I) oxide, copper(I) sulfate, or any combination of two or more thereof. Copper(II) salts include, but are not limited to, copper(II) carbonate, copper(II) chloride, copper(II) phosphate, copper(II) nitrate, copper(II) perchlorate, copper(II) phosphate, copper(II) sulfate, copper(II) tetrafluoroborate, copper(II) triflate, or any combination of two or more thereof. Non-kraft fiber ligands of copper and / or its salts may be included in the fluff pulp, where such ligands may include, but are not limited to, ethylenediaminetetraacetic acid, (S,S')-ethylenediamine-N,N'-disuccinic acid, diethylenetriaminepentaacetic acid, ethyleneglycol-bis(2-aminoethyl)-N,N,N',N'-tetraacetic acid, trans-1,2-diaminocyclohexanetetraacetic acid, or a mixture of any two or more thereof. The non-kraft fiber ligands may not be included in the fluff pulp. In comparison to non-kraft fiber ligands, "kraft fiber ligands" are a portion or part of the kraft fiber.

[0016]

[0018] The copper ion content of fluff pulp, determined by the weight of bleached kraft fiber, is about 0. The copper ion content may be about 0.2 ppm, about 0.5 ppm, about 1 ppm, about 2 ppm, about 3 ppm, about 4 ppm, about 5 ppm, about 6 ppm, about 7 ppm, about 8 ppm, about 9 ppm, about 10 ppm, about 12 ppm, about 14 ppm, about 16 ppm, about 18 ppm, about 20 ppm, about 22 ppm, about 24 ppm, about 26 ppm, about 28 ppm, about 30 ppm, about 32 ppm, about 34 ppm, about 36 ppm, about 38 ppm, about 40 ppm, about 42 ppm, about 44 ppm, about 46 ppm, about 48 ppm, about 50 ppm, and any range including and / or between any two of these values. The copper ion content may be determined by common analytical methods such as ICP-atomic absorption. Thus, the copper ion content value is expressed as the percentage of Cu relative to the total mass of copper salts (e.g., the total mass of copper sulfate). +1 ions and / or Cu +2 It refers to the mass of the ion itself. As a further example, the mass of the copper ion in copper sulfate is about 0.4 of the total mass of copper sulfate.

[0017]

[0019] The fluff pulp may or may not also contain iron ions. The iron ions associated with the bleached kraft fibers are ferrous (Fe 2+ ) salt, ferric iron (Fe 3+) salts, their hydrates, and combinations of any two or more thereof. The divalent iron salts and / or trivalent iron salts include halides, sulfates, nitrates, phosphates, carbonates, and combinations of any two or more thereof. Examples include, but are not limited to, ferrous sulfate (e.g., ferrous sulfate heptahydrate), ferrous chloride, ferrous ammonium sulfate, ferric chloride, ferric ammonium sulfate, or ferric ammonium citrate. The amount of iron ions in the fluff pulp ("iron ion content") may be from about 0.2 ppm to about 50 ppm by weight of the bleached kraft fiber, and thus the amount of iron ions relative to the weight of the bleached kraft fiber may be about 0.2 ppm, about 0.5 ppm, about 1 ppm, about 2 ppm, about 3 ppm, about 4 ppm, about 5 ppm, about 6 ppm, about 7 ppm, about 8 ppm, about 9 ppm, about 10 ppm, about 12 ppm, about 16 ppm, about 18 ppm, about 20 ppm, about 22 ppm, about 26 ppm, about 28 ppm, about 30 ppm, about 32 ppm, about 36 ppm, about 38 ppm, about 39 ppm, about 40 ... The iron content may be about 14 ppm, about 16 ppm, about 18 ppm, about 20 ppm, about 22 ppm, about 24 ppm, about 26 ppm, about 28 ppm, about 30 ppm, about 32 ppm, about 34 ppm, about 36 ppm, about 38 ppm, about 40 ppm, about 42 ppm, about 44 ppm, about 46 ppm, about 48 ppm, about 50 ppm, or any range including and / or between any two of these values. The iron content may be determined by common analytical methods such as ICP-atomic absorption.

[0018]

[0020] As previously discussed, bleached kraft fibers have a length-weighted average fiber length of at least about 2 mm. Bleached kraft fibers have a length-weighted average fiber length of about 2 mm, about 2.1 mm, about 2.2 mm, about 2.3 mm, about 2.4 mm, about 2.5 mm, about 2.6 mm, about 2.7 mm, about 2.8 mm, about 2.9 mm, about 3.0 mm, about 3.1 mm, about 3.2 mm, about 3.3 mm, about 3.4 mm, about 3.5 mm, about 3.6 mm, about 3.7 mm, about 32.8 mm, about 3.9 mm, about 4.0 mm, or any range of one or more of any of these values, or any range including and / or between any two of these values. Such length-weighted average fiber length may be determined by a Fiber Quality Analyzer™ from OPTEST, Hawkesbury, Ontario, according to the manufacturer's standard procedures.

[0019]

[0021] Bleached kraft fibers have a copper number of less than about 7. Such copper numbers are based on the TAPPI The carboxyl content of bleached kraft fiber may be greater than about 3.5 meq / 100 grams, where the carboxyl content may be measured by TAPPI T430-cm99. The bleached kraft fiber may have a carboxyl content of about 1, about 2, about 3, about 4, about 5, about 6, about 7, or any range less than any one of these values, or any range including and / or between any two of these values. The bleached kraft fiber may also have a carboxyl content greater than about 3.5 meq / 100 grams, where the carboxyl content may be measured by TAPPI T237-cm98. Thus, the carboxyl content of bleached kraft fiber (expressed in meq / 100 grams) may be greater than about 3.6, about 3.8, about 4.0, about 4.5, about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, about 8, or any range including and / or between any two of these values. or any range between the two. The carboxyl content may be measured by TAPPI T237-cm98.

[0020]

[0022] The bleached kraft fiber of the fluff pulp has an ISO brightness of at least 80. The ISO brightness may be determined by TAPPI T525-om02. The ISO brightness of the bleached kraft fiber may be 80, about 82, about 84, about 86, about 88, about 90, about 91, about 92, about 93, about 94, about 95, or any range including and / or between any two of these values. In any embodiment herein, the fluff pulp may be free of optical brighteners.

[0021]

[0023] As previously described herein, the bleached kraft fiber of fluff pulp has a viscosity of about 2 cps to about 9 cps. The viscosity of the bleached kraft fiber may be determined by the TAPPI T230-om99 procedure. Thus, the viscosity of the bleached kraft fiber may be about 2, about 2.5, about 3, about 3.5, about 4, about 4.5, about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, about 8, about 8.5, about 9, or any range including and / or between any two of these values.

[0022]

[0024] In a related aspect, a method for preparing fluff pulp is provided. The method includes treating the lignocellulosic material by adding about 50 ppm to about 200 ppm by weight of the lignocellulosic material of a catalyst consisting of a combination of copper and / or a salt thereof and iron and / or a salt thereof in the presence of about 0.5% to about 5% by weight of the lignocellulosic material of an oxidizing agent to produce a treated lignocellulosic material. In the method, the weight ratio of iron and iron salts to copper and copper salts is up to about 10:1. The treated lignocellulosic material has a viscosity of about 2 cps to about 6 cps and has at least 50% greater inhibition of ammonia formation than a second treated lignocellulosic material formed by a similar method that does not include copper. The inhibitory effect can be at least about 50% greater, at least about 55% greater, at least about 60% greater, at least about 65% greater, at least about 70% greater, at least about 75% greater, at least about 80% greater, at least about 85% greater, at least about 90% greater, at least about 92% greater, at least about 94% greater, at least about 96% greater, at least about 98% greater, at least about 99% greater, about 100% greater, or any range including and / or between any two of these values.

[0023]

[0025] The lignocellulosic material may preferably be wood pulp. The lignocellulosic material may be in fibrous and / or particulate form, such as pulp fibers, fines and / or other pulp fragments, hemicellulose, starch, and / or polysaccharide particles and powders. The lignocellulosic material may also include cellulose derivatives, such as carboxymethyl cellulose, hydroxypropyl cellulose, etc. Useful lignocellulosic materials include, but are not limited to, those derived from known sources of such materials, such as plants. Illustrative examples of useful lignocellulosic materials are polysaccharides, such as starch, as described in U.S. Pat. No. 8,007,635, which is incorporated herein by reference. Illustrative lignocellulosic materials for use in the methods described in any of the embodiments herein are pulp fibers used in the form of tissue paper, towels, diapers, feminine hygiene products and adult incontinence products, and used to make other types of pulp products, paper, and / or cardboard. Such pulp fibers include those derived from hardwood, softwood, or combinations of hardwood and softwood trees that are prepared for use in a papermaking furnish by any known suitable cooking, beating, and / or bleaching operations, such as known mechanical, thermomechanical, chemical and semi-chemical pulping and other pulping processes known to those skilled in the art. As used herein, the term "hardwood pulp" refers to fibrous pulp derived from the woody material of deciduous trees (angiosperms), whereas In the present specification, "softwood pulp" is a fibrous pulp derived from the woody material of conifers (gymnosperms). Useful pulp fibers may be prepared from non-woody herbaceous plants, including, but not limited to, kenaf, hemp, jute, flax, sisal, and / or abaca, although legal regulations and other considerations may make the use of hemp and other fiber sources impractical or impossible. Either bleached or unbleached pulp fibers, such as, for example, unbleached kraft and bleached kraft pulp (collectively, "lignocellulosic kraft pulp"), and / or recycled pulp, may be utilized in any of the embodiments of the methods described herein. The pulp may have been subjected to any of the processing steps that are standard in pulping and bleaching, and may be intentionally modified, for example, by controlled pre-hydrolysis and / or caustic extractives of the chips prior to kraft pulping, acid and / or enzymatic (e.g. cellulase and / or hemicellulase) hydrolysis of the kraft pulp, and / or "cold soda" treatment of the pulp (up to mercerization strength).

[0024]

[0026] "Copper and / or its salts" means elemental copper (Cu 0), copper(I) salts, copper(II) salts, hydrates thereof, or combinations of any two or more thereof. Copper(I) salts include, but are not limited to, copper(I) chloride, copper(I) oxide, copper(I) sulfate, or combinations of any two or more thereof. Copper(II) salts include, but are not limited to, copper(II) carbonate, copper(II) chloride, copper(II) phosphate, copper(II) nitrate, copper(II) perchlorate, copper(II) phosphate, copper(II) sulfate, copper(II) tetrafluoroborate, copper(II) triflate, or combinations of any two or more thereof. In any of the embodiments herein, the amount of copper and / or its salts added may be from about 3.5 ppm to about 199.8 ppm by weight of the lignocellulosic material, and thus the amount of copper or its salts added may be about 3.5 ppm, about 4 ppm, about 4.5 ppm, about 5 ppm, about 5.5 ppm, about 6 ppm, about 7 ppm, about 8 ppm, about 9 ppm, about 10 ppm, about 12 ppm, about 14 ppm, about 16 ppm, about 18 ppm, about 20 ppm, about 22 ppm, about 24 ppm, about 26 ppm, about 28 ppm, about 30 ppm, about 32 ppm, about 36 ppm, about 38 ppm, about 39 ppm, about 40 ppm, about 41 ppm, about 42 ppm, about 43 ppm, about 44 ppm, about 45 ppm, about 46 ppm, about 47 ppm, about 48 ppm, about 49 ppm, about 50 ppm, about 51 ppm, about 52 ppm, about 53 ppm, about 54 ppm, about 55 ppm, about 56 ppm, about 57 ppm, about 58 ppm, about 59 ppm, about 60 ppm, about 61 ppm, about 62 ppm, about 63 ppm, about 64 ppm, about 65 ppm, about 66 ppm, about 67 ppm, about 68 ppm, about 69 ppm, about 70 ppm, about 71 ppm, about 72 ppm, about 75 ppm, about 76 ppm, about 77 ppm, about 78 ppm, about 79 ppm, about 80 ppm, about 81 ppm, about 82 ppm, about 83 ppm, about 84 ppm, about 85 ppm, about 86 ppm, about 87 ppm, about 88 ppm, about 89 ppm, about 90 ppm, about 90 ppm, about 91 ppm, about pm, about 34 ppm, about 36 ppm, about 38 ppm, about 40 ppm, about 42 ppm, about 44 ppm, about 46 ppm, about 48 ppm, about 50 ppm, about 55 ppm, about 60 ppm, about 65 ppm, about 70 ppm, about 75 ppm, about 80 ppm, about 85 ppm, about 90 ppm, about 95 ppm, about 100 ppm, about 120 ppm, about 140 ppm, about 160 ppm, about 180 ppm, about 190 ppm, about 199.8 ppm, about 200 ppm, or any range including and / or between any two of these values.

[0025]

[0027] "Iron and / or its salts" means elemental iron (Fe 0 ), divalent iron (Fe 2+ ) salt, ferric iron (Fe 3+) salts, their hydrates, and combinations of any two or more thereof. Preferred salts of ferrous and / or ferric salts include halides, sulfates, nitrates, phosphates, carbonates, and combinations of any two or more thereof. Examples include, but are not limited to, ferrous sulfate (e.g., ferrous sulfate heptahydrate), ferrous chloride, ferrous ammonium sulfate, ferric chloride, ferric ammonium sulfate, or ferric ammonium citrate. In any of the embodiments herein, the amount of iron or a salt thereof added may be from about 0.2 ppm to about 180 ppm by weight of the lignocellulosic material, and thus the amount of iron or a salt thereof added may be from about 0.2 ppm, about 0.5 ppm, about 1 ppm, about 2 ppm, about 3 ppm, about 4 ppm, about 5 ppm, about 6 ppm, about 7 ppm, about 8 ppm, about 9 ppm, about 10 ppm, about 12 ppm, about 14 ppm, about 16 ppm, about 18 ppm, about 20 ppm, about 22 ppm, about 24 ppm, about 26 ppm, about 28 ppm, about 30 ppm, about 32 ppm, about 34 ppm, about 36 ppm, about 38 ppm, about 40 ppm, about 42 ppm, about 44 ppm, about 46 ppm, about 48 ppm, about 50 ppm, about 55 ppm, about 60 ppm, about 65 ppm, about 70 ppm, about 75 ppm, about 80 ppm, about 85 ppm, about 90 ppm, about 95 ppm, about 100 ppm, about 120 ppm, about 140 ppm, about 160 ppm, about 180 ppm, or any of these values. It may be any range inclusive and / or between the two.

[0026]

[0028] In the method, the weight ratio of iron and iron salts to copper and copper salts is at most about 10:1. By "at most about 10:1," the phrase is meant to include lower ratios of iron and iron salts to copper and copper salts, such as 11:1, but does not encompass ranges in which no iron is included, i.e., there is no ratio at all. The weight ratio of iron and iron salts to copper and copper salts can be about 10:1, about 9:1, about 8:1, about 7:1, about 6:1, about 5:1, about 4:1, about 3:1, about 2:1, about 1:1, about 1:2, about 1:3, about 1:4, about 1:5, about 1:6, about 1:7, about 1:8, about 1:9, about 1:10, or any range including and / or between any two of these values.

[0027]

[0029] The oxidizing agent may include one or more of hydrogen peroxide, chlorine dioxide, hypochlorite, and hypochlorous acid. A preferred oxidizing agent includes hydrogen peroxide. The amount of oxidizing agent is about 0.5% to about 5% oxidizing agent by weight of the lignocellulosic material, and thus the amount of oxidizing agent may be about 0.5%, about 0.6%, about 0.7%, about 0.8%, about 0.9%, about 1%, about 1.2%, about 1.4%, about 1.6%, about 1.8%, about 2%, about 2.2%, about 2.4%, about 2.6%, about 2.8%, about 3%, about 3.2%, about 3.4%, about 3.6%, about 3.8%, about 4%, about 4.2%, about 4.4%, about 4.6%, about 4.8%, about 5%, or any range including and / or between any two of these values.

[0028]

[0030] The catalyst may be added in the presence of an oxidizing agent relative to the weight of the lignocellulosic material at a pH of about 1 to about 9. The treatment pH may vary widely and any temperature sufficient to form the desired treated lignocellulosic material may be used. The treatment pH may be about 1.0, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, about 5.0, about 5.5, about 6.0, about 6.5, about 7.0, about 7.5, about 8.0, about 8.5, about 9.0, or any range including and / or between any two of these values. For example, the pH may be an acidic pH (i.e., from about 1 to less than about 7), and the pH may preferably be from about 2 to about 6, and more preferably from about 2.5 to about 5.

[0029]

[0031] When the amount of another component, e.g., lignocellulosic material, is determined by weight, it is based on the dry weight of the lignocellulosic material. The lignocellulosic material (e.g., lignocellulosic kraft pulp) may be present in the aqueous solution from about 8 wt% to about 16 wt% of the lignocellulosic material based on the water in the solution. Thus, the lignocellulosic material may be present in the aqueous solution at about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, or any range including and / or between these values.

[0030]

[0032] The treatment temperature may vary widely, and any temperature sufficient to form the desired treated lignocellulosic product may be used. The treatment temperature is usually at least about 20°C, although lower temperatures may be used if effective to provide the desired lignocellulosic material. The treatment temperature may be about 20°C, about 40°C, about 50°C, about 60°C, about 65°C, about 70°C, about 75°C, about 80°C, about 85°C, about 90°C, about 95°C, about 100°C, about 110°C, about 120°C, or any range including and / or between any two of these values. The treatment temperature is preferably from about 40°C to about 120°C, even more preferably from about 40°C to about 90°C, and most preferably from about 65°C to about 90°C.

[0031]

[0033] Treatment times may vary widely, and any time sufficient to form the desired treated lignocellulosic product may be used. Treatment times are typically at least about 5 minutes, although longer treatment times may be used if effective to prepare the desired lignocellulosic material. Treatment times of about 5 minutes to about 20 hours, more preferably about 15 minutes to about 10 hours, and even more preferably about 30 minutes to about 4 hours, may be used. Suitable treatment times include about 5 minutes, about 10 minutes, about 30 minutes, about 1 hour, about 1.5 hours, about 2 hours, about 3 hours, about 4 hours, about 6 hours, about 8 hours, about 10 hours, about 15 hours, about 20 hours, or any two of these values ​​and / or any range between two of them.

[0032]

[0034] Alternatively, the method may or may not be carried out in the presence of UV irradiation, preferably when hydrogen peroxide is used as the oxidizing agent in addition to the catalyst and oxidizing agent. Including UV irradiation has the advantage of being more effective at lower temperatures, such as room temperature (or ambient temperature), without the need to heat the equipment, and may be used to extend the pH effective range. For example, the method can be effectively carried out in the presence of UV irradiation, for example at ambient temperature (or without heating), at a near neutral pH (i.e., about 6.8 to about 7.2), and / or for very short periods of time, from a few seconds to about an hour, depending on the UV lamp power. The UV lamp used in the method is preferably a high intensity lamp, such as a medium pressure mercury lamp or variant thereof, a pulsed xenon flash lamp, or an excimer lamp. It is most preferred to use a medium pressure mercury lamp, which is low cost and readily available from commercial sources. One or more UV lamps, typically inserted into a quartz sleeve, may be inserted (submerged) into the pulp for irradiation. It may be more advantageous to place the UV lamp above the mixed suspension of lignocellulosic material. For this type of UV irradiation, mercury lamps and electrodeless power lamps (such as from Fusion UV) may be used. Because UV penetration in water is very low and most chemical action occurs from UV decomposition of peroxides in aqueous solution, it is preferred that the pulp is thoroughly mixed and well agitated during the reaction. In any of the embodiments herein, the UV treatment may be performed with or without the addition of a UV catalyst. Useful UV catalysts include, but are not limited to, micro- or nanoparticulate titanium dioxide or zinc oxide photocatalysts, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis(2-methylpropionitrile) (AIBN), 1,1'-azobiscyclohexanecarbonitrile (e.g., DuPont VAZO® catalyst 88), and / or azo-based water-soluble organic catalysts such as (2,2,6,6-tetramethylpiperidinyl)oxyl (TEMPO).

[0033]

[0035] The method may be carried out batchwise, continuously, or semi-continuously. The method may also be carried out as part of a pulping process, as a process step at the end of a mechanical, semi-chemical, or chemical pulping process, or as part of a multi-stage bleaching process, as a step at the end of a bleaching process (i.e., no further bleaching step is performed after the treatment step of the process). The method may also be used to treat commercial paper pulp and / or fluff pulp, for example by reslashing the commercial paper pulp or fluff pulp in a hydropulper or similar device. Treatment in a hydropulper or similar device has the flexibility to adjust the conditions. As an example, the treatment may start at an acidic pH, and after some suitable time, the treatment includes adjusting to an alkaline pH by adding a caustic agent and continuing the reaction at a higher pH. This combined acid-alkaline treatment can be used to change the ratio of carboxyl to carbonyl groups in the treated lignocellulosic material.

[0034]

[0036] The treated lignocellulosic material may have any one or more of the characteristics described above for fluff pulp (e.g., a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of greater than about 3.5 meq / 100 grams, an ISO brightness of at least 80, and a viscosity of about 2 cps to about 9 cps, or a combination of any two or more thereof), and any ranges described herein. In any embodiment herein, the treated lignocellulosic material may be treated as described above for fluff pulp. The cellulosic material may have a copper ion content of about 0.2 ppm to about 50 ppm by weight of the treated lignocellulosic material, or any range described herein. In any embodiment herein, the treated lignocellulosic material may have an iron ion content of about 0.2 ppm to about 50 ppm by weight of the treated lignocellulosic material, as discussed above for fluff pulp.

[0035]

[0037] In a further related embodiment, a method of improving odor control properties of fluff pulp is provided, the method comprising treating a first lignocellulosic material by adding about 0.5 ppm to about 200 ppm of a copper salt at a pH of about 1 to about 9 to form a second lignocellulosic material, wherein the dried second lignocellulosic material has an inhibitory effect on ammonia formation that is at least 50% greater than the dried first lignocellulosic material. The inhibitory effect may be at least about 50% greater, at least about 55% greater, at least about 60% greater, at least about 65% greater, at least about 70% greater, at least about 75% greater, at least about 80% greater, at least about 85% greater, at least about 90% greater, at least about 92% greater, at least about 94% greater, at least about 96% greater, at least about 98% greater, at least about 99% greater, about 100% greater, or any range including and / or between any two of these values. The pH can be about 1.0, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, about 5.0, about 5.5, about 6.0, about 6.5, about 7.0, about 7.5, about 8.0, about 8.5, about 9.0, or any range including and / or between any two of these values.

[0036]

[0038] In any embodiment of such methods herein, the first lignocellulosic material may contain no more than about 0.2 ppm copper, preferably no more than about 0.1 ppm copper, and more preferably no more than about 0.01 ppm copper. In any embodiment herein, the first lignocellulosic material may contain no detectable copper as measured by ICP-atomic absorption.

[0037]

[0039] Copper salts are described above, and the term "copper salt" is intended to mean any of a single copper salt, a mixture of any two or more copper salts, hydrates of any one or more of the foregoing, and combinations of any two or more thereof, where the amount of copper salt added is about 0.5 ppm, about 0.6 ppm, about 0.7 ppm, about 0.8 ppm, about 0.9 ppm, about 1.0 ppm, about 1.2 ppm, about 1.4 ppm, about 1.6 ppm, about 1.8 ppm, about 2.0 ppm, about 2.5 ppm, about 3.5 ppm, about 4 ppm, about 4.5 ppm, about 5 ppm, about 5.5 ppm, about 6 ppm, about 7 ppm, about 8 ppm, about 9 ppm, about 10 ppm, about 12 ppm, about 14 ppm, about 16 ppm, about 18 ppm, about 20 ppm, about 22 ppm, about 24 ppm, about 26 ppm, about 28 ppm, about 29 ppm, about 30 ppm, about 31 ppm, about 32 ppm, about 33 ppm, about 34 ppm, about 35 ppm, about 36 ppm, about 37 ppm, about 38 ppm, about 39 ppm, about 40 ppm, about 41 ppm, about 42 ppm, about 43 ppm, about 44 ppm, about 45 ppm, about 46 ppm, about 47 ppm, about 48 ppm, about 49 ppm, about 50 ppm, about 51 ppm, about 52 ppm, about 53 ppm, about 54 ppm, about 55 ppm, about 56 ppm, about 57 ppm, about 58 ppm, about 59 ppm, about 60 ppm, about 61 ppm, about 62 ppm, about 63 ppm, about 64 ppm, about 65 ppm, about 66 ppm, about 67 ppm, about 68 ppm, about 69 ppm, about ppm, about 18 ppm, about 20 ppm, about 22 ppm, about 24 ppm, about 25 ppm, about 26 ppm, about 28 ppm, about 30 ppm, about 32 ppm, about 34 ppm, about 36 ppm, about 38 ppm, about 40 ppm, about 42 ppm, about 44 ppm, about 46 ppm, about 48 ppm, about 50 ppm, about 55 ppm, about 60 ppm, about 65 ppm, about 70 ppm, about 75 ppm, about 80 ppm, about 85 ppm, about 90 ppm, about 95 ppm, about 100 ppm, about 120 ppm, about 140 ppm, about 160 ppm, about 180 ppm, about 199.8 ppm, about 200 ppm, or any range including and / or between any two of these values.

[0038]

[0040] The lignocellulosic material is also described above. In the method, the lignocellulosic material is preferably bleached kraft pulp, more preferably fluff pulp comprising bleached kraft fibers. The bleached kraft fiber / pulp may have any one or more characteristics described for the bleached kraft fibers of the fluff pulp of the present technology, such as a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of more than about 3.5 meq / 100 grams, an ISO brightness of at least 80, and a viscosity of about 2 cps to about 9 cps, and or a combination of any two or more thereof), and may have any range described herein.

[0039]

[0041] Additionally, an iron salt, such as about 25 ppm to about 175 ppm of an iron salt, may be added along with the copper salt. The iron salts are described above, where the term "iron salt" is intended to mean any one iron salt, a mixture of any two or more iron salts, a hydrate of any one or more of the foregoing, and combinations of any two or more thereof. The amount of iron salt added can be about 25 ppm, about 26 ppm, about 28 ppm, about 30 ppm, about 32 ppm, about 34 ppm, about 36 ppm, about 38 ppm, about 40 ppm, about 42 ppm, about 44 ppm, about 46 ppm, about 48 ppm, about 50 ppm, about 55 ppm, about 60 ppm, about 65 ppm, about 70 ppm, about 75 ppm, about 80 ppm, about 85 ppm, about 90 ppm, about 95 ppm, about 100 ppm, about 120 ppm, about 140 ppm, about 160 ppm, about 165 ppm, about 170 ppm, about 175 ppm, or any range including and / or between any two of these values. In the method, the weight ratio of iron salt to copper salt is up to about 10:1. By "up to about 10:1," the phrase is meant to include ratios of iron salt to copper salt below, such as 11:1, but does not inclusively include ranges where there is no iron, i.e., no ratio at all. The weight ratio of iron salt to copper salt can be about 10:1, about 9:1, about 8:1, about 7:1, about 6:1, about 5:1, about 4:1, about 3:1, about 2:1, about 1:1, about 1:2, about 1:3, about 1:4, about 1:5, about 1:6, about 1:7, about 1:8, about 1:9, about 1:10, or any range including and / or between any two of these values.

[0040]

[0042] For example, the method includes treating a first lignocellulosic material by adding about 3.5 ppm to about 200 ppm of a copper salt and about 25 ppm to about 175 ppm of an iron salt at a pH of about 1 to about 9 to form a second lignocellulosic material.

[0041]

[0043] In any of the embodiments herein, the copper salt (and, if applicable, the iron salt) may be added as an aqueous solution. In such embodiments, the method may include treating the first lignocellulosic material by adding an aqueous solution of the copper salt (and, if applicable, the iron salt) at a pH of about 1 to about 9 to obtain a wet lignocellulosic material, and drying the wet lignocellulosic material to form a second lignocellulosic material, where the second lignocellulosic material may contain about 0.5 ppm to about 200 ppm (or any of the aforementioned ranges) of copper salt, and, if iron salt is included, about 25 ppm to about 175 ppm (or any of the aforementioned ranges) of iron salt. Additionally, the method may include drying the wet lignocellulosic material followed by fiberization to form the second lignocellulosic material.

[0042]

[0044] In any embodiment herein, the second lignocellulosic material may have any one or more of the characteristics described above for fluff pulp (e.g., a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of more than about 3.5 meq / 100 grams, an ISO brightness of at least 80, and a viscosity of about 2 cps to about 9 cps, or a combination of any two or more thereof), and any range described herein. In any embodiment herein, as discussed above for fluff pulp, the treated lignocellulosic material may have a copper ion content of about 0.2 ppm to about 50 ppm by weight of the treated lignocellulosic material, or any range of copper ion contents described herein. In any embodiment herein, as discussed above for fluff pulp, the treated lignocellulosic material may have an iron ion content of about 0.2 ppm to about 50 ppm by weight of the treated lignocellulosic material.

[0043]

[0045] The treated lignocellulosic material or the second lignocellulosic material may be subjected to a number of subsequent treatments to further alter the properties of the material. For example, in any of the embodiments herein, the treated lignocellulosic material or the second lignocellulosic material may be treated with a cationic agent that is believed (without being bound by theory) to bind to reducing functional groups of the treated material. Useful cationic materials can vary widely and include polyamines, l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC), hexadimethrine bromide, polyethyleneimine (linear and / or branched), copolymers of diallyldimethylammonium chloride (DADMAC), copolymers of vinylpyrrolidone (VP) with quaternized diethylaminoethyl methacrylate (DEAMEMA), polyamides, cationic polyurethane latexes, cationic polyvinyl alcohols, polyalkylamines, dicyandiamide copolymers, glycidylamine-added polymers, poly[oxyethylene Cationic nitrogen-containing polymers such as (dimethyliminio)ethylene(dimethyliminio)ethylene]dichloride, high charge density polyvinylamines, polyallylamines (PAHs), poly(hexamethylene biguanide hydrochloride) (PHMB), polyamidoamines (or polyethyleneimines), cationic metal ions such as water-soluble aluminum, calcium, and / or zirconium salts, and cationic dendrimers such as (polyamidoamine) dendrimers with amino surface groups (PAMAM dendrimers) and polypropyleneimine dendrimers with amino surface groups. Without being bound by theory, it is believed that treatment with such cationic materials may alter properties such as increased paper bulk, desirable for fine paper, board, tissue, towels, and absorbent products, while maintaining good strength and having reduced water retention value (WRV) and increased latitude.

[0044]

[0046] The treated lignocellulosic material or the second lignocellulosic material may be treated with micro- or nanoparticulate metal oxides, such as aluminum oxide, titanium oxide, zinc oxide, and / or silica, where such materials are retained by the treated lignocellulosic material to alter properties such as colorant fixation, dye fixation, optical brightener fixation, printability, and / or odor control characteristics. The treated lignocellulosic material or the second lignocellulosic material may be treated with cross-linking materials during papermaking or fiber network formation. Exemplary cross-linking materials include water-dispersible or water-soluble di- or polyfunctional carbodiimides and / or polycarbodiimides such as 1,6-hexamethylene bis(ethylcarbodiimide), 1,8-octamethylene bis(ethylcarbodiimide), 1,10-decamethylene bis(ethylcarbodiimide), 1,12-dodecamethylene bis(ethylcarbodiimide), PEG-bis(propyl(ethylcarbodiimide)), 2,2'-dithioethyl bis(ethylcarbodiimide), 1,1'-dithio-p-phenylene bis(ethylcarbodiimide), and 1,1'-dithio-m-phenylene bis(ethylcarbodiimide). The di- or polyfunctional carbodiimide groups react with the reducing functional groups of the treated lignocellulosic material (or second lignocellulosic material) and with the cross-linked fibers of the material within the paper or fiber network structure.

[0045]

[0047] The treated lignocellulosic material or the second lignocellulosic material may be used for conventional purposes in situ or after isolation using conventional product isolation techniques. For example, the treated lignocellulosic material or the second lignocellulosic material may be used to make a paper or cardboard substrate or web. Methods and apparatus for preparing lignocellulosic fiber-formed substrates are well known in the paper and cardboard art. See, for example, "Handbook For Pulp & Paper Technologies", 2nd Edition, GASmook, Angus Wilde Publications (1992) and references cited therein. Any conventional methods and apparatus may be used. Preferably, such methods using the treated lignocellulosic material (or the second lignocellulosic material) include a) treating the lignocellulosic material (or the second lignocellulosic material) with a) a pulp-forming agent (or a pulp-forming agent) and a pulp-forming agent (or a pulp-forming agent). The method includes the steps of: a) depositing an aqueous suspension of lignocellulosic fibers from the used lignocellulosic material onto a forming wire of a papermaking machine to form a wet paper or cardboard web, b) drying the wet paper or cardboard web to obtain a dried paper or cardboard web, and c) calendering the dried paper or cardboard web. In addition to these, additional steps known to those skilled in the art may be used, such as, for example, a coating step of coating one or more surfaces of the dried paper or cardboard web with a coating agent comprising a binder containing a dispersed pigment, and / or treating the dried paper or cardboard in a size press with a size agent such as starch.

[0046]

[0048] The treated lignocellulosic material or the second lignocellulosic material may be used to prepare absorbent articles, such as, for example, diapers, tissues, towels, and / or personal hygiene products, using conventional methods. Such products and their manufacturing methods are known to those skilled in the art. See, for example, U.S. Patent Nos. 6,063,982 and 5,766,159 (both of which are incorporated herein by reference, except for any portions thereof that may be inconsistent with the present teachings), and the references cited therein. The treated lignocellulosic kraft pulp (which necessarily includes treated kraft pulp fibers) may be used to make impregnated kraft paper. Impregnated kraft paper is a paper sheet made from unbleached kraft pulp (typically a mixture of mostly hardwoods and some softwoods, such as southern pine), which is used as a substrate for impregnation and curing with resin polymers. Impregnated kraft paper is used as a home and office building material, such as kitchen countertops. A useful property of impregnated kraft paper is to control the rate of liquid (typically polymer resin solution) penetration into the sheet while maintaining the air permeability and density of the paper. All hardwood kraft fibers in the impregnated sheet may be replaced with softwood, such as Southern pine kraft (exterior liner grade pine kraft) treated by the method of any embodiment herein, to provide an impregnated kraft paper with good liquid transport properties. EXAMPLES

[0047]

[0049] The examples herein are provided to illustrate the advantages of the present technology and to further assist those skilled in the art in preparing or using the methods of the present technology. The examples herein are also presented to more fully illustrate the preferred aspects of the present technology. The examples should not be interpreted as limiting the scope of the present technology in any way. The examples may include or incorporate any of the variations, embodiments, or aspects of the present technology described above. The variations, embodiments, or aspects described above may also include or incorporate any or all of the variations of other variations, embodiments, or aspects of the present technology.

[0048] Example 1

[0050] A technique for measuring the ammonia inhibition properties of SAP-free fluff pulp.

[0051] The sheets of fluff pulp are cut into 2-inch strips and fiberized using a Kamas H01 laboratory hammer mill. The fiberized pulp is made into aeolian 50 mm diameter pads using an aeolian pad former. Unless otherwise stated, each pad is made of 4 grams of fiberized pulp. The pads are compressed to approximately 0.15 g / cc density in a Carver press. Two compressed pads are placed in an airtight 1-liter jar. 40 mL of a freshly prepared 1.0% urease (urease from Canavalia ensiformis (Jack Bean), purchased from Sigma) solution in synthetic urine (RICCA Chemical Company) is added to each 4-gram pad and the jar is sealed. After 8 hours, ammonia concentration in the headspace of the jar is detected using a Draeger tube. As provided by this procedure, the lower the concentration of ammonia, the better the ammonia inhibition effect of the fiberized fluff pulp.

[0049] Example 2

[0052] Technique for measuring ammonia inhibition properties of fluff pulp with SAP.

[0053] The fluff pulp sheets are cut into 2 inch strips and fiberized using a Kamas H01 laboratory hammer mill. The fiberized pulp is mixed with SAP for a total of 10 grams. For example, if a 10% SAP pad is desired, then 9 grams of fiberized pulp is mixed with 1 gram of SAP. Unless otherwise noted, the SAP used is HySorb® 9400 (BASF). The fiberized pulp and SAP mixture is then fed into an aeolian pad former and spun to a depth of 100 cm. 2A circular pad is formed. The pad is compressed to approximately 0.15 g / cc using a Carver press. The pad is placed in a 7 liter airtight container. 100 ml of a 1.0% urease solution (described in Example 1) is added to the pad and the container is sealed. After 8 hours, ammonia concentration in the headspace of the container is detected using a Dräger tube.

[0050] Example 3

[0054]

[0055] Commercial Scale D 0 E op D 1 D 2 The first chlorine dioxide whitening (D 1 The pulp was collected after the bleaching step and had a viscosity of 16.5 cps. The pulp was treated in an acid bleaching step containing different types and amounts of metal salts as shown in Table 1. Each treatment utilized 100 grams of dry pulp at a 10% consistency (i.e., 10 wt% pulp in solution) and 3% hydrogen peroxide (i.e., 3 wt% based on pulp) at a temperature of 85° C. for a period of 130 minutes.

[0051]

[0056] After treatment, the pulp was washed with 4 L of deionized water and compacted to approximately 20% solids. The compacted pulp was then diluted with deionized water to approximately 1% consistency and formed into 750 gsm handsheets on an 8 inch by 8 inch handsheet mold. The wet pulp sheets were pressed between blotter papers to remove excess liquid and then dried in a rotary drum dryer at 250°F. The ammonia inhibition properties of the dried sheets were then investigated with and without SAP as described in Examples 1 and 2. As shown in Table 1, FeSO 4 Combined with only 25 ppm CuSO 4 The use of 25 ppm CuSO had a clear inhibitory effect on ammonia formation. 4 When used in acid peroxide bleaching for entry 1, the reduction in pH was approximately 50% (100%-(3 ppmNH 3 / 6 ppmNH 3× 100%) = 50%) of ammonia inhibition. 4 55 ppm FeSO 4 When used in combination with no SAP, there was 100% ammonia inhibition and with 10% SAP there was approximately 82% ammonia inhibition.

[0052] [Table 1]

[0053] Example 4

[0057]

[0058] Commercial production conditions were performed at International Paper's Riegelwood, NC mill, which produces kraft softwood pulp in D 0 E op D 1 D 2 Bleaching in the bleaching sequence. D 2 The steps were changed to produce low viscosity pulps using 3% hydrogen peroxide and metal salts of varying composition and content. The first pulp (Table 2, entry 1) was made with 150 ppm FeSO as the only metal salt. 4 The second pulp (Table 2, entry 2) was produced using 125 ppm FeSO 4 and 25 ppm CuSO 4 Both of these reaction conditions produced a low viscosity pulp.

[0054]

[0059] Each pulp was then made into fluff pulp sheets on a Fourdrinier paper machine equipped with a cylindrical steam heated can dryer. Samples of each dried sheet were then collected and tested for ammonia inhibition as described in Examples 1 and 2. As shown in Table 2, only 25 ppm of CuSO was used in the acidic hydrogen peroxide bleaching step. 4 had a clear inhibitory effect on ammonia formation. This result was also found for pads made with and without SAP.

[0055] [Table 2]

[0056] Example 5

[0060]

[0061] Fluff pulp sheet (RW SuperSoft® Plus; I (commercially produced by International Paper) was replaced with copper(II) sulfate pentahydrate (CuSO 4 5H 2 The pulp sheets were then immersed in a deionized water bath containing increasing concentrations of CuO for 1 minute at room temperature (72°F). After the immersion procedure, the pulp sheets were pressed between blotter papers to remove excess liquid, and the sheets were dried in a rotary drum dryer at 250°F. The dried sheets were then tested for ammonia inhibition as described in Examples 1 and 2, and Table 3 shows the results of these tests. 2+ had a clear inhibitory effect on ammonia formation.

[0057] [Table 3]

[0058] Example 6

[0062]

[0063] Fluff pulp sheets (RW SuperSoft® Plus; commercially produced by International Paper) were soaked in deionized water and saturated with copper(II) sulfate pentahydrate (CuSO 4 5H 2 Various aqueous solutions containing varying concentrations of CuO were sprayed onto fluff pulp sheets until visibly wet. After the spraying procedure, each pulp sheet was pressed between blotter paper to remove excess liquid, and the sheets were dried in a rotary drum dryer at 250°F. Each dried sheet was then tested for ammonia inhibition as described in Example 1, and Table 4 shows the results of these tests. 2+ had a clear inhibitory effect on ammonia formation.

[0059] [Table 4]

[0060]

[0064] The present technology is not limited with respect to the specific figures and examples described herein, which are intended as illustrations of individual aspects of the technology. Many modifications and variations of the present technology can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods within the scope of the present technology will be apparent to those skilled in the art from the foregoing description, in addition to those recited herein. Such modifications and variations are intended to be within the scope of the appended claims. It is understood that the present technology is not limited to specific methods, reagents, compounds, compositions, or labeling compounds, which may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0061]

[0065] The embodiments illustratively described herein may suitably be practiced without any element(s) or limitation(s) not expressly disclosed herein. Thus, for example, terms such as "comprising," "including," "containing," and the like, shall be read broadly and without limitation. In addition, the terms and expressions utilized herein are used as terms of description and without limitation, and in the use of such terms and expressions, there is no intention to exclude any equivalents or portions thereof of the features shown and described, but it is recognized that various modifications are possible within the scope of the claimed technology. In addition, the phrase "consisting essentially of" will be understood to include those elements expressly described and those additional elements that do not materially affect the basis and novel features of the claimed technology. The phrase "consisting of" excludes any elements not described.

[0062]

[0066] In addition, when features or aspects of the disclosure are described in terms of the Markush group, one of ordinary skill in the art will recognize that the disclosure is also described in terms of any individual member or subgroup of members of the Markush group. Each narrower species and subgeneric group falling within the scope of the generic disclosure also forms part of the invention. This includes the generic description of the invention with any provisos or negative limitations that remove any subject matter from the concept, whether or not the omitted material is expressly described herein.

[0063]

[0067] All publications, patent applications, issued patents, and other documents (e.g., journals, articles, and / or textbooks) mentioned herein are incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety herein. Definitions contained in the incorporated text are excluded to the extent that they are inconsistent with definitions in this disclosure.

[0064]

[0068] Other embodiments are set forth in the following claims, along with the full scope of equivalents to which such claims are entitled. [Mode of the invention] [1] a length-weighted average fiber length of at least about 2 mm; Copper number less than about 7, Carboxyl content of more than about 3.5 meq / 100 grams; ISO whiteness of at least 80, and Viscosity of about 2 cps to about 9 cps Bleached kraft fibers, including Copper ion content of bleached kraft fiber from about 0.2 ppm to about 50 ppm by weight Fluff pulp, including [2] 2. The fluff pulp of claim 1, wherein the copper ions in the copper ion content include copper(I) salts, copper(II) salts, hydrates thereof, or a combination of any two or more thereof. [3] The copper ion content is expressed as elemental copper, copper(I) chloride, copper(I) oxide, copper(I) sulfate, and charcoal. 3. The fluff pulp according to claim 1 or 2, comprising one or more of copper(II) acid, copper(II) chloride, copper(II) phosphate, copper(II) nitrate, copper(II) perchlorate, copper(II) phosphate, copper(II) sulfate, copper(II) tetrafluoroborate, and copper(II) triflate. [4] 4. Fluff pulp according to any one of 1 to 3, further comprising iron ions. [5] 5. The fluff pulp described in 4, comprising an iron ion content of about 0.2 ppm to about 50 ppm by weight of bleached kraft fiber. [6] 6. Fluff pulp according to any one of claims 1 to 5, wherein the fluff pulp does not contain a superabsorbent polymer (SAP). [7] treating the lignocellulosic material by adding about 50 ppm to about 200 ppm by weight of the lignocellulosic material of a catalyst consisting of a combination of copper and iron or salts thereof in the presence of about 0.5% to about 5% by weight of the lignocellulosic material of an oxidizing agent to produce a treated lignocellulosic material. 1. A method for preparing fluff pulp comprising: a weight ratio of iron and iron salts to copper and copper salts of up to about 10:1; the treated lignocellulosic material having a viscosity of about 2 cps to about 6 cps; the treated lignocellulosic material has an inhibitory effect on ammonia formation that is at least 50% greater than a second treated lignocellulosic material formed by a similar process that does not include copper; method. [8] Copper or its salts are elemental copper (Cu 0 8. The method of claim 7, wherein the catalyst comprises one or more of a copper(I) salt, a copper(II) salt, and a copper(II) salt. [9] 9. The method of claim 7 or 8, wherein the copper or a salt thereof comprises elemental copper, copper(I) chloride, copper(I) oxide, copper(I) sulfate, copper(II) carbonate, copper(II) chloride, copper(II) phosphate, copper(II) nitrate, copper(II) perchlorate, copper(II) phosphate, copper(II) sulfate, copper(II) tetrafluoroborate, copper(II) triflate, hydrates thereof, or a combination of any two or more thereof.

[10] Iron or its salts are classified as elemental iron, ferrous iron (Fe 2+ ) salt, ferric iron (Fe 3+ 10. The method of any one of claims 7 to 9, wherein the compound comprises a carboxylate or carboxyl group, a carboxylate or carboxyl group salt, a hydrate thereof, or a combination of any two or more thereof.

[11] 11. The method of any one of claims 7 to 10, wherein the iron or a salt thereof comprises elemental iron, ferrous sulfate, ferrous chloride, ferrous ammonium sulfate, ferric chloride, ferric ammonium sulfate, ferric ammonium citrate, a hydrate thereof, or a combination of any two or more thereof.

[12] 12. The method of any one of claims 7 to 11, wherein the weight ratio of iron and iron salts to copper and copper salts is from about 10:1 to about 1:10.

[13] 12. The method of any one of claims 7 to 11, wherein the weight ratio of iron and iron salts to copper and copper salts is from about 3:1 to about 1:3.

[14] 14. The method of any one of claims 7 to 13, wherein the oxidizing agent comprises hydrogen peroxide.

[15] 15. The method of any one of claims 7 to 14, wherein the method comprises a multi-stage bleaching process and the treatment step is the final bleaching step in the multi-stage bleaching process.

[16] 16. The method of any one of claims 7 to 15, wherein the treated lignocellulosic material does not contain a superabsorbent polymer (SAP).

[17] treating the lignocellulosic kraft pulp by adding about 50 ppm to about 200 ppm by weight of the lignocellulosic material of a catalyst consisting of a combination of copper and iron, or salts thereof, in the presence of about 0.5% to about 5% by weight of the lignocellulosic material of an oxidizing agent at an acidic pH to produce a treated lignocellulosic material. 1. A method for preparing fluff pulp comprising: The weight ratio of added iron and iron salts to copper and copper salts is up to 10:1; the treated lignocellulosic material having a viscosity of about 2 cps to about 6 cps; the treated lignocellulosic material has an inhibitory effect on ammonia formation that is at least 50% greater than a second treated lignocellulosic material formed by a similar process that does not include copper; method.

[18] 18. The method of claim 17, wherein the copper or a salt thereof comprises elemental copper, copper(I) chloride, copper(I) oxide, copper(I) sulfate, copper(II) carbonate, copper(II) chloride, copper(II) phosphate, copper(II) nitrate, copper(II) perchlorate, copper(II) phosphate, copper(II) sulfate, copper(II) tetrafluoroborate, copper(II) triflate, hydrates thereof, or a combination of any two or more thereof.

[19] 19. The method of claim 17 or 18, wherein the iron or a salt thereof comprises elemental iron, ferrous sulfate, ferrous chloride, ferrous ammonium sulfate, ferric chloride, ferric ammonium sulfate, ferric ammonium citrate, a hydrate thereof, or a combination of any two or more thereof.

[20] 20. The method of any one of claims 17 to 19, wherein the weight ratio of iron and iron salts to copper and copper salts is from about 10:1 to about 1:10. [twenty one] 21. The method of any one of claims 17 to 20, wherein the oxidizing agent comprises hydrogen peroxide. [twenty two] 1. A method for preparing fluff pulp comprising treating lignocellulosic kraft pulp by adding about 50 ppm to about 150 ppm by weight of the lignocellulosic material of a catalyst consisting of a combination of copper and iron, or salts thereof, in the presence of about 0.5% to about 5% by weight of the lignocellulosic material of an oxidizing agent at a pH of about 2.5 to about 5 to produce a treated lignocellulosic material, The lignocellulosic kraft pulp is present in an aqueous solution of about 8 wt % to about 12 wt % lignocellulosic kraft pulp based on the water in the solution. a weight ratio of iron and iron salts to copper and copper salts of about 8:1 to about 1:8; the treated lignocellulosic material having a viscosity of about 3 cps to about 5 cps; the treated lignocellulosic material has an inhibitory effect on ammonia formation that is at least 50% greater than a second treated lignocellulosic material formed by a similar process that does not include copper; method. [twenty three] 23. The method of claim 22, wherein the method comprises a multi-stage bleaching process and the treatment step is the final bleaching step in the multi-stage bleaching process. [twenty four] 24. The method of claim 22 or 23, wherein the treated lignocellulosic material does not contain a superabsorbent polymer (SAP). [twenty five] 1. A method for improving the odor control properties of fluff pulp, comprising: treating the first lignocellulosic material by adding about 3.5 ppm to about 200 ppm of a copper salt and about 25 ppm to about 175 ppm of an iron salt at a pH of about 1 to about 9 to form a second lignocellulosic material. Including, a weight ratio of the iron salt to the copper salt of about 8:1 to about 1:1; the dried second lignocellulosic material has an inhibitory effect on ammonia formation that is at least 50% greater than the dried first lignocellulosic material; method.

[26] 26. The method of claim 25, wherein the second lignocellulosic material does not contain a superabsorbent polymer (SAP).

Claims

1. a length-weighted average fiber length of at least about 2 mm; A copper number of less than about 7, and ISO whiteness of at least 80 Bleached kraft fibers, including A copper ion content of about 0.2 ppm by weight or more and less than 43 ppm by weight of bleached kraft fiber. Fluff pulp, including

2. 2. The fluff pulp of claim 1, wherein the copper ions in the copper ion content include copper (I) salts, copper (II) salts, hydrates thereof, or a combination of any two or more thereof.

3. 2. The fluff pulp of claim 1, wherein the copper ions in the copper ion content include one or more of elemental copper, copper (I) chloride, copper (I) oxide, copper (I) sulfate, copper (II) carbonate, copper (II) chloride, copper (II) phosphate, copper (II) nitrate, copper (II) perchlorate, copper (II) phosphate, copper (II) sulfate, copper (II) tetrafluoroborate, and copper (II) triflate.

4. The fluff pulp of claim 1 , wherein the fluff pulp further comprises iron ions.

5. 5. The fluff pulp of claim 4, comprising an iron ion content of about 0.2 ppm to about 50 ppm by weight of the bleached kraft fibers.

6. The fluff pulp of claim 1 , wherein the fluff pulp does not contain a superabsorbent polymer (SAP).

7. The fluff pulp of claim 1 , wherein the fluff pulp has a carboxyl content greater than about 3.5 meq / 100 grams.

8. 2. The fluff pulp of claim 1, wherein the fluff pulp comprises a copper ion content of about 0.7 ppm to 5.2 ppm by weight of bleached kraft fibers.

9. After 8 hours of the fluff pulp being subjected to the ammonia generation test in the absence of superabsorbent polymer (SAP), the ammonia formation result was inhibited to 22 ppm or less of ammonia formation, and the ammonia generation test was carried out by the steps of: i) cutting the fluff pulp into 2 inch pieces and fiberizing the fluff pulp using a Kamas H01 laboratory hammer mill; ii) forming the fiberized fluff pulp into an aeolian 50 mm diameter pad using an aeolian pad former; iii) each pad is made with 4 grams of fiberized fluff pulp and the pads are compressed in a Carver press to a density of approximately 0.15 g / cc; iv) placing the two compressed pads into an airtight 1 liter jar; v) adding 40 mL of a freshly prepared solution of 1.0% urease (urease from Canavalia ensiformis (Jack Bean), purchased from Sigma) in synthetic urine (RICCA Chemical Company) to each 4 gram pad and sealing the bottle; and vi) Using a Dräger tube to detect ammonia concentration in the headspace of a bottle The fluff pulp of claim 1, comprising:

10. treating bleached kraft fiber by adding about 0.2 ppm or more and less than 43 ppm copper or a salt thereof by weight of the bleached kraft fiber to produce fluff pulp; The fluff pulp has an inhibitory effect on ammonia formation that is at least 50% greater than a second fluff pulp formed in the same manner in the absence of copper; A method for producing fluff pulp according to claim 1.

11. Copper or a salt thereof is elemental copper (Cu ０ 11. The method of claim 10, wherein the copper(I) salt comprises one or more of a copper(II) salt.

12. 11. The method of claim 10, wherein the copper or a salt thereof comprises elemental copper, copper(I) chloride, copper(I) oxide, copper(I) sulfate, copper(II) carbonate, copper(II) chloride, copper(II) phosphate, copper(II) nitrate, copper(II) perchlorate, copper(II) phosphate, copper(II) sulfate, copper(II) tetrafluoroborate, copper(II) triflate, hydrates thereof, or a combination of any two or more thereof.

13. 11. The method of claim 10, further comprising bleaching the kraft fiber in a multi-stage bleaching process to produce bleached kraft fiber, said treating occurring after bleaching.

14. 11. The method of claim 10, further comprising bleaching the kraft fiber in a multi-stage bleaching process to produce bleached kraft fiber, wherein no further bleaching is performed after said treatment.

15. The method of claim 10, wherein the fluff pulp does not contain a superabsorbent polymer (SAP).

16. The method of claim 10, wherein the fluff pulp has a carboxyl content greater than about 3.5 meq / 100 grams.

17. The method of claim 10, wherein the fluff pulp further comprises iron ions.

18. 18. The method of claim 17, wherein the fluff pulp comprises an iron ion content of about 0.2 ppm to about 50 ppm by weight of bleached kraft fibers.

19. 1. A method for improving the odor control properties of fluff pulp, comprising: treating bleached kraft fiber by adding about 0.2 ppm or more and less than 43 ppm copper or a salt thereof by weight of the bleached kraft fiber to produce fluff pulp; The method, wherein the fluff pulp has an inhibitory effect on ammonia formation that is at least 50% greater than a second fluff pulp formed in the same manner but without the presence of copper.

20. The method of claim 19, wherein the fluff pulp does not contain a superabsorbent polymer (SAP).

21. The method of claim 19, wherein the fluff pulp contains from 0.7 ppm to 5.2 ppm of copper ions by weight of the fluff pulp.

22. The method of claim 19, wherein the fluff pulp further comprises iron ions.

23. 23. The method of claim 22, wherein the fluff pulp comprises an iron ion content of about 0.2 ppm to about 50 ppm by weight of bleached kraft fibers.

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