JP7708548B2 - Odor-controlling absorbent materials and absorbent articles and related methods of use and methods of making - Patents.com - Google Patents

Description

Trimethylamine (TMA) is a chemical that has a strong fishy odor even at low concentrations and is responsible for the fishy odor that is a symptom of bacterial vaginosis.
During and after menstruation, an increase in the pH of the vaginal environment is common. Vaginal pH is normally between 4 and 4.5, but during menstruation, the vaginal pH can increase to as high as 6.6. This increase in pH can promote the overgrowth of anaerobic bacteria and sometimes results in increased amounts of TMA being released from the more alkaline environment of the vagina.

Feminine hygiene products, such as sanitary napkins, are products commonly used to absorb menstrual fluids, blood, and urinary incontinence leakage. Because these products absorb potentially malodorous fluids (e.g., those containing TMA) and are worn for hours while held close to the body with minimal airflow, malodors can become concentrated in these products. For this reason, TMA is a chemical of interest for odor control in feminine hygiene products.

Currently, absorbent hygiene products that promote odor control do so using fragrances, antimicrobial properties, activated carbon, or "odor lock" technology. However, conventional absorbent hygiene products do not attempt to specifically address the malodors associated with TMA, e.g., by sequestering the TMA.

TMA is also associated with meat products, particularly fish products. Bacteria and fish enzymes convert TMA oxides present in fish meat to TMA. Absorbent pads included in meat packaging absorb meat juices and other liquids associated with meat products. However, conventional absorbent pads for meat packaging do not sequester or otherwise reduce TMA malodors, particularly those associated with meat products.

Thus, there is a long-felt need for absorbent products that absorb liquid and sequester TMA, thereby reducing TMA malodor. The present disclosure seeks to meet these needs and provide further related advantages.

This Summary is provided in a simplified form to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In one aspect, the present disclosure provides a method for reducing free trimethylamine ("TMA") molecules comprising contacting an absorbent material comprising a cellulose fiber matrix and a carboxylic acid linked to the cellulose fiber matrix, where the reduction in free TMA is relative to a control.

In another aspect, the present disclosure provides a method of sequestering TMA molecules, comprising contacting the TMA molecules with an absorbent material comprising a cellulose fiber matrix and a carboxylic acid linked to the cellulose fiber matrix.

In yet another aspect, the present disclosure provides an absorbent article comprising an absorbent material, wherein the absorbent material comprises a fiber matrix and a carboxylic acid linked to the fiber matrix, the fiber matrix comprises fibers selected from the group consisting of cellulosic fibers and cellulose-based fibers, and the absorbent article is a feminine hygiene product or a meat packaging pad.

In another aspect, the present disclosure provides a method for measuring the reduction in free TMA sequestered by an absorbent material, comprising contacting an absorbent material disposed in a container with a quantity of TMA; withdrawing a portion of the gas headspace of the container; measuring the amount of free TMA in the withdrawn portion of the gas headspace; and determining the reduction in free TMA in the gas headspace relative to a control.

In yet another aspect, the present disclosure provides a method of making an absorbent article, comprising: preparing an absorbent material comprising a fiber matrix and a carboxylic acid coupled to the fiber matrix; and coupling a fluid-permeable top sheet and a fluid-impermeable back sheet to the absorbent material.

The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings.

FIG. 1 graphically illustrates trimethylamine (TMA) levels in the gas headspace of containers holding absorbent materials according to embodiments of the present disclosure and controls, each invaded with different concentrations of TMA solution.

Described herein are absorbent materials configured to sequester trimethylamine (TMA), absorbent articles made therefrom, related methods of use, methods for measuring free TMA, methods for measuring reduction in free TMA relative to a control, and related methods for making absorbent articles.

The detailed description set forth below, in conjunction with the accompanying figures, is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.

In the following description, numerous specific details are set forth to provide a thorough understanding of one or more embodiments of the present disclosure. However, it will be apparent to one of ordinary skill in the art that many embodiments of the present disclosure can be practiced without some or all of the specific details. In some instances, well-known methods and steps have not been described in detail so as not to unnecessarily obscure various aspects of the present disclosure. Furthermore, it will be appreciated that embodiments of the present disclosure may employ any combination of the features described herein.
Absorbent Materials In one aspect, the present disclosure provides absorbent materials configured to sequester TMA. As used herein, "sequester" means to absorb, adsorb, reduce, bind, neutralize, and/or remove TMA. In this regard, the absorbent materials described herein are configured to remove TMA from, for example, gas and liquid phases in contact with the absorbent material by sequestering TMA. As discussed further herein, such sequestering reduces the level of free TMA in the gas and liquid phases.

In one embodiment, the absorbent material described herein includes a fiber matrix and a carboxylic acid linked to the fiber matrix. As further described herein, many carboxylic acids are water soluble, and therefore aqueous or other solution-based treatments can be applied to link the carboxylic acid to the fiber matrix. Some conventional absorbent materials use powders of non-carboxylic acid compositions, such as activated charcoal and activated carbon, for odor control. In practice, the odor control components of such powders tend to agglomerate, are often flammable, and can become airborne causing contamination and inhalation hazards.

In addition, many carboxylic acids are readily available and inexpensive, making them suitable for inclusion in products that include absorbent materials. Moreover, many carboxylic acids are also colorless and thus may be included in absorbent materials, for example, without changing the color of the fibrous matrix of the absorbent material. This is in contrast to certain conventional odor control ingredients that have a dark color, such as activated charcoal and activated carbon, which are used in some conventional absorbent articles and darken the color of the absorbent article.

In one embodiment, the carboxylic acid is a polycarboxylic acid. In one embodiment, the polycarboxylic acid is a partially or fully neutralized salt. Without being bound by theory, it is believed that the carboxylic acid group of the carboxylic acid aids in sequestering TMA, as further discussed herein with respect to FIG. 1 and Example 1. Thus, since polycarboxylic acids have two or more carboxylic acid groups per carboxylic acid molecule, it is believed that each polycarboxylic acid molecule is configured to aid in sequestering more TMA molecules than, for example, a monocarboxylic acid.

In one embodiment, the carboxylic acid is selected from the group consisting of malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In yet another embodiment, the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In another embodiment, the carboxylic acid is selected from the group consisting of citric acid, lactic acid, salts thereof, and combinations thereof. In one embodiment, the carboxylic acid is citric acid or a salt thereof.

In one embodiment, the carboxylate salt includes a carboxylate salt selected from the group consisting of sodium salts, potassium salts, ammonium salts, other metal salts, and combinations thereof.

In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.01 wt% and about 10 wt% (also referred to herein as weight percent). In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.05 wt% and about 5 wt%. In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.1 wt% and about 1 wt%. In one embodiment, the absorbent material comprises a carboxylic acid content of about 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, or 0.09 wt%. In one embodiment, the absorbent material comprises a carboxylic acid content of about 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, or 0.9 wt%. In one embodiment, the absorbent material comprises a carboxylic acid content of about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9% by weight.

Furthermore, because the absorbent materials and absorbent articles described herein sequester TMA, ingredients that mask TMA malodors (e.g., fragrances) are not necessary to reduce TMA malodors. Thus, in one embodiment, the absorbent materials described herein are fragrance-free. Such fragrance-free absorbent materials may be advantageous, for example, for users who have sensitivities or allergies to fragrances or who prefer not to use products that contain fragrances. It should also be noted that the absorbent materials and absorbent articles described herein can react with and sequester other basic molecules that have malodors.

In one embodiment, the fiber matrix comprises a cellulose pulp structure. In one embodiment, the cellulose pulp structure comprises a matrix of cellulose fibers, cellulose-based fibers, or combinations thereof, and a carboxylic acid linked to the fiber matrix. In one embodiment, the cellulose-based fibers are selected from the group consisting of viscose fibers, modal fibers, lyocell fibers, and combinations thereof. In one embodiment, the fiber matrix comprises fluff pulp. In one embodiment, the fiber matrix comprises southern bleached softwood kraft pulp.

In one embodiment, the fiber matrix comprises synthetic fibers. In one embodiment, the fiber matrix comprises non-woven synthetic fibers. In one embodiment, the fiber matrix comprises a mixture of synthetic and natural fibers.

As discussed further herein, the absorbent materials described herein include a carboxylic acid linked to a fiber matrix. In one embodiment, the carboxylic acid is linked directly to the fiber matrix without, for example, a binder, linker, or other intermediate composition or molecule between the carboxylic acid and the fiber matrix. In one embodiment, the carboxylic acid linked to the fiber matrix includes a carboxylic acid that is covalently bonded to the fiber matrix. In one embodiment, the carboxylic acid linked to the fiber matrix includes a carboxylic acid that is non-covalently bonded to the fiber matrix. Such non-covalent linkages can occur, for example, by hydrogen bonding, van der Waals forces, ionic bonding, and combinations thereof.

In one embodiment, the absorbent materials described herein do not include a binder, e.g., an organosilicone polymer binder, that is linked to the carboxylic acid and binds the carboxylic acid to the fiber matrix. Without being bound by theory, it is believed that the carboxylic acid, in some embodiments, is configured to directly link to the fiber matrix itself without the need for a binder. For example, in some embodiments, the fiber matrix is a natural fiber that includes hydroxyl groups that link to the carboxylic acid without a binder, e.g., an organosilicone polymer binder.

In this regard, absorbent materials including carboxylic acids directly linked to a fiber matrix and absorbent articles made therefrom also do not require a pouch or other sealed container to contain, for example, powders (e.g., activated charcoal or activated carbon) that may leak from the absorbent material or absorbent article.

In one embodiment, the carboxylic acid is applied to the fiber matrix in a solid form, e.g., in a powdered or granular form. In one embodiment, the solid carboxylic acid is bonded to the fiber matrix with an adhesive. In one embodiment, the adhesive is a physical adhesive. In one embodiment, the adhesive is a chemical adhesive.

In one embodiment, the solid carboxylic acid is applied to a fiber matrix having a moisture content at or above the fiber saturation point ("FSP"), which is typically about 20% to about 25% water by weight. Without being bound by theory, in one embodiment, it is believed that the solid carboxylic acid, when contacted with the wet fiber matrix, at least partially dissolves and bonds to the wet fiber matrix. Thus, for the fiber matrix in this embodiment, a moisture content of about 20% to about 99.9% water by weight is sufficient to at least partially dissolve the solid carboxylic acid.

In one embodiment, the absorbent materials described herein are free or substantially free of inorganic peroxides (where "substantially free of inorganic peroxides" will be understood to mean an amount of inorganic peroxides between 0 wt% and 1 wt%, as limited by known detection methods).

TMA sequestration can also be observed by utilizing oxidized cellulose fibers, which can be produced by known methods (see, e.g., U.S. Patent No. 8,007,635, the entirety of which is incorporated herein by reference).

As noted above, the absorbent material of the present disclosure is configured to sequester TMA. In one embodiment, the absorbent material of the present disclosure is configured to sequester about 6.15409×10 −5 g or more of TMA per about 1 g of absorbent material at equilibrium at 25° ^C. (where “equilibrium” should be understood to mean the point at which TMA entering the gas headspace of the test apparatus reaches a steady state), where the absorbent material has been treated with 0.01% by weight of a carboxylic acid selected from one of the groups provided herein. In one embodiment, the absorbent material is configured to sequester about 6.15409×10 ⁻⁵ g or more of TMA per about 1 g of absorbent material at equilibrium at 25° C., where the absorbent material has been treated with 0.01% by weight of citric acid.

As further discussed herein with respect to the methods of the present disclosure, in one embodiment, the amount of TMA sequestered by the absorbent material described herein is determined by measuring the amount of TMA in the gas headspace of a closed container holding the absorbent material and the initial amount of TMA. In one embodiment, determining the amount of free TMA upon sequestering of TMA by the absorbent material includes contacting a known amount of absorbent material disposed in a closed container with an initial known amount of TMA; extracting a portion of the gas headspace from the closed container after exposing the absorbent material to the initial amount of TMA and allowing it to reach equilibrium in the gas headspace; and measuring the gas concentration of TMA (e.g., in ppm) in the extracted portion of the gas headspace.

In one embodiment, the gas headspace has a volume of less than 1 L. In one embodiment, the gas headspace has a volume of about 0.5 L. In one embodiment, the container is a flexible container.

As discussed further herein, in one embodiment, the amount of TMA sequestered by the absorbent material is measured relative to a control absorbent material, e.g., a control absorbent material that does not contain a carboxylic acid linked to the fiber matrix, as discussed further herein with respect to Example 1, or a control sample can be performed using a container that does not contain an absorbent material (i.e., a blank control).

In one embodiment, the absorbent materials described herein are configured to sequester TMA from a solution in contact with the absorbent material and to sequester TMA from a gas phase in contact with the absorbent material. In this regard, the absorbent materials are configured to eliminate or reduce TMA malodors by sequestering both gaseous TMA and dissolved or liquid TMA.

As discussed further herein, the absorbent material of the present disclosure is configured to sequester TMA. In one embodiment, the absorbent material is configured to quantify the ability to sequester TMA, thereby reducing the gas concentration of free TMA in the gas headspace of a test device (described in detail below) by 50% compared to a control (see above for a discussion of suitable controls). In one embodiment, the absorbent material is configured to reduce the amount of free TMA that enters the gas headspace (or would otherwise enter) by 75% compared to a control. In one embodiment, the absorbent material is configured to reduce the amount of free TMA that enters the gas headspace (or would otherwise enter) by 85% compared to a control. In one embodiment, the absorbent material is configured to reduce the amount of free TMA that enters the gas headspace (or would otherwise enter) by 90% compared to a control. In one embodiment, the absorbent material is configured to reduce the amount of free TMA that enters the gas headspace (or would otherwise enter) by 95% compared to a control. In one embodiment, the absorbent material is configured to reduce the amount of free TMA that would otherwise enter the gas headspace by 99% compared to a control. In one embodiment, the absorbent material is configured to reduce the amount of free TMA that would otherwise enter the gas headspace by substantially 100% compared to a control (where "substantially 100%" should be understood to mean an amount between 99% and 100%, as limited by the detection methods described herein).

As discussed further herein, in one embodiment, the cellulose fiber matrix of the absorbent material can reduce free TMA from the gas headspace by sequestering TMA. In one embodiment, when the absorbent material contains 0.45% by weight citric acid, TMA is introduced in a solution of about 0.034% by weight, and the control is an equivalent amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulose fiber matrix of the absorbent material can reduce free TMA by at least about 95 ppm in about 0.5 L of gas headspace. In this case, "the same amount" should be understood to mean an amount of control fluff pulp having a mass between 95% and 105% of the mass of the absorbent material, as limited by known detection methods.

In one embodiment, when the absorbent material contains 0.45 wt. % citric acid, the TMA is introduced in a solution of about 0.027 wt. %, and the control is an equivalent amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulose fiber matrix can reduce free TMA by at least about 99% in a gas headspace of about 0.5 L. In one embodiment, when the absorbent material contains 0.45 wt. % citric acid, the TMA is introduced in a solution of about 0.05 wt. %, and the control is an equivalent amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulose fiber matrix can reduce free TMA by at least about 50% in a gas headspace of about 0.5 L.

As discussed further herein with respect to methods for reducing the amount of free TMA, in one embodiment, measuring the reduction in free TMA sequestered by the absorbent material of the present disclosure includes contacting an absorbent material disposed in a container with a quantity of TMA; withdrawing a portion of the gas headspace of the container; measuring the amount of free TMA in the withdrawn portion of the gas headspace; and determining the reduction in free TMA in the gas headspace relative to a control.

In one embodiment, the absorbent materials described herein may optionally further comprise an additive selected from the group consisting of activated charcoal, activated carbon, fragrances, zeolites, and combinations thereof. While the absorbent materials of the present disclosure are configured to sequester TMA without such additives, in certain embodiments, the absorbent materials further comprise materials including, but not limited to, activated charcoal, activated carbon, zeolites, or fragrances, configured, for example, to non-selectively absorb or mask certain other malodors or to supplement other TMA malodor-inhibiting components of the absorbent material.

In one embodiment, the absorbent material further comprises a superabsorbent polymer to aid in the absorption of fluids.
In another aspect, the present disclosure provides absorbent articles comprising the absorbent material of the present disclosure.As discussed further herein, odor suppression and prevention is of concern in feminine hygiene products and meat packaging products, particularly related to TMA malodor.Because the absorbent materials of the present disclosure are configured to sequester TMA, they are particularly suitable for use in feminine hygiene products and meat packaging products.

Thus, in one embodiment, the absorbent article comprises a fiber matrix and a carboxylic acid linked to the fiber matrix. In one embodiment, the fiber matrix comprises fibers selected from the group consisting of cellulose fibers, cellulose-based fibers, and combinations thereof.

In one embodiment, the absorbent article includes a fluid-permeable topsheet. The fluid-permeable topsheet includes a highly fluid-permeable material configured, for example, to transfer liquid from the wearer to the absorbent material. In one embodiment, the fluid-permeable topsheet includes a material selected from the group consisting of hydrophilic woven fabrics, hydrophilic nonwoven fabrics, airlaid sheets, wet-laid sheets, membranes containing apertures, open-cell foams, and batting.

In one embodiment, the absorbent article includes a fluid-impermeable backsheet. The fluid-impermeable backsheet is configured to prevent liquid from migrating from the absorbent material through the fluid-impermeable sheet, for example, to the wearer's clothing.

In one embodiment, the absorbent material forms at least a portion of the absorbent core of the absorbent article. In one embodiment, the absorbent material is disposed between a fluid permeable topsheet and a fluid impermeable backsheet. In one embodiment, the fluid permeable topsheet and the fluid impermeable backsheet are suitably sealed around the absorbent material. In one embodiment, the absorbent material is disposed within the fluid permeable topsheet.

In one embodiment, the absorbent article is a feminine hygiene product. As further described herein, in one embodiment, the absorbent material described herein comprises a fiber matrix and a carboxylic acid linked to the fiber matrix. In this regard, without being bound by theory, as further discussed herein, it is believed that absorbent articles comprising the absorbent material of the present disclosure reduce TMA malodor associated with vaginal fluid in at least two ways: (1) the carboxylic acid reduces the vaginal pH, thereby inhibiting the growth of anaerobic bacteria, and (2) the carboxylic acid sequestering the TMA molecule, thereby reducing free TMA.

In one embodiment, the feminine hygiene product is selected from the group consisting of panty liners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, disposable menstrual protection undergarments, and tampons. In one embodiment, the feminine hygiene product is selected from the group consisting of panty liners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, and disposable menstrual protection undergarments. In some embodiments, the absorbent article of the present disclosure is not in the form of a tampon. The feminine hygiene product may be manufactured by known methods (see, e.g., U.S. Pat. No. 9,717,817, which is incorporated herein by reference in its entirety, and patents referenced therein).

In one embodiment, the feminine hygiene product is configured to be worn externally. As used herein, a feminine hygiene product configured to be worn externally is configured to be worn externally to the vagina. In one embodiment, the feminine hygiene product is not configured to be worn internally. As used herein, a feminine hygiene product configured to be worn internally is a feminine hygiene product that is configured to be worn at least partially inside the vagina.

In one embodiment, the absorbent material in the feminine hygiene product includes an absorbent material comprising a fiber matrix and a carboxylic acid linked to the fiber matrix, where the absorbent material has a carboxylic acid content of between about 0.01 wt % and about 10 wt %.

In one embodiment, the absorbent article is a meat packaging pad. Meat packaging pads may include those known in the art and may be manufactured by known methods (see, e.g., U.S. Pat. Nos. 5,908,649 and 7,655,829, which are incorporated herein by reference in their entireties). As further described herein, TMA malodors emanate from meat products, e.g., fish products, and require sealing of the TMA in meat packaging products. Because the absorbent materials described herein are configured to seal the TMA, they are particularly suitable for use in meat packaging products. In one embodiment, the meat packaging product is a meat packaging pad. In one embodiment, the meat packaging pad is a fish packaging pad. In one embodiment, meat packaging pads comprising the absorbent materials of the present disclosure are configured to absorb meat juices, e.g., fish juices, and other liquids and seal the TMA.

In one embodiment, the absorbent material in the meat packaging pad comprises a fiber matrix and a carboxylic acid associated with the fiber matrix, where the absorbent material comprises a carboxylic acid content of between about 0.01 wt % and about 10 wt %. In one embodiment, the meat packaging pad comprises a superabsorbent polymer to aid in the absorption of fluids. In one embodiment, the superabsorbent polymer is disposed within the absorbent material.
Methods of Reducing Free TMA As described further herein, TMA molecules from, for example, vaginal fluids or meat juices, and the resulting TMA malodor, can be reduced through sequestering of TMA with the absorbent materials or absorbent articles of the present disclosure. By sequestering TMA into absorbent materials or absorbent articles made therefrom, the TMA malodor is reduced, as compared to a similar scenario in which the TMA is not sequestered, for example, such that free TMA is present at levels that cannot be smelled by the human nose, or can be smelled by the human nose at greatly reduced levels.

Thus, in another aspect, the disclosure provides a method for reducing free TMA. As used herein, "free TMA" means an amount of TMA that is in or will equilibrate to the gas headspace and that can be measured and/or smelled by the human nose. Free TMA is in contrast to TMA molecules that are sequestered, for example, by an absorbent material or article, and thus are not available for measurement or detection by the human nose.

In one embodiment, the method of reducing the level of free TMA includes contacting the TMA molecules with an absorbent material that includes a cellulose fiber matrix and a carboxylic acid linked to the cellulose fiber matrix. In one embodiment, the method further includes sequestering the TMA molecules.

As further described herein, the absorbent materials and absorbent articles made therefrom of the present disclosure are configured to sequester TMA from either or both the liquid and/or gas phases. Thus, in one embodiment, contacting the TMA with the absorbent material or absorbent article includes contacting TMA in a solution phase, e.g., TMA dissolved in vaginal fluid, menses, or meat juices. In one embodiment, the TMA molecules are in a liquid. In one embodiment, the liquid TMA is TMA molecules dissolved in a solution or suspension. In one embodiment, the liquid TMA is pure TMA liquid. In one embodiment, contacting the TMA with the absorbent material or absorbent article includes contacting menstrual fluid containing TMA with the absorbent material or absorbent article. In one embodiment, contacting the TMA with the absorbent material or absorbent article includes contacting meat fluid, e.g., fish meat fluid containing TMA, with the absorbent material or absorbent article.

Similarly, in one embodiment, contacting the TMA with the absorbent material or absorbent article includes contacting TMA in the gas phase, e.g., TMA volatilizing from vaginal fluid, menstrual fluid, or meat juices.

In one embodiment, the absorbent material is any absorbent material described herein. In one embodiment, the absorbent article is any absorbent article described herein. In one embodiment, the fiber matrix is a cellulose fiber matrix (see below).

In one embodiment, the carboxylic acid is selected from the group consisting of malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In one embodiment, the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In one embodiment, the carboxylic acid is citric acid or a salt thereof.

In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.01% and about 10% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.05% and about 5% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.1% and about 1% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, or 0.09% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, or 0.9% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9% by weight.

In one embodiment, the fiber matrix comprises a cellulose pulp structure. In one embodiment, the cellulose pulp structure comprises a matrix of cellulose fibers, cellulose-based fibers, or combinations thereof, and a carboxylic acid linked to the fiber matrix. In one embodiment, the cellulose-based fibers are selected from the group consisting of viscose fibers, modal fibers, lyocell fibers, and combinations thereof. In one embodiment, the fiber matrix comprises fluff pulp. In one embodiment, the fiber matrix comprises southern bleached softwood kraft pulp.

In one embodiment, the fiber matrix comprises synthetic fibers. In one embodiment, the fiber matrix comprises non-woven synthetic fibers. In one embodiment, the fiber matrix comprises a mixture of synthetic and natural fibers.

In one embodiment, contacting the TMA with the absorbent material or absorbent article made therefrom reduces at least 50% of the free TMA available to exit or re-enter the absorbent material or absorbent article as a gaseous compound. In one embodiment, contacting the TMA with the absorbent material or absorbent article made therefrom reduces at least 75% of the free TMA available to exit or re-enter the absorbent material or absorbent article as a gaseous compound. In one embodiment, contacting the TMA with the absorbent material or absorbent article made therefrom reduces at least 85% of the free TMA available to exit or re-enter the absorbent material or absorbent article. In one embodiment, contacting the TMA with the absorbent material or absorbent article made therefrom reduces at least 95% of the free TMA available to exit or re-enter the absorbent material or absorbent article. In one embodiment, contacting the TMA with an absorbent material or absorbent article made therefrom reduces at least 99% of the free TMA available to exit or re-enter the absorbent material or absorbent article.
Method for measuring the reduction of free TMA In another aspect, the present disclosure provides a method for measuring the reduction of free TMA sequestered by an absorbent material, such as an absorbent material of the present disclosure or an absorbent article made therefrom. In one embodiment, the absorbent material is placed in a closed container and contacted with a quantity of TMA. After the absorbent material has had a chance to sequester at least a portion of the amount of TMA, for example, after the amount of TMA reaches equilibrium between the gas head space of the closed container and the absorbent material, a portion of the gas head space is withdrawn from the closed container. In one embodiment, the amount of TMA can be contacted with the absorbent material for a sufficient time to reach equilibrium before a portion of the gas head space is withdrawn from the closed container, thereby also providing sufficient time for at least a portion of the initial amount of TMA to be sequestered within the absorbent material. Those skilled in the art will readily know how to create an equilibrium curve or other suitable technique to monitor and confirm equilibrium.

In one embodiment, the closed container is a flexible container configured to at least partially collapse in response to a portion of the gas headspace being extracted. In this regard, it is easier for a user to extract a portion of the gas headspace from the closed container.

The extracted portion of the gas headspace is analyzed to determine the gas concentration of free TMA present in the headspace. In one embodiment, measuring the amount of free TMA in the extracted portion includes passing the extracted portion of the gas headspace over a stationary phase loaded with a colorimetric marker that changes color upon contact with TMA; and measuring the amount of color change in the stationary phase in response to passing the extracted portion of the gas headspace over the stationary phase. In one embodiment, analyzing the extracted portion of the gas headspace to measure the gas concentration of free TMA includes using a colorimetric gas detector tube, such as a Sensidyne® gas detector tube system. While a colorimetric detection method is described, it will be understood that other methods of TMA detection, such as, but not limited to, gas chromatography, can be used consistent with the methods of the present disclosure.

The reduction in free TMA is measured relative to a control. In one embodiment, the control is a blank control, where the blank control includes a control that does not include contacting TMA molecules with the absorbent material. In one embodiment, the control is an absorbent material control, where the absorbent material control is an absorbent material that has substantially no or no added carboxylic acid linked to the fiber matrix (in this case, "substantially no added carboxylic acid" or "substantially no added carboxylic acid" should be understood to mean no added carboxylic acid or an amount of added carboxylic acid between 0 wt% and 1 wt%, as limited by known detection methods). As used herein, "added carboxylic acid" should be understood to mean the amount of carboxylic acid added or otherwise linked to the absorbent material during processing or manufacture, in addition to any carboxylic acid present in the untreated absorbent material. In one embodiment, the control absorbent material includes fluff pulp, e.g., southern bleached softwood kraft pulp that has not been treated with carboxylic acid or that has not otherwise been linked to carboxylic acid. In this regard, the user can determine the amount of TMA reduction due to the carboxylic acid attached to the fiber matrix of the absorbent material described herein compared to a selected control.

In one embodiment, the amount of TMA that is not sequestered by the absorbent material and that equilibrates in the gas headspace (TMA _g ) is compared to the amount of TMA that is not sequestered in a control experiment that equilibrates in the gas headspace of the control (TMA _c ). The reduction in the gas concentration of free TMA measured in the headspace above the absorbent material compared to that of the control can be expressed as a percent reduction in free TMA (% TMA _red ). This percent reduction can be calculated using the following formula:

It should be noted that TMA-containing fluids present on one side or other of the closed container, such as fluids used to infiltrate onto the absorbent material or absorbent article, may skew the results of the TMA reduction. Such TMA-containing fluids that do not contact the absorbent material or absorbent article may result in increased volatilization of TMA from the TMA-containing solution into the gas headspace of the closed container. Such increased TMA volatilization may result in a higher relative gaseous TMA concentration than if the TMA-containing solution were to infiltrate directly onto the absorbent material or absorbent article, which may misrepresent the ability (or lack thereof) of the absorbent material or absorbent article to sequester TMA.
Methods for Sequestering TMA As further described herein, absorbent materials and absorbent articles made therefrom can sequester TMA. Thus, in another aspect, the present disclosure provides a method for sequestering TMA molecules. In one embodiment, the method for sequestering TMA includes contacting TMA molecules with an absorbent material, or an absorbent article made therefrom, comprising a fiber matrix and a carboxylic acid linked to the fiber matrix. In one embodiment, the method further includes sequestering the TMA molecules in the absorbent material or the absorbent article made therefrom.

In one embodiment, the absorbent material is any absorbent material described herein. In one embodiment, the absorbent article is any absorbent article described herein. In one embodiment, the fiber matrix is a cellulose fiber matrix. In one embodiment, the cellulose fiber matrix comprises a cellulose pulp structure. In one embodiment, the cellulose fiber matrix comprises fibers selected from the group consisting of cellulose fibers and cellulose-based fibers. In one embodiment, the cellulose-based fibers are selected from the group consisting of viscose fibers, modal fibers, lyocell fibers, and combinations thereof.

In one embodiment, the carboxylic acid is selected from the group consisting of malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In one embodiment, the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In one embodiment, the carboxylic acid is citric acid or a salt thereof.

In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.01% and about 10% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.05% and about 5% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of between about 0.1% and about 1% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, or 0.09% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, or 0.9% by weight. In one embodiment, the absorbent material comprises a carboxylic acid content of about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9% by weight.

In one embodiment, contacting the TMA molecules with the absorbent material or absorbent article includes contacting a liquid, e.g., menstrual fluid, containing TMA, with the absorbent material or absorbent article made therefrom. In one embodiment, contacting the TMA molecules with the absorbent material includes contacting a meat fluid containing TMA with the absorbent material or absorbent article made therefrom. In one embodiment, the TMA molecules are in the gas phase and contact the absorbent material or absorbent article.

In one embodiment, when the absorbent material comprises 0.45 wt. % citric acid, the fiber matrix of the absorbent material of the present disclosure and absorbent articles made therefrom can sequester TMA molecules such that at equilibrium, about 0.5 L of gas headspace contains less than about 1 ppm, 2 ppm, 3 ppm, 4 ppm, 5 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, or 50 ppm of free TMA. In one embodiment, when the absorbent material comprises 0.01 wt. % citric acid and the TMA molecules are introduced into a solution of between about 0.0005 wt. % and about 0.034 wt. %, the fiber matrix of the absorbent material of the present disclosure and absorbent articles made therefrom can sequester TMA molecules such that at equilibrium, about 0.5 L of gas headspace contains less than about 50 ppm of free TMA. In one embodiment, when an absorbent material comprises 0.01 wt.% citric acid and TMA molecules are introduced into a solution of about 0.0005 wt.%, 0.001 wt.%, 0.005 wt.%, 0.01 wt.%, 0.015 wt.%, 0.02 wt.%, 0.025 wt.%, 0.027 wt.%, 0.03 wt.%, 0.034 wt.%, or 0.035 wt.%, the fiber matrix of the absorbent material of the present disclosure and absorbent articles made therefrom can sequester the TMA molecules such that at equilibrium, about 0.5 L of gas headspace contains less than about 50 ppm of free TMA. In one embodiment, when the absorbent material comprises 0.01 wt% citric acid and the TMA molecules are introduced into a solution of about 0.034 wt%, the cellulose fiber matrix can sequester the TMA molecules such that at equilibrium, about 0.5 L of gas headspace contains less than about 10 ppm of free TMA. In one embodiment, when the absorbent material comprises 0.01 wt% citric acid and the TMA molecules are introduced into a solution of about 0.027 wt%, the cellulose fiber matrix can sequester the TMA molecules such that at equilibrium, about 0.5 L of gas headspace contains less than about 5 ppm of free TMA.

In one embodiment, when an absorbent material contains 0.01 wt. % citric acid, TMA is introduced into the solution at about 0.034 wt. %, and a control is an equal amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulose fiber matrix can reduce free TMA by at least about 95 ppm in about 0.5 L of gas headspace.

In one embodiment, when the absorbent material contains 0.01 wt. % citric acid, the TMA is introduced in a solution of about 0.027 wt. %, and the control is an equivalent amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulose fiber matrix can reduce free TMA by at least about 99% in a gas headspace of about 0.5 L. In one embodiment, when the absorbent material contains 0.01 wt. % citric acid, the TMA is introduced in a solution of about 0.05 wt. %, and the control is an equivalent amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulose fiber matrix can reduce free TMA by at least about 50% in a gas headspace of about 0.5 L.

In one embodiment, determining the amount of free TMA after it has been sequestered by the absorbent material described herein includes contacting the absorbent material disposed in a vessel with an initial amount of TMA in solution; withdrawing a portion of the gas headspace of the vessel; and measuring the amount of free TMA in the withdrawn portion of the gas headspace, e.g., in ppm. Measuring can be performed in any suitable manner, including solid phase colorimetric gas detector tubes described herein, gas chromatography, and the like. Without being bound by theory, it is believed that the TMA in solution in contact with the absorbent material reacts with the carboxylic acid to reduce the salt RCOO ^- N ⁺ (Me) ₃ , thus sequestering the TMA by reducing the TMA available for volatilization and equilibrating into the gas headspace of the experimental vessel apparatus, thereby eliminating the TMA malodor.
Method of Making Absorbent Articles As described further herein, the absorbent materials of the present disclosure and absorbent articles made therefrom are suitable as absorbent articles, such as absorbent cores or other absorbent parts of feminine hygiene products, due to their ability to sequester TMA. Thus, in another aspect, the present disclosure provides a method of making absorbent articles, such as feminine hygiene products and meat packaging pads, that include the absorbent materials of the present disclosure. In one embodiment, the method includes preparing an absorbent material that includes a fiber matrix and a carboxylic acid linked to the fiber matrix; and linking a fluid-permeable top sheet and a fluid-impermeable back sheet to the absorbent material. In one embodiment, preparing the absorbent material includes forming a cellulose pulp sheet from a cellulose pulp slurry and forming a matrix of cellulose fibers from the cellulose pulp sheet to form a cellulose pulp structure. In one embodiment, the carboxylic acid is added by applying an aqueous form of the acid to the pulp sheet. As also described further herein, in one embodiment, the carboxylic acid is added in solid form, for example with a binder or adhesive.

In one embodiment, the absorbent material is any of the absorbent materials described herein that include a fiber matrix and carboxylic acids linked to the fiber matrix. In one embodiment, the fluid-permeable topsheet is any of the fluid-permeable topsheets described herein. In one embodiment, the fluid-impermeable backsheet is any of the fluid-impermeable backsheets described herein.

In one embodiment, the fluid permeable top sheet and the fluid impermeable back sheet are connected to the absorbent material by a connection method selected from the group consisting of sewing, adhesive connection, heat sealing, ultrasonic welding, and combinations thereof.

In one embodiment, the fluid permeable top sheet and the fluid impermeable back sheet are connected around the absorbent material, the absorbent material being disposed between the fluid permeable top sheet and the fluid impermeable back sheet. In this respect, the absorbent material forms at least a portion of the absorbent core of the absorbent article. In one embodiment, the absorbent material is disposed within the fluid permeable top sheet.

In one embodiment, the feminine hygiene product is selected from the group consisting of panty liners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, disposable menstrual protection undergarments, and tampons. In one embodiment, the feminine hygiene product is selected from the group consisting of panty liners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, and disposable menstrual protection undergarments. In some embodiments, the absorbent articles of the present disclosure are not in the form of tampons. The feminine hygiene product may be manufactured by known methods (see, e.g., U.S. Pat. No. 9,717,817, the entirety of which is incorporated herein by reference).

In one embodiment, the feminine hygiene product is configured to be worn externally. In one embodiment, the feminine hygiene product is not configured to be worn internally.
In one embodiment, the absorbent article is a meat packaging pad. In one embodiment, the meat packaging pad is a fish packaging pad. The meat packaging pad may include those known in the art and may be manufactured by known methods (see U.S. Pat. Nos. 5,908,649 and 7,655,829, which are incorporated herein by reference in their entireties).

Example 1: Sequestration of TMA using fluff pulp treated with citric acid Fluff pulp treated with citric acid (0.45 wt%) and untreated fluff pulp were fiberized, formed into pads, placed in a closed container, and infiltrated with a TMA solution. The untreated fluff pulp was from the same mill as the citric acid treated fluff pulp, but did not contain a buffering treatment.

The fluff pulp sheets were broken down into fibers and the fluff pulp was then formed into 2 inch diameter pads with an average weight of 0.94±0.02 g. These pads were compressed in a press at a pressure of 2000 psi.

Test vessels were constructed from 500 mL water bottles, selected for their compressibility. A 16-gauge needle was passed through the plastic lid of the water bottle, glued in place, and sealed with silicone caulk. A rubber tube was placed around the hilt of the needle to allow for an airtight seal between the hilt and the measurement device.

A compressed fluff round was introduced into the test vessel, infiltrated with 15 g of solution, sealed, and then after 2 hours the headspace was tested for TMA. TMA solutions were tested at four concentrations: 0.0005%, 0.027%, 0.034%, and 0.05% by weight. Normal vaginal fluid not associated with bacterial vaginosis has a TMA level of 0.0005% by weight according to literature values.

The concentration of TMA in the headspace of the vessel was tested 2 hours after infiltration on both the control and test pulps. Model 105SE Sensidyne® tubes were used. These tubes are labeled for use with ammonia, but can also be used with TMA. The actual TMA concentration is found by multiplying the Sensidyne® reading by a conversion factor of 0.5.

A total of 25 samples were tested: 11 untreated control fluff pulp samples, and 14 test fluff pulp samples treated with citric acid. A minimum of two samples per concentration were averaged. Three or more samples per concentration were tested if the results of the first two varied. The 25 samples were allowed to interact with the TMA ingress for approximately 2 hours at 25°C to ensure equilibration before measuring the TMA in the gas headspace of the vessel.

The TMA concentration in the headspace above the pad was compared for the test fluff pulp treated with citric acid and the untreated control fluff pulp. As summarized in Table 2 and Figure 1, the citric acid treated fluff pulp was found to reduce the headspace concentration of TMA at various amounts. As shown, the citric acid treated fluff was found to eliminate TMA volatilization at 0.0005 wt%, the literature concentration in healthy vaginal fluid, and at 0.027 wt%, 60 times this concentration. At 0.034 wt%, 70 times the literature value, the citric acid treated fluff was found to reduce odorant volatilization into the headspace by an average of 95%. The ability of the citric acid treated fluff to steadily inhibit TMA volatilization into the headspace was not overwhelming up to 0.05 wt%, a 100 times higher TMA concentration found in healthy vaginal fluid. Even at this concentration, the citric acid-treated fluff had headspace odorant levels that were, on average, 71.1% lower than the untreated fluff.

For the 0.027% TMA solution, the average concentration of TMA in the headspace for the citric acid treated fluff pads was 0.33 ppm. The untreated pulp had an average concentration of TMA in the headspace of 72 ppm. The citric acid treated fluff reduced TMA in the headspace by 99.5%.

In the 0.034% TMA solution, the citric acid treated fluff had an average concentration of TMA in the headspace reading of 5 ppm, while the untreated pulp had an average TMA level in the gas headspace of 100 ppm. Note that the detection limit of the Sensidyne® tube is 100 ppm. Therefore, the actual average TMA level in the gas headspace may have been higher than 100 ppm. The citric acid treated fluff reduced the TMA in the headspace reading by at least 95%.

At the 0.05% solution, the citric acid treated fluff had an average concentration of TMA in the headspace reading of 26.8 ppm. However, readings for the citric acid treated fluff ranged from 10 to 51 ppm at this concentration. In contrast, the maximum variation between all other two sample points at other concentrations was 7 ppm (between 68 ppm and 75 ppm for untreated pulp at 0.03%).

The TMA concentration in the headspace above the untreated fluff exceeded the maximum sensor reading for two of the three readings taken. Since it is not possible to know the exact concentration, these data are reported as a sensor reading of 100 ppm. Based on how quickly the sensor reached its maximum, how far past the maximum the colorimetric reading stopped, and the odor encountered by the tester (TMA has a fishy odor at low concentrations, but an ammonia-like odor at higher concentrations), one may estimate how much higher the actual concentration was than the maximum reading, but this is merely an estimate. These observations were recorded in the test record.

For purposes of this disclosure, it should be noted that terms such as "upper," "lower," "vertical," "horizontal," "into," "out," "in," "outer," "front," "rear," and the like, are descriptive and should not be construed as limiting the scope of the claimed subject matter. Furthermore, the use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless otherwise limited, the terms "connected," "coupled," and "attached" and variations thereof herein are used broadly and include direct and indirect connections, couplings, and attachments. The term "about" means plus or minus 5% of the stated value.

The principles, representative embodiments, and modes of operation of the present disclosure have been described in the preceding description. However, the aspects of the present disclosure that are intended to be protected should not be construed as being limited to the particular embodiments disclosed. Moreover, the embodiments described herein should be considered as illustrative rather than limiting. It will be recognized that others may make modifications and changes without departing from the spirit of the present disclosure, and equivalents may be employed. Accordingly, all such modifications, changes, and equivalents are expressly intended to be included within the spirit and scope of the present disclosure as set forth in the claims.

[Mode of the invention]
[1]
A method for reducing free trimethylamine ("TMA"), comprising contacting TMA molecules with an absorbent material comprising a cellulose fiber matrix and a carboxylic acid linked to the cellulose fiber matrix, wherein the reduction in free TMA is compared to a control.
[2]
2. The method of claim 1, wherein the TMA molecules are in a liquid.
[3]
3. The method of claim 2, wherein the TMA molecule is in menstrual fluid.
[4]
3. The method of claim 2, wherein the TMA molecules are in meat fluids.
[5]
2. The method of claim 1, wherein the TMA molecules are in a gas.
[6]
2. The method according to claim 1, wherein the control is a blank control.
[7]
2. The method of claim 1, wherein the control is an absorbent material control.
[8]
1. The method of claim 1, wherein the cellulose fiber matrix comprises a cellulose pulp structure.
[9]
13. The method of claim 1, wherein the cellulose fiber matrix comprises fibers selected from the group consisting of cellulose fibers and cellulose-based fibers.
[10]
10. The method of claim 9, wherein the cellulose-based fibers are selected from the group consisting of viscose fibers, modal fibers, lyocell fibers, and combinations thereof.
[11]
2. The method of claim 1, wherein the carboxylic acid is selected from the group consisting of malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.
[12]
2. The method of claim 1, wherein the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.
[13]
2. The method according to claim 1, wherein the carboxylic acid is citric acid or a salt thereof.
[14]
14. The method of any one of 1 to 13, wherein the absorbent material comprises a carboxylic acid content of between about 0.01% and about 10% by weight.
[15]
2. The method of claim 1, wherein the cellulose fiber matrix is capable of reducing free TMA by at least about 95 ppm in a headspace of about 0.5 L when the absorbent material contains 0.01 wt. % citric acid, TMA is introduced in a solution of about 0.034 wt. %, and the control is an equal amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid.
[16]
The reduction in free TMA
contacting an absorbent material disposed in a container with a quantity of TMA;
Removing a portion of the gas headspace of the container;
16. The method of claim 15, wherein the free TMA is measured by a process comprising: measuring the amount of free TMA in the extracted portion of the gas headspace; and determining a reduction in free TMA in the gas headspace relative to a control.
[17]
2. The method of claim 1, wherein the cellulose fiber matrix is capable of reducing free TMA by at least about 99% in a headspace of about 0.5 L when the absorbent material contains 0.01% by weight citric acid, TMA is introduced in a solution of about 0.027% by weight, and the control is an equal amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid.
[18]
2. The method of claim 1, wherein the cellulose fiber matrix is capable of reducing free TMA by at least about 50% in a headspace of about 0.5 L when the absorbent material contains 0.01% by weight citric acid, TMA is introduced in a solution of about 0.05% by weight, and the control is an equal amount of absorbent material consisting of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid.
[19]
The reduction in free TMA
contacting an absorbent material disposed in a container with a quantity of TMA;
Removing a portion of the gas headspace of the container;
19. The method of claim 17 or 18, wherein the amount of free TMA is measured by a process comprising: measuring the amount of free TMA in the extracted portion of the gas headspace; and determining a reduction in free TMA in the gas headspace relative to a control.
[20]
A method of sequestering TMA molecules comprising contacting the TMA molecules with an absorbent material comprising a cellulose fiber matrix and a carboxylic acid linked to the cellulose fiber matrix.
[21]
21. The method of claim 20, wherein the TMA molecules are in a liquid.
[22]
22. The method of claim 21, wherein the TMA molecule is in menstrual fluid.
[23]
22. The method of claim 21, wherein the TMA molecule is in a meat fluid.
[24]
21. The method of claim 20, wherein the TMA molecules are in a gas.
[25]
21. The method of claim 20, wherein the cellulose fiber matrix comprises a cellulose pulp structure.
[26]
21. The method of claim 20, wherein the cellulose fiber matrix comprises fibers selected from the group consisting of cellulose fibers and cellulose-based fibers.
[27]
27. The method of claim 26, wherein the cellulose-based fibers are selected from the group consisting of viscose fibers, modal fibers, lyocell fibers, and combinations thereof.
[28]
21. The method of claim 20, wherein the carboxylic acid is selected from the group consisting of malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.
[29]
21. The method of claim 20, wherein the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.
[30]
21. The method of claim 20, wherein the carboxylic acid is citric acid or a salt thereof.
[31]
31. The method of any one of claims 20 to 30, wherein the absorbent material comprises a carboxylic acid content of between about 0.01% and about 10% by weight.
[32]
21. The method of claim 20, wherein the cellulose fiber matrix is capable of sequestering TMA molecules such that when the absorbent material comprises 0.45 wt. % citric acid and the TMA molecules are introduced into a solution of about 0.05 wt. %, at equilibrium, about 0.5 L of headspace contains less than about 50 ppm of free TMA.
[33]
21. The method of claim 20, wherein the cellulose fiber matrix is capable of sequestering TMA molecules such that when the absorbent material comprises 0.45 wt. % citric acid and the TMA molecules are introduced into a solution of about 0.034 wt. %, at equilibrium, about 0.5 L of headspace contains less than about 10 ppm of free TMA.
[34]
21. The method of claim 20, wherein the cellulose fiber matrix is capable of sequestering TMA molecules such that when the absorbent material comprises 0.45 wt. % citric acid and the TMA molecules are introduced into a solution of about 0.027 wt. %, at equilibrium, about 0.5 L of headspace contains less than about 5 ppm of free TMA.
[35]
The amount of free TMA is
contacting an absorbent material disposed in a container with a quantity of TMA in solution;
35. The method of any one of claims 32 to 34, wherein the amount of free TMA is measured by a process comprising: withdrawing a portion of the gas headspace of the container; and measuring the amount of free TMA in the withdrawn portion of the gas headspace.
[36]
1. An absorbent article comprising an absorbent material, the absorbent material comprising a fiber matrix and a carboxylic acid linked to the fiber matrix, the fiber matrix comprising fibers selected from the group consisting of cellulosic fibers and cellulose-based fibers, and the absorbent article being a feminine hygiene product or a meat packaging pad.
[37]
37. The absorbent article of claim 36, wherein the absorbent material does not include a carboxylic acid linked organosilicone polymer binder and the absorbent material does not include an inorganic peroxide.
[38]
37. The absorbent article of claim 36, wherein the cellulose-based fibers are selected from the group consisting of viscose fibers, modal fibers, lyocell fibers, and combinations thereof.
[39]
37. The absorbent article of claim 36, further comprising a fluid permeable topsheet; and a fluid impermeable backsheet, the absorbent material being disposed between the fluid permeable topsheet and the fluid impermeable backsheet.
[40]
37. The absorbent article of claim 36, further comprising a fluid permeable topsheet; and a fluid impermeable backsheet, wherein the absorbent material is disposed within the fluid permeable topsheet.
[41]
41. The absorbent article of any one of claims 36 to 40, wherein the absorbent material forms at least a portion of an absorbent core of the absorbent article.
[42]
42. The absorbent article of any one of claims 36 to 41, further comprising a superabsorbent polymer.
[43]
43. The absorbent article of any one of claims 36 to 42, wherein the carboxylic acid is a polycarboxylic acid.
[44]
44. The absorbent article according to claim 43, wherein the polycarboxylic acid is a partially or fully neutralized salt.
[45]
43. The absorbent article of any one of claims 36 to 42, wherein the carboxylic acid is selected from the group consisting of malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.
[46]
43. The absorbent article of any one of claims 36 to 42, wherein the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.
[47]
43. The absorbent article of any one of claims 36 to 42, wherein the carboxylic acid is citric acid or a salt thereof.
[48]
48. The absorbent article of any one of claims 36 to 47, wherein the absorbent material comprises a carboxylic acid content of between about 0.01% and about 10% by weight.
[49]
49. The absorbent article of any one of claims 36 to 48, wherein the absorbent article is a feminine hygiene product, the feminine hygiene product being selected from the group consisting of panty liners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, tampons, and disposable menstrual protection undergarments.
[50]
50. The feminine hygiene product of claim 49, wherein the feminine hygiene product is configured to be worn externally.
[51]
50. The feminine hygiene product of claim 49, wherein the feminine hygiene product is not configured to be worn internally.
[52]
49. The absorbent article of any one of claims 36 to 48, wherein the absorbent article is a meat packaging pad and the meat packaging pad is a fish packaging pad.
[53]
1. A method for measuring the reduction of free TMA sequestered by an absorbent material, comprising:
contacting an absorbent material disposed in the container with a quantity of TMA;
Removing a portion of the gas headspace of the container;
measuring the amount of free TMA in the extracted portion of the gas headspace; and determining a reduction in free TMA in the gas headspace compared to a control.
[54]
54. The method of claim 53, wherein the absorbent material comprises a fiber matrix and a carboxylic acid linked to the fiber matrix.
[55]
54. The method of claim 53, wherein a portion of the headspace is withdrawn after the free TMA has reached equilibrium.
[56]
54. The method of claim 53, wherein the control is a blank control.
[57]
54. The method of claim 53, wherein the control is an absorbent material control.
[58]
Measuring the amount of free TMA in the extracted portion of the gas headspace;
54. The method of claim 53, comprising: passing an extracted portion of the gas headspace over a stationary phase loaded with a colorimetric marker that changes color when contacted with TMA; and measuring the amount of color change in the stationary phase as the extracted portion of the gas headspace passes over the stationary phase.
[59]
1. A method of making an absorbent article, comprising:
A method comprising: preparing an absorbent material comprising a fiber matrix and a carboxylic acid attached to the fiber matrix; and attaching a fluid-permeable topsheet and a fluid-impermeable backsheet to the absorbent material.
[60]
60. The method of claim 59, wherein the absorbent material is disposed between a fluid permeable topsheet and a fluid impermeable backsheet.
[61]
60. The method of claim 59, wherein the absorbent material is disposed within a fluid pervious topsheet.
[62]
60. The method of claim 59, wherein the absorbent article is a feminine hygiene product.
[63]
63. The method of claim 62, wherein the feminine hygiene product is selected from the group consisting of panty liners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, and disposable menstrual protection undergarments.
[64]
64. The method of claim 62 or 63, wherein the feminine hygiene product is configured to be worn externally.
[65]
65. The method of any one of claims 62 to 64, wherein the feminine hygiene product is not configured to be worn internally.
[66]
60. The method of claim 59, wherein the absorbent article is a meat packaging pad.
[67]
60. The method of claim 59, wherein the absorbent article is an absorbent article according to any one of claims 36 to 52.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

Claims (14)

1. A method for reducing free trimethylamine ("TMA"), comprising contacting the TMA molecules with an absorbent material comprising a cellulose fiber matrix and citric acid directly linked to the cellulose fiber matrix;
1. A method according to claim 1, wherein when an absorbent material comprises 0.01 wt. % citric acid and is placed in a closed container, and TMA molecules are introduced in a solution of 0.0005 wt. % to 0.034 wt. %, the gas headspace of said closed container contains less than 50 ppm free TMA at equilibrium. The method of claim 1, wherein the TMA molecule is in menstrual fluid. The method of claim 1, wherein the TMA molecules are in a meat fluid. The method of claim 1, wherein the cellulose fiber matrix comprises a cellulose pulp structure. The method of claim 1, wherein the cellulose fiber matrix comprises fibers selected from the group consisting of cellulose fibers and cellulose-based fibers. The method of claim 5, wherein the cellulose-based fibers are selected from the group consisting of viscose fibers, modal fibers, lyocell fibers, and combinations thereof. The method of claim 1, wherein an absorbent material comprising a cellulose fiber matrix and citric acid directly linked to the cellulose fiber matrix contains 0.01 wt.% citric acid, TMA is introduced in a solution of 0.034 wt.%, and the control is an equal amount of absorbent material consisting of untreated fluff pulp substantially free of any added carboxylic acid, the absorbent material is capable of reducing free TMA by at least 95 ppm in a 0.5 L headspace. The reduction in free TMA
contacting an absorbent material disposed in a container with a quantity of TMA;
Removing a portion of the gas headspace of the container;
8. The method of claim 7, wherein the free TMA is measured by a process comprising: measuring the amount of free TMA in the extracted portion of the gas headspace; and determining the reduction of free TMA in the gas headspace compared to the control. The method of claim 1, wherein an absorbent material comprising a cellulose fiber matrix and citric acid directly linked to the cellulose fiber matrix contains 0.01 wt% citric acid, TMA is introduced in a solution of 0.027 wt%, and the control is an equal amount of absorbent material consisting of untreated fluff pulp substantially free of any added carboxylic acid, wherein the absorbent material is capable of reducing free TMA by at least 99% in a 0.5 L headspace. The method of claim 1, wherein an absorbent material comprising a cellulose fiber matrix and citric acid directly linked to the cellulose fiber matrix contains 0.01 wt% citric acid, TMA is introduced in a 0.05 wt% solution, and the control is an equal amount of absorbent material consisting of untreated fluff pulp substantially free of any added carboxylic acid, wherein the absorbent material is capable of reducing free TMA by at least 50% in a 0.5 L headspace. The reduction in free TMA
contacting an absorbent material disposed in a container with a quantity of TMA;
Removing a portion of the gas headspace of the container;
11. The method of claim 9 or 10, wherein the free TMA is measured by a process comprising: measuring the amount of free TMA in an extracted portion of the gas headspace; and determining the reduction of free TMA in the gas headspace compared to the control. 1. A method for measuring the reduction of free TMA sequestered by an absorbent material, comprising:
contacting an absorbent material disposed in a container with a quantity of TMA;
Removing a portion of the gas headspace of the container;
measuring the amount of free TMA in the removed portion of the gas headspace; and determining the reduction in free TMA in the gas headspace relative to a control, where the control is a blank control or the control is an equal amount of absorbent material consisting of untreated fluff pulp substantially free of any added carboxylic acid.
Including,
the absorbent material comprises a fiber matrix and citric acid directly coupled to the fiber matrix;
When the absorbent material contains 0.01 wt. % citric acid and is placed in a closed container, and TMA molecules are introduced in a solution of 0.0005 wt. % to 0.034 wt. % , the gas headspace of the closed container contains less than 50 ppm free TMA at equilibrium.
method. The method of claim 12, wherein a portion of the headspace is withdrawn after the free TMA has reached equilibrium. Measuring the amount of free TMA in the extracted portion of the gas headspace;
13. The method of claim 12, comprising: passing the withdrawn portion of the gas headspace over a stationary phase loaded with a colorimetric marker that changes color when contacted with TMA; and measuring the amount of color change in the stationary phase as the withdrawn portion of the gas headspace passes over the stationary phase.