JP2018075495A - Modified cellulose from chemical kraft fiber and methods of making and using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide modified cellulose from a chemical kraft fiber and methods of making and using the same.SOLUTION: Provided are urine absorbers including a modified kraft pulp fiber with unique properties. The kraft fiber can be produced by at least one iron catalyzed peroxide treatment process under an acidic condition that can be incorporated into a single stage of a multi-stage bleaching process. Products using such a fiber include diapers, incontinence products, and other urine absorbent articles. This disclosure provides novel methods that offer vast improvements over methods attempted in the prior art. Generally, oxidation of cellulose kraft fibers, in the prior art, is conducted after the bleaching process. Surprisingly, the inventors have discovered that it is possible to use the existing stages of a bleaching sequence, particularly the fourth stage of a five-stage bleaching sequence, for oxidation of cellulose fibers.SELECTED DRAWING: None

Description

The present application is 35 U.S. Pat. S. C. PCT International Application No. PCT / US2010 / 036763 filed May 28, 2010 under § 371, 201
Which is a continuation application of US Application No. 13 / 322,419, filed on November 23, 1
US application Ser. No. 13 / 314,493, filed Dec. 8, 2011, all of which are hereby incorporated by reference.
Claims priority and benefit of filing date for US Provisional Patent Application No. 61 / 182,000, filed May 28, 2009.

The present disclosure relates to chemical modification of cellulose fibers. More specifically, the present disclosure improves its performance over standard cellulose fibers derived from kraft pulp and has previously been limited to expensive fibers such as cotton or high alpha content sulfite pulp. It relates to chemically modified cellulose fibers derived from bleached kraft pulp that make it useful in a unique set of features. In particular, the chemically modified bleached kraft fiber has one of the following advantageous characteristics (including but not limited to improved odor control, improved compressibility, and / or improved brightness): Or a plurality may be indicated. Chemically modified bleached kraft fibers maintain one or more other characteristics of unchemically modified bleached kraft fibers, for example, these advantageous characteristics while maintaining fiber length and / or freeness One or more of them may be indicated.

The present disclosure further exhibits a low or ultra-low degree of polymerization, as a fluff pulp in absorbent products, as a chemical cellulose raw material in the production of cellulose derivatives (including cellulose ethers and esters), and in consumer products It relates to chemically modified cellulose fibers derived from bleached softwood and / or hardwood kraft pulp, which are suitable for use. As used herein, “degree of polymerization” can be shortened to “DP”. The present disclosure further relates to cellulose derived from chemically modified kraft fibers having a degree of level-off polymerization of less than about 80. More specifically, a low polymerization degree or an ultra-low polymerization degree (in this specification, “L
The chemically modified kraft fibers described herein, designated DP "or" ULDP ") may be acid or so as to further reduce the degree of polymerization to less than about 80, for example, less than about 50. It can be processed by alkaline hydrolysis to make it suitable for various downstream applications.

The present disclosure relates to a method for producing the described improved fibers. The present disclosure provides in part a method for simultaneously increasing the carboxylic acid and aldehyde functionality of a kraft fiber. The described fiber undergoes a catalytic oxidation treatment. In some embodiments, the fibers are oxidized with iron or copper and then further bleached to provide fibers having beneficial lightness characteristics, such as lightness comparable to standard bleached fibers. In addition, at least one process is disclosed that can provide the above-described improved beneficial features without introducing an additional step after the processing of bleached fibers. In this low cost embodiment, the fibers can be processed in a single stage of a kraft process, such as a kraft bleaching process. Further embodiments also provide D ₀
For a five-stage bleaching process involving the sequence E1D1E2D2, the fourth stage (E2)
Includes catalytic oxidation treatment.

Finally, the present disclosure relates to consumer products, cellulose derivatives (including cellulose ethers and esters), and microcrystalline cellulose, all produced using chemically modified cellulose fibers as described.

Cellulose fibers and derivatives are used in paper, absorbent products, food or food related applications, pharmaceuticals,
And widely used in industrial applications. The main sources of cellulose fibers are wood pulp and cotton. Cellulose source and cellulose processing conditions generally determine the characteristics of the cellulose fiber and thus the applicability of the fiber to certain end uses. There is a need for cellulose fibers that are relatively inexpensive to process, but very versatile and allow their use in a variety of applications.

Cellulose generally exists as polymer chains containing hundreds to tens of thousands of glucose units. Various methods for oxidizing cellulose are known. In cellulose oxidation, the hydroxyl group of the glycoside of the cellulose chain can be converted into a carbonyl group such as an aldehyde group or a carboxylic acid group. The type, degree, and position of the carbonyl modification can vary depending on the oxidation method and conditions used. It is known that certain oxidation conditions can degrade the cellulose chain itself, for example, by cleaving the glycosidic ring in the cellulose chain, resulting in depolymerization. In most instances, depolymerized cellulose not only has a reduced viscosity, but also has a shorter fiber length than the starting cellulosic material. When cellulose is degraded, such as by depolymerizing and / or significantly reducing fiber length and / or fiber strength, it may be difficult to process and / or unsuitable for many downstream applications possible. There remains a need for a method of modifying cellulose fibers that can improve both carboxylic acid and aldehyde functionality, which does not significantly degrade the cellulose fibers. The present disclosure provides a unique way to solve one or more of these deficiencies.

Various attempts have been made to oxidize cellulose and provide both carboxylic acid and aldehyde functionality to the cellulose chain without breaking the cellulose fibers. In conventional cellulose oxidation methods, it may be difficult to control or limit cellulose degradation when aldehyde groups are present on the cellulose. Previous attempts to resolve these issues
Use of a multi-step oxidation process, eg, site-specific modification of one carbonyl group in one step, oxidation of another hydroxyl group in another step, and / or providing mediators and / or protectants All of which can add additional costs and by-products to the cellulose oxidation process. Thus, there is a need for a method of modifying cellulose that is cost effective and / or can be performed in a single step of a process, such as a kraft process.

The present disclosure provides a new method that offers significant improvements over methods attempted in the prior art. In general, the oxidation of cellulose kraft fibers in the prior art takes place after the bleaching process. Surprisingly, the inventors have found that it is possible to use an existing stage of the bleaching sequence, in particular the fourth stage of a five-stage bleaching sequence, for the oxidation of cellulose fibers. Moreover, surprisingly, we have found that, for example, the catalyst remains not bound in the cellulose, and at least some of the residual iron before the end of the bleaching sequence is more than expected based on knowledge in the art. It has been found that this oxidation can be achieved without interfering with the final product using a metal catalyst, in particular an iron catalyst, in the bleaching sequence. Moreover, unexpectedly, the inventors have found that such a method can be performed without substantial degradation of the fibers.

It is known in the art that cellulose fibers, including kraft pulp, can be oxidized with metals and peroxides and / or peracids. For example, cellulose can be oxidized with iron and peroxide ("Fenton reagent"). Kishimoto et al., Holzfors
chung, 52, 2 (1998), pages 180-184. Metals and peroxides such as Fenton reagent are relatively inexpensive oxidants, which make them somewhat desirable for large scale applications such as kraft processes. In the case of the Fenton reagent, it is known that this oxidation method can degrade cellulose under oxidizing conditions. Therefore,
It would not have been anticipated that the Fenton reagent could be used in acid conditions, without extensive degradation of the fiber, for example, in a kraft process with concomitant fiber length loss. In order to prevent the degradation of cellulose, Fenton reagent is often used under alkaline conditions, where Fenton reagent is greatly inhibited. However, there can be additional disadvantages in using the Fenton reagent under alkaline conditions. For example, cellulose
Nevertheless, it can be decomposed or discolored. In kraft pulp processing, cellulose fibers are often traditionally at least one at or near the end of the bleaching sequence.
Bleaching is carried out in a multi-stage sequence comprising strongly acidic and strongly alkaline bleaching steps, including one alkaline step. Thus, unlike what was known in the art, fibers oxidized with iron in the acidic stage of the kraft bleaching process result in fibers with improved chemical properties but without physical degradation or discoloration. I was really surprised to be able to.

Thus, both aldehyde and carboxylic acid functionality can be imparted to cellulose fibers, such as fibers derived from kraft pulp, without significantly degrading cellulose and / or making it unsuitable for many downstream applications. There is a need for low cost and / or single step oxidation. Moreover, there remains a need for imparting high levels of carbonyl groups, such as carboxylic acid, ketone, and aldehyde groups, to cellulose fibers. For example, unlike the use of Fenton reagents at alkaline pH, it may be desirable to impart high levels of carbonyl groups, for example using an oxidizing agent under conditions that do not inhibit the oxidation reaction. The inventors of the present invention provide a method that overcomes many of the difficulties of the prior art and meets these needs.

In addition to the difficulty in controlling the chemical structure of cellulosic products and the degradation of these products, the oxidation method affects the chemical and physical properties of the final product and / or other properties, including impurities. It is known that it can affect. For example, the oxidation method can affect the crystallinity, hemicellulose content, color, and / or level of impurities in the final product. Ultimately, the oxidation process can impart the ability to process cellulosic products for industrial or other applications.

Wood pulp bleaching is generally for the purpose of selectively increasing the whiteness or lightness of the pulp, typically by removing lignin and other impurities without negatively impacting physical properties. Done. Bleaching of chemical pulp such as kraft pulp is generally
A variety of different bleaching steps are required to achieve the desired brightness with excellent selectivity.
Typically, the bleaching sequence employs steps that are performed at varying pH ranges. This change helps remove impurities generated in the bleaching sequence, for example, by solubilizing the product of lignin disruption. Thus, it is generally expected that the use of a series of acidic stages in a bleaching sequence, such as three oxidation stages in the sequence, will not provide the same brightness as a changing acidic / alkaline stage, such as acidic alkaline acidity. For example, typical DEDE
The D sequence produces a brighter product than the DEDAD sequence (A refers to acid treatment). Thus, a sequence that produces a product that has no intervening alkaline stage but has a similar lightness would not have been predicted by one skilled in the art.

In general, it is known that certain bleaching sequences can have advantages over other sequences in the kraft process, but the reasons behind any advantages are less well understood. With respect to oxidation, research does not reveal any preference for oxidation at a particular stage of a multi-stage sequence, or any recognition that fiber properties can be influenced by post-oxidation stages / treatments. For example, the prior art does not disclose any preference for late-stage oxidation over early-stage oxidation. In some embodiments, the present disclosure has advantages in a craft process and uniquely at a particular stage (eg, the second stage of a bleaching process) that results in a fiber having a unique set of physical and chemical characteristics. Provide a way to be done.

In addition, with respect to lightness in the kraft bleaching process, it is known that metals in certain transition metals that are naturally present in the pulp starting material are detrimental to the lightness of the product. Thus, bleaching sequences are often aimed at removing certain transition metals from the final product to achieve target brightness. For example, chelating agents can be employed to remove naturally occurring metals from the pulp. Therefore, since it is important to remove metals that are naturally present in the pulp, those skilled in the art will generally find it difficult to achieve a brighter product for the compound,
Do not add any metal to the bleaching sequence.

Moreover, for iron, the addition of this metal to the pulp leads to a significant discoloration, similar to the discoloration present, for example, when paper is incinerated. This discoloration has so far been considered irreversible, similar to the discoloration of incinerated paper. Thus, upon discoloration of the wood pulp with added iron, the pulp is expected to experience a permanent loss of brightness that cannot be recovered with additional bleaching.

Thus, while iron or copper and peroxides are known to be able to oxidize cellulose at low cost, so far they do not employ an iron or copper oxidation step and are as light as a standard sequence. In a manner to achieve, it was not employed in the pulp bleaching process. In general, their use has been avoided in pulp bleaching processes. Surprisingly, the inventors have overcome these difficulties and, in some embodiments, provide new methods for inexpensively oxidizing cellulose with iron or copper in a pulp bleaching process. In some embodiments, the methods disclosed herein are highly surprising and result in a product that has different characteristics than expected based on the teachings of the prior art. Therefore,
The method of the present disclosure may provide a product that is superior to prior art products and can be produced more cost-effectively.

For example, it is generally understood in the art that metals such as iron bind well to cellulose and cannot be removed by normal washing. Typically, removing iron from cellulose is difficult and expensive and requires additional processing steps. The presence of high levels of residual iron in cellulosic products is known to have several drawbacks, especially in pulp and papermaking applications. For example, iron may lead to discoloration of the final product and / or may be unsuitable for applications where the final product such as diapers and wound dressings are in contact with the skin. Thus, the use of iron in the kraft bleaching process would be expected to suffer from a number of drawbacks.

In the past, kraft fiber oxidation treatment to improve functionality has often been limited to oxidation treatment after the fiber has been bleached. Moreover, known processes for making fibers more aldehydes also cause a simultaneous loss of fiber brightness or quality. In addition, known processes that result in enhanced aldehyde functionality of the fiber also result in loss of carboxylic acid functionality. The method of the present disclosure does not suffer from one or more of these drawbacks.

Kraft fibers produced by chemical kraft pulp methods generally provide an inexpensive source of cellulose fibers that maintain their fiber length through pulping and generally provide a final product with excellent lightness and strength properties To do. Therefore, it is widely used for paper applications. However, standard kraft fibers have limited applicability in downstream applications such as cellulose derivative production due to the chemical structure of cellulose resulting from standard kraft pulping and bleaching. In general, standard kraft fibers contain excessive residual hemicellulose and other naturally occurring materials that can intervene in subsequent physical and / or chemical modification of the fibers. Moreover, standard kraft fibers have limited chemical functionality and are generally rigid and not very compressible.

The stiffness and coarse nature of kraft fibers require applications that require contact with human skin, for example, stratification in diapers, hygiene products, and tissue products, or the addition of different types of materials such as cotton Can do. Thus, it may be desirable to provide cellulosic fibers with greater flexibility and / or softness, for example, so as to reduce the need to use other materials in multilayer products.

Cellulose fibers in applications involving the absorption of body waste and / or fluids, such as diapers, adult incontinence products, wound dressings, sanitary napkins, and / or tampons, are often present in body waste Exposure to ammonia and / or ammonia produced by bacteria associated with body waste and / or fluids. Cellulose fibers that not only provide bulk and absorbency, but also have odor reducing properties and / or antibacterial properties, for example, can reduce odors from nitrogen compounds such as ammonia (NH ₃ ),
It may be desirable to use in such applications. To date, modification of kraft fiber by oxidation to improve its odor control ability has always resulted in undesirable lightness reduction. There is a need for an inexpensive modified kraft fiber that exhibits excellent absorbency characteristics and / or odor control capabilities while maintaining excellent lightness characteristics.

In today's market, consumers want absorbent products such as thinner, diapers, adult incontinence products, and sanitary napkins. Ultra-thin product designs require lighter fiber weights and can suffer from loss of product integrity if the fibers used are too short. Chemical modification of kraft fibers can result in fiber length loss and is unacceptable for use in certain types of products, such as ultra-thin products. More specifically, kraft fibers treated to improve aldehyde functionality, associated with improved odor control, can suffer from fiber length loss during chemical modification, which can be used in ultra-thin product design. Make it unsuitable for use. It exhibits compressibility without loss of fiber length, making it uniquely suitable for ultra-thin designs (i.e., products can be compressed into smaller gaps while maintaining product integrity at lighter fiber weights) There is a need for inexpensive fibers that maintain excellent absorbency based on the amount of fibers that can be produced.

Traditionally, cellulose sources that were useful in the production of absorbent products or tissues were not useful in the production of downstream cellulose derivatives such as cellulose ethers and cellulose esters. The production of low-viscosity cellulose derivatives derived from high-viscosity cellulose raw materials such as standard kraft fibers adds unnecessary side products and reduces the overall quality of the cellulose derivatives while adding additional manufacturing that can add significant costs A step was necessary. Cotton waste and high alpha cellulose content sulfite pulp, which generally have a high degree of polymerization, are used in the manufacture of cellulose derivatives such as cellulose ethers and esters. However, a high degree of polymerization and / or
Or the production of cotton scrap and sulfite fibers with viscosity, in the case of cotton, the cost of the starting material,
In the case of sulfite pulp, it is expensive because of the high energy of pulping and bleaching, chemical and environmental costs, and the extensive refining process applied in both cases.
In addition to high costs, there is a weak supply of commercially available sulfite pulp. Thus, these fibers are very expensive and have limited applicability in pulp and paper applications, for example, higher DP or higher viscosity pulps may be required. For cellulose derivative manufacturers, these pulps constitute a significant part of their overall manufacturing costs. Accordingly, there is a need for low cost fibers such as modified kraft fibers that can be used in the production of cellulose derivatives.

There is also a need for an inexpensive cellulosic material that can be used in the production of microcrystalline cellulose. Microcrystalline cellulose is a purified crystalline form of partially depolymerized cellulose that is widely used in food, pharmaceutical, cosmetic, and industrial applications.
Until now, the use of kraft fibers in microcrystalline cellulose production without the addition of extensive post-bleaching processing steps has been limited. Microcrystalline cellulose production generally requires a highly purified cellulose starting material, which is acid hydrolysis to remove the amorphous segments of the cellulose chain. See U.S. Pat. No. 2,978,446 to Battista et al. And U.S. Pat. No. 5,346,589 to Braunstein et al. The degree of low polymerization of the chain upon removal of the amorphous segment of cellulose called “level-off DP” is
Often it is the starting point for microcrystalline cellulose production, the number of which depends mainly on the cellulose fiber source and processing. Dissolution of amorphous segments from standard kraft fibers generally results in 1) residual impurities, 2) lack of sufficiently long crystalline segments, or 3) typically 20
Degrading the fiber to the extent that it makes it unsuitable for most applications, at least one of resulting in a cellulose fiber having a degree of polymerization that is too high in the range of 0-400, to produce microcrystalline cellulose Make it useful. For example, kraft fibers with excellent purity and / or lower level-off DP values may be desirable because draft fibers can provide greater versatility in microcrystalline cellulose production and applications.

In the present disclosure, fibers having one or more of the described properties can simply be produced via a typical kraft pulping modification and bleaching process. The fibers of the present disclosure overcome many of the limitations associated with the known modified kraft fibers described above.
For example, the present invention provides the following items.
(Item 1)
Oxidized kraft produced by bleaching cellulosic kraft pulp using a multi-stage bleaching process and oxidizing the kraft pulp with peroxide and catalyst under acidic conditions during at least one stage of the multi-stage bleaching process A diaper, incontinence device or other urine absorbing product comprising fiber, wherein the multi-stage bleaching process comprises at least one chlorine bleaching stage after the oxidation stage;
The urine absorbing product exhibits at least a 10% improvement in vertical wicking, horizontal wicking or 45 degree wicking;
Diapers, incontinence devices or other urine absorbing products.
(Item 2)
The urine absorption product of item 1, wherein the urine absorption product exhibits at least 15% improvement in vertical wicking, horizontal wicking or 45 degree wicking.
(Item 3)
The urine absorption product of item 1, wherein the urine absorption product exhibits at least a 20% improvement in vertical wicking, horizontal wicking or 45 degree wicking.
(Item 4)
The urine absorption product according to Item 1, wherein the modified kraft fiber is treated with a surfactant.
(Item 5)
The urine absorbent product according to item 1, wherein the product contains multilayer absorbent fibers.
(Item 6)
The urine absorption product of item 1, wherein at least one layer comprises oxidized kraft fiber treated with a surfactant.
(Item 7)
6. The urine absorption product of item 5, wherein at least two layers comprise oxidized kraft fiber.
(Item 8)
Item 6. The urine absorption product according to Item 5, wherein at least one layer of oxidized kraft fiber is treated with a surfactant.
(Item 9)
Item 8. The urine absorbent product of item 7, wherein at least two layers of oxidized kraft fiber are treated with a surfactant.
(Item 10)
Urine absorbent tool has a density of about 0.45 g / cm ³ from 0.1 g / cm ^3, urine absorbent product of claim 1.
(Item 11)
Item 11. The urine absorption product of item 10, wherein the density is at least about 0.15 g / cm ³ .
(Item 12)
Item 11. The urine absorption product of item 10, wherein the density is at least about 0.25 g / cm3.
(Item 13)
Item 11. The urine absorption product of item 10, wherein the density is at least about 0.35 g / cm3.
(Item 14)
13. A urine absorbent product according to item 12, wherein the product has an increased absorption rate and capacity compared to a similar product made only with standard kraft fibers.
(Item 15)
Item 13. The urine absorbent product of item 12, wherein the product has improved dimensional stability compared to a similar product made solely from standard kraft fibers.
(Item 16)
Item 6. The urine absorption product according to Item 5, wherein at least the uppermost layer contains oxidized fibers.
(Item 17)
Item 6. The urine absorption product according to Item 5, wherein at least the lowermost layer contains oxidized fibers.
(Item 18)
Item 18. The urine absorption product according to Item 17, wherein at least both the uppermost layer and the lowermost layer both contain oxidized fibers.
(Item 19)
The urine absorption product according to item 1, wherein the retention rate of the product improves as the weighing and density of the oxidized fibers increase.
(Item 20)
20. The urine absorbent product according to item 19, wherein the basis weight of the fibers in the product is at least about 150 gms.

FIG. 1 shows a chart of the final 0.5% hairy CED viscosity as a function of the percentage of peroxide consumed.

FIG. 2 shows a chart of wet strength to dry strength ratio as a function of wet strength resin level.

I. Method The present disclosure provides a novel method for treating cellulose fibers. In some embodiments, the present disclosure provides a method of modifying a cellulose fiber, the method comprising providing the cellulose fiber and oxidizing the cellulose fiber. As used herein, “
“Oxidized”, “catalytically oxidized”, “catalytic oxidation”, and “oxidation” are all interchangeable and at least so that at least some of the hydroxyl groups of the cellulose fiber are oxidized. It should be understood to refer to the treatment of cellulose fibers having a catalytic amount of iron or copper and at least one of at least one peroxide. "Iron or copper"
And similarly, the phrase “iron (or copper)” means “iron or copper, or a combination thereof”. In some embodiments, the oxidation includes simultaneously increasing the carboxylic acid and aldehyde content of the cellulose fiber.

The cellulose fibers used in the methods described herein can be derived from coniferous fibers, hardwood fibers, and mixtures thereof. In some embodiments, the modified cellulose fiber is derived from a conifer such as Southern pine. In some embodiments, the modified cellulose fibers are derived from hardwoods such as eucalyptus. In some embodiments, the modified cellulose fibers are derived from a mixture of conifers and hardwoods. In yet another embodiment, the modified cellulose fibers are derived from cellulose fibers that have previously undergone all or part of the kraft process, ie kraft fibers.

References in this disclosure to “cellulose fibers” or “craft fibers” are interchangeable unless specifically indicated as different or would be understood by one skilled in the art to be different. is there.

In at least one embodiment, the method includes providing cellulose fibers and oxidizing the cellulose fibers while generally maintaining the fiber length of the cellulose fibers.

“Fiber length” and “average fiber length” are used interchangeably when used to describe the properties of a fiber and mean a length-weight average fiber length. Thus, for example, a fiber having an average fiber length of 2 mm should be understood to mean a fiber having a length-weight average fiber length of 2 mm.

In at least one embodiment, the method includes providing cellulose fibers, partially bleaching the cellulose fibers, and oxidizing the cellulose fibers. In some embodiments, the oxidation is performed in a bleaching process. In some embodiments, the oxidation occurs after the bleaching process.

In at least one embodiment, the method includes providing cellulose fibers and oxidizing the cellulose fibers, thereby reducing the degree of polymerization of the cellulose fibers.

In at least one embodiment, the method includes providing cellulose fibers and oxidizing the cellulose fibers while maintaining the Canadian standard freeness (“freeness”) of the cellulose fibers.

In at least one embodiment, the method includes providing cellulose fibers, oxidizing the cellulose fibers, and increasing the lightness of the oxidized cellulose fibers over the standard cellulose fibers.

As mentioned above, according to the present disclosure, the oxidation of the cellulose fibers involves the treatment of the cellulose fibers with at least catalytic amounts of iron or copper and hydrogen peroxide. In at least one embodiment, the method includes oxidizing cellulosic fibers with iron and hydrogen peroxide. Iron sources may be recognized by those skilled in the art, for example, ferrous sulfate (eg, ferrous sulfate heptahydrate), ferrous chloride, ferrous ammonium sulfate, ferric chloride, ferric sulfate. It can be any suitable source, such as ferric ammonium or ferric ammonium citrate.

In some embodiments, the method includes oxidizing cellulosic fibers with copper and hydrogen peroxide. Similarly, the copper source can be any suitable source that those skilled in the art will recognize. Finally, in some embodiments, the method includes oxidizing cellulosic fibers with a combination of copper and iron and hydrogen peroxide.

In some embodiments, the present disclosure treats cellulose fibers comprising providing cellulose fibers, pulping the cellulose fibers, bleaching the cellulose fibers, and oxidizing the cellulose fibers. Provide a way to do that.

In some embodiments, the method further comprises oxygen delignifying the cellulose fiber. Oxygen delignification can be performed by any method known to those skilled in the art. For example, oxygen delignification can be conventional two-stage oxygen delignification. For example, it is known that oxygen delignification of cellulose fibers such as kraft fibers can change the carboxylic acid and / or aldehyde content of the cellulose fibers during processing. In some embodiments, the method includes oxygen delignification of the cellulose fibers prior to bleaching the cellulose fibers.

In at least one embodiment, the method includes oxidizing the cellulose fibers in at least one of a kraft pulping step, an oxygen delignification step, and a kraft bleaching step. In a preferred embodiment, the method includes oxidizing cellulosic fibers in at least one kraft bleaching step. In at least one embodiment, the method includes oxidizing the cellulose fibers in two or more kraft bleaching steps.

When cellulose fibers are oxidized in the bleaching step, the cellulose fibers should not be subject to substantially alkaline conditions in the bleaching process during or after oxidation.
In some embodiments, the method includes oxidizing cellulose fibers at an acidic pH.
In some embodiments, the method includes providing the cellulose fiber, acidifying the cellulose fiber, and then oxidizing the cellulose fiber at an acidic pH. In some embodiments, the pH ranges from about 2 to about 6, such as from about 2 to about 5, or from about 2 to about 4.

The pH is recognized by those skilled in the art using any suitable acid, such as sulfuric acid or hydrochloric acid, or the filtrate from the acidic bleaching stage of the bleaching process, such as the chlorine dioxide (D) stage of the multistage bleaching process. Can be adjusted. For example, cellulose fibers can be acidified by adding foreign acids. Examples of exogenous acids are known in the art and include, but are not limited to, sulfuric acid, hydrochloric acid, and carbonic acid. In some embodiments, the cellulose fibers are acidified with an acidic filtrate from a bleaching step, such as a drained filtrate. In some embodiments, the acidic filtrate from the bleaching step does not have a high iron content. In at least one embodiment, the cellulose fibers are acidified with an acidic filtrate from stage D of the multi-stage bleaching process.

In some embodiments, the method includes oxidizing the cellulose fibers in one or more stages of a multi-stage bleaching sequence. In some embodiments, the method includes oxidizing the cellulose fibers in a single stage of a multi-stage bleaching sequence. In some embodiments, the method includes oxidizing cellulosic fibers at or near the end of a multi-stage bleaching sequence. In some embodiments, the method includes oxidizing the cellulose fibers in at least the fourth stage of a five-stage bleaching sequence.

In accordance with the present disclosure, the multi-stage bleaching sequence can be any bleaching sequence that does not include an alkaline bleaching step after the oxidation step. In at least one embodiment, the multi-stage bleaching sequence is a five-stage bleaching sequence. In some embodiments, the bleaching sequence is a DEDED sequence. In some embodiments, the bleaching sequence is a D ₀ E1D1E2D2 sequence. In some embodiments, the bleaching sequence is a D ₀ (EoP) D1E2D2 sequence. In some embodiments, the bleaching sequence is D ₀ (EO) D1E2D2.

The non-oxidizing stage of the multi-stage bleaching sequence can include any conventional or post-discovery series of steps performed under conventional conditions, provided that it is useful in the production of modified fibers as described in this disclosure, The bleaching step cannot be performed after the oxidation step.

In some embodiments, oxidation is incorporated into the fourth stage of the multi-stage bleaching process.
In some embodiments, the method is performed in a five-stage bleaching process having a sequence of D ₀ E1D1E2D2, and the fourth stage (E2) is used to oxidize kraft fibers.

In some embodiments, the kappa number increases after oxidation of the cellulose fibers. More specifically, based on the expected decrease in materials such as lignin that react with permanganate reagents, one would typically expect a decrease in kappa over this bleaching stage. However, in the methods described herein, the kappa number of cellulose fibers can be reduced due to the loss of impurities, such as lignin, but the kappa number can be increased due to chemical modification of the fibers. Without being bound by theory, it is believed that the increased functionality of the modified cellulose provides an additional site that can react with the permanganate reagent. Therefore, the κ number of the modified kraft fiber is increased relative to the κ number of the standard kraft fiber.

In at least one embodiment, the oxidation occurs in a single stage of the bleaching sequence after both iron or copper and peroxide are added and after a certain retention time is provided. Proper retention is the amount of time that is sufficient to catalyze hydrogen peroxide with iron or copper.
Such time can be easily understood by those skilled in the art.

In accordance with the present disclosure, the oxidation is carried out for a time and at a temperature sufficient to produce the desired reaction completion. For example, the oxidation may be at a temperature in the range of about 60 to about 80 ° C. and from about 40 to about 8
It can be run for a time in the range of 0 minutes. The desired time and temperature of the oxidation reaction will be readily apparent to those skilled in the art.

Advantageously, the cellulose fibers are digested to the target κ number before bleaching. For example, when oxidized cellulose is desired for paper grade or fluff pulp cellulose,
Before bleaching and oxidizing the cellulose, Lo-Soli up to a kappa number in the range of about 30 to about 32.
It can be digested in a two container hydraulic digester using ds® cooking. Alternatively, if oxidized cellulose is desired for cellulose derivative applications, such as the production of cellulose ethers, the cellulose fibers may be about 20 to about 24 before bleaching and oxidizing the cellulose according to the methods of the present disclosure. Can be digested to κ numbers in the range In some embodiments, the cellulose fibers are digested and delignified in a conventional two-stage oxygen delignification step prior to bleaching and oxidizing the cellulose fibers. Advantageously, delignification is used when the oxidized cellulose is intended for paper and / or fluff applications, up to a target kappa number in the range of about 6 to about 8, when the oxidized cellulose is intended for cellulose derivative applications. Is performed up to a target kappa number in the range of about 12 to about 14.

In some embodiments, the bleaching process is from about 85 to about 95%, or from about 88% to about 9
Performed under conditions that target a final ISO brightness of about 88-90%, such as a range of 0%.

The present disclosure also provides a method for treating cellulose fibers comprising providing cellulose fibers, reducing the DP of the cellulose fibers, and maintaining the fiber length of the cellulose fibers. In some embodiments, the cellulose fibers are kraft fibers. In some embodiments, the DP of cellulose fibers is reduced in the bleaching process. In some embodiments, the DP of the cellulose fiber is at the end of the multi-stage bleaching sequence,
Or it is reduced near the end. In some embodiments, DP is reduced in at least the fourth stage of the multi-stage bleaching sequence. In some embodiments, DP is reduced in or after the fourth stage of the multi-stage bleaching sequence.

Alternatively, the multi-stage bleaching sequence can be changed to provide more robust bleaching conditions prior to oxidizing the cellulose fibers. In some embodiments, the method includes providing more robust bleaching conditions prior to the oxidation step. More robust bleaching conditions
With lower amounts of iron or copper, and / or hydrogen peroxide, the degree of polymerization and / or viscosity of the cellulose fibers can be allowed to be reduced in the oxidation step. Thus, it may be possible to modify the bleaching sequence conditions so that the brightness and / or viscosity of the final cellulosic product can be further controlled. For example, reducing the amount of peroxide and metal while providing more robust bleaching conditions prior to oxidation is the same oxidation condition but over oxidized products produced with less robust bleaching Products with low viscosity and high brightness can be provided. Such conditions are, in some embodiments, in particular,
It may be advantageous in cellulose ether applications.

In some embodiments, the methods of the present disclosure further comprise reducing the crystallization of the cellulose fibers such that it is lower than the crystallinity of the cellulose fibers measured before the oxidation step. For example, according to the method of the present disclosure, the crystallinity index of cellulose fibers can be reduced by up to 20% relative to the starting crystallinity index measured before the oxidation stage.

In some embodiments, the disclosed method further includes treating the modified cellulose fiber with at least one corrosive or alkaline material. For example, in at least one embodiment, a method of treating cellulose fibers comprises providing oxidized cellulose fibers of the present disclosure, exposing the oxidized cellulose fibers to an alkaline or corrosive substance, and then Drying and drying the cellulosic product. Without being bound by theory, it is believed that the addition of at least one corrosive substance to the modified cellulose can result in cellulose fibers having a very high functionality and a very short fiber length.

It is known that cellulose containing increased aldehyde groups can have advantageous properties in improving the wet strength of cellulose fibers. For example, Smith et al., US Pat. No. 6,319.
361, and Thornton et al., 6,582,559. Such properties can be beneficial, for example, in absorbent material applications. In some embodiments, the present disclosure improves the wet strength of a product, such as a paper product, comprising providing the modified cellulose fiber of the present disclosure and adding the modified cellulose fiber of the present disclosure to the product. Provide a method. For example, the method can include oxidizing cellulose fibers in a bleaching process, further treating cellulose fibers oxidized with an acidic or corrosive substance, and adding the treated fibers to a cellulosic product.

In accordance with the present disclosure, hydrogen peroxide is added to the cellulose fibers in an acidic medium in an amount sufficient to achieve the desired oxidation and / or degree of polymerization and / or viscosity of the final cellulose product. For example, the peroxide may be about 0.1 to about 4%, or about 1%, based on the dry weight of the pulp
To about 3%, or about 1% to about 2%, or about 2% to about 3%.

Iron or copper is added in an amount at least sufficient to catalyze the oxidation of cellulose with peroxide. For example, iron is about 25 to about 200 p based on the dry weight of kraft pulp.
It can be added in amounts in the pm range. Those skilled in the art will be able to oxidize the final cellulose product and / or
Or the amount of iron or copper could be easily optimized to achieve the desired level or amount of degree of polymerization and / or viscosity.

In some embodiments, the method further involves adding steam either before or after the addition of hydrogen peroxide.

In some embodiments, the final DP and / or viscosity of the pulp can be controlled by the amount of iron or copper and hydrogen peroxide and the robustness of the bleaching conditions prior to the oxidation step. One skilled in the art will recognize that other properties of the modified kraft fiber of the present disclosure can be influenced by the robustness of the iron or copper and hydrogen peroxide and bleaching conditions prior to the oxidation step. For example, one skilled in the art will adjust the amount of iron or copper and hydrogen peroxide and the robustness of the bleaching conditions prior to the oxidation step to target the desired brightness and / or desired degree of polymerization or viscosity of the final product. Or can be achieved.

In some embodiments, the present disclosure provides a method of modifying cellulose fibers comprising providing cellulose fibers, reducing the degree of polymerization of cellulose fibers, and maintaining the fiber length of the cellulose fibers. provide.

In some embodiments, the oxidized kraft fiber of the present disclosure is not purified. Purification of oxidized kraft fiber can have a negative impact on its fiber length and integrity, for example, fiber purification can disrupt the fiber.

In some embodiments, each stage of the five-stage bleaching process (as known to those skilled in the art)
At least a mixer, a reactor, and a washer are included.

In some embodiments, the kraft pulp is acidified on the D1 stage washer, the iron source is also added to the kraft pulp on the D1 stage washer, and the peroxide is in the E2 stage tower. Added before the iron source (or copper source) at the addition point in the mixer or pump, the kraft pulp is reacted in the E2 tower and washed on the E2 scrubber, and the steam is steam mixer It can optionally be added in front of the E2 tower.

In some embodiments, can the iron (or copper) be added until the end of the D1 stage, provided that the pulp is first acidified in the D1 stage (ie, prior to the addition of iron)? Or iron (or copper) can also be added at the beginning of the E2 stage.
Steam can optionally be added either before or after the peroxide addition.

In an exemplary embodiment, a method of preparing a modified cellulosic fiber of low viscosity uses bleaching kraft pulp in a multi-stage bleaching process and treatment with hydrogen peroxide in the presence of an acidic medium and iron, At or near the end of the multi-stage bleaching process (
For example, in the fourth stage of a multi-stage bleaching process, for example, the fourth stage of a five-stage bleaching process.
Reducing the DP of the pulp). For example, the final DP of the pulp can be controlled by appropriate use of iron or copper and hydrogen peroxide, as further described in the Examples section. In some embodiments, the iron or copper and hydrogen peroxide are low DP fibers (ie DPw in the range of about 1180 to about 1830, or 0.5% hairy in the range of about 7 to about 13 mPa · s). Provided in an amount and under conditions suitable to produce a fiber having a CED viscosity. In some exemplary embodiments, the iron or copper and hydrogen peroxide are ultra-low DP fibers (ie, DPw in the range of about 700 to about 1180, or 0.000 in the range of about 3.0 to about 7 mPa · s). Fiber with 5% 0.5% hairy CED viscosity)
Can be provided in an amount and under conditions suitable for producing.

For example, in some embodiments, treatment with hydrogen peroxide in an acidic medium with iron or copper can adjust the pH of the kraft pulp to a pH in the range of about 2 to about 5 and acidify the iron source. Adding to the pulverized pulp and adding hydrogen peroxide to the kraft pulp.

In some embodiments, for example, methods of preparing modified cellulose fibers within the scope of this disclosure acidify kraft pulp to a pH in the range of about 2 to about 5 (eg, using sulfuric acid). And an iron source (eg, ferrous sulfate, eg, ferrous sulfate heptahydrate) at a consistency in the range of about 1% to about 15%, based on the dry weight of the kraft pulp, from about 25 to about 250 ppm F
e ^{+ 2} applied acidified kraft pulp, and a solution having a concentration of about 1% to about 50% by weight in an amount ranging from about 0.1% to about 1.5% based on the dry weight of the kraft pulp Mixing with hydrogen peroxide which can be added as: In some embodiments, the ferrous sulfate solution is mixed with kraft pulp with a consistency ranging from about 7% to about 15%. In some embodiments, acidic kraft pulp is mixed with an iron source and reacted with hydrogen peroxide at a temperature in the range of about 60 to about 80 ° C. for a period in the range of about 40 to about 80 minutes.

In some embodiments, a method of preparing modified cellulose fibers within the scope of this disclosure reduces DP by treating kraft pulp with hydrogen peroxide in an acidic medium in the presence of iron (or copper). As such, acidic hydrogen peroxide and iron (or copper) treatment is incorporated into a multi-stage bleaching process. In some embodiments, treatment with iron, acid, and hydrogen peroxide is incorporated into a single stage of a multi-stage bleaching process. In some embodiments, treatment with iron (or copper), acid, and hydrogen peroxide is incorporated into a single stage at or near the end of the multi-stage bleaching process. In some embodiments, iron (
(Or copper), acid, and hydrogen peroxide treatment is incorporated into the fourth stage of the multi-stage bleaching process. For example, pulping can occur in a single stage, such as the E2 stage, after both iron (or copper) and peroxide have been added and a certain retention time has been provided. In some embodiments, each stage of the five stage bleaching process includes at least a mixer, a reactor, and a washer (as is known to those skilled in the art), and the kraft pulp is acidified on the D1 stage washer The iron source can also be added to the kraft pulp on the D1 stage washer, and the peroxide can be added to the iron source (or copper source) at the addition point in the mixer or pump before the E2 stage tower. The kraft pulp can be reacted later in the E2 tower and washed on the E2 scrubber, and steam can optionally be added before the E2 tower in the steam mixer. In some embodiments, the pulp may be acidified first (ie, prior to the addition of iron) in the D1 stage, and extra acid may be added as necessary to bring the pH in the range of about 3 to about 5. For example, iron (or copper) is D1 provided that the peroxide can be added after iron (or copper).
It can be added until the end of the stage, or iron (or copper) could also be added at the beginning of the E2 stage. The steam may be added before or after the peroxide is added.

For example, in one embodiment, the above-described five-stage bleaching process performed with the conifer cellulose starting material has the following properties (average fiber length of at least 2.2 mm, about 3.0 mPa · s to 13 mP):
a viscosity in the range of less than a · s, S10 corrosion solubility in the range of about 16% to about 20%, S18 corrosion solubility in the range of about 14% to about 18%, carboxyl in the range of about 2 meq / 100 g to about 6 meq / 100 g. Content, aldehyde content in the range of about 1 meq / 100 g to about 3 meq / 100 g, carbonyl content of about 1-4, freeness in the range of about 700 ml to about 760 ml,
Modified cellulose fibers having one or more of a fiber length in the range of about 5 km to about 8 km, and a lightness in the range of about 85 to about 95 ISO may be produced. For example, in some embodiments, the exemplary five-stage bleaching process described above can produce modified cellulose conifer fibers having each of the aforementioned characteristics.

In accordance with another embodiment where the cellulose fibers are coniferous fibers, the exemplary five-step bleaching process described above is at least 2.0 mm (eg, from about 2.0 mm to about 3.7 mm, or about 2.2 m).
m to an average fiber length of about 3.7 mm), a viscosity of less than 13 mPa · s (eg, about 3
. 0 mPa · s to less than 13 mPa · s, or about 3.0 mPa · s to about 5.5 mPa · s
Or about 3.0 mPa · s to about 7 mPa · s, or about 7 mPa · s to 13 mPa · s
Modified cellulose softwood fibers having a viscosity in the range of less than 85, and a brightness of at least 85 (e.g., in the range of about 85 to about 95).

In some embodiments, the present disclosure provides a method of producing fluff pulp comprising providing a modified kraft fiber of the present disclosure and then producing fluff pulp. For example, the method includes bleaching kraft fibers in a multi-stage bleaching process and, under acidic conditions, fibers with hydrogen peroxide and a catalytic amount of iron or copper in at least the fourth or fifth stage of the multi-stage bleaching process. And then forming fluff pulp. In at least one embodiment, the fiber is not purified after the multi-stage bleaching process.

The present disclosure also provides a method of reducing odors from bodily waste products, such as urine or blood. In some embodiments, the present disclosure provides a bleached kraft fiber modified in accordance with the present disclosure and an air odorant upon application of an equivalent amount of odorant relative to the equivalent weight of standard kraft fiber; In comparison, an odor control method is provided that includes applying an odorant to bleached kraft fiber such that the amount of odorant in the atmosphere is reduced. In some embodiments, the present disclosure provides a method of controlling odor comprising inhibiting the production of a bacterial odor.
In some embodiments, the present disclosure provides a method of controlling odor comprising absorbing an odorant, such as a nitrogen odorant, onto a modified kraft fiber. As used herein, “nitrogen odorant” is understood to mean an odorant containing at least one nitrogen.

In at least one embodiment, a method of reducing odor includes providing modified cellulose fibers in accordance with the present disclosure and generating odorants such as nitrogen compounds, eg, ammonia, or nitrogen compounds in modified craft fibers. Applying possible organisms. In some embodiments, the method further includes forming fluff pulp from the modified cellulose fiber prior to adding the odorant to the modified kraft fiber. In some embodiments, the odorant comprises at least one bacterium capable of producing a nitrogen compound. In some embodiments, the odorant comprises a nitrogen compound such as ammonia.

In some embodiments, the method of reducing odor further comprises absorbing ammonia into the modified cellulose fibers. In some embodiments, the method of reducing odor further comprises inhibiting bacterial ammonia production. In some embodiments, the method of inhibiting bacterial ammonia production comprises inhibiting bacterial growth. In some embodiments,
A method of inhibiting bacterial ammonia production includes inhibiting bacterial urea synthesis.

In some embodiments, the method of reducing odor includes combining the modified cellulose fiber with at least one other odor reducing agent and then applying the odorant to the modified cellulose fiber in combination with the odor reducing agent. Including.

Exemplary odor reducing agents are known in the art and include, for example, odor reducing agents, odor masking agents, biocides, enzymes, and urea inhibitors. For example, modified cellulose fibers include zeolite, activated carbon, diatomaceous earth, cyclodextrin, clay, chelating agents (such as those containing metal ions such as copper ions, silver ions, or zinc ions), ion exchange resins, antibacterial or antimicrobial It may be mixed with at least one odor reducing agent selected from functional polymers and / or fragrances.

In some embodiments, the modified cellulose fiber is combined with at least one superabsorbent polymer (SAP). In some embodiments, the SAP can be an odor reducing agent. Examples of SAPs that can be used in accordance with the present disclosure include Hy sold by BASF
sorb (trademark), Aqua Keep (registered trade mark) sold by Sumitomo
, And FAVOR® sold by Evonik, but are not limited to these.

II. Kraft Fiber References herein to “standard”, “traditional” or “traditional” kraft fiber, kraft bleached fiber, kraft pulp, or kraft bleached pulp. Such fibers or pulp are often described as reference points for defining the improved properties of the present invention. As used herein, these terms are interchangeable and equivalent to a composition and are used alone or in one or more alkaline or acid treatments (ie, processed in standard or conventional manner). ) Refers to fiber or pulp processed in a similar manner to the target fiber or pulp without any subsequent oxidation. As used herein, the term “modified” refers to a fiber that has undergone oxidation treatment either alone or after one or more alkali treatments or acid treatments.

Physical characteristics (eg, fiber length and viscosity) of the modified cellulose fibers described herein
Is measured according to the protocol provided in the Examples section.

The present disclosure provides kraft fibers having low viscosity and very low viscosity. Unless otherwise specified, as used herein, “viscosity” is TAPPI as referred to in the protocol.
Refers to a hairy CED viscosity of 0.5%, measured according to T230-om99. The modified kraft fiber of the present invention exhibits unique features that indicate the chemical modifications made to it. More specifically, the fibers of the present invention exhibit characteristics similar to those of standard kraft fibers, i.e., length and freeness, but are a function of an increased number of functional groups contained in the modified fibers. Some very different features are also shown. This modified fiber exhibits unique characteristics when it undergoes a TAPPI test to measure the stated viscosity. Specifically, the described TAPPI test treats fibers with caustic as part of the test method. As explained, the application of a caustic agent to the modified fiber causes the modified fiber to hydrolyze unlike the standard kraft fiber, and thus generally reports a viscosity lower than that of the standard kraft fiber. Thus, those skilled in the art will appreciate that the reported viscosity can be affected by the viscosity measurement method. For the purposes of the present invention, the described TAP
The viscosity reported herein, measured by the PI method, represents the viscosity of the kraft fiber that was used to calculate the degree of polymerization of the fiber.

Unless otherwise specified, as used herein, “DP” is TAPPI T230-
Average polymerization weight calculated from 0.5% hairy CED viscosity measured according to om99 (
DPw). For example, J. et al. F. Cellucon Conference in
The Chemistry and Processing of Wood an
d Plant Fibrous Materials, 155 pages, test proto
ocol 8, 1994 (Woodhead Publishing Ltd.,
Abington Hall, Abinton Cambridge CBI 6 A
H England, J .; F. See Kennedy et al. "Low DP"
Means a DP in the range of about 1160 to about 1860, or a viscosity in the range of about 7 to about 13 mPa · s. “Ultra-low DP” fiber means a DP in the range of about 350 to about 1160, or a viscosity in the range of about 3 to about 7 mPa · s.

Without being bound by theory, the fiber of the present invention has a DP of TAPPI T230-om99.
When calculated via the CED viscosity measured according to In particular, the catalytic oxidation treatment of the fibers of the present invention does not break the cellulose to the extent indicated by the measured DP, but instead of breaking the cellulose chain, it breaks the bond to make the cellulose more reactive. Instead, it is conceivable to have mainly the effect of adding. In addition, the CED viscosity test (TAPPI T230-om starting with the addition of corrosives)
99) is believed to have the effect of cleaving the cellulose chains at the new reactive sites, resulting in a cellulose polymer having a much larger number of shorter segments than found in the fiber pre-test state. This is confirmed by the fact that the fiber length does not decrease significantly during production.

In some embodiments, the modified cellulose fiber has a DP in the range of about 350 to about 1860.
Have In some embodiments, the DP ranges from about 710 to about 1860. In some embodiments, DP ranges from about 350 to about 910. In some embodiments, DP ranges from about 350 to about 1160. In some embodiments, DP ranges from about 1160 to about 1860. In some embodiments, the DP is less than 1860,
Less than 1550, less than 1300, less than 820, or less than 600.

In some embodiments, the modified cellulose fibers are from about 3.0 mPa · s to about 13 mPa.
Has a viscosity in the range of s. In some embodiments, the viscosity ranges from about 4.5 mPa · s to about 13 mPa · s. In some embodiments, the viscosity is about 3.0 mPa · s to
The range is about 5.5 mPa · s. In some embodiments, the viscosity is about 3.0 mPa · s.
The range is from s to about 7 mPa · s. In some embodiments, the viscosity is about 7 mPa · s to
The range is about 13 mPa · s. In some embodiments, the viscosity is less than about 13 mPa · s, less than 10 mPa · s, less than 8 mPa · s, less than 5 mPa · s, or less than 4 mPa · s.

In some embodiments, the modified kraft fiber of the present disclosure maintains its freeness during the bleaching process. In some embodiments, the modified cellulose fiber is at least about 700 ml.
Or at least about 69, such as about 710 ml, or about 720 ml, or about 730 ml
It has 0 ml “freeness”.

In some embodiments, the modified kraft fiber of the present disclosure maintains its fiber length during the bleaching process.

In some embodiments, when the modified cellulose fiber is a conifer fiber, the modified cellulose fiber has an average fiber length of about 2 mm or greater, measured according to test protocol 12 described in the Examples section below. In some embodiments, the average fiber length does not exceed about 3.7 mm. In some embodiments, the average fiber length is at least about 2.2 m
m, 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, or about 3.7 mm. In some embodiments, the average fiber length is from about 2 mm to about 3.7 mm, or from about 2.2 mm to about 3.7 mm.
Range.

In some embodiments, when the modified cellulose fiber is hardwood fiber, the modified cellulose fiber has an average fiber length of about 0.75 to about 1.25 mm. For example, the average fiber length is
At least about 0.8, such as about 0.95 mm, or about 1.05 mm, or about 1.15 mm;
It can be 5 mm.

In some embodiments, the modified kraft fiber of the present disclosure has a lightness equivalent to a standard kraft fiber of kraft fiber. In some embodiments, the modified cellulose fiber has a brightness of at least 85, 86, 87, 88, 89, or 90 ISO. In some embodiments, the brightness does not exceed about 92. In some embodiments, the brightness is from about 85 to about 92.
Or about 86 to about 90, or about 87 to about 90, or about 88 to about 90.

In some embodiments, the modified cellulose fibers of the present disclosure are more compressible and / or embossable than standard kraft fibers. In some embodiments, modified cellulose fibers may be used to produce structures that are thinner and / or have a higher density than structures produced with an equivalent amount of standard kraft fibers.

In some embodiments, the modified cellulose fiber of the present disclosure is at least about 0.21 g /
cc, for example about 0.22 g / cc, or about 0.23 g / cc, or about 0.24 g / cc
It can be compressed to a density of cc. In some embodiments, the modified cellulose fibers of the present disclosure can be compressed to a density in the range of about 0.21 to about 0.24 g / cc. In at least one embodiment, the modified cellulosic fiber of the present disclosure is about 0 when compressed at 20 psi gauge pressure.
. Having a density in the range of 21 to about 0.24 g / cc.

In some embodiments, the modified cellulose fibers of the present disclosure have a density in the range of about 0.110 to about 0.114 g / cc when compressed under a gauge pressure of about 5 psi. For example, the modified cellulose fibers of the present disclosure have at least about 0 when compressed under a gauge pressure of about 5 psi.
. 110 g / cc, such as at least about 0.112 g / cc, or about 0.113 g / cc
cc, or a density of about 0.114 g / cc.

In some embodiments, the modified cellulose fibers of the present disclosure have a density in the range of about 0.130 to about 0.155 g / cc when compressed under a gauge pressure of about 10 psi. For example,
The modified cellulose fibers of the present disclosure have at least about 0.130 g / cc, such as at least about 0.135 g / cc, or about 0.140 when compressed under a gauge pressure of about 10 psi.
It may have a density of g / cc, or about 0.145 g / cc, or about 0.150 g / cc.

In some embodiments, the modified cellulose fibers of the present disclosure can be compressed to a density that is at least about 8% higher than that of standard kraft fibers. In some embodiments, the modified cellulose fibers of the present disclosure are about 8% to about 16% higher than the density of standard kraft fibers, such as about 10% to about 16% higher, or about 12% to about 16%. High, or about 13% to about 16
%, Or about 14% to about 16% higher, or about 15% to about 16% higher density.

In some embodiments, the modified kraft fiber of the present disclosure has an increased carboxyl content relative to standard kraft fiber.

In some embodiments, the modified cellulose fibers are from about 2 meq / 100 g to about 9 meq.
Having a carboxyl content in the range of / 100 g. In some embodiments, the carboxyl content ranges from about 3 meq / 100 g to about 8 meq / 100 g. In some embodiments, the carboxyl content is about 4 meq / 100 g. In some embodiments, the carboxyl content is at least about 2 meq / 100 g, such as at least about 2.5 meq / 100 g, such as at least about 3.0 meq / 100 g, such as at least about 3.5 meq / 100 g, such as At least about 4.0 meq / 100 g, such as at least about 4.5 meq / 100 g, or such as at least about 5.0 meq /
100 g.

The modified kraft fiber of the present disclosure has an increased aldehyde content relative to standard bleached kraft fiber. In some embodiments, the modified kraft fiber has an aldehyde content ranging from about 1 meq / 100 g to about 9 meq / 100 g. In some embodiments, the aldehyde content is at least about 1.5 meq / 100 g, about 2 meq / 100 g, about 2.
5 meq / 100 g, about 3.0 meq / 100 g, about 3.5 meq / 100 g, about 4.0
meq / 100 g, about 4.5 meq / 100 g, or about 5.0 meq / 100 g, or at least about 6.5 meq, or at least about 7.0 meq.

In some embodiments, the modified cellulosic fibers are greater than about 0.5, such as greater than about 1, such as greater than about 1.4.
It has a ratio of total aldehyde to carboxyl content of greater than about 0.3, such as greater than. In some embodiments, the ratio of aldehyde to carboxyl ranges from about 0.3 to about 1.5.
In some embodiments, the ratio ranges from about 0.3 to about 0.5. In some embodiments, the ratio ranges from about 0.5 to about 1. In some embodiments, the ratio is about 1
Is in the range of ~ 1.5.

In some embodiments, the modified kraft fiber has a higher kink and curl than standard kraft fiber. The modified kraft fiber according to the present invention has a kink index in the range of about 1.3 to about 2.3. For example, the kink index is from about 1.5 to about 2.3, or from about 1.7 to about 2.
. 3, or about 1.8 to about 2.3, or about 2.0 to about 2.3. Modified kraft fibers according to the present disclosure may have a length weighted curl index in the range of about 0.11 to about 0.23, such as about 0.15 to about 0.2.

In some embodiments, the crystallinity index of the modified kraft fiber is from about 5% to about 20%, such as from about 10% to about 20%, or from about 15% to about 15% relative to the crystallinity index of the standard kraft fiber. 2
Reduced by 0%.

In some embodiments, the modified cellulose according to the present disclosure has an R10 value in the range of about 65% to about 85%, such as about 70% to about 85%, or about 75% to about 85%. In some embodiments, modified fibers according to the present disclosure have about 75% to about 90%, such as about 80% to
It has an R18 value in the range of about 90%, for example about 80% to about 87%. R18 and R10
The content of is described in TAPPI 235. R10 represents the residual undissolved material remaining after extraction of the pulp with 10 wt% corrosion, and R18 represents the residual amount of undissolved material remaining after extraction of the pulp with 18% caustic solution. Generally, in a 10% caustic solution, hemicellulose and chemically degraded short chain cellulose are dissolved and removed in the solution. In contrast, generally only hemicellulose is dissolved and removed in 18% caustic dissolution. Thus, the difference between R10 and R18 values (R = R18-R10) represents the amount of chemically degraded short chain cellulose present in the pulp sample.

Based on one or more of the above properties such as fiber kink and curl, increased functionality of the modified kraft fiber, and crystallinity, one of ordinary skill in the art will recognize that the modified kraft fiber of the present disclosure is
It would be expected that standard kraft fibers have certain characteristics that do not retain. For example, it is believed that the kraft fibers of the present disclosure may be more flexible, elongated and / or curved and / or elastic and / or increase wicking than standard kraft fibers. Yes. Moreover, without being bound by theory, modified kraft fibers, for example, in fluff pulp, have been entangled with fibers and / It is anticipated that a physical structure could be provided that would result in fiber adhesion or entangle the material applied to the pulp. In addition, due to at least reduced crystallinity relative to standard kraft fibers, the modified kraft fibers of the present disclosure are more flexible than standard kraft fibers and are applicable in absorbent product applications such as diaper and bandage applications It is expected to enhance sex.

In some embodiments, the modified cellulose fibers are about 16% to about 30%, or about 14
S10 has a corrosion solubility in the range of about 16% to about 16%. In some embodiments, the modified cellulosic fibers have a corrosion solubility of S18 ranging from about 14% to about 22%, or from about 14% to about 16%. In some embodiments, the modified cellulose fibers have a ΔR (difference between S10 and S18) of about 2.9 or greater. In some embodiments, ΔR is about 6.0 or greater.

In some embodiments, the modified cellulose fiber strength ranges from about 4 km to about 10 km, such as from about 5 km to about 8 km, as measured by wet zero span break length.
In some embodiments, the fiber strength is at least about 4 km, about 5 km, about 6 km, about 7
km, or about 8 km. In some embodiments, the fiber strength is about 5 km to about 7 k.
m, or in the range of about 6 km to about 7 km.

In some embodiments, the modified kraft fiber has odor control properties. In some embodiments, the modified kraft fiber can reduce the odor of bodily waste products such as urine or menstruation. In some embodiments, the modified kraft fiber absorbs ammonia.
In some embodiments, the modified kraft fiber inhibits bacterial odor production, for example, in some embodiments, the modified kraft fiber inhibits bacterial ammonia production.

In at least one embodiment, the modified kraft fiber is capable of absorbing a nitrogen-containing odorant, such as an odorant such as ammonia.

As used herein, the term “odorant” means a chemical material that has an odor or odor or is capable of interacting with an olfactory receptor or produces an odor or odor. It should be understood that it refers to an organism such as a bacterium capable of producing a compound, for example a bacterium producing urea.

In some embodiments, the modified kraft fiber reduces atmospheric ammonia concentration more than standard bleached kraft fiber reduces atmospheric ammonia. For example, the modified kraft fiber may reduce atmospheric ammonia by absorbing at least a portion of the ammonia sample applied to the modified kraft fiber or inhibiting bacterial ammonia production. In at least one embodiment, the modified kraft fiber absorbs ammonia and inhibits bacterial ammonia production.

In some embodiments, the modified kraft fiber has at least about 40% more atmospheric ammonia than standard kraft fiber, for example, ammonia has at least about 50% more than standard kraft fiber, or about 60% more Or about 70% more, or about 75% more,
Or about 80% more, or about 90% more.

In some embodiments, the modified kraft fiber of the present disclosure after application of a solution of 0.12 g of 50% ammonia hydroxide to about 9 g of modified cellulose, and a 45 minute incubation time,
Reduce atmospheric ammonia concentrations in volumes of 1.6 L to less than 150 ppm, such as less than about 125 ppm, such as less than about 100 ppm, such as less than about 75 ppm, such as less than about 50 ppm.

In some embodiments, the modified kraft fiber absorbs about 5 to about 10 ppm ammonia per gram of fiber. For example, the modified cellulose is about 6 to about 10 ppm per gram of fiber.
Or about 7 to about 10 ppm, or about 8 to about 10 ppm of ammonia.

In some embodiments, the modified kraft fiber has both improved odor control properties and improved lightness compared to standard kraft fiber. In at least one embodiment,
The modified cellulose fiber has a lightness in the range of about 85 to about 92 and can reduce odor. For example, the modified cellulose can have a lightness in the range of about 85 to about 92 and 1 g of fiber
Absorbs about 5 to about 10 ppm of ammonia each time.

In some embodiments, the modified cellulose fiber has a MEM elution cytotoxicity test, grade 0-4 and less than 2 ISO 10993-5. For example, the cytotoxicity can be less than about 1.5, or less than about 1.

It is known that oxidized celluloses, particularly those containing aldehyde groups and / or carboxylic acid groups, exhibit antiviral and / or antimicrobial activity. For example, Son
g et al., Novel antivirus activity of dialdehyd
e start, Electronic J. et al. Biotech. Vol.12, No.2, 2
See U.S. Pat. No. 7,019,191 to Looney et al. For example,
Aldehyde groups in dialdehyde starch provide antiviral activity, for example, oxidized cellulose and oxidized regenerated cellulose containing carboxylic acid groups are used for wound care because of their bactericidal and hemostatic properties It is known that some of them are used frequently. Thus, in some embodiments, the cellulose fibers of the present disclosure can exhibit antiviral activity and / or antimicrobial activity. In at least one embodiment, the modified cellulose fiber exhibits antibacterial activity. In some embodiments, the modified cellulose fiber exhibits antiviral activity.

In some embodiments, the modified kraft fiber of the present disclosure is less than about 100, or about 80
200, such as less than, or less than about 75, or less than about 50, or less than about 48 or equivalent.
Having a level-off DP of less than Level off DP can be obtained by methods known in the art, for example, Battista et al. Level Off Degree of Ply.
meritation, Division of Cellulose Chemis
try, Symposium on Degradation of Cellulo
se and Cellulose Derivatives, 127 ^th Meet
ing, ACS, Cincinnati, Ohio, May 1955 to April 1955.

In some embodiments, the modified kraft fiber has a kappa number less than about 2. For example, the modified kraft fiber can have a kappa number less than about 1.9. In some embodiments, the modified kraft fiber is about 0.1 to about 0.9, about 0.1 to about 0.8, such as about 0.1 to about 0.7
For example, about 0, such as about 0.1 to about 0.6, about 0.1 to about 0.5, or about 0.2 to about 0.5.
. It has a kappa number in the range of 1 to about 1.

In some embodiments, the modified kraft fiber is a kraft fiber that has been bleached in a multi-stage process, and the oxidation step is performed prior to at least one bleaching process. In such embodiments, the modified fiber after at least one bleaching step is TAPPI UM2
Having a “κ number” measured in accordance with 51 in the range of about 0.2 to about 1.2. For example, the kappa number ranges from about 0.4 to about 1.2, or from about 0.6 to about 1.2, or from about 0.8 to about 1.2, or from about 1.0 to about 1.2. It can be.

In some embodiments, the modified cellulose fiber has a copper number greater than about 2. In some embodiments, the copper number is greater than 2.0. In some embodiments, the copper number is greater than about 2.5. For example, the copper value may be greater than about 3. In some embodiments, the copper number ranges from about 2.5 to about 5.5, such as from about 3 to about 5.5, such as from about 3 to about 5.2.

In at least one embodiment, the hemicellulose content of the modified kraft fiber is substantially the same as standard unbleached kraft fiber. For example, the hemicellulose content for conifer craft fibers can range from about 16% to about 18%. For example, the hemicellulose content of hardwood kraft fiber can range from about 18% to about 25%.

III. Further Processing—Acid / Alkaline Hydrolysis In some embodiments, the modified kraft fibers of the present disclosure are suitable for the production of cellulose derivatives, eg, low viscosity cellulose ethers, cellulose esters, and microcrystalline cellulose. . In some embodiments, the modified kraft fiber of the present disclosure is a hydrolyzed modified kraft fiber. As used herein, “hydrolyzed modified kraft fiber”, “hydrolyzed kraft fiber”, and the like can be treated with any acid or alkali treatment known by depolymerizing cellulose chains. It should be understood to mean hydrolyzed fibers. In some embodiments, the kraft fiber according to the present disclosure is further treated to reduce its viscosity and / or degree of polymerization. For example, kraft fibers according to the present disclosure can be treated with acids or bases.

In some embodiments, the present disclosure provides a method of treating kraft fibers comprising bleaching kraft fibers according to the present disclosure and then hydrolyzing the bleached kraft fibers. Hydrolysis can be any method known to those skilled in the art. In some embodiments, the bleached kraft fiber is hydrolyzed with at least one acid. In some embodiments, the bleached kraft fiber is hydrolyzed with an acid selected from sulfuric acid, mineral acid, and hydrochloric acid.

The present disclosure also provides a method of producing cellulose ether. In some embodiments, a method of producing a cellulose ether comprises bleaching kraft fiber, treating bleached kraft fiber with at least one alkaline agent, such as sodium hydroxide, and at least one according to the present disclosure. Reacting the fiber with the etherifying agent.

The present disclosure also provides a method of producing a cellulose ester. In some embodiments, a method of producing a cellulose ester comprises bleaching kraft fiber according to the present disclosure, treating the bleached kraft fiber with a catalyst such as sulfuric acid, and then with at least one acetic anhydride or acetic acid. Treating the fiber. In an alternative embodiment, the method of producing cellulose acetate is hydrolyzed with bleaching kraft fiber according to the present disclosure, hydrolyzing bleached kraft fiber with sulfuric acid, and at least one acetic anhydride or acetic acid. Treating the craft fiber.

The present disclosure also provides a method for producing microcrystalline cellulose. In some embodiments, the method of producing microcrystalline cellulose comprises at least one of providing a kraft fiber according to the present disclosure and under conditions that reach a desired DP or reach a level-off DP.
Hydrolyzing bleached kraft fiber with two acids. In further embodiments, the hydrolyzed bleached kraft fiber is mechanically processed, for example, by grinding, milling, or shearing. Methods for mechanically treating hydrolyzed kraft fibers in microcrystalline cellulose production are known to those skilled in the art and can provide the desired particle size. Other parameters and conditions for producing microcrystalline cellulose are known and are described, for example, in US Pat. No. 2,9.
78,446 and 5,346,589.

In some embodiments, the modified kraft fiber according to the present disclosure further comprises its viscosity and / or
Alternatively, it is further treated with an alkaline or corrosive agent to reduce the degree of polymerization. About 9
An alkali treatment with a pH exceeding □ causes the dialdehyde to react and eliminate β-hydroxy.
This further modified fiber, treated with an alkaline agent, may also be useful in the production of tissues, towels, and other absorbent products, and in cellulose derivative applications. In more conventional papermaking, reinforcing agents are often added to the fiber slurry to modify the physical properties of the final product. This alkali modified fiber can be used to replace some or all of the strength modifiers used in tissue and towel production.

As mentioned above, there are three types of textile products that can be prepared by the process described herein. The first type is a fiber that has been treated by catalytic oxidation, which fiber is almost indistinguishable from its conventional counterpart (at least as far as physical and papermaking properties are concerned), but its associated functions. It has one or more of its odor control properties, compressibility, low DP and ultra low DP, and / or alkaline or acid hydrolysis conditions (cellulose derivative production, eg ether or acetate The ability to convert “in-situ” to low DP / low viscosity fiber under production conditions, etc.). The physical characteristics and papermaking properties of this type of fiber make it suitable for use in typical papermaking and absorbent product applications. On the other hand, increased functionality (eg, aldehydes and carboxylic acids), and properties associated with the functionality, make the fibers more desirable and versatile than standard kraft fibers.

The second type of fiber is a fiber that has been subjected to catalytic oxidation and then treated with an alkaline or corrosive agent. Alkaline agents break down the fibers at sites of carbonyl functionality added through an oxidation process. This fiber has different physical and papermaking properties than fibers that have undergone oxidation only, but the test used to measure viscosity, and thereby
Because the DP exposes the fiber to the caustic, it can exhibit the same or similar DP level. It will be apparent to those skilled in the art that different alkaline agents and levels can provide different DP levels.

The third type of fiber is a fiber that has undergone catalytic oxidation and is subsequently treated in an acid hydrolysis step. Acid hydrolysis probably leads to fiber degradation to a level consistent with its level-off DP.

The fibers produced as described above may be treated with a surfactant in some embodiments. Surfactants for use in the present invention may be solid or liquid. The surfactant may be any surfactant, including but not limited to softeners, release agents, and surfactants, which are not substantial to the fiber, ie, do not interfere with its specific absorption rate. As used herein, a surfactant that is “substantial” to the fiber exhibits a specific absorption increase of 30% or less as measured using the preliminary tests described above. According to one embodiment, the specific absorption rate is
Increase by 25% or less, for example 20% or less, for example 15% or less, for example 10% or less. Without being bound by theory, the addition of a surfactant is
Cause competition at the same site on the test fluid and cellulose. Thus, if the surfactant is too substantial, it will react at too many sites and reduce the fiber's absorption capacity.

As used herein, PFI is the SCA of the Scandinavian Pulp and Paper Board Test Committee.
Measured according to the N-C-33: 80 test standard. This method is generally as follows. First, samples are prepared using PFI Pad Former. The vacuum is turned on and approximately 3.01 g of fluff pulp is fed into the pad former inlet. Turn off the vacuum, remove the specimen, place it on a scale and check the pad mass. The mass of fluff is 3.00+
Adjust to 0.01 g and record as dry mass (Massdry). Place fluff in the test cylinder. Place the cylinder containing the fluff in the shallow perforation dish of the Absorption Tester and turn on the water valve. 500g on a fluff pad while lifting the specimen cylinder
Gently apply the load and immediately press the start button. After moving this Tester for 30 seconds, the display reads 00.00. When the display reads 20 seconds, record the dry pad height at the nearest 0.5 mm (dry height: Heightdry). When the display reads 00.00 again, press the start button again to immediately raise the tray automatically from the water and then record the time display (absorption time, T). This Tester keeps moving for 30 seconds. The water tray is automatically lowered and left for another 30 seconds. When the display reads 20 seconds, record the wet pad height at the nearest 0.5 mm (wet height: Heightwe
t). Remove the sample holder, move the wet pad to the balance and wet mass (Massw
et) and close the water valve. The specific absorption rate (s / g) is T / Massdry. The specific capacity (g / g) is (Masswet-Massdry) / Massdry. The wet bulk (cc / g) is [19.64 cm 2 × Heightwet / 3] / 10. The dried bulk is [19.64 cm 2 × Heightdry / 3] / 10.
The reference standard for comparison of surfactant treated fibers is the same fiber with no added surfactant.

It is generally recognized that softeners and release agents are often only marketed as complex mixtures, rather than as a single compound. The following discussion focuses on the main species, but it should be understood that in general, commercially available mixtures may be used.
Suitable softeners, release agents and surfactants are readily apparent to those skilled in the art and are widely reported in the literature.

Suitable surfactants include cationic surfactants, anionic surfactants, and nonionic surfactants that are not substantial to the fiber. According to one embodiment, the surfactant is a nonionic surfactant. According to one embodiment, the surfactant is a cationic surfactant. According to one embodiment, the surfactant is a plant surfactant, for example, a plant fatty acid, such as a plant fatty acid quaternary ammonium salt. Such compounds include DB999 and DB1009, both of which are Cellulose So.
available from lutions. Other surfactants include Berol 388, an ethoxylated nonylphenol ether from Akzo Nobel, and Ashland, Inc. Examples include, but are not limited to, TQ-2021 and TQ-2028.

Biodegradable softeners may be used. Exemplary biodegradable cationic softeners / release agents are described in US Pat. Nos. 5,312,522; 5,415,737; 5,262,007; 5,264,082. No .; and 5,223,096, all of which are incorporated herein by reference in their entirety. These compounds are biodegradable diesters of quaternary ammonia compounds, quaternized amine esters, and biodegradable vegetable oil-based esters that are functional with quaternary ammonium chloride and diester dielsyldimethylammonium chloride. , A representative biodegradable softener.

The surfactant is added in an amount of at most 8 lbs / ton, such as 2 lbs / ton to 7 lbs / ton, such as 4 lbs / ton to 7 lbs / ton, such as 6 lbs / ton to 7 lbs / ton.

The surfactant may be added at any point prior to forming the pulp roll, bail or sheet. According to one embodiment, the surfactant is added just before the head box of the pulp machine, in particular at the inlet of the main cleaner feed pump.

According to one embodiment, the fibers of the present invention, when utilized in a viscose process,
It has an improved filtration rate over the same fiber without added surfactant. For example, the filtration rate of a viscose solution containing the fibers of the present invention is at least 10% lower than a viscose solution made in the same way with the same fiber without surfactant, for example at least 15
%, Eg at least 30% lower, eg at least 40% lower. The filtration rate of the viscose solution is measured by the following method. 1 / 16-3 at the bottom of the solution
Place in a nitrogen pressurized (27 psi) container with a 16 inch filtered orifice and filter media from outside to inside of the container as follows: perforated metal plate, 20 mesh stainless steel screen, muslin Two layers of nap flannel with cloth, Whatman 54 filter paper, and fuzzy sides on top of the contents of the container. The solution was allowed to filter through the medium for 40 minutes, then the volume of the filtered solution was measured (weight) at 40 minutes for 40 minutes (ie, t = 0 at 40 minutes) and the elapsed time was X The slope of this plot is the number of filtrations, with the coordinates and the weight of filtered viscose as the Y coordinate. Record at 10 minute intervals. The reference standard for comparison with the surfactant treated fiber is the same fiber without added surfactant.

According to one embodiment of the present invention, the surfactant-treated fibers of the present invention exhibit a limited specific absorption increase of, for example, less than 30%, for example, with a simultaneous decrease in filtration rate of, for example, at least 10%. Show. According to one embodiment, the surfactant-treated fibers have a specific absorption increase of less than 30% and a filtration rate decrease of at least 20%, such as at least 30%, such as at least 40%. According to another embodiment, the surfactant-treated fiber has a specific absorption increase of 2
Less than 5% and a reduction in filtration rate of at least 10%, such as at least about 20%, such as at least 30%, such as at least 40%. According to yet another embodiment, the surfactant-treated fiber has a specific absorption increase of less than 20% and a decrease in filtration rate of at least 10%, such as at least about 20%, such as at least 30%, such as at least 40%
It is. According to another embodiment, the surfactant-treated fibers have an increase in specific absorbency of less than 15% and a decrease in filtration rate of at least 10%, such as at least about 20%, such as at least 30%, such as at least 40. %. According to yet another embodiment, the surfactant-treated fiber has a specific absorption increase of less than 10% and a filtration rate decrease of at least 10%.
%, Such as at least about 20%, such as at least 30%, such as at least 40%.

IV. Products Made from Kraft Fibers The present disclosure provides products made from the modified kraft fibers described herein. In some embodiments, the product is typically a product made from standard kraft fibers.
In other embodiments, the product is typically a product made from cotton waste or sulfite pulp. More specifically, the modified fibers of the present invention can be used without further modification in the production of absorbent products and as starting materials (such as ethers and esters) in the preparation of chemical derivatives. To date, high alpha content cellulose, such as cotton and sulfite pulp, and fibers that have been useful for replacing traditional kraft fibers have not been usable.

"Can be substituted for cotton waste (or sulfite pulp)" and "Compatible with cotton waste (or sulfite pulp)" and "Used in place of cotton waste (or sulfite pulp)" The phrase “can” as well as the equivalent means only that the fiber has properties that are suitable for use in end-uses typically made using cotton waste (or sulfite pulp). The phrase is not intended to mean that the fiber necessarily has all of the same characteristics as cotton waste (or sulfite pulp).

In some embodiments, the product includes medical devices (including wound care (eg, bandages)), infant diapers, nursing pads, adult incontinence products, feminine hygiene products (eg, sanitary napkins and tampons). Absorbent products, including, but not limited to, airlaid nonwoven products, airlaid compositions, “tabletop” wipes, napkins, tissues, towels, and the like. Absorbent products according to the present disclosure may be disposable. In these embodiments, the modified fibers according to the present invention can be used as all or partial substitutes for bleached hardwood or softwood fibers typically used in the production of these products.

In some embodiments, the modified cellulose fibers are in the form of fluff pulp and have one or more properties that make the modified cellulose fibers more effective than conventional fluff pulp of absorbent products. More specifically, the modified fibers of the present invention may have improved compressibility and improved odor control, both of which make it desirable as a replacement for currently available fluff pulp fibers. . Because of the improved compressibility of the fibers of the present disclosure, it is useful in embodiments that seek to produce thinner, smaller absorbent structures. With an understanding of the compressible nature of the fiber of the present disclosure, one skilled in the art can readily envision an absorbent product that can use the fiber. By way of example, in some embodiments, the present disclosure provides an ultra-thin sanitary product comprising a modified kraft fiber of the present disclosure. Ultra-thin fluff cores are typically
Used for feminine hygiene products or infant diapers. Other products that can be produced with the fibers of the present disclosure can be anything that requires an absorbent core or a compressed absorbent layer. When compressed, the fibers of the present invention show no loss of absorbency, or substantial loss thereof, but show improved flexibility.

According to one embodiment, the absorbent product may be a product such as a diaper or an incontinence device that absorbs and retains urine. Such devices generally contain an absorbent fluff core. The fibers of the present disclosure can be used to produce absorbent devices that can result in a more comfortable garment or device for the user by improving both urine wicking and retention.

The fibers of the present disclosure can improve vertical wicking, horizontal wicking, and / or 45 degree wicking. According to one embodiment, an absorbent product made with fibers of the present disclosure improves vertical wicking by 10% over products made from fibers that have not been subjected to an oxidation step. According to another embodiment, an absorbent product made with fibers of the present disclosure improves vertical wicking by 15% over products made from fibers that have not been subjected to an oxidation step. According to yet another embodiment, an absorbent product made with fibers of the present disclosure improves vertical wicking by at least 20% over products made from fibers that have not been subjected to an oxidation step. Similar improvements can be seen in horizontal and 45 degree wicking.

The fibers of the present disclosure can improve absorption and retention. According to one embodiment,
Absorbent products made with the fibers of the present disclosure improve the absorption rate by 10% over products made from fibers that have not been subjected to an oxidation step. According to another embodiment, an absorbent product made with fibers of the present disclosure improves the absorption rate by 15% over products made from fibers that have not been subjected to an oxidation step. According to yet another embodiment, an absorbent product made with the fibers of the present disclosure improves the absorption rate by 20% over a product made from fibers that have not been subjected to an oxidation step. Similar improvements can be seen in horizontal and 45 degree wicking. Similarly, according to one embodiment, an absorbent product made with fibers of the present disclosure improves total absorption by 5% over products made from fibers that have not been subjected to an oxidation step. According to another embodiment, absorbent products made with fibers of the present disclosure improve total absorption by 10% over products made from fibers that have not been subjected to an oxidation step. According to yet another embodiment, absorbent products made with fibers of the present disclosure improve total absorption by 15% over products made from fibers that have not been subjected to an oxidation step.

The product described has improved flexibility (especially when used on the bending side of a multilayer core), improved urine addition when compared to products made from fibers that have not been subjected to an oxidation step Post dimensional stability, as well as improved wet dry strength (especially when the disclosed fibers are placed on the top layer of a multilayer core) and elongation can be demonstrated.

According to one embodiment, an absorbent core for use in an absorbent device can include one or more fiber layers that have been treated separately to improve the overall uptake and retention of the device. As used herein, treated refers to any chemical or physical process that changes the absorbency, wicking or retention of the fiber. One common treatment is the addition of a surfactant. According to one embodiment, the core has a plurality of layers, eg 2, 3,
It can have 4 or 5 layers. According to one embodiment, the fibers of the present invention may be used in any layer of a multilayer absorbent core and may or may not be treated.

According to another embodiment, the fibers of the present invention are used in the top layer of the absorbent core. As used herein, “top” refers to the location on the core where urine is first added and closest to the skin. Similarly, “bottom” refers to the layer furthest away from the user. Other layers may be referred to as “intermediate”. The fibers of the present disclosure may be used as any “untreated”, eg, referring to fibers that have not been post-treated with a surfactant. The fiber is
It may be used in the “treated” state and is referred to as a fiber modified by the inclusion of a surfactant. Treated or untreated fibers may be used in any layer and in any combination.

According to one embodiment, the fibers of the present invention are used in the top layer of the absorbent core. According to another embodiment, the fibers of the present invention are used in the bottom layer of the absorbent core. According to yet another embodiment, the fibers of the present invention are used in an intermediate layer of an absorbent core.

In yet another embodiment, the fibers of the present disclosure are used in more than one layer of the absorbent core. The fibers of the present disclosure may be used in both the top and bottom layers of the absorbent core. Furthermore, the fibers of the present disclosure may be used in the top, bottom and middle layers of the absorbent core. According to one embodiment, the fibers in the top layer are treated fibers. According to another embodiment,
The fibers in the bottom layer are treated fibers. According to yet another embodiment, the fibers in the intermediate layer are treated fibers.

The treated and untreated fibers of the present disclosure may be combined in a single layer or used in separate layers of the absorbent core. According to one embodiment, the top layer of the absorbent core includes untreated fibers of the present disclosure, and the bottom layer of the absorbent core includes treated fibers of the present disclosure. According to another embodiment, the absorbent core is treated with the treated fibers of the present disclosure in the top layer, the untreated fibers of the present disclosure in one or more intermediate layers, and the treated fibers of the present disclosure in the bottom layer. Made with fibers.

The density of the absorbent core may vary and is typically 0.10 g / cm ^{3 to} 0.45 g / c.
m is in the range of ^3. According to one embodiment, the absorbent core may have a density of about 0.15 g / cm ³ . According to another embodiment, the absorbent core may have a density of about 0.20 g / cm ³ . According to yet another embodiment, the absorbent core may have a density of about 0.25 g / cm ³ .

Without further modification, the modified fibers of the present invention may also be used in the production of absorbent products, including but not limited to tissues, towels, napkins, and other paper products formed with traditional paper machines. Can be done. Traditional papermaking processes typically involve the preparation of an aqueous fiber slurry that is placed on a forming wire from which water is subsequently removed. The increased functionality of the modified cellulose fibers of the present disclosure can provide improved product characteristics of products that include these modified fibers. For the reasons described above, the modified fiber of the present invention is used to make a product so that it may exhibit a strength improvement likely related to the increased functionality of the fiber. The modified fibers of the present invention can also result in products with improved flexibility.

In some embodiments, the modified fibers of the present disclosure, without further modification, are cellulose ethers such as those derived from cotton waste and bleached softwood fibers produced by the acid sulfite pulp process (eg, carboxymethylcellulose), and about 2950 Very high DP of ~ 3980 (ie about 30 mPa as measured by 0.5% Capillary CED
• fibers with viscosities in the range of s to about 60 mPa · s), and can be used in the manufacture of esters as a substitute for fibers having a very high proportion of cellulose (eg, 95% or more). The modified fibers of the present invention that have not undergone acid hydrolysis are generally subjected to such acid hydrolysis treatment in the production process for making cellulose ethers or esters.

As will be described, the second and third types of fibers are produced via a process of derivatizing or hydrolyzing the fibers. These fibers can also be useful in the production of absorbent articles, absorbent paper products, and cellulose derivatives (including ethers and esters).

V. Acid / Alkaline Hydrolyzed Products In some embodiments, the present disclosure provides modified kraft fibers that can be used as a substitute for cotton waste or sulfite pulp. In some embodiments, the present disclosure provides modified kraft fibers that can be used as a substitute for cotton waste or sulfite pulp, for example, in the manufacture of cellulose ethers, cellulose acetates, and microcrystalline cellulose.

Without being bound by theory, increased aldehyde content relative to conventional kraft pulp provides additional active sites for etherification in final products such as carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, and the like, making paper It is believed to allow the production of fibers that can be used for both cellulose derivatives.

In some embodiments, the modified kraft fiber has chemical properties that make it suitable for the production of cellulose ethers. Accordingly, the present disclosure provides cellulose ethers derived from the modified kraft fibers described. In some embodiments, the cellulose ether is selected from ethylcellulose, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, and hydroxyethylmethylcellulose. It is believed that the cellulose ethers of the present disclosure can be used in any application where traditional cellulose ethers are used. For example and without limitation, the cellulose ethers of the present disclosure can be used in coatings, inks, binders, controlled release drug tablets, and films.

In some embodiments, the modified kraft fiber has chemical properties that make it suitable for the production of cellulose esters. Accordingly, the present disclosure provides cellulose esters such as cellulose acetate derived from the modified kraft fiber of the present disclosure. In some embodiments, the present disclosure provides a product comprising cellulose acetate derived from the modified kraft fiber of the present disclosure. For example, without limitation, the cellulose esters of the present disclosure can be used in household furniture, tobacco, inks, absorbent products, pharmaceutical devices, and plastics (including, for example, LCD and plasma screens and windscreens). .

In some embodiments, the modified kraft fiber has chemical properties that make it suitable for the production of microcrystalline cellulose. Microcrystalline cellulose production requires a relatively clean and highly purified starting cellulose material. Therefore, traditionally, expensive sulfite pulp is mainly used for its production. The present disclosure provides microcrystalline cellulose derived from the modified kraft fiber of the present disclosure. Accordingly, the present disclosure provides a cost-effective cellulose source for microcrystalline cellulose production. In some embodiments, the microcrystalline cellulose is derived from a modified kraft fiber having a DP that is less than about 100, such as less than about 75, or less than about 50. In some embodiments, the microcrystalline cellulose has an R10 value ranging from about 65% to about 85%, such as from about 70% to about 85%, or from about 75% to about 85%, and from about 75% to Derived from modified kraft fibers having an R18 value in the range of about 90%, such as from about 80% to about 90%, such as from about 80% to about 87%.

The modified cellulose of the present disclosure can be used in any application where microcrystalline cellulose is traditionally used. For example, without limitation, the modified cellulose of the present disclosure can be used in pharmaceutical or nutraceutical applications, food applications, cosmetic applications, paper applications, or as a structural composite. For example, the modified cellulose of the present disclosure includes a binder, a diluent, a disintegrant, a lubricant, a tableting aid, a stabilizer, a texture agent, a fat substitute, a filler, an anticoagulant,
It can be a foaming agent, an emulsifier, a thickener, a separating agent, a gelling agent, a carrier material, an opacifier, or a viscosity modifier. In some embodiments, the microcrystalline cellulose is a colloid.

VI. Products comprising acid hydrolyzed products In some embodiments, the present disclosure provides pharmaceutical products comprising microcrystalline cellulose that are produced from the modified kraft fibers of the present disclosure that are hydrolyzed. The pharmaceutical product can be any pharmaceutical product for which microcrystalline cellulose is traditionally used. For example, without limitation, the pharmaceutical product can be selected from tablets and capsules. For example, the microcrystalline cellulose of the present disclosure can be a diluent, disintegrant, binder, compression aid, coating, and / or lubricant. In other embodiments, the present disclosure provides a pharmaceutical product comprising at least one modified derivatized kraft fiber of the present disclosure, such as a hydrolyzed modified kraft fiber.

In some embodiments, the present disclosure provides a food product comprising the bleached kraft fiber of the present disclosure that has been hydrolyzed. In some embodiments, the present disclosure provides a food product comprising at least one product derived from the bleached kraft fiber of the present disclosure. In a further embodiment, the present disclosure provides a food product comprising microcrystalline cellulose derived from the kraft fiber of the present disclosure. In some embodiments, the food product comprises colloidal microcrystalline cellulose derived from the kraft fiber of the present disclosure. The food product can be any food product in which microcrystalline cellulose is traditionally used. Exemplary food categories in which microcrystalline cellulose can be used are well known to those skilled in the art, for example, the International Food Standards (Codex
ius), for example, in Table 3. For example, microcrystalline cellulose derived from the chemically modified kraft fiber of the present disclosure may be a coagulation inhibitor, filler, emulsifier, foaming agent, stabilizer, thickener, gelling agent, and / or suspending agent. possible.

Other products comprising cellulose derivatives and microcrystalline cellulose derived from chemically modified kraft fibers according to the present disclosure can also be envisioned by those skilled in the art. Such products are, for example,
It can be identified in cosmetic and industrial applications.

As used herein, “about” means to account for variation due to experimental error. It will be understood that all measurements are modified by the term “about”, unless expressly stated otherwise, whether or not “about” is expressly stated. Thus, for example, the description “a fiber having a length of 2 mm” is understood to mean “a fiber having a length of about 2 mm”.

The details of one or more non-limiting embodiments of the invention are set forth in the Examples below. Other embodiments of the invention should be apparent to those skilled in the art after consideration of the present disclosure.

A. Test protocol Corrosion solubility (R10, S10, R18, S18) is TAPPI T235-cm0
Measured according to 0.
2. The carboxyl content is measured according to TAPPI T237-cm98.
3. Aldehyde content is measured according to Econotech Services LTD (owner's producer procedure ESM055B).
4). The copper value is measured according to TAPPI T430-cm99.
5. The carbonyl content is determined according to Biomacromolecules 2002, Vol. 3, 9
It is calculated from the copper value according to the formula from page 69 to 975: carbonyl = (Cu.No.-0.07) /0.6.
6. 0.5% Capillary CED viscosity is measured according to TAPPI T230-om99.
7). Intrinsic viscosity is measured according to ASTM D1795 (2007).
8). DP is The Chemistry and Processing Of Wo
od And Plant Fibrous Materials, 155 pages, Wood
head publishing Ltd, Abington Hall, Abingt
on, Cambridge CBI 6AH, England, J .; F. Kenne
The formula from 1994 Cellucon Conference published in dy et al.
DPw = −449.6 + 598.4ln (0.5% hairy CED) + 118.02ln ²
(0.5% Capillary CED)) is calculated from the viscosity of 0.5% Capillary CED.
9. Carbohydrate is TAPP using analysis by Dionex ion chromatography
It is measured according to IT249-cm00.
10. Cellulose content is TAPPI Journal 65 (12): 78-80.
It is calculated from the carbohydrate composition according to the formula from 1982 (cellulose = glucan- (mannan / 3)).
11. The hemicellulose content is calculated from the total sugar-cellulose content.
12 The fiber length and roughness are determined according to the manufacturer's standard procedure, OPTEST, Hawkesbu.
ry, determined on Fiber Quality Analyzer ™ from Ontario.
13. Wet zero span tension is determined according to TAPPI T273-pm99.
14 The freeness is determined according to TAPPI T227-om99.
15. The water retention value is determined according to TAPPI UM256.
16. DCM (dichloromethane) extract is determined according to TAPPI T204-cm97.
17. Iron content is determined by acid digestion and analysis by ICP.
18. Ash content is determined according to TAPPI T211-om02.
19. Peroxide residues are determined according to the Interox procedure.
20. The brightness is determined according to TAPPI T525-om02.
21. The porosity is determined according to TAPPI 460-om02.
22. The burst factor is determined according to TAPPI T403-om02.
23. The shear factor is determined according to TAPPI T414-om98.
24. Break length and elongation are determined according to TAPPI T494-om01.
25. Opacity is determined according to TAPPI T425-om01.
26. Frazier porosity is determined according to the manufacturer's procedure.
Determined on the Frazier low air infiltration device of ents, Hagerstown, MD.
27. Fiber length and shape factors are determined according to the manufacturer's standard procedure, Lorentzen & W
Determined on L & W fiber tester from ettre, Kista, Sweden.
28. Contaminants and debris are determined according to TAPPI T213-om01.

B. Exemplary Method for Making Modified Cellulose Fibers Half-bleached or nearly bleached kraft pulp can be treated with acid, iron, and hydrogen peroxide in order to reduce fiber viscosity or DP. The fibers are filtered using a filtrate from an acid bleaching stage scrubber, such as a sulfur, hydrogen chloride, acetic acid, or chlorine dioxide stage, at a pH (from about 2 to about 5).
If not already in this range). Iron can be added in the form of Fe ⁺²
For example, iron can be added as ferrous sulfate heptahydrate (FeSO ₄ · 7H ₂ O). Ferrous sulfate can be dissolved in water at concentrations ranging from about 0.1 to about 48.5 g / L. The ferrous sulfate solution can be added as a Fe ^{+2 at} a spread rate in the range of about 25 to about 200 ppm, based on the dry weight of the pulp. The ferrous sulfate solution can then be thoroughly mixed with the pH adjusted pulp with a consistency of about 1% to about 15% measured as the dry pulp content of the total weight of the wet pulp. Hydrogen peroxide (H ₂ O ₂ ) is then about 0.1 based on the dry weight of the pulp.
It can be added as a solution having a concentration of about 1% to about 50% by weight of H ₂ O _{2 in} water in an amount of% to about 3%. The pulp having a pH of about 2 to about 5 mixed with ferrous sulfate and peroxide is allowed to react at a temperature of about 60 to about 80 ° C. for a time in the range of about 40 to about 80 minutes. obtain.
The decrease in viscosity (or DP) depends on the amount of peroxide consumed in the reaction,
It is a function of the concentration and amount of peroxide and iron applied, as well as retention time and temperature.

Processing can be accomplished in a typical 5-stage bleach plant with a standard sequence of D ₀ E1D1E2D2. With that scheme, additional tanks, pumps, mixers, towers, or washers are unnecessary. The fourth stage, or E2 stage, may preferably be used for processing. The fibers on the D1 stage scrubber are acid or D2 as required.
The pH can be adjusted to about 2 to about 5 by the addition of filtrate from the stage. The ferrous sulfate solution can be added to the pulp. (1) Add to pulp by spraying it onto D1 stage washer mat through existing shower header or new header, (2) Add via spray mechanism in repulper, or (3) No. It can be added via a four stage mixer or additional point in front of the pump. The peroxide as a solution can be added after the ferrous sulfate at the addition point in the mixer or pump, before the fourth stage tower. Steam can also be added before the tower in the steam mixer, if desired. The pulp can then be reacted in the tower for an appropriate holding time. The chemically modified pulp can then be washed on a fourth stage washer in the usual manner. Additional bleaching can optionally be achieved after treatment with the fifth or D2 stage operated in the usual way.

Example 1
Methods for preparing the fibers of the present disclosure Mill method A
Southern pine cellulose was digested and oxygen was delignified to a kappa number of about 9 to about 10 in a conventional two-stage oxygen delignification step. Delignified pulp is treated with D ₀ (EO
) Bleached in a 5 stage bleach plant with the sequence D1E2D2. Prior to the fourth or E2 stage, the pH of the pulp was adjusted to the range of about 2 to about 5 with the filtrate from the D stage of the sequence. After adjusting the pH, based on the dry weight of the pulp, 0.2% hydrogen peroxide, and based on the dry weight of the pulp, 25 ppm Fe ⁺² in the form of FeSO ₄ .7H ₂ O,
It was added to the kraft fiber in an E2 stage tower and allowed to react for about 90 minutes at a temperature of about 78 to about 82 ° C. The reacted fibers were then washed on a fourth stage washer and then bleached with chlorine dioxide in the fifth (D2) stage.

B. Mill method B
Fibers were prepared as described in Mill Method A, except that the pulp was treated with 0.6% peroxide and 75 ppm Fe ⁺² .

C. Mill method C
Fibers were prepared as described in Mill Method A, except that the pulp was treated with 1.4% peroxide and 100 ppm Fe ⁺² .

Exemplary Fiber Properties Fiber samples prepared according to Mill Method A (Sample 2), B (Sample 3), and C (Sample 4) were collected after the five-step bleaching sequence described above. Standard fluff grade fiber (
In addition to the GP Leaf River Cellulose, New Augusta, MS; Sample 1), and commercially available samples (PEACH ™ sold by Weyerhaeuser Co .; Sample 5), the various properties of these samples were determined according to the protocol described above. It was measured. The results of these measurements are reported in Table 1 below.

As reported in Table 1, the iron content of the control fiber (Sample 1) was not measured. However, the iron content of a pulp sample made with four mills treated under the same conditions as reported in Sample 1 was collected. The iron content of these samples is 2.6pp
Averaged to m. Therefore, in sample 1, one would expect the iron content to be similar to about 2.5 ppm.

As can be seen in Table 1, the modified fibers according to the present invention unexpectedly had a control fiber (total carbonyl content, as well as carboxyl content and aldehyde content (
Different from both sample 1) and alternative commercial oxidized fibers (sample 5). To the extent that there is a difference between the total carbonyl group and the aldehyde group, the additional carbonyl functionality is
It can be in the form of other ketones. The data shows that while we retain the carboxylic acid group,
And an almost uniform ratio of aldehyde to total carbonyl groups (as seen in Table 1, about 1.
Shows that relatively high levels of aldehyde are achieved while retaining 0 (0.95) -1.6). This is more surprising in fibers that exhibit high brightness, are relatively strong and absorbent.

As can be seen in Table 1, the standard fluff grade fiber (Sample 1) is 3.13 m.
It had a carboxyl content of eq / 100 g and an aldehyde content of 0.97 meq / 100 g. Low dose treatment with 0.2% H ₂ O ₂ and 25 ppm Fe ⁺² (Sample 2), or High dose treatment with 0.6% H ₂ O ₂ and 75 ppm Fe ⁺² (Sample 3), or After high dose treatment with 1.4% H ₂ O ₂ and 100 ppm Fe ⁺² (Sample 4), fiber length and calculated cellulose content remained relatively unchanged and were measured by the wet zero span method. Although the fiber strength decreased somewhat, the carboxyl, carbonyl, and aldehyde contents all increased, indicating significant oxidation of the cellulose.

In comparison, a commercial sample of oxidized kraft conifer Southern pine fiber produced by an alternative method (Sample 5) is as measured by the wet zero span method compared to the fluff grade fiber reported as Sample 1. Show a significant decrease in fiber length, and a loss of about 70% in fiber strength. The aldehyde content of Sample 5 did not change visually compared to standard fluff grade fibers, but the fibers of the present invention prepared by milling methods AC (
Samples 2-4) are about 70 to about 100% of the calculated total carbonyl content of cellulose.
It had a very elevated aldehyde level representing In contrast, PEACH®
The aldehyde level was less than 30% of the calculated total carbonyl content of cellulose. The ratio of total carbonyl to aldehyde is particularly in the range of about 1 to about 2 (sample 2
4) would appear to be the best index of fibers with a broad applicability of modified fibers within the scope of this disclosure. Low viscosity fibers, such as Samples 3 and 4, and having a carbonyl / aldehyde ratio of less than about 1.5 to 2.0 maintained the fiber length, but the fiber length of Comparative Sample 5 was not maintained.

The freeness, density, and strength of the standard fiber (Sample 1) described above were compared with those of Sample 3 described above. The results of this analysis are illustrated in Table 2.

As can be seen in Table 2 above, the modified cellulose fibers according to the present disclosure may have a freeness corresponding to standard fluff fibers that have not undergone oxidation treatment in the bleaching sequence.

(Example 2)
OD (EOP) D (EP with 0.5% Capillary CED viscosity of about 14.6 mPa · s
) Samples of southern pine pulp from stage D1 of the D bleaching plant, from 0.25% to 1.
5 or 50 or 100 ppm of Fe ⁺² added as FeSO ₄ · 7H ₂ O
For each hydrogen peroxide application at a consistency of about 10%. Fe ⁺² was added as a solution in water and mixed well with the pulp. Hydrogen peroxide as a 3% solution in water was then mixed with the pulp. The mixed pulp was maintained in a water bath at 78 ° C. for 1 hour. After the reaction time, the pulp was filtered and the filtrate was measured for pH and residual peroxide. The pulp was washed and a 0.5% hairy CED viscosity was determined according to TAPPI T230. The results are shown in Table 3.

(Example 3)
A sample of D1 pulp from the bleaching plant described in Example 2 having a hairy CED viscosity of 0.5% of 15.8 mPa · s (DPw2101) was treated with 0.75% hydrogen peroxide applied. In addition, 50 to 200 ppm of Fe ⁺² was added in the same manner as in Example 2 except that the holding time was different in 45 to 80 minutes. The results are shown in Table 4.

Example 4
A sample of D1 pulp from the bleaching plant described in Example 2 having a hairy CED viscosity of 0.5% of 14.8 mPa · s (DPw 2020), except that the processing time is 80 minutes. 0.75% hydrogen peroxide, and 15 in the same way as described in 2.
Treated with 0 ppm Fe ⁺² . The results are shown in Table 5.

(Example 5)
OD ₀ with a hairy CED viscosity of 0.5% of 15.6 mPa · s (DPw 2085)
Southern pine pulp from the D1 stage of the (EO) D1 (EP) D2 sequence with 10% consistency, either 0.25% or 0.5% by weight hydrogen peroxide on the pulp, and FeSO ₄ · 7H ₂ O appended as 25, 50 or 100ppm of ^{Fe +2,}
Was processed. Fe ⁺² was added as a solution in water and mixed well with the pulp. Hydrogen peroxide is then a 3% solution in water mixed with the pulp, and the mixed pulp is
Maintained in a water bath at 8 ° C. for 1 hour. After the reaction time, the pulp was filtered and the filtrate was measured for pH and residual peroxide. The pulp was washed and a 0.5% hairy CED viscosity was
Determined according to PIT230. The results are shown in Table 6.

(Example 6)
In the same manner as in Example 5, 0.5% hairy C of 15.2 mPa · s (DPw2053)
Another sample of D1 pulp with ED viscosity was treated with 0.10, 0.25, 0.50, or 0.65% hydrogen peroxide and 25, 50, or 75 ppm Fe ⁺² . The results are shown in Table 7.

(Example 7)
After the degree of delignification in the kraft and oxygen stages is increased, Southern pine pulp is collected from the D1 stage of the OD (EO) D (EP) D bleaching sequence and the lower DP
A pulp with w or 0.5% hairy CED viscosity was produced. Starting 0.5% hairy C
The ED viscosity was 12.7 mPa · s (DPw1834). 0.50 or 1.0%
Any of the hydrogen peroxide was added at 100 ppm Fe ⁺² . Other processing conditions are 10
% Consistency, 78 ° C., and 1 hour processing time. The results are shown in Table 8.

(Example 8)
Except that the processing time is 80 minutes, it is 11.5 mPa · s (in the same manner as in Example 7).
A low viscosity sample of D1 pulp from the D1 stage of the OD (EO) D (EP) D sequence with a capillary CED viscosity of 0.5% of DPw1716), either 0.75 or 1.0% Treated with hydrogen peroxide and 75 or 150 ppm Fe ⁺² . The results are shown in Table 9.

Example 9
Southern pine pulp was collected from stage D1 of the OD (EO) D (EP) D sequence. The starting 0.5% Capillary CED viscosity was 11.6 mPa · s (DPw1726). Either 1.0%, 1.5%, or 2% hydrogen peroxide, 75, 150, or 2
Added with 00 ppm Fe ⁺² . Other processing conditions were 10% consistency, 78 ° C., and 1.
The processing time was 5 hours. The results are shown in Table 10.

(Example 10)
Southern pine pulp was collected from stage D1 of the OD (EO) D (EP) D sequence. The starting 0.5% Capillary CED viscosity was 14.4 mPa · s (DPw 1986). Either 1.0%, 1.5%, or 2% hydrogen peroxide, 75, 150, or 2
Added with 00 ppm Fe ⁺² . Other processing conditions were 10% consistency, 78 ° C., and 1.
The reaction time was 5 hours. The results are shown in Table 11.

(Example 11)
Southern pine pulp was collected from stage D1 of the OD (EO) D (EP) D sequence. The starting 0.5% Capillary CED viscosity was 15.3 mPa · s (DPw 2061). Hydrogen peroxide was added at 3% to the pulp with 200 ppm Fe ⁺² . Other processing conditions were 10% consistency, 80 ° C., and 1.5 hours reaction time. The results are shown in Table 12.

Examples 2-11 above show that a significant reduction in 0.5% Capillary CED viscosity and / or degree of polymerization can be achieved with the acidic catalyzed peroxide treatment of the present disclosure. The final viscosity of DPw appears to depend on the amount of peroxide consumed by the reaction, as shown in FIG. 1, and is represented by two different mills (“Brunwick” and Leaf Ri).
ver ("LR")) is reported as a function of the percentage of peroxide consumed. Peroxide consumption is a function of the amount and concentration of peroxide and iron applied, reaction time, and reaction temperature.

(Example 12)
Southern pine pulp was collected from stage D1 of the OD (EO) D (EP) D sequence. The starting 0.5% Capillary CED viscosity was 14.8 mPa · s (DPw 2020). Hydrogen peroxide added as CuSO ₄ .5H ₂ O, 100, 150, or 20
Added to 1% of the pulp with Cu ⁺² of 0 pm at 1%. Other processing conditions were 10% consistency, 80 ° C., and 3.5 hours reaction time. The results are shown in Table 13.

The use of copper instead of iron resulted in a slower reaction and less reduction in viscosity, but still resulted in significant changes in viscosity, carboxyl content, and aldehyde content over the control untreated pulp. It was.

(Example 13)
The E2 (EP) stage of the OD (EOP) D (EP) D sequence was modified to produce ultra low polymerization pulp. A solution of FeSO ₄ .7H ₂ O was sprayed onto the pulp with a D1 stage washer repulper at an application rate of 150 ppm as Fe ⁺² . No caustic (NaOH) was added to the E2 stage and the peroxide application was increased to 0.75%. The holding time was about 1 hour and the temperature was 79 ° C. The pH was 2.9. The treated pulp was washed on a vacuum drum washer and then treated at 91 ° C. with 0.7% ClO ₂ for about 2 hours in the final D2 stage. The final bleached pulp has a 0.5% hairy CED viscosity of 6.5 mPa · s (D
Pw 1084) and the ISO brightness was 87.

(Example 14)
The pulp produced in Example 13 was purchased from Fourdri with a standard dryer can.
It was made into a pulp board on a nier type pulp dryer. Samples of control pulp and inventive pulp (ULDP) were collected and analyzed for chemical composition and fiber properties. The results are shown in Table 14.

The treated pulp (ULDP) had higher alkali solubility and higher aldehyde and total carbonyl content at 10% and 18% NaOH. U
LDP was significantly lower in DP as measured by 0.5% hairy CED viscosity. The decrease in fiber integrity was also determined by a decrease in wet zero span tensile strength.
Despite a significant decrease in DPw, fiber length and freeness remained essentially unchanged. There was no detrimental effect on machine emissions or board production.

(Example 15)
In the same manner as in Example 13, the E2 (EP) stage of the OD (EO) D (EP) D sequence was changed to produce an ultra-low polymerization pulp. In this example, FeSO ₄ .7H ₂ O was added at 75 ppm as Fe ⁺² and the hydrogen peroxide applied in the E2 stage was 0.
It was 6%. The pH of the treatment stage is 3.0, the temperature is 82 ° C., and the holding time is
It was about 80 minutes. The pulp was washed and then 0.2% C at 92 ° C. for about 150 minutes.
In lO _2, it was treated in the D2 stage. 0.5% hairy CED of fully bleached pulp
The viscosity was 5.5 mPa · s (DPw914), and the ISO brightness was 88.2.

(Example 16)
The pulp produced in Example 15 was made into a pulp board on a Fourdriner type pulp dryer with an Airborne Flakt ™ dryer section. Samples of standard and inventive pulp (ULDP) were collected and analyzed for chemical composition and fiber properties. The results are shown in Table 15.

The treated pulp (ULDP) had higher alkali solubility at 10% and 18% NaOH, and higher aldehyde, and total carbonyl content. UL
The DP was significantly lower in the DP as measured by 0.5% capillary CED viscosity and lower wet zero span break length. The brightness was still an acceptable value of 88.2. The treatment preserved fiber length and freeness, formed the board and had no operational problems to dry.

(Example 17)
In the same manner as in Example 13, the E2 (EP) stage of the OD (EO) D (EP) D sequence was changed to produce a low polymerization pulp. In this case, FeSO ₄ .7H ₂ O is replaced by F
e ⁺² was added at 25 ppm and the hydrogen peroxide applied in the E2 stage was 0.2%
Met. The pH of the treatment stage is 3.0, the temperature is 82 ° C., and the holding time is about 8
0 minutes. The pulp was washed and then 0.2% ClO at 92 ° C. for about 150 minutes.
₂ and processed in stage D2. The fully bleached pulp had a 0.5% hairy CED viscosity of 8.9 mPa · s (DPw1423) and an ISO brightness of 89.

(Example 18)
The pulp produced in Example 15 was made into a pulp board on a Fourdriner type pulp dryer with an Airborne Flakt ™ dryer section. Collect samples of standard pulp and low polymerization pulp (LDP) of the present invention;
Analyzed for chemical composition and fiber properties. The results are shown in Table 16.

The treated pulp (LDP) had higher alkali solubility at 10% and 18% NaOH, and higher aldehyde, and total carbonyl content. LDP
Was lower in DP as measured by 0.5% Capillary CED viscosity. There was minimal loss in brightness. The treatment had no operational problems of preserving fiber length, forming board and drying.

(Example 19)
The pulp board described in Example 14 was made into fiber and Kamas Laboratory.
Hammermill (Kamas Industries, Sweden) was used to aerate 4 "x 7" pads. The air-formed pad was then compressed at various gauge pressures using an experimental press. After pressing, the pad caliper is 0.089p
Measurements were made using an Embeco micro gauge caliper gauge model 200-A with a foot pressure of si. Pad density was calculated from pad weight and caliper. Table 1 shows the results.
This is illustrated in FIG.

The data in Table 17 shows that the modified fibers produced within the scope of this disclosure resulted in a thinner and higher density structure that was more compressible and better suited to today's disposable absorbent product designs. Show.

Without being bound by theory, the oxidation of cellulose is believed to disrupt the crystalline structure of the polymer, making it less stiff and more compatible. The fibers consisting of the modified cellulose structure will then become more compressible, allowing the production of higher density absorbent structures.

(Example 20)
Southern pine pulp was collected from stage D1 of the OD (EO) D (EP) D sequence. The starting 0.5% Capillary CED viscosity was 14.9 mPa · s (DPw2028). Either 1.0% or 2% hydrogen peroxide, 100 or 200 ppm Fe ⁺²
Respectively. Other processing conditions were 10% consistency, 80 ° C., and 1 hour hold time. These fluff pulps are then slurried with deionized water and spread wet on a screen to form a fiber mat, dehydrated through a roller press, 250 ° F.
Dried. The dried sheet was defibered and Kamas Laboratory Hamme
8.5 g using rmill (Kamas Industries, Sweden)
Air was formed on a 4 "x 7" airlaid pad weighing (air dried). A single complete coverage sheet of nonwoven coverstock is applied to one side of each pad and the sample is
Densification was performed using a Carver hydraulic platen press applying a 5 psig load.

These pads were placed in individual 1.6L hermetic plastic containers with removable lids fitted with check valves and 1/4 "ID Tygon (R) tubing. Before securing the container lids , 60 grams of deionized water at room temperature and 0.12 grams of 50% N
The urine equivalent of H ₄ OH was injected throughout the sample into a central 1 ″ ID vertical tube on the delivery device capable of applying a 0.1 psi load. Upon complete absorption of the urine equivalent,
The delivery device was removed from the sample and a lid with a sealed sampling port was fitted with the container and a countdown timer was started. At the end of the 45 minute period, the headspace sample was taken from an ammonia selective short-term gas detector tube and an ACCURO® bellows pump (both Draeger Safety Inc., Pittsburgh, P
From the sampling port. The data in Table 18 show that modified fibers produced within the scope of this disclosure reduce the amount of ammonia gas in the headspace and are often listed as volatile malodorous compounds that are listed as undesirable in moist incontinence products. It shows that it was possible to provide a structure that provides inhibition.

(Example 21)
In the same manner as in Example 14, OD (EO) D (EP) D of a commercial kraft pulping facility
The E2 stage of the sequence was changed to produce low polymerization pulp. In this example, Fe
SO ₄ · 7H ₂ O was added at 100 ppm as Fe ⁺² and the hydrogen peroxide applied in the E2 stage was 1.4%. The pulp properties are shown in Table 19.

The produced modified chemical cellulose was made into a pulp board on a Fourdriner type pulp dryer with an Airborne Flakt ™ dryer section. Samples of this product and the control kraft pulpboard were added to the Kamas Labora
Defibrillated using a tory Hammermill. Optical analysis of the fiber properties was performed according to the manufacturer's protocol in Optest Equipment, Inc. , Hawkesbu
Through the HiRes fiber quality analyzer available from ry, ON, Canada, Kama
It was carried out before and after the s mill sample. The results are illustrated in the table below.

As can be seen in Table 20, ULDP fibers prepared according to the present disclosure have higher kinks and curls than control fibers not treated with iron and peroxide.

The defibrillated fiber was air-formed into a 4 "x 7" pad weighing 4.25 grams (air dried). Sodium polyacrylate superabsorbent (SAP) supplied from BASF
The granules were uniformly applied between two 4.25 gram pads. Full coverage nonwoven coverstock was applied to the top surface of the fiber / SAP matrix and the pad was densified by a 145 psig load applied via a Carver platen press.

Synthetic urine in deionized water with 2% urea, 0.9% sodium chloride, and 0.24%
Nutrition Bouillon (Hardy Diagnostics, Santa Maria, CA)
By adding an aliquot of Proteus bulgaris, which lyses the Criterion ™ available from and results in a starting bacterial concentration of 1.4 × 10 ⁷ CFU / ml
Prepared. The pad described above was then placed in the headspace chamber and 80 ml of synthetic urine solution was added as described in Example 20. Immediately after addition of the urine solution, the chamber was sealed and placed in an environment at a temperature of 30 ° C. Drager sampling was performed in sequence at 4 and 7 hour intervals. The experiment is repeated three times and the average results are reported in Table 21.

As can be seen from the data, the atmospheric ammonia resulting from the bacterial hydrolysis of urea is compared to the composite structure produced with standard kraft Southern pine fibre, modified cellulose fiber produced within the scope of this disclosure. Lower in embedded composite structure (similar in structure to commercial urinary incontinence products). Therefore, the structure comprising modified cellulose fibers according to the present disclosure had better odor control properties than standard craft Southern pine fibers.

(Example 22)
Comparison of the fourth stage and post-bleaching treatment Southern pine pulp was collected from stage D1 of the OD (EO) D1 (EP) D2 sequence. The starting 0.5% Capillary CED viscosity was 14.1 mPa · s. Hydrogen peroxide was added as 1.5% based on the dry weight of the pulp with 150 ppm of Fe ⁺² . As used herein, “P ^* ” is used to indicate the iron and hydrogen peroxide treatment stage. In the fourth stage of the sequence, the treatment was performed for 1 hour at 78 ° C. with 10% consistency. The treated pulp is then washed and in the D2 stage at 78 ° C. for 2 hours, 0.25
It was bleached with% of ClO _2. The results are shown in Table 22.

The D2 sample above was also tested for brightness restoration by placing it in an oven at 105 ° C. for 1 hour. The brightness and L ^* (whiteness), a ^* (red to green), and b ^* (blue to yellow) values were determined according to the manufacturer's protocol before and after the restoration process, Hunterlab Mi.
Measured by niScan. The results are shown in Table 23 below. A more positive b value indicates a more yellow color. Thus, higher b values are undesirable in most paper and pulp applications. The number after discoloration reported below is the ratio of k / s before and after aging (k = absorption coefficient and s = scattering coefficient, ie, number after discoloration = 100 {(k / s) _{after aging−} (k / s ) _Pre-aging }) (for example, HW Giertz, Svensk Paperstid)
. 48 (No. 13), p. 317 (1945)).

Southern pine pulp with the same starting hairy CED viscosity was collected from the D2 stage of the same bleaching plant as described above and treated with hydrogen peroxide and Fe ^{+2 as} described above.
Hydrogen peroxide was added as 1.5% based on the dry weight of the pulp with 150 ppm of Fe ⁺² . The properties of this treated pulp are illustrated in Table 24.

P ^* pulp was tested for lightness restoration as described above. The results are illustrated in Table 25 below.

As can be ascertained from the above data, the acidic catalyzed peroxide treatment in the fourth stage of the five-stage bleach plant has a beneficial lightness compared to the treatment after the final stage of the five-stage bleach plant. Bring properties. In the fourth stage of processing, any lightness loss from the processing stage can be compensated for in the final D2 bleaching stage so that high brightness pulp is still obtained. In the case of post-bleaching treatment, there is a significant lightness loss of 3.4 points that cannot be compensated. After the accelerated brightness restoration process, the latter case still has a significantly lower brightness.

(Example 23)
Strength data The strength of fluff pulp produced from modified cellulose having a viscosity of 5.1 mPa · s according to the present disclosure was compared to a conventional fluff pulp having a viscosity of 15.4 mPa · s. The results are illustrated in Table 26 below.

(Example 24)
Derivatization of modified cellulose A sample of ULDP from Example 21 was prepared at 122 ° C. for 3 hours, 5% consistency, 0.0%
Acid hydrolysis with 5M HCI. Initial pulp from the D1 stage, ULDP, and acid hydrolyzed ULDP were tested for average molecular weight or degree of polymerization by the following methods.

Three pulp samples were pulverized to pass through a 20 mesh screen. Cellulose samples (15 mg) were placed in a separate tube equipped with a micro stir bar and dried overnight at 40 ° C. under vacuum. The test tube was then capped with a rubber septa. Anhydrous pyridine (4.00 mL) and phenyl isocyanate (0.50 mL) were added sequentially via syringe. The test tube was placed in a 70 ° C. oil bath and allowed to stir for 48 hours. Methanol (1.00 mL) was added to quench any residual phenyl isocyanate. Then
The contents of each tube were added dropwise to a 7: 3 methanol / water mixture (100 mL) to facilitate precipitation of the derivatized cellulose. The solid is collected by filtration and then methanol /
Washed with water (1 × 50 mL) followed by water (2 × 50 mL). The derivatized cellulose was then dried overnight at 40 ° C. under vacuum. Prior to GPC analysis, the derivatized cellulose was dissolved in THF (1 mg / mL), filtered through a 0.45 μm filter and placed in a 2 mL autosampler vial. The resulting DPw and DPn (average number of degrees of polymerization) are reported in Table 27 below.

As can be seen in the table above, the modified cellulose after acid hydrolysis according to the present disclosure can have a DPn of 48.

(Example 25)
Slurry the fiber, adjust the pH to about 5.5, then use Ke as a temporary wet strength agent.
Leaf River ULDP fibers and standard softwood fibers were made into handsheets by adding the Mira Chemicals glyoxylated polyacrylamide. Fibers were then formed, pressed into sheets and dried. Sheet characteristics were measured by known methods. The results are reported in Table 28 below.

As can be seen in Table 28 above, ULDP according to the present disclosure may be used in the manufacture of wet press paper. As shown in FIG. 2, the wet / dry ratio of handsheets formed from ULDP is higher than the wet / dry ratio of a comparative sheet made only from standard Southern conifers.
(Example 26)
Wicking, rewet, and strength data

Various densities (0.15, 0.25, and 0.35 g / cm ³ ) and basis weights (6) made from modified cellulose according to the present disclosure and 10% composite fiber
The wicking capacity of synthetic urine of 0, 150, 300 gsm) sheets was compared with sheets made from conventional kraft pulp. Exams, Kalamazoo, MI Materials
Tested by Testing Service using this company's testing equipment and procedures. The synthetic urine wicking capacity of the product was tested using a 6.0 cm × 16.0 cm sample and a pin read time of 600 seconds. The results are shown in Table 29 below.

Retention, thickness change and wicking height were also determined. The results are shown in Table 30 below:

The same sheet was also subjected to a rewet test. Product rewet was tested with a 9.0 cm x 20.3 cm sample cut using the dosing tube method and a single dose of 10 ml 0.9% saline solution. 120 seconds after dosing, the dosing tube was removed and the recorded, pre-weighed 6 "x 6" Verigood blotter sheet was placed on top and a 3 kpa load was applied for 60 seconds. The results are shown in Table 31 below.

The same sheet was also subjected to dry and wet tensile strength and elongation (%) tests. Tensile strength and elongation (%) were measured at a gauge length of 5.00 cms, 1.3 cms. Sample width,
Each product was determined in the machine direction using a crosshead speed of 5 cm / min and a 30 kg load cell. The results are shown in Tables 32 and 33 below.


(Example 27)
Wetness, vertical wicking and horizontal wicking data

Various densities (0...) Made from pulp made from modified cellulose according to the present disclosure.
The wetness, vertical wicking, and horizontal wicking of sheets of 15, 0.30, and 0.45 g / cm ³ ) were compared to sheets made from conventional pulp. Testing was performed by Materials Testing Service of Kalamazoo, MI using the company's testing equipment and procedures.

The required wetness characteristics were determined using ten 50 cm ² samples. The results are shown in Tables 34 to 36 below.

Vertical wicking characteristics were determined using 10 samples and a probe reading time of 600 seconds. The results are shown in Tables 37 to 38 below.

Horizontal wicking characteristics were determined using 10 samples, 600 sec probe reading time and a single 30 ml dose at 7 ml / sec. The results are shown in Table 39 below.

(Example 28)
Multilayer absorbent sheet

Five different airlaid multilayer sheets were prepared and cut into 200 4 × 8 inch rectangles. Different sets were labeled as shown in Table 40. Where noted, conventional sheets were treated with TQ-2021, modified sheets were treated with TQ-2028, and both surfactants were supplied by Asland, Inc.

The product was tested for fluid capture, profile and volume. Fluid capture was performed by applying 5 ml of 0.9% saline solution to the sample and then allowing the fluid to wick for 5 minutes. After 5 minutes, the rewet was collected for 2 minutes using standard laboratory filter paper. The product had the characteristics shown in Tables 41 and 42.

The synthetic urine wicking capacity of the product was tested using 10 6.0 cm × 16.0 cm samples and a pin read time of 600 seconds. Trial, Kalamazoo, MI Ma
Performed by the Terials Testing Service using this company's testing equipment and procedures. The results are shown in Tables 43 and 44 below.

With Materials Testing Service, product rewet is 1
Tests were performed using 0 9.0 cm x 20.3 cm sample cuts, dosing tube method, and a single dose of 10 ml 0.9% saline solution. The results are shown in Table 45.

Materials Testing Service provides a wet tensile strength of 1
0 samples, gauge length of 5.00 cms, 1.3 cms. Sample width, 2.5c
Each product was tested in the machine direction using a crosshead speed of m / min and a 30 kg load cell. The results are shown in Table 46.

Materials Testing Service provides a dry tensile strength of 1
0 samples, gauge length of 5.00 cms, 1.3 cms. Sample width, 2.5c
Each product was tested in the machine direction using a crosshead speed of m / min and a 30 kg load cell. The results are shown in Table 47.

Other Invention Embodiments While the invention presently desired by the applicant is defined in the appended claims, the present invention may also be defined in accordance with the following embodiments and does not necessarily exclude or limit these claims Please understand that.
A. The fiber is about 13 mPa · s or less, preferably less than about 10 mPa · s, more preferably less than 8 mPa · s, even more preferably less than about 5 mPa · s, or even more preferably about 4 mPa · s. Fibers derived from bleached coniferous or hardwood kraft pulp with a hairy CED viscosity of less than 0.5 s.
B. The fibers are at least about 2 mm, preferably at least about 2.2 mm, such as at least about 2.3 mm, or such as at least about 2.4 mm, or such as about 2.5.
A fiber derived from bleached softwood kraft pulp having an average fiber length of mm, more preferably from about 2 mm to about 3.7 mm, and even more preferably from about 2.2 mm to about 3.7 mm.
C. The fibers are at least about 0.75 mm, preferably at least about 0.85 mm, or at least about 0.95 mm, or more preferably at least about 1.15, or in the range of about 0.75 mm to about 1.25 mm. A fiber derived from bleached hardwood kraft pulp with an average fiber length.
D. Fibers derived from bleached softwood kraft pulp, wherein the fibers have a 0.5% capillary CED viscosity of about 13 mPa · s or less, an average fiber length of at least about 2 mm, and an ISO brightness in the range of about 85 to about 95 .
E. The viscosity is from about 3.0 mPa · s to about 13 mPa · s, such as from about 4.5 mPa · s to about 13 mPa · s, preferably from about 7 mPa · s to about 13 mPa · s, or such as from about 3
. 0 mPa · s to about 7 mPa · s, preferably about 3.0 mPa · s to about 5.5 mPa · s
A fiber according to any of embodiments AD, in the range of s.
F. A fiber according to embodiments AD, wherein the viscosity is less than about 7 mPa · s.
G. A fiber according to embodiments AD, wherein the viscosity is at least about 3.5 mPa · s.
H. A fiber according to embodiments AD, wherein the viscosity is less than about 4.5 mPa · s.
I. A fiber according to embodiments AD, wherein the viscosity is at least about 5.5 mPa · s.
J. et al. A fiber according to embodiment E, wherein the viscosity does not exceed about 6 mPa · s.
K. A fiber according to one of the embodiments above, in which the viscosity is less than about 13 mPa · s.
L. A fiber according to one of embodiments AB and DK, in which the average fiber length is at least about 2.2 mm.
M.M. A fiber according to one of embodiments AB and DL, in which the average fiber length does not exceed about 3.7 mm.
N. A fiber according to one of embodiments AM, in which the fiber has a corrosion solubility of S10 in the range of about 16% to about 30%, preferably about 16% to about 20%.
O. Embodiments AM wherein the fiber has an S10 corrosion solubility in the range of about 14% to about 16%.
A fiber according to one of the following.
P. The fiber is about 14% to about 22%, preferably about 14% to about 18%, more preferably
A fiber according to one of embodiments A-O, having a corrosion solubility of S18 in the range of about 14% to about 16%.
Q. Embodiments AP wherein the fiber has an S18 corrosion solubility in the range of about 14% to about 16%.
A fiber according to one of the following.
R. A fiber according to one of embodiments A-Q, in which the fiber has a ΔR of about 2.9 or greater.
S. A fiber according to one of embodiments A-Q, in which the fiber has a ΔR of about 3.0 or greater, preferably about 6.0 or greater.
T.A. The fiber is about 2 meq / 100 g to about 8 meq / 100 g, preferably about 2 meq /
100 g to about 6 meq / 100 g, more preferably about 3 meq / 100 g to about 6 meq
A fiber according to one of embodiments AS, having a carboxyl content in the range of 100 g.
U. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of at least about 2 meq / 100 g.
V. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of at least about 2.5 meq / 100 g.
W. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of at least about 3 meq / 100 g.
X. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of at least about 3.5 meq / 100 g.
Y. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of at least about 4 meq / 100 g.
Z. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of at least about 4.5 meq / 100 g.
AA. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of at least about 5 meq / 100 g.
BB. A fiber according to one of embodiments AS, in which the fiber has a carboxyl content of about 4 meq / 100 g.
CC. The fiber is about 1 meq / 100 g to about 9 meq / 100 g, preferably about 1 meq
Embodiments AB having an aldehyde content in the range of / 100 g to about 3 meq / 100 g
A fiber according to one of B.
DD. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 1.5 meq / 100 g.
EE.
FF. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 2.0 meq / 100 g.
GG. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 2.5 meq / 100 g.
HH. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 3.0 meq / 100 g.
II. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 3.5 meq / 100 g.
JJ. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 4.0 meq / 100 g.
KK. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 5.5 meq / 100 g.
LL. A fiber according to one of embodiments A-BB, in which the fiber has an aldehyde content of at least about 5.0 meq / 100 g.
MM. The fiber is greater than about 2, preferably greater than about 2.5, more preferably greater than about 3, a carbonyl content, as determined by the copper number, or from about 2.5 to about 5.5.
Preferably having a carbonyl content determined by a copper number of from about 3 to about 5.5, more preferably from about 3 to about 5.5, and the fiber is determined by a copper number of from about 1 to about 4 A fiber according to one of embodiments A to MM, having a carbonyl content.
NN. A fiber according to one of embodiments A-NN, in which the carbonyl content ranges from about 2 to about 3.
OO. The fiber has a carbonyl content determined by a copper number of about 3 or more;
A fiber according to one of embodiments A-NN.
PP. A fiber according to one of embodiments A-NN, in which the fiber has a ratio of total carbonyl to aldehyde content ranging from about 0.9 to about 1.6.
QQ. The ratio of total carbonyl to aldehyde content ranges from about 0.8 to about 1.0.
A fiber according to one of embodiments A-NN.
RR. The Canadian standard freeness (“freeness”) of at least about 690 ml, preferably at least about 700 ml, more preferably at least about 710 ml, or such as at least about 720 ml, or at least about 730 ml. A fiber according to one of the above embodiments.
SS. A fiber according to one of the embodiments above, wherein the fiber has a freeness of at least about 710 ml.
TT. A fiber according to one of the embodiments above, in which the fiber has a freeness of at least about 720 ml.
UU. A fiber according to one of the embodiments above, in which the fiber has a freeness of at least about 730 ml.
VV. A fiber according to one of the embodiments above, in which the fiber has a freeness not exceeding about 760 ml.
WW. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength in the range of about 4 km to about 10 km as measured by wet zero span break length.
XX. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength in the range of about 5 km to about 8 km.
YY. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength of at least about 4 km as measured by wet zero span break length.
ZZ. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength of at least about 5 km, as measured by wet zero span break length.
AAA. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength of at least about 6 km as measured by wet zero span break length.
BBB. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength of at least about 7 km as measured by wet zero span break length.
CCC. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength of at least about 8 km as measured by wet zero span break length.
DDD. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength in the range of about 5 km to about 7 km as measured by wet zero span break length.
EEE. A fiber according to one of embodiments A-WW, in which the fiber has a fiber strength in the range of about 6 km to about 7 km as measured by wet zero span break length.
FFF. One of the above embodiments, wherein the ISO brightness is in the range of about 85 to about 92, preferably about 86 to about 90, more preferably about 87 to about 90, or about 88 to about 90 Fiber according to one.
GGG. ISO brightness is ISO of at least about 85, preferably at least about 86, more preferably at least about 87, specifically at least about 88, more specifically at least about 89, or about 90, A fiber according to one of the embodiments above.
HHH. A fiber according to one of embodiments A-FFF, in which the ISO brightness is at least about 87.
III. A fiber according to one of embodiments A-FFF, in which the ISO brightness is at least about 88.
JJ. A fiber according to one of embodiments A-FFF, in which the ISO brightness is at least about 89.
KKK. A fiber according to one of embodiments A-FFF, in which the ISO brightness is at least about 90.
LLL. A fiber according to any of the previous embodiments, wherein the fiber has approximately the same length as a standard kraft fiber.
MMM. A fiber according to one of embodiments AS and SS to MMM, having a higher carboxyl content than standard kraft fiber.
NNN. A fiber according to one of embodiments AS and SS to NNN, which has a higher aldehyde content than a standard kraft fiber.
OOO. Greater than about 0.3, preferably greater than about 0.5, more preferably greater than about 1.4, or such as in the range of about 0.3 to about 0.5, or in the range of about 0.5 to about 1. Or about 1 to about 1.5
A fiber according to embodiments AS and SS to MMM having a ratio of total aldehyde to carboxyl content in the range of
PPP. Higher kink index than standard kraft fiber, such as in the range of about 1.3 to about 2.3, preferably about 1.7 to about 2.3, more preferably about 1.8 to about 2.3; Or about 2.
A fiber according to any of the previous embodiments, having a kink index in the range of 0 to about 2.3.
QQQ. A fiber according to any of the embodiments above, having a length weighted curl index in the range of about 0.11 to about 0.2, preferably about 0.15 to about 0.2.
RRR. Lower crystallinity index than standard kraft fiber, for example, about 5% to about 20% reduction relative to standard kraft fiber, more preferably about 10% to about 20% reduction relative to standard kraft fiber, more preferably A fiber according to any of the previous embodiments, having a crystallinity index reduced by 15% to 20% relative to standard kraft fiber.
SSS. A fiber according to any of the previous embodiments, in which the R10 value ranges from about 65% to about 85%, preferably from about 70% to about 85%, more preferably from about 75% to about 85%. .
TTT. A fiber according to any of the previous embodiments, in which the R18 value ranges from about 75% to about 90%, preferably from about 80% to about 90%, more preferably from about 80% to about 87%. .
UUU. A fiber according to any of the previous embodiments, wherein the fiber has odor control properties.
VVV. The fiber has an atmospheric ammonia concentration of at least 40% greater than the standard kraft fiber, preferably at least about 50% greater, more preferably at least about 60% greater, specifically at least about 70% greater, or at least About 75% more, more specifically,
A fiber according to any of the embodiments above, which reduces by at least about 80% more, or about 90% more.
WWW. The fiber is about 5 to about 10 ppm, preferably about 7 to about 10 pp per gram of fiber.
m, more preferably absorbs about 8 to about 10 ppm ammonia per gram of fiber,
A fiber according to any of the embodiments above.
XXX. ME with less than 2, preferably less than about 1.5, more preferably less than about 1
A fiber according to any of the embodiments above having an M-eluting cytotoxicity test value.
YYY. A fiber according to any of the embodiments above, wherein the copper number is less than 2, preferably less than 1.9, more preferably less than 1.8, and even more preferably less than 1.7.
ZZZ. About 0.1 to about 1, preferably about 0.1 to about 0.9, more preferably about 0.1
To about 0.8, such as about 0.1 to about 0.7, or about 0.1 to about 0.6, or about 0.1.
Embodiment A having a kappa number in the range of about 0.5 to about 0.5, more preferably about 0.2 to about 0.5.
A fiber according to any of YYY.
AAAA. Substantially the same as standard kraft fiber, for example, when the fiber is a conifer fiber,
A fiber according to any of the preceding embodiments having a hemicellulose content in the range of about 16% to about 18%, and when the fiber is a hardwood fiber, in the range of about 18% to about 25%.
BBBB. A fiber according to any of the embodiments above, wherein the fiber exhibits antimicrobial and / or antiviral activity.
CCCC. Embodiments B to C, or L to CCCC, wherein DP ranges from about 350 to about 1860, such as from about 710 to about 1860, preferably from about 350 to about 910, or such as from about 1160 to about 1860. Fiber according to one.
DDDD. Any of Embodiments B-C or L-CCCC, wherein DP is less than about 1860, preferably less than about 1550, more preferably less than about 1300, even more preferably less than about 820, or less than about 600. Fiber according to.
EEEE. A fiber according to any of the previous embodiments, wherein the fiber is more compressible and / or embossable than standard kraft fiber.
FFFF. The fiber is at least about 0.210 g / cc, preferably at least about 0.2
A fiber according to embodiments A-OOO, which can be compressed to a density of 20 g / cc, more preferably at least about 0.230 g / cc, specifically at least about 0.240 g / cc.
GGGG. The fiber is at least about 8% higher than the density of standard kraft fiber, specifically,
About 8% to about 16% higher than the density of standard kraft fiber, preferably about 8% to about 10%;
Or about 12% to about 16% higher, more preferably about 13% to about 16% higher, more preferably about 14% to about 16% higher, specifically about 15% to about 16% higher. A fiber according to embodiments A to OOO, which can be compressed to a density of.

A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other embodiments are within the scope of the following claims.

Claims (1)

  Invention described in the specification.