Method for producing a liquid impermeable backsheet structure

Abstract

To provide materials and structural elements for absorbent articles that incorporate at least one component of a chemiluminescent system configured to produce light upon contact with an aqueous system.SOLUTION: A structural element 900 for incorporation into an absorbent article comprises a first surface 902 having a treated area 904. The treated area is treated with at least one component of a chemiluminescent system adapted to react in the presence of an aqueous system to produce light. The at least one component is selected from a luciferin and a luciferase. The treated area is less than the area of the first surface.SELECTED DRAWING: Figure 9A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 753,024, filed October 30, 2018, and U.S. Provisional Patent Application No. 62 / 692,502, filed June 29, 2018, and U.S. Patent Application No. 16 / 457,732, filed June 28, 2019, each of which is expressly incorporated by reference herein in its entirety.

[0002] Some chemiluminescent systems react to produce light in the presence of an aqueous system. Some of these chemiluminescent systems include components that react to produce light in the presence of an aqueous system, such as bioluminescent systems including luciferin and luciferase. The present disclosure relates to materials or structural elements for absorbent articles that have been treated with or incorporate at least one component of such chemiluminescent systems. The present disclosure also relates to absorbent articles incorporating such chemiluminescent systems, for example, into the aforementioned materials or structural elements. The present disclosure also relates to formulations and methods for treating materials or structural elements with one or more components of such chemiluminescent systems. [Background technology]

[0003] Personal care absorbent products such as baby diapers, adult incontinence pads, and feminine care products, as well as related absorbent articles that are not commonly worn, such as absorbent bed pads, absorbent pet pads, and the like, typically contain a fluid-absorbent core comprising one or more absorbent materials. While many configurations exist, most absorbent articles include a fluid-absorbent core disposed between a topsheet and a backsheet. The topsheet is typically formed from a fluid-permeable material adapted to facilitate fluid transport into the absorbent core, such as during liquid excretion, and typically minimizes fluid retention by the topsheet. One absorbent material commonly used in absorbent cores is U.S. Southern pine fluff pulp, generally in the form of a fibrous matrix, sometimes combined with a superabsorbent polymer (SAP) dispersed throughout the fibrous matrix. Fluff pulp is recognized worldwide as the preferred fiber for absorbent products based on factors such as fluff pulp's long fiber length, fiber coarseness, and its relative ease of processing from wet-laid and dried pulp sheets to airlaid webs. This type of cellulosic fluff pulp is sourced from southern pine (e.g., loblolly pine, Pinus taeda L.). This source is renewable, and the pulp is readily biodegradable. Compared to SAP, these fibers tend to be less expensive per mass but more expensive per unit of retained liquid. These fluff pulp fibers absorb most of the liquid within the interfiber spaces. For this reason, the fibrous matrix readily releases trapped liquid upon application of pressure. This tendency to release trapped liquid can lead to significant skin wetting during use of absorbent products containing cores formed solely from cellulosic fibers. Such products also tend to leak trapped liquid because the liquid is not effectively retained within the fibrous absorbent core.

[0004] SAPs are water-swellable, generally water-insoluble absorbent materials with high absorptive capacity for fluids. SAPs are used in absorbent articles such as baby diapers or adult incontinence products to absorb and retain body fluids. Upon absorbing fluids, SAPs swell to form a gel that retains such fluids in excess of its weight. Commonly used SAPs are mostly derived from acrylic acid. Acrylic acid-based polymers also constitute a significant part of the cost structure of diapers and incontinence pads. SAPs are known for their high absorbency under load or SAP particles are designed to have a high gel strength (denoted by AUL). The high gel strength (when swollen) of currently used SAP particles helps them maintain significant void space between particles, which aids in rapid fluid uptake. However, this large "void volume" also results in significant interstitial (interparticle) liquid within the saturated product. When interstitial liquid is present, the "rewet" value or "wet feel" of the absorbent product is compromised.

[0005] Advances in SAP technology have made it possible to design absorbent core configurations in which fluff pulp contributes less to the core's absorbency and more to providing a matrix structure in which the SAP is stably held in place. Fluff pulp fibers also provide a fluid distribution function, directing fluid to the SAP. However, it has been discovered that these structural fluid distribution functions can be provided by synthetic fibers in some configurations, leading to the development of absorbent cores containing both fluff pulp fibers and synthetic fibers, and even "fluff-less" absorbent cores that contain no fluff pulp fibers. These configurations can offer the advantage of less physical bulk without sacrificing absorbency.

[0006] Regardless of its configuration, the absorbent core is an absorbent structure that includes one or more materials adapted to absorb fluid exudates. In some configurations, the absorbent core is an integral component placed within the absorbent article during production. In such configurations, the absorbent material of the absorbent core (e.g., fluff pulp, synthetic fibers, SAP, etc.) may be wrapped or at least partially surrounded within a fluid-permeable material such as a tissue sheet.

[0007] Some absorbent articles, such as diapers or adult incontinence pads, also include an acquisition and distribution layer (ADL) to collect fluid from fluid exudates and distribute it evenly and timely to the absorbent core. The ADL is typically placed between the topsheet and the absorbent core and typically takes the form of a composite fabric. In one example configuration, the top third of such a fabric has a lower density (higher denier fibers) with relatively large voids and a larger void volume, effectively capturing the fluid even at relatively higher discharge rates. The middle third of the ADL composite fabric is typically made of higher density (lower denier) fibers with smaller voids, while the bottom third of the fabric is made of even higher density (lower, smaller denier) fibers with finer voids. The denser portions of the composite fabric have more and finer capillaries, thus generating greater capillary pressure and therefore moving a greater amount of fluid to areas outside the structure, thus enabling proper channeling and distribution of fluid evenly, allowing the absorbent core to capture all liquid exudates in a limited amount of time, allowing the SAPs within the absorbent core to retain and gel the exudates neither too slowly nor too quickly. The ADL provides more rapid liquid acquisition (minimizing overflow in the target zone) and ensures more rapid transport and complete distribution of fluid into the absorbent core.

[0008] As noted above, whatever the configuration, the absorbent core functions to retain fluid and may itself be comprised of one or more layers, such as layers that acquire, distribute, and / or store fluid. Often, a matrix of cellulosic fibers, such as in the form of an airlaid pad and / or nonwoven web, is used within (or as) the absorbent core of an absorbent article. In some cases, different layers may be comprised of one or more different types of cellulosic fibers, such as crosslinked cellulosic fibers. In some cases, synthetic fibers may be used with or without cellulosic fibers. The absorbent core may also include one or more fluid retention agents or other absorbent materials, such as one or more SAPs, distributed typically as particles throughout the fiber matrix.

[0009] The backsheet is typically formed from a fluid impermeable material to prevent the retained fluid from leaking. This creates a barrier that prevents Regardless of the structure, when an absorbent article becomes wet due to one or more liquid excretions, the chances of fluid contacting the skin are greatly increased. If left unchanged for a long period of time, this can lead to diaper rash in infants and dermatitis in adults, thereby posing a risk to skin health. However, the only way to know whether an absorbent article is dry or wet is to physically inspect it. During the day, this may not be a significant problem because caregivers can inspect worn articles, such as diapers or adult incontinence products, or other articles, such as bed pads, as often as desired. In contrast, inspections at night can cause discomfort and disrupt sleep for both adults and babies. Furthermore, frequent inspections at night, such as several times per night, can disrupt the wearer's sleep patterns, posing a risk to the health of both infants and adult users. In addition, for worn articles such as diapers or incontinence pads, clothing, such as pants, pajamas, and / or underwear, is typically worn over the absorbent article. For items such as bed pads or pet pads, the position of the user (human or animal) on the pad may obscure the caregiver's view of the pad, making it difficult to detect excrement in a timely manner, even with absorbent articles that incorporate different types of wetness and / or moisture indicators.

[0010] As a result, there is typically a time lag between urination and its detection. If this time lag is prolonged, diaper rash, skin irritation, and / or peeling may occur. These conditions can be very distressing for the affected individual. This is particularly true for babies and adults in care homes, especially for nighttime urination, when the time between changes of absorbent articles may be longer.

[0011] While these may not be immediate concerns for absorbent products that are not typically worn on the body, such as absorbent bed pads, maintaining hygiene and comfort for the user remains an important goal.

[0012] Previous moisture indicators incorporated into absorbent articles utilize a color change as a visual indication of wetness detection. Inks that appear or disappear upon contact with liquid are common mechanisms for wetness detection. Fluorescence has also been used for wetness detection, such as by incorporating compounds that fluoresce in the presence of liquid. Such indicator mechanisms generally fall into three broad categories: (1) imprinting a moisture indicating pattern onto one of the plies of the absorbent article, (2) discrete moisture indicating strips or layers incorporated between layers of the absorbent article, and (3) discrete (i.e., not part of the structure of the absorbent article) indicating strips that are secured to the interior of the absorbent article immediately prior to use.

[0013] Regardless of the mechanism, these visual indicators are all inadequate in low-light (e.g., nighttime) situations. The appearing or disappearing ink must be detected directly visually, requiring the caregiver to directly observe the absorbent product. In low-light situations, this may require not only the removal of covering clothing (e.g., pajamas or underwear) but also a light source (e.g., overhead lighting or a flashlight). Fluorescent indicators have a similar problem, as they require an external light source to excite the fluorescent compound. Such excitation is typically achieved by exposing the indicator to ultraviolet light (which poses health concerns for the wearer and caregiver) and must be in direct optical communication with the fluorescent compound, which then requires the removal of covering clothing, blankets, etc. Thus, the use of visual indicators previously used to detect wetness in absorbent garments has many disadvantages in low-light situations, which greatly reduces the usefulness of the indication mechanism.

[0014] None of these solutions to wetness detection for absorbent articles are sufficient for the needs of nighttime excretion detection: none of the technologies reliably triggers, and even when they do trigger, they require direct, illuminated visual inspection to detect.

[0015] Thus, conventional absorbent articles are inadequate when it comes to alerting caregivers to loss of urine that occurs at night and / or under clothing. U.S. Patent Application No. 14 / 516,255, the complete disclosure of which is incorporated herein by reference, discloses fluff pulp compositions treated with a chemiluminescence system configured to produce visible light upon contact with an aqueous system, and absorbent articles incorporating such treated fluff pulp compositions. Summary of the Invention

[0016] This Summary is provided to introduce a selection of concepts in a simplified form 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.

[0017] In one aspect of the present disclosure, a material is provided that is treated with one or more reactive components of a chemiluminescence system. Generally, a two-component system, such as a bioluminescence system, is discussed, which includes luciferin and luciferase. In such an embodiment, the treated material includes at least one reactive component of such a chemiluminescence system. However, these components react to generate light in the presence of an aqueous system. Therefore, the challenge is to incorporate the reactive component into the material and / or absorbent article so that the light-generating reaction does not start prematurely, such as during production or storage, but only during the use of the absorbent article, specifically when the absorbent article is subjected to fluid excretion.

[0018] Thus, some materials are treated with only one reactive component. In use, embodiments in which the treatment material includes only one reactive component will typically be incorporated into an absorbent article along with other reactive components disposed elsewhere in the absorbent article—such as in another treatment material or layer—in an arrangement in which one reactive component will be transferred to the other reactive component upon receipt of fluid exudates by the absorbent article, such as when aqueous exudate fluids migrate from the topsheet toward (for example) the backsheet, thereby reacting to initiate a light-generating reaction. However, in some embodiments, the treatment material includes two components that react with each other to generate light. In use, the reaction will typically be initiated when an aqueous system contacts the treatment material.

[0019] The material is a material that is typically incorporated into absorbent articles. The material can be an absorbent or non-absorbent material. In some embodiments, the treatment material is a treated tissue composition, in which a liquid-permeable tissue sheet is treated with one or both of luciferin and luciferase on at least one surface to retain the components on the surface. The treated tissue composition may be incorporated into an absorbent article, for example, as a material within which an absorbent core is wrapped. In some embodiments, the material is an indicator particle formed of hydrogen-bonded cellulose pulp fibers, which have been treated with one or more of luciferin and luciferase retained on the particle surface and / or on the fibers throughout the particle. In such embodiments, the indicator particle may take a variety of physical forms. For example, the indicator particle may have two opposing faces and an aspect ratio (ratio of length to width) of less than 1.5, with one or both faces having an area of 0.1 to 300 mm. 2 In another example, the indicator particles have an aspect ratio of 1.5 or greater and a cross-sectional area of 0.01 to 200 mm 2 Available in lengths from 1 to 800 mm In use, one or more indicator particles may be incorporated into the absorbent article, such as disposed or distributed within the absorbent core or between the absorbent core and the backsheet. The physical form of the particles may vary depending on the particular configuration and / or size of the absorbent core or absorbent article.

[0020] In another aspect of the present disclosure, an article includes synthetic fibers and at least one of luciferin and luciferase. In some embodiments, the synthetic fibers form a nonwoven absorbent matrix, and thus the article may be suitable for use in or as an absorbent core (such as a fluffless absorbent core) for an absorbent article.

[0021] In another aspect of the present disclosure, an absorbent article is provided that includes a chemiluminescent system configured to generate visible light upon contact with an aqueous system. In some embodiments, the absorbent article includes a liquid-permeable topsheet, a liquid-impermeable backsheet, an absorbent material disposed therebetween, and a chemiluminescent system, with the reactive components of the chemiluminescent system separately disposed within the absorbent article in a configuration in which one reactive component is transferred to another reactive component by an aqueous system moving through the absorbent article. In such embodiments, the reactive components are disposed within or on different structural elements of the absorbent article, such as the absorbent material, the topsheet, the backsheet, the liquid-permeable tissue sheet, treatment indicator particles, etc. In one illustrative and non-limiting example of such an embodiment, the chemiluminescent system includes a luciferin disposed on the tissue sheet and a luciferase disposed within a fibrous absorbent material, and the tissue sheet may form a wrap for the absorbent material such that the absorbent material and the tissue sheet together form an absorbent core. In this example, when the absorbent article is subjected to fluid excretion, fluid moving through the absorbent article toward the absorbent core will encounter luciferin on the tissue sheet and transfer it to luciferase within the absorbent material (and / or vice versa), thereby initiating the light-generating reaction. In some embodiments incorporating a fluffless absorbent core, the chemiluminescence system includes luciferin disposed on a tissue sheet and luciferase disposed within the absorbent material containing a superabsorbent material, and the tissue sheet may form a wrap for the absorbent material. In some embodiments incorporating a fluffless absorbent core, the chemiluminescence system is disposed within the core material or other structure(s) without a tissue wrapping. In some embodiments, a structural element for incorporation into an absorbent article includes a first surface having a treated area, the treated area being treated with at least one component of the chemiluminescence system, the treated area being smaller in total than the area of the first surface.

[0022] In yet another aspect of the present disclosure, a formulation for treating a substrate material with one or more reactive components of a chemiluminescence system—particularly luciferin and luciferase—is provided. In some embodiments, the formulation includes at least one reactive component (e.g., luciferin) and a liquid carrier (which may include, for example, a solvent in which the luciferin is dissolved). Some such embodiments include a binder adapted to hold the reactive component(s) on the substrate material. Some such embodiments include a viscosity modifier that imparts a desired viscosity to the formulation, e.g., a viscosity suitable for an application process such as streaming, printing, or coating. Some such embodiments include a porous transfer agent. When the formulation-treated substrate material is contacted by an aqueous system, the porous transfer agent is adapted to facilitate transfer of the reactive component(s) and / or the aqueous system relative to the substrate material. In other embodiments, at least one component of the chemiluminescence system is applied to one or more substrates as a dry formulation within a dry carrier material. Dry carrier materials include, but are not limited to, sugars, minerals or their salts, starches, silica, clays, talc, finely divided wood or other celluloses, gelatin, agar, and SAPs that are flowable or dispersible in the coating machine. The composition may contain any inert material that allows for the blending.

[0023] In some embodiments, the formulation includes both luciferin and luciferase, and the liquid carrier is or includes a solvent. In such embodiments, the luciferin is dissolved in the solvent and the luciferase is dispersed in the liquid carrier.

[0024] In some embodiments, particularly for applying luciferin to a substrate material, a partially aqueous formulation is used. Such embodiments include luciferin and a solvent that dissolves the luciferin, including water and an excipient adapted to promote the solubility of the luciferin in water (e.g., water-soluble polymers such as hydroxypropyl-β-cyclodextrin, ethanol, poly(ethylene glycol), poly(vinyl alcohol), partially hydrolyzed poly(vinyl alcohol), polyvinylpyrrolidone, poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate), poly(1-vinylpyrrolidone-co-vinyl acetate), and combinations thereof; sugars (monosaccharides, polysaccharides, and branched polysaccharides); cellulose and cellulose derivatives; minerals and their salts; and the like). Some such embodiments include a binder adapted to bind the luciferin to the substrate material. Some excipients are inert in the chemiluminescence reaction but provide additional benefits. Such additional benefits include, for example, an effect on the solubility of a given component of the chemiluminescent system in various aqueous and non-aqueous solvent systems, an effect on the availability of water in absorbent articles, a retention effect (e.g., binder) on various substrates for one or both components of the chemiluminescent system, a release effect (e.g., porous transport agent) for one or both components of the chemiluminescent system, etc. Some such excipients may have these or multiple other functions. Thus, the use of excipients in the present teachings is not limited to partially aqueous formulations.

[0025] Within these broad parameters, formulations according to the present disclosure may include components, and their relative amounts, suitable for a wide variety of applications. In one illustrative, non-limiting example of such an embodiment, a formulation suitable for applying coelenterazine (luciferin) to a liquid-impermeable backsheet, typically formed from a synthetic material, includes ethanol, coelenterazine, a binder, and a porous transport agent. In another illustrative, non-limiting example, a formulation suitable for applying coelenterazine and luciferase to a cellulosic substrate material includes ethanol, coelenterazine, a luciferase (such as Gaussia, Renilla, and / or Metridia luciferase), a binder and / or viscosity modifier, and a porous transport agent. As described in more detail herein, the nature of the substrate material to which the formulation is being applied will determine whether a binder is suitable. For example, a binder may be beneficial for a formulation applied to a substrate material containing synthetic fibers, whereas a binder may not be required for a formulation applied to a substrate material made of cellulosic fibers.

[0026] In yet another aspect of the present disclosure, methods are provided for treating a substrate material with one or more reactive components of a chemiluminescence system. As described above, these components react to generate light in the presence of an aqueous system. Therefore, one challenge in incorporating reactive components into materials and / or absorbent articles is to do so in a way that does not prematurely initiate the light-generating reaction. In some embodiments, a method includes applying to the substrate material a formulation of luciferase dispersed in an aqueous liquid sufficient to achieve a desired luciferase concentration on the substrate material, but not enough to raise the moisture content of the substrate material above a moisture threshold level. Such a method may offer the advantage of reducing the need for a subsequent drying step, such as when luciferin is also applied to the substrate material. In some embodiments, a method includes treating an area on the surface of a substrate material with a luciferase formulation comprising luciferase dispersed in an aqueous liquid and luciferin dissolved in a non-aqueous solvent. The method includes separate luciferase and luciferin treatment steps, in which the cells are treated separately with a luciferin formulation containing luciferin.

[0027] In yet another aspect, a method for producing an absorbent article or a structural element for incorporation into an absorbent article, for example, utilizing one or more of the aforementioned treated materials, is provided. In some embodiments, the treated tissue composition can be produced by applying a formulation including luciferin dissolved in a solvent to a liquid-permeable tissue sheet, for example, by streaming the formulation onto the surface, and then removing the solvent from the tissue sheet. In some such embodiments, the tissue sheet can be a continuous sheet that is moved relative to one or more nozzles that stream the formulation, and the surface of the tissue sheet to which the formulation is applied is suspended between two fixed points. In such embodiments, the solvent can be removed by subsequent heat treatment of the treated surface, for example, by moving the treated surface through a heating zone.

[0028] In yet another aspect, a chemiluminescent system is provided in a form suitable for use in an absorbent article or one or more materials and / or structural elements thereof. In some embodiments, a composition comprises an encapsulating material consisting of particles containing a predetermined amount of a first component of a chemiluminescent system, the particles having a water-permeable or water-soluble coating covering the entire surface of the particle, and a predetermined amount of a second component of the chemiluminescent system. Such a composition may be suitable for incorporation into an absorbent article, or a component thereof, for example, during production or by an end user prior to use of the absorbent article. Some embodiments may be in the form of a kit including an absorbent article incorporating a first component of the chemiluminescent system and a measured amount of a second component of the chemiluminescent system suitable for reacting with the first component to produce light of a predetermined duration and / or intensity. In some such embodiments, the measured amount may be in the form of a liquid formulation, gel, powder, etc., for application to the absorbent article by the end user prior to use.

[0029] Representative absorbent articles include disposable diapers and adult incontinence products. The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein: [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a photograph showing an example absorbent article incorporating a chemiluminescent fluff pulp composition. [Figure 2A] FIG. 1 shows the chemical structures of representative luciferin compounds useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 2B] FIG. 1 shows the chemical structures of representative luciferin compounds useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 2C]FIG. 1 shows the chemical structure of another representative luciferin compound useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 2D] FIG. 1 shows the chemical structure of another representative luciferin compound useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 2E] FIG. 1 shows the chemical structure of another representative luciferin compound useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 2F] FIG. 1 shows the chemical structure of another representative luciferin compound useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 2G] FIG. 1 shows the chemical structure of another representative luciferin compound useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 2H] FIG. 1 shows the chemical structure of another representative luciferin compound useful in chemiluminescence systems according to embodiments disclosed herein. [Figure 3] 1 is a graph illustrating the spectral characteristics of exemplary luciferins according to embodiments disclosed herein. [Figure 4A] 1 is a perspective view of a non-limiting representative example of an absorbent article (in the form of a diaper) according to embodiments disclosed herein. [Figure 4B] FIG. 4B is a plan view of the absorbent article of FIG. 4A viewed from above. [Figure 4C] 4B illustrates a cross section of an example absorbent article of FIG. 4A according to an embodiment of the present disclosure. [Figure 4D] 4B illustrates a cross section of an example absorbent article of FIG. 4A according to an embodiment of the present disclosure. [Figure 4E] 4B illustrates a cross section of an example absorbent article of FIG. 4A according to an embodiment of the present disclosure. [Figure 4F] 4B illustrates a cross section of an example absorbent article of FIG. 4A according to an embodiment of the present disclosure. [Figure 5A] 1 is a perspective view of a non-limiting representative example of a treated tissue composition according to an embodiment disclosed herein. [Figure 5B] FIG. 2 is a perspective view of a non-limiting representative example of another treated tissue composition according to embodiments disclosed herein. [Figure 5C] FIG. 2 is a perspective view of a non-limiting representative example of another treated tissue composition according to embodiments disclosed herein. [Figure 5D] 1 is a cross-sectional view of a non-limiting representative example of a treated tissue composition according to certain embodiments of the present disclosure. [Figure 5E] 1 is a cross-sectional view of a non-limiting representative example of another treated tissue composition according to an embodiment of the present disclosure. [Figure 5F] 1 is a cross-sectional view of a non-limiting representative example of another treated tissue composition according to an embodiment of the present disclosure. [Figure 5G] 1 is a cross-sectional view of a non-limiting representative example of another treated tissue composition according to an embodiment of the present disclosure. [Figure 6] Figure 6A shows a non-limiting representative example of an indicator particle according to an embodiment disclosed herein, and Figure 6B shows a non-limiting representative example of another indicator particle according to an embodiment disclosed herein. [Figure 7] 1A-1C illustrate non-limiting representative examples of articles in the form of absorbent cores according to embodiments disclosed herein. [Figure 8] Figures 8A and 8B are schematic diagrams of non-limiting representative examples of streaming apparatus suitable for use in producing treated tissue compositions according to embodiments disclosed herein. [Figure 9A] 1A-1C illustrate non-limiting representative examples of structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9B] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9C] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9D] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9E] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9F] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9G] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9H] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9I] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 9J] 10A-10C illustrate non-limiting representative examples of alternative structural elements for incorporation into absorbent articles according to embodiments disclosed herein. [Figure 10] 1 is a graph illustrating chemiluminescence intensity as a function of time exhibited by exemplary treated materials according to embodiments disclosed herein. [Figure 11] 1 is a graph illustrating chemiluminescence intensity as a function of time exhibited by exemplary treated materials according to embodiments disclosed herein. [Figure 12] 1 is a graph illustrating chemiluminescence intensity as a function of time exhibited by exemplary treated materials according to embodiments disclosed herein. [Figure 13] 1 is a graph illustrating chemiluminescence intensity as a function of time exhibited by exemplary treated materials according to embodiments disclosed herein. [Figure 14]14A and 14B are graphs showing the chemiluminescence intensity as a function of time exhibited by exemplary treatment materials according to embodiments disclosed herein. [Figure 15] 15A and 15B are graphs showing the chemiluminescence intensity as a function of time exhibited by exemplary treatment materials according to embodiments disclosed herein. [Figure 16] 1 is a graph illustrating chemiluminescence intensity as a function of time exhibited by exemplary treated materials according to embodiments disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0031] While exemplary embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. Disclosed herein are materials treated with one or more reactive components of a chemiluminescent system, absorbent articles and structural elements for absorbent articles incorporating these materials, formulations, and compositions, as well as treatment and manufacturing methods for the chemiluminescent system and its use in absorbent articles. The chemiluminescent system is configured to generate light upon contact with an aqueous system. The reactive components of the chemiluminescent system are generally disposed in one or more treatment materials and / or compositions incorporated into the absorbent article. Exemplary absorbent articles include disposable diapers and adult incontinence products. Exemplary chemiluminescent systems include bioluminescent systems.

[0032] Chemiluminescence results from a chemical reaction that produces light, thus providing a glowing moisture indicator that can be seen through clothing in low light and / or the absence of light. Furthermore, chemiluminescence does not require an external excitation light, as is required for photoluminescent (e.g., fluorescent) indicators. Thus, by generating light upon contact with an aqueous system (e.g., urine), the incorporation of a chemiluminescent system greatly enhances the ability of an absorbent article to indicate the occurrence of an excretion under dark conditions (e.g., at night). Furthermore, by generating light that can be detected through clothing, a caregiver may be able to confirm the occurrence of an excretion, such as during sleep, without having to move or wake the infant or adult wearer of such absorbent article. Thus, the various compositions and articles provided herein can offer the distinct advantage of nighttime excretion indication through clothing, which eliminates the need for a caregiver to wake a sleeper wearing such an absorbent article (e.g., by waking the wearer) to check for an excretion. This can reduce or even eliminate the need for obstruction (by drawing down materials and / or shining light on them). Furthermore, because the chemiluminescent systems disclosed herein produce visible light (i.e., light in the visible spectrum), it is not necessary to expose the absorbent article incorporating the system and / or the wearer to ultraviolet light to determine whether excretion has occurred, thereby avoiding health concerns associated with ultraviolet light.

[0033] Low-light detection enabled by chemiluminescent systems, and particularly by certain embodiments of absorbent articles incorporating such systems, is discussed in Applicant's aforementioned co-pending U.S. patent application Ser. No. 14 / 516,255 and is illustrated in several of the drawings therein. For example, Figure 1, reproduced from Application Ser. No. '255, is a photograph of an absorbent article (diaper) incorporating an absorbent core containing a chemiluminescent fluff pulp composition (fluff pulp treated with both luciferase and luciferin). In Figure 1, simulated fecal waste (saline solution) was applied, and an image was captured showing chemiluminescence shining through the diaper backsheet and lightweight cotton fabric for easy visual detection in low-light conditions. A comparative absorbent article formed using fluorescent fluff instead of chemiluminescent fluff would not function through the diaper material because excitation by an external light source would be prevented (see, e.g., Figure 9A of Application Ser. No. '255). Activation of fluorescent wetness indicators requires the removal of clothing and application of excitation light (e.g., ultraviolet light) to visually detect excretion. Chemiluminescence does not require the removal of clothing or excitation light.

[0034] The improved ease with which excretions may be detected by the absorbent articles disclosed herein allows caregivers to check excretions as needed (e.g., more frequently) because fewer interruptions are required. More frequent checking may allow excretions to be detected sooner and the absorbent article to be replaced sooner after an excretion, thereby reducing the time that excretions contact the wearer's skin and the likelihood that fluids from multiple excretions will contact the wearer's skin. Reducing the time that fluids contact the skin improves the wearer's skin health and overall comfort.

[0035] In one embodiment, a material is provided that is treated with one or more reactive components of a chemiluminescent system that reacts in the presence of an aqueous system to generate visible light. The term "visible light" herein refers to light in the visible spectrum. The material is a material that is typically incorporated into absorbent articles. The material can be absorbent or non-absorbent. Chemiluminescence A chemiluminescent system includes at least two reactive components configured to react in the presence of an aqueous system to produce visible light. In other words, the aqueous system initiates a chemiluminescent reaction between the reactive components to produce light. The chemiluminescent system is adapted to react in the presence of an aqueous system to produce light. In preferred embodiments, the generated light is visible light observable by humans. In some embodiments, only a single reactive component selected from luciferin and luciferase is present in a given structural element within an article described herein. In such embodiments, the chemiluminescent system is configured to generate light in the presence of an aqueous system and one of the reactive components. In preferred embodiments, the generated light is visible light observable by humans. In some embodiments, the aqueous system functions to transport one reactive component to the other reactive component, thereby initiating the light-generating reaction. As used herein, the term "aqueous system" refers to water or a water-containing composition. In the context of the present disclosure, such water-containing compositions are generally in the form of bodily fluids, such as urine, menstrual fluids, feces, etc. The occurrence of the release of bodily fluids (or the bodily fluids themselves) is referred to herein as an “excretion,” “liquid excretion,” or “fluid excretion.” Thus, the chemiluminescent systems of the present disclosure generate light upon excretion into an article into which the reactive component of the chemiluminescent system is incorporated.

[0036] In a chemiluminescent system configured to generate visible light upon contact with an aqueous system, one of the reactive components luminesces when the reactive component reacts in the presence of the aqueous system. In some embodiments, water is the component of the aqueous system that initiates the light-generating reaction. In these embodiments, the reactive component does not react in the absence of an aqueous system. In these embodiments, the reactive component does not luminesce alone.

[0037] Exemplary chemiluminescent systems containing two or more reactive components include bioluminescent systems, such as systems containing luciferin and luciferase. Bioluminescence is light produced by chemical reactions occurring within the bodies or secretions of certain types of organisms. Bioluminescence requires the combination of two types of substances in the light-producing reaction: luciferin and luciferase. Luciferin is the compound that actually luminesces—i.e., produces light. Luciferase is the enzyme that catalyzes the reaction. In some cases, luciferase is a protein known as a photoprotein, and the light-producing process requires a charged ion (e.g., a cation such as calcium) to activate the reaction. In many cases, the bioluminescence process requires the presence of a substance such as oxygen or adenosine triphosphate (ATP) to initiate the oxidation reaction. The rate of the luciferin reaction is often controlled by the luciferase. The luciferin-luciferase reaction can also produce by-products such as inactive oxyluciferin and water.

[0038] Luciferin and luciferase are general names rather than specific materials.For example, coelenterazine (natural form), which is luciferin, is common in marine bioluminescence, but variants can be chemically synthesized, and these various forms are collectively called luciferin.Several methods for synthesizing coelenterazine are disclosed in U.S. Provisional Patent Application No. 62 / 692,485, the entire contents of which are incorporated herein by reference.

[0039] The mechanism of light production by a chemical reaction distinguishes bioluminescence from other optical phenomena such as fluorescence or phosphorescence. For example, fluorescent molecules do not emit light of their own. They require an external photon source to excite their electrons to a higher energy state. Upon relaxation from the higher energy state to its natural ground state, the fluorescent molecule releases the acquired energy as a light source, usually at a longer wavelength. Because excitation and relaxation occur simultaneously, fluorescence is only visible when illuminated (excited).

[0040] The term phosphorescence technically refers to a special case of photoexcited light emission in which the relaxation from the excited state to the ground state is not immediate, as in fluorescence, and photon emission persists for several seconds to minutes after the initial excitation.

[0041] Although the technical distinction between bioluminescence and fluorescence can be blurred in practical contexts, technically they are two distinct phenomena. In most cases, bioluminescence can be autofluorescence, but the reverse is not true for fluorescence. The latter still requires photons to excite and emit light. In some cases, bioluminescent cnidarians, crustaceans, or fish contain fluorescent proteins such as green fluorescent protein (GFP), and the light emitted by bioluminescence will act as photons to excite GFP. Consequently, GFP will emit light at a different wavelength (most likely a longer wavelength) than the wavelength of the bioluminescent light it receives as a photon under relaxed conditions. In this example, GFP can be excited by blue light (470 nm) emitted by bioluminescence, but will emit green light (510–520 nm) under relaxed conditions.

[0042] The bioluminescent system can be incorporated into the absorbent article in any manner that produces the desired chemiluminescence, several of which are disclosed herein. In some embodiments, the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine. Coelenterazine exists in its native form as well as in numerous analogs or variants, any of which may be used in the embodiments and methods disclosed herein. For clarity, the term "coelenterazine analog" refers to substances such as methylcoelenterazine, coelenterazine 400a, (2-2'(4-dehydroxy))coelenterazine, coelenterazine e, coelenterazine f, coelenterazine h, coelenterazine i, coelenterazine n, coelenterazine cp, coelenterazine ip, coelenterazine fcp, and coelenterazine hcp, while "coelenterazine" refers to naturally occurring coelenterazine. Thus, in some embodiments, the coelenterazine may be one or more of naturally occurring coelenterazine and a coelenterazine analog. As one example, the coelenterazine can be one or more of native coelenterazine, coelenterazine 400a, methyl coelenterazine, coelenterazine f, coelenterazine cp, coelenterazine fcp, and coelenterazine hcp. As yet another example, the coelenterazine can be one or more of coelenterazine 400a, methyl coelenterazine, and coelenterazine fcp. As yet another example, the coelenterazine can be one or more of coelenterazine 400a, methyl coelenterazine, and coelenterazine hcp. In yet another example, the coelenterazine can be one or more of coelenterazine 400a and coelenterazine hcp.

[0043] In some embodiments, the luciferase is selected from the group consisting of Gaussia luciferase (GLuc), Renilla luciferase (RLuc), Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, firefly luciferase, fungal luciferase, bacterial luciferase, copepod luciferase, and vargula luciferase. Particular embodiments of luciferases consistent with the present disclosure include one or more of Gaussia luciferase, Renilla luciferase, dinoflagellate luciferase, and firefly luciferase. As a further example, the luciferase can be one or more of Gaussia luciferase, Renilla luciferase, dinoflagellate luciferase, and firefly luciferase. In yet another example, the luciferase may be one or more of Gaussia luciferase, Renilla luciferase, and Metridia luciferase.

[0044] In some embodiments, the chemiluminescence system includes coelenterazine as the luciferin and / or Gaussia, Renilla, and Metridia luciferases, or combinations thereof.

[0045] Coelenterazine, in its native form and its analogs, has various luminescence properties due to the diversity of their structural moieties. Given the structural diversity within the coelenterazine family, some are good substrates for luciferase, while others are not. Below is a brief description of native coelenterazine and representative analogs.

[0046] Coelenterazine (native form), shown in Figure 2A, is a luminescent enzyme substrate for Renilla (reniformis) luciferase (RLuc). Renilla luciferase / coelenterazine has also been used as a bioluminescence donor in bioluminescence resonance transfer (BRET) studies. Unless otherwise specified, the unmodified term "coelenterazine" refers to coelenterazine in its native form.

[0047] Coelenterazine 400a, shown in Figure 2B, is a derivative of coelenterazine that is a good substrate for Renilla luciferase (RLuc) but is poorly oxidized by Gaussia luciferase (GLuc). This coelenterazine is a preferred substrate for BRET (bioluminescence resonance energy transfer) because its emission maximum at 400 nm minimally interferes with GFP emission.

[0048] Fluorescence resonance energy transfer (FRET), BRET, resonance energy transfer (RET), and electronic energy transfer (EET) are mechanisms that describe energy transfer between two photosensitive molecules (chromophores). They typically define the interference of one luminescent chemistry with the energy transfer of another, thus lowering the energy state to which this luminescent chemistry can transition, which is crucial in terms of the relaxation energy released upon returning to the ground state. The donor chromophore is initially in its electronically excited state and can transfer energy to the acceptor chromophore through nonradiative dipole-dipole coupling. The efficiency of this energy transfer is inversely proportional to the sixth power of the distance between the donor and acceptor, making FRET extremely sensitive to small changes in distance. Measurement of FRET efficiency can be used to determine whether two fluorophores are within a certain distance of each other. Such measurements are used as research tools in fields including biology and chemistry.

[0049] For example, BRET in the presence of Renilla luciferase (RLuc) with coelenterazine 400a was compared to coelenterazine (native), and this BRET clearly showed minimal interference with GFP emission, as shown in Figures 2A and 2B, where "hRluc" is the Renilla luciferase and coelenterazine h bioluminescence system, "FLuc" is the Renilla luciferase system with native coelenterazine, "lucroron" is a luciferase and luciferin system containing GFP2 as a photon acceptor that fluoresces as a result of hRLuc bioluminescence emission, and "GFP2" is green fluorescent protein (second generation).

[0050] Coelenterazine cp shown in FIG. 2C is a coelenterazine-aequorin complex that produces luminescence intensity 15 times higher than that of coelenterazine (native form). Coelenterazine f shown in FIG. 2D has a luminescence intensity 20 times higher than that of native coelenterazine (coelenterazine-apoaequorin complex), while its emission maximum is approximately 8 nm longer than that of the native form.

[0051] Coelenterazine fcp, shown in Figure 2E, is an analogue of coelenterazine f in which the o-benzene structure in the elenterazine moiety is replaced with a cyclic pentane (similar to coelenterazine cp). Coelenterazine fcp has a luminescence intensity 135 times higher than that of coelenterazine (native form).

[0052] Coelenterazine fcp complexes with aequorin to form a coelenterazine fcp-apoaequorin complex, which, as a substrate for aequorin, has a relative luminescence intensity 135-fold higher than that of native coelenterazine, but is a poor substrate for Renilla luciferase.

[0053] Other representative analogs of coelenterazine as substrates for the Renilla luciferase enzyme are coelenterazines e, h, and n, shown in Figures 2F, 2G, and 2H, respectively. These three analogs are good to excellent substrates for Renilla luciferase but are poor substrates for apoaequorin.

[0054] Coelenterazine analogs vary in their luminescence properties. For example, certain analogs: They emit dimmer light (measured as lumens) but have higher luminescence intensity (lumens / steradian). Table 1 lists the luminescence properties of coelenterazine (native) and its analogs and Renilla luciferase. Luminescence intensity is reported as % initial intensity. For example, an analog with 900% initial intensity is 20 times more intense than native coelenterazine, which has 45% initial intensity.

[0055] [Table 1]

[0056] The (normalized) emission spectra of coelenterazine e (which has a luminescence intensity 20 times higher than that of native coelenterazine) and native coelenterazine are shown in Figure 3. In Figure 3, coelenterazine e (solid line) and native coelenterazine (dotted line) are measured in the presence of recombinant Renilla luciferase (RLuc). One is at 418 nm and the other is at 475 nm wavelength (λ em Note the presence of two intense peaks of coelenterazine e.

[0057] Visible light, i.e., light in the visible spectrum, is generated by the chemiluminescence system. This light can be visually detected by caregivers through clothing and / or covers in the dark, and therefore has sufficient wavelength, intensity, and duration to provide the required indication. These spectral characteristics of the chemiluminescence system can be adjusted based on one or more chemiluminescence compounds. For example, in a bioluminescence system, luciferin and luciferase can be selected to produce desired light characteristics. Depending on the bioluminescence system used, various spectral characteristics can be produced. In the presence of superoxide anion and / or peroxynitrile compounds, coelenterazine can also emit light independently of enzyme (luciferase) oxidation, a process known as autoluminescence.

[0058] Chemiluminescent systems can be tuned to produce specific colors of visible light. As noted above in Table 1, even within the coelenterazine family, emission wavelengths can range from about 400 nm (blue-violet) to about 475 nm (greenish-blue).

[0059] Regarding duration, the duration of light emitted can be controlled by the choice of coelenterazine (luciferin), either native or its analog, and the choice of enzyme (luciferase), e.g., Gaussia or Renilla. The ratio and concentration of luciferin and luciferase used can also alter the duration of light emission. To give one illustrative and non-limiting example, the luciferin analog coelenterazine e has a similar activity to native coelenterazine. Compared to the conventional method, the total light output is 130% and the initial intensity is 900% (see Figure 3). By judiciously selecting the concentrations of coelenterazine and Renilla luciferase, the duration of the emitted visible light can last for as long as 8-10 hours.

[0060] In some embodiments, the visible light has a duration of 0.5 to 6 hours. In some embodiments, the visible light has a duration of 1 to 4 hours. In some embodiments, the visible light has a duration of 2 to 3 hours. For example, the visible light can have a duration of 1 to 2 hours, 1 to 3 hours, 1 to 4 hours, 1 to 5 hours, 1 to 6 hours, or any range within any of these ranges, and all other possible subranges.

[0061] With respect to intensity, the quantum efficiency of the chemiluminescence contributes to the intensity, depth, and hue of the color of the emission. Quantum efficiency (QE) is the fraction of photon flux used to excite a luminescent chemistry to a higher energy state. Quantum efficiency is one of the most important parameters used to evaluate detector quality and is often referred to as "spectral sensitivity" to reflect its wavelength dependence. It is defined as the number of signal electrons generated per incident photon. In some cases, this can exceed 100% (i.e., when more than one electron is generated per incident photon). When the spectral sensitivity is greater than 100%, the intensity and depth of the emitted color are vivid, but the duration of the emission will depend on the excited state of the primary electrons (i.e., the more excited the state, the longer it takes to return to the ground (normal) state).

[0062] Spectral responsivity is a similar measurement but has different units; this metric is in amperes or watts (ie, how much current comes out of the device per incident photon of a given energy and wavelength).

[0063] Both quantum efficiency and spectral responsivity are functions of the wavelength of the photon. For example, in the case of the luciferin coelenterazine, between the native form and one of its analogs, coelenterazine e, the latter not only has a higher light intensity but also emits 30% more light energy than the former. This is because the latter generates two electrons when excited by an incident photon of a given quantum (hν), and the primary electron at wavelength 475 has the same radiant intensity as native coelenterazine but 20 times higher lumen intensity than that of the native product. Therefore, the light emitted by the excited coelenterazine analog will be 20 times brighter than the native form, but the 130% total light energy will last longer than the native form.

[0064] The wavelength determines the color of the visible light that is emitted. Chemiluminescence systems of the present disclosure typically include two reactive components, such as luciferin and luciferase, sometimes referred to herein as the "luciferin component" and the "luciferase component," respectively. Treatment materials according to certain aspects of the present disclosure include at least one of the reactive components, and in some embodiments, two of the reactive components. Absorbent articles according to other aspects of the present disclosure generally incorporate both of the aforementioned reactive components, such as by including one or more materials that have been treated with the reactive components. The term "incorporated," when referring to a reactive component, indicates that the component is included in the absorbent article in some manner. In some embodiments, one or more components are held on or within a particular material or structural element of the absorbent article, such as on the cellulose and / or other fibers of the treatment material, for example, by a binder or through chemical or mechanical interactions. In some embodiments, one or more components are distributed (e.g., in granular, powder, or other particulate form) on or throughout a particular material, such as within a cellulose and / or synthetic fiber matrix. In some embodiments, at least one component of the chemiluminescence system is a dry composition within a dry carrier material. The dry carrier material is applied to one or more substrates as a mixture. Dry carrier materials may include any inert material that allows for a flowable or dispersible formulation in an applicator, such as, but not limited to, sugars, minerals or their salts, starches, silica, clays, talc, finely divided wood or other celluloses, gelatin, agar, and SAP. In one embodiment, an absorbent article includes a liquid-permeable topsheet, a liquid-impermeable backsheet, a fibrous absorbent material containing luciferase-treated fibers, and a luciferin-treated tissue sheet, wherein the absorbent material and tissue sheet are disposed between the topsheet and backsheet in a configuration in which one of the chemiluminescent components is transferred to the other by an aqueous system moving from the topsheet toward the backsheet. For example, the treated tissue sheet may form a wrapping for an absorbent core containing the treated absorbent material. Photoluminescent Compounds A chemiluminescent system can interact with a photoluminescent (e.g., fluorescent and / or phosphorescent) compound that has a photoluminescent absorption wavelength range that overlaps with the chemiluminescent emission wavelength range of the chemiluminescent system and has a photoluminescent emission wavelength range that is different from the chemiluminescent emission wavelength range. Thus, the photoluminescent compound can be used to "shift" the emission wavelength of the chemiluminescent system. For example, photoluminescence can be used to change or adjust the color (or other spectral quality) of the generated light.

[0065] Although chemiluminescent systems produce light, the chemiluminescence itself is not necessarily in the visible spectrum. Chemiluminescence produces electromagnetic radiation in some wavelength range, but the disclosed embodiments are not limited to chemiluminescent radiation in the visible range. Thus, in certain embodiments, chemiluminescent systems can produce chemiluminescent radiation that is not in the visible wavelength range. In such embodiments, photoluminescent compounds may be used to shift the emission spectrum into the visible range.

[0066] The photoluminescent compound may be selected from the group consisting of fluorescent compounds and phosphorescent compounds.Fluorescent compounds include, but are not limited to, xanthene derivatives such as fluorescein, rhodamine, Oregon green, eosin, and Texas red; cyanine derivatives such as indocarbocyanine; naphthene derivatives; coumarin derivatives; oxadiazole derivatives such as pyridyloxazole; anthracene derivatives such as anthraquinone; pyrene derivatives such as Cascade blue; acridine derivatives such as proflavine, acridine orange, and acridine yellow; arylmethine derivatives such as auramine, crystal violet, and malachite green; tetrapyrrole derivatives such as porphine; bilirubin; phosphorescent compounds such as silver-activated zinc sulfide and doped strontium aluminate.

[0067] The photoluminescent compound can be disposed in any suitable material (e.g., absorbent material) or component (e.g., topsheet) for the absorbent article, or in an adjacent layer (e.g., topsheet) when incorporated into the absorbent article. What is important is that the photoluminescent compound is in optical communication with the chemiluminescence (at the emission wavelength and excitation wavelength). For example, the photoluminescent compound can be disposed on the backsheet of the absorbent article. pH buffers A pH buffer may be present in the material and / or absorbent article. The pH buffer may be configured to modify the spectral characteristics, such as the intensity, of the chemiluminescence system. For example, pH control may be used to improve the efficiency of chemiluminescence.

[0068] Exemplary improvements in chemiluminescence efficiency can be achieved by increasing the desired time for detecting excretion. The pH buffer may be configured to enhance the efficiency of visible light from a chemiluminescent system upon contact with the aqueous system.

[0069] The pH buffering agent may be selected from the group consisting of sodium bicarbonate, sodium acetate, sodium citrate, sodium lactate, sodium lactate citrate, sodium borate, calcium acetate, calcium citrate, calcium bromide, calcium gluconate, calcium lactate, calcium lactate malate, calcium carbonate, calcium bicarbonate, and potassium dihydrogen phosphate. Calcium salts are particularly effective in increasing the efficiency of the chemiluminescence reaction.

[0070] The pH buffering agent can be disposed in any suitable material (e.g., absorbent material) or component (e.g., topsheet) for the absorbent article, or in an adjacent layer (e.g., topsheet) if incorporated into the absorbent article. What is important is that the pH buffering agent contacts the chemiluminescent system upon excretion. Therefore, the pH buffering agent should be disposed in the absorbent article such that it is brought into contact with the chemiluminescent system upon excretion. Processing materials and structural elements In one aspect of the present disclosure, materials and structural elements are provided that are treated with one or more reactive components of a chemiluminescence system. In such embodiments, the treated material or structural element comprises one or both reactive components of a bioluminescence system—i.e., luciferin and luciferase.

[0071] The material is a material typically incorporated into absorbent articles. The material can be absorbent or non-absorbent. Exemplary absorbent articles include children's or baby diapers, adult diapers and incontinence products, feminine hygiene products, absorbent underpads, bandages and other wound care dressings, absorbent bed pads, and absorbent pet pads.

[0072] To illustrate example materials, a representative absorbent article is shown as diaper 100 in FIGS. 4A and 4B, which show a simplified and somewhat schematic top view of the diaper in a flattened configuration. However, the following description applies to all types of absorbent articles. The diaper includes a topsheet, generally indicated at 102, and a backsheet at 104. The topsheet 102 is formed from a fluid-permeable material adapted to facilitate fluid transport to the interior of the diaper, typically with minimal fluid retention by the topsheet. Example materials include nonwoven fibrous sheets incorporating synthetic and / or cellulosic fibers. In contrast, the backsheet 104 is formed from a fluid-impermeable material to prevent any fluid leakage from the interior of the diaper. The example backsheet, sometimes referred to as a "poly sheet," includes a polyethylene sheet or film. Each of the topsheet and backsheet may be a composite of and / or may be formed from one or more materials or layers that function together or alone to impart fluid-permeable or fluid-impermeable properties to the sheet.

[0073] The interior of the diaper includes an absorbent region 106 and a target region 108, which generally represents the area where excretion is expected. The exact boundaries of regions 106 and 108 will vary depending on the design of the diaper or absorbent article.

[0074] 4C shows a cross section 200 through the target area 108. In cross section 200, it can be seen that in addition to the topsheet 102 and backsheet 104, the diaper includes an absorbent material, generally indicated at 110, disposed between the topsheet and the backsheet. The absorbent material may be any material or combination of materials suitable for absorbing fluid exudates. For example, an absorbent material may be a polyester or polyester blend. The absorbent material may include a fibrous matrix formed from cellulosic and / or synthetic fibers, SAP, and the like.

[0075] A chemiluminescent system is also disposed within the diaper 100 . In some embodiments, the chemiluminescence system includes a luciferin component and a luciferase component, which are adapted to react with each other to produce light in the presence of an aqueous system. In some such embodiments, the components are separately disposed within the diaper in a configuration in which one component is transferred to the other by an aqueous system, such as fluid exudates, e.g., fluid exudates migrating from the topsheet toward the backsheet. The components may be disposed on, within, and / or throughout two or more materials incorporated into the diaper structure.

[0076] Example materials include both absorbent materials (e.g., materials typically incorporated into the absorbent core) and non-absorbent materials (e.g., materials typically incorporated elsewhere in the structure of an absorbent article), and combinations thereof. Examples of absorbent materials include fluff pulp, SAP, synthetic fibers, etc. Examples of non-absorbent materials include the topsheet 102, the backsheet 104, tissue sheets or compositions, one or more layers of material used in an acquisition distribution layer (ADL), etc.

[0077] As mentioned above, the applicant's co-pending U.S. patent application Ser. No. 14 / 516,255 discloses a fluff pulp composition treated with a chemiluminescence system configured to generate visible light upon contact with an aqueous system, which may be incorporated into an absorbent article, for example as an absorbent material. Treated tissue composition In one embodiment of a treatment material according to the present disclosure, a treated tissue composition is provided. Figure 5A shows an example of such a tissue composition 300, which includes a liquid-permeable tissue sheet 302. The tissue sheet includes fibers, such as fibers selected from cellulosic fibers, synthetic fibers, and combinations thereof, and may be of any structure and configuration suitable for incorporation into an absorbent article, for example, as a wrapping material for an absorbent core.

[0078] The tissue sheet 302 has at least two opposing surfaces. The tissue sheet 302 has at least one surface 304 that is treated with at least one component of a chemiluminescence system selected from luciferin and luciferase, the component being retained on the treated surface. In some embodiments, the component is a luciferin selected from coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, furimazine, and combinations thereof. For example, in some such embodiments, the component is coelenterazine. In some embodiments, the component is a luciferase selected from Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase. For example, in some such embodiments, the component is Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase. In some embodiments, the treated tissue composition incorporates both luciferin and luciferase such that a light-generating reaction is initiated when the treated tissue composition is contacted by liquid waste. For example, in some such embodiments, the luciferin is coelenterazine and the luciferase is Gaussia luciferase. In another example, in some such embodiments, the luciferin is coelenterazine and the luciferase is Renilla luciferase. In yet another example, in some such embodiments, the luciferin is coelenterazine and the luciferase is M etridia luciferase.

[0079] Although not required, a binder may optionally be used to aid in retention of the chemiluminescent components on the tissue sheet, such as on the fibers of the tissue sheet. Generally speaking, a binder is any material or substance that mechanically, chemically, adhesively, or cohesively binds or holds together other materials to form a cohesive whole. While cellulose fibers are primarily capable of retaining luciferin applied to their surface through molecular interactions, it has been found that some synthetic fibers and / or surfaces are less able, or even unable, to do so. In such cases, it has also been found that one or more binders can facilitate retention of luciferin on such materials, and that the binder can provide similar benefits even on substrate materials capable of retaining luciferin. When the component is luciferin, suitable binders may include ethyl cellulose, methyl cellulose, nitrocellulose, polyurethane, etc., and various combinations thereof. Thus, in some embodiments, the components of the chemiluminescent system are retained on the surface of the tissue sheet by a suitable binder.

[0080] Some binders function by forming a coating or film over the surface of the substrate material, retaining the chemiluminescent component to the material, yet resisting penetration by an aqueous system that solubilizes and / or releases the chemiluminescent component for transport to the site of chemiluminescence. This may manifest, for example, as a delay before chemiluminescence becomes visible after excretion in the absorbent article, lower chemiluminescence intensity upon excretion, such as the first excretion, etc. Such a delay may be useful as a sustained-release mechanism in some embodiments. However, in many applications, it will be preferable for chemiluminescence to be visible as soon as practicable after excretion. In some such embodiments, the presence of a release agent can hasten or accelerate the release of the chemiluminescent component retained by the binder. Suitable release agents include poly(1-vinylpyrrolidone-co-vinyl acetate) (PVPA), hydroxypropyl-β-cyclodextrin (HPBC), etc. Accordingly, some embodiments that include one or more binders also include one or more release agents.

[0081] Some embodiments include luciferin, an aqueous or non-aqueous solvent that dissolves the luciferin, and an excipient adapted to promote solubility of the luciferin in water (e.g., hydroxypropyl-β-cyclodextrin; ethanol; a water-soluble polymer selected from the group consisting of poly(ethylene glycol), poly(vinyl alcohol), partially hydrolyzed poly(vinyl alcohol), polyvinylpyrrolidone, poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate), poly(1-vinylpyrrolidone-co-vinyl acetate), and combinations thereof; sugars (monosaccharides, polysaccharides, and branched polysaccharides); cellulose and cellulose derivatives; minerals and salts thereof; etc.). Some such embodiments include a binder adapted to bind the luciferin to a substrate material. Some excipients are inert in the chemiluminescence reaction but provide additional benefits. Such additional benefits include, for example, an effect on the solubility of a given component of the chemiluminescent system in various aqueous and non-aqueous solvent systems, an effect on the availability of water in absorbent articles, a retention effect on various substrates (e.g., binder) for one or both components of the chemiluminescent system, a release effect (e.g., porous transport agent) for one or both components of the chemiluminescent system, etc. Some such excipients may have multiple functions, such as these or others.

[0082] Described here are some non-limiting examples within the scope of this disclosure. In a first example, an excipient is selected for its ability to affect the availability of water within an absorbent article. Varying the relative amount of superabsorbent material (e.g., SAP) within the diaper structure affects the amount of free water available to activate the chemiluminescent system by combining the two components (i.e., luciferase and luciferin) or to initiate a reaction in an aqueous environment. SAP binds water, with less SAP allowing for more free water and earlier peak photon production in an absorbent article without SAP, staggered peak photon production at 12-24 wt% SAP, or later peak photon production at 36 wt% SAP (see Figures 14A and 14B; note that the chemiluminescent system components and all other variables remain constant). In a second example, an excipient may be selected for its ability to modulate the effect of the binder excipient when exposed to an aqueous system, thereby releasing one or more components of the chemiluminescent system for reaction within the absorbent article. Varying the amount or type of such porous transport agent excipient within the diaper structure affects the availability of the bound component(s). In diapers in which luciferin (coelenterazine) is placed on an absorbent core tissue wrap, the inclusion of hydroxypropyl-β-cyclodextrin (see Figures 15A and 15B; "HPBC") in the application formulation reduces the availability of luciferin to react with luciferase (Gaussia) placed in the core fluff pulp, thereby delaying peak generation and allowing for longer-lasting photon generation (right shoulder on the plot). Hydroxypropyl-β-cyclodextrin also aids in the solubility of coelenterazine in aqueous solutions for application to the tissue core wrap structure. However, the inclusion of poly(1-vinylpyrrolidone-co-vinyl acetate) (see Figure 15A; "PVPA") in the coating formulation provides robust availability of luciferin, as shown by a bright initial response after excretion with an aqueous system, which weakens with each subsequent excretion due to a decrease in reactant. In a third example, an excipient may be selected for its ability to suppress the reaction conditions of the chemiluminescence system.Varying the amount and type of salt treatment of the absorbent material can affect the pH of the aqueous system that results after voiding in the absorbent article. By providing an unfavorable reaction environment upon addition of polyvalent minerals and / or their salts (see FIG. 16; aluminum and magnesium salts), the reaction is inhibited unless or until the pH conditions are changed over time (e.g., raised by the addition of a buffer component or urine output(s)).

[0083] The area of surface 304 being treated may have any desired size or shape. For example, in Figure 5A, surface 304 is shown having a treatment area 306 in the form of a longitudinal strip having a width of about 1 / 3 the width of a tissue sheet, such as may be applied by the methods disclosed herein, for example, by streaming a formulation onto a continuously moving sheet of tissue by a fixed nozzle in a tissue printing and / or production apparatus.

[0084] Some aspects of the treated tissue composition can be customized for its use, particularly the manner (or manners) in which the treated tissue composition is incorporated into an absorbent article. As noted above, embodiments in which the treated tissue composition includes one reactive component will typically be incorporated into an absorbent article along with other reactive components disposed elsewhere in the absorbent article—such as in another treatment material or layer—in an arrangement in which one reactive component will be transferred to the other reactive component upon receipt of fluid exudates by the absorbent article, such as when aqueous fluids of the exudates migrate from the topsheet toward (for example) the backsheet and thereby react to initiate a light-generating reaction.

[0085] In one example of such an absorbent article, other reactive components may be disposed within the absorbent material of the absorbent article. As mentioned above, in some diaper constructions, the absorbent core is placed within the diaper during production. It is an internal component. Thus, in one example use of a treated tissue composition, the absorbent material of the absorbent core (e.g., fluff pulp, synthetic fibers, SAP, etc.) may be encased or at least partially surrounded within the treated tissue composition. In such a configuration, fluid exudates will transfer a first reactive component from the absorbent core to a second reactive component, such as a second reactive component disposed within the treated tissue composition (or to the treated tissue composition or other location of the second reactive component from elsewhere), initiating chemiluminescence.

[0086] Accordingly, Figure 4D shows a cross section 200' of an example diaper 100 similar to that shown in Figure 4C, but featuring an absorbent core 112 disposed between the topsheet 102 and the backsheet 104. In the absorbent core 112, a treated tissue composition 300 is shown enveloping the absorbent material 110.

[0087] The treated tissue composition may be incorporated into absorbent articles in various ways other than those shown. For example, instead of (or in addition to) being used as a wrapping material for the absorbent core, a layer of the treated tissue composition may be placed in the diaper structure adjacent to or at least partially surrounding the absorbent core, such as to reduce the tendency of loose SAP particles to migrate from the absorbent core. In some embodiments of absorbent cores according to the present disclosure, the absorbent structure is at least partially surrounded by the treated tissue composition incorporating luciferin, and the absorbent structure incorporates luciferase. In other configurations, the treated tissue composition (e.g., one layer, or multiple layers, or discrete pieces) may be placed in the diaper upstream of where another component of a chemiluminescence system is located, as desired, so that fluid exudates migrating through the diaper encounter the treated tissue composition and transfer reactive components of the tissue sheet to the other components, where they react and exhibit chemiluminescence. In yet other variations, a treated tissue composition may be placed in the diaper downstream of another component so that the other component is transported to the treated tissue composition by fluid exudates. In some variations, the treated tissue composition is placed adjacent to or in close proximity to the backsheet, such as to optimize chemiluminescence visibility. While the typical path of fluid exudates in absorbent articles is from the topsheet to the backsheet, this is not necessarily the case (e.g., fluid exudates may proceed laterally through the diaper structure). Thus, the terms "upstream" and "downstream" are used herein for convenience and do not require or imply a particular direction of flow relative to the absorbent article.

[0088] Thus, the treated tissue sheet 302 may have any suitable dimensions. A standard baby diaper, discussed herein as a useful reference for size, is approximately 235 mm wide and approximately 350 mm long. However, while some dimensional aspects of the materials and structural elements disclosed herein are discussed with reference to a standard baby diaper, it will be understood that such reference is not a limitation to such dimensional aspects, but is provided only as an illustrative, non-exclusive example of an absorbent article. Furthermore, while reference is made to standard baby diaper sizes, baby diaper sizes and dimensions vary considerably, and such ranges vary to some extent between different manufacturers. Also, other absorbent articles within the scope of the present disclosure may be larger than baby diapers (e.g., adult incontinence products, pet pads, bed pads), smaller than baby diapers (e.g., feminine hygiene products), have different dimensional aspects, etc. Thus, while some embodiments of the treated tissue sheet 302 (and other treated materials) are discussed as having particular dimensional ranges, such ranges are provided only as non-limiting examples.

[0089] Thus, in some embodiments suitable for use with standard size diapers, the width of the treated tissue sheet may range from 0.1 mm to about 235 mm. The width of the treated tissue sheet may range from about 0.1 mm to about 2 mm, from about 1 mm to about 10 mm, from about 1 mm to about 25 mm, from about 5 mm to about 50 mm, from 5 mm to about 100 mm, from about 25 mm to about 150 mm, from about 50 mm to about 200 mm, from about 50 mm to about 235 mm, or any range within any of these ranges, and all other possible subranges. Of course, this may be wider or narrower depending on the configuration of the tissue sheet, if used in a diaper, or wrapping. The length may also be as desired, such as the length needed to form a wrapping for an absorbent core, or up to the length of the absorbent article if a layer of treated tissue composition is used.

[0090] Also, although typically thin and flexible, the treated tissue sheet 302 may be of any suitable thickness or basis weight. For example, in some embodiments, the tissue sheet has a basis weight of 10 to 1500 g / m 2 (also expressed as "gsm"). In one embodiment, the tissue sheet has a basis weight of about 10 g / m 2 ~about 50g / m 2 , about 25g / m 2 ~about 100g / m 2 , about 50g / m 2 ~about 250g / m 2 , about 100g / m 2 ~about 500g / m 2 , about 250g / m 2 ~About 1000g / m 2 , about 500g / m 2 ~About 1500g / m 2 or within any range within any of these ranges, and all other possible sub-ranges.

[0091] The treated tissue composition 300 may incorporate a wide range of concentrations of the component(s) of the chemiluminescent composition, with the appropriate concentration determined by factors such as the surface area of the tissue sheet being treated with the reactive component, the portion of the treated surface area expected to be exposed to fluid exudates, the desired intensity and / or duration of light, the nature of the other reactive component(s) of the chemiluminescent system incorporated or to be incorporated into the diaper, etc. Following the principles and concepts disclosed herein, one skilled in the art will be able to determine the appropriate combination of factors for any absorbent article configuration with only reasonable experimentation. In some embodiments where the reactive component is coelenterazine, which is luciferin, the treated tissue composition may comprise 0.00002 to 20 weight percent coelenterazine, based on a standard diaper size having a 235 mm wide tissue sheet as the core wrapping, where the tissue sheet has a mass of 1.32 grams. For example, in one such embodiment, the treated tissue composition comprises 1 to 6 weight percent coelenterazine. In one embodiment, the treated tissue composition comprises 0.00002 to 0.01 weight percent coelenterazine. In one embodiment, the treated tissue composition comprises 10 to 20 weight percent coelenterazine. In one embodiment, the treated tissue composition comprises 0.01 to 2 weight percent coelenterazine. In one embodiment, the treated tissue composition comprises 2 to 10 weight percent coelenterazine.

[0092] The concentration of the component(s) in the treated tissue composition 300 is not particularly limited, other than by the volume of the tissue sheet. In general, it is usually economically preferable to use only that amount of component needed to generate the desired intensity or duration of chemiluminescence. However, the present disclosure is not so limited, as it may be desirable to incorporate larger amounts of one or more components, such as to ensure sufficient amounts are reactive even after extended storage. Another way to express the concentration range of the reactive component(s) of the chemiluminescence system on the tissue sheet is in terms of weight or mass of component per surface area of the tissue sheet. Typically, tissue sheets are produced as continuous rolls, usually with widths ranging from about 0.1 mm to the width of a standard diaper (about 235 mm), or even larger widths for larger diapers and incontinence products, that are cut to standard lengths, such as 30.48 cm (12 inches) long. In embodiments where the reactive component is coelenterazine, which is luciferin, the treated tissue composition has a weight of coelenterazine per 12 inches of length that is less than or equal to the weight of an untreated 12 inch length of tissue sheet, of 0.01 mg to 12 inches of length. In another embodiment where the reactive component is coelenterazine that is luciferin, the treated tissue composition may comprise up to 0.1 to 100 mg of coelenterazine per 12 inches of length, where the weight of coelenterazine per 12 inches of length is less than or equal to the weight of an untreated 12 inch tissue sheet.

[0093] The tissue sheet 302 may be of any suitable construction or composition. In one variation, the tissue sheet is composed entirely of cellulosic fibers. In another variation, the tissue sheet includes synthetic fibers.

[0094] Additionally, although the treated area 306 on the surface 304 is shown as a longitudinal strip, the treated area (or areas) may have any desired shape and dimensions, such as a desired pattern, and the chemiluminescence may therefore take the form of such a pattern. For example, the treated area may be in the form of a strip running perpendicular or perpendicular to the longitudinal direction of the tissue sheet. The strip may be continuous or discontinuous (such as a dotted or dashed line), straight or curved, or may include curved and / or straight portions. The treated area may be in the form of one or more shapes, or other shapes, etc.

[0095] Additionally, the total treated surface area may be of any size relative to the surface area of the tissue sheet, such as from about 0.003 to 100% of the area of the tissue sheet, with a lower limit of a single dot of sufficient density to react and produce light, and an upper limit of about 0.003 to 100% of the area of the tissue sheet that will completely cover the tissue sheet surface. In this regard, the treated area may be anywhere from 1 to 99% of the area of the surface, e.g., 1-2%, 1-10%, 5-20%, 1-25%, 10-50%, 20-90%, or any range within any of these ranges, and all other possible subranges.

[0096] 5A as having only one treated surface 304, the disclosure is not so limited, as the opposing surface may also be treated with the same or a different composition, etc. Furthermore, surface 304 may be treated with both compositions, such as in non-overlapping areas, in some embodiments.

[0097] While the treated tissue composition 300 is shown in FIG. 5A as a single ply of treated tissue sheet 302, the disclosure is not so limited, as the treated tissue composition may incorporate multiple layers, for example, a multi-layer structure in which one layer is a treated tissue sheet. FIG. 5B shows an example embodiment of a treated tissue composition 300′ shown comprising two tissue sheets 302a, 302b that have been treated with different components of a chemiluminescent system so as to initiate a light-generating reaction when the treated tissue composition is contacted by liquid waste (similar effect to embodiments in which a single tissue sheet is treated with more than one reactive component). In variations on this configuration, multiple plies of tissue sheet may each be treated with the same or different components of the chemiluminescent system. FIG. 5C shows another example embodiment of a treated tissue composition 300″ in which a treated tissue sheet 302 is sandwiched between two layers 308, 310 of liquid-permeable material, such as untreated plies of tissue sheet. Multi-layer embodiments may be incorporated into absorbent articles according to the principles discussed above.

[0098] In some embodiments, the overlapping areas on surface 302 may be treated by applying one or both components in a substantially non-aqueous combination. Non-limiting examples of such embodiments include:

[0099] One of the components in the aqueous-based solution is applied to the surface 302 to form the first treatment area 30 forming 6a, allowing the solution to substantially dry (i.e., insufficient water to consume more than 5% of one or both components in the treated area in a chemiluminescence reaction without adding more water), and applying the other of the components onto surface 302 in any manner without water to form second treated area 306b (see FIG. 5D); applying one of the components in a non-aqueous solvent-based solution onto the surface 302 to form a first treated area 306c, allowing the solution to substantially dry, and applying the other of the components onto the surface 302 in a manner that limits the availability of water (i.e., by fast drying or a non-aqueous solvent system) to form a second treated area 306d (see FIG. 5E); and Applying both components in a non-aqueous solvent-based solution onto surface 302 to create a single treated area 306e (see FIG. 5F).

[0100] The treated areas 306a-d may be of any desired dimensions, and the dimensions need not match (as shown in FIGS. 5D and 5E). Rather, in some embodiments, the first treated area 306f may have a larger dimension than the second treated area 306g (see FIG. 5G). One and / or the other components of the chemiluminescent system may comprise a coating material that forms the first treated area 306f and the second treated area 306g. The first treated area 306f and the second treated area 306g may fully overlap (as shown in FIG. 5G for the second treated area 306g), partially overlap (not shown), or may be in any other pattern. Furthermore, in some embodiments, one and / or the other components of the chemiluminescent system may be included in different absorbent article structural elements 300''' (e.g., when the structural element 300''' is a fluff pulp core and the structural element 300 is a tissue sheet). Depending on the application method for treating the chemiluminescent component(s), any structural element within the absorbent article may be realized as structural element 300 and structural element 300'''. Note that Figures 5D-5G are shown in two-dimensional cross-sectional schematic views.

[0101] Optionally, treated tissue compositions according to the present disclosure may include other additive materials as described elsewhere herein, such as photoluminescent compounds, pH buffers, porosity transport agents, and the like. Indicator particles In another embodiment of a treatment material according to the present disclosure, an indicator particle is provided. Figure 6A shows an example of such a particle 400, which is formed from hydrogen-bonded cellulose pulp fibers and incorporates at least one component of a chemiluminescence system selected from luciferin and luciferase, held on the fibers. The component may be disposed on one or more surfaces 402 of the particle and / or on the fibers throughout the particle. In some embodiments, the component is a luciferin selected from coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, furimazine, and combinations thereof. For example, in some such embodiments, the component is coelenterazine. In some embodiments, the component is a luciferase selected from Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase. For example, in some such embodiments, the component is Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase. In some embodiments, the indicator particle incorporates both a luciferin and a luciferase such that a light-producing reaction is initiated when the indicator particle is contacted by liquid waste. For example, in some such embodiments, the luciferin is coelenterazine and the luciferase is Gaussia luciferase. As another example, in some such embodiments, the luciferin is coelenterazine and the luciferase is Renilla luciferase. As yet another example, in some such embodiments, the luciferin is coelenterazine and the luciferase is Metridia luciferase.

[0102] Although not required, a binder may optionally be used to help retain the chemiluminescent component on the indicator particles, such as on the fibers of the indicator particles. As noted above, when the component is luciferin, suitable binders may include ethyl cellulose, methyl cellulose, nitrocellulose, polyurethane, and the like, as well as various combinations thereof. Thus, in some embodiments, the components of the chemiluminescent system are retained on the surface of the tissue sheet by a suitable binder.

[0103] Although not required, a porous transport agent may be incorporated into the indicator particles. It has been found that some porous media function to facilitate mass transport of reactive component(s) and / or aqueous systems in some applications, such as applications in which the reactive component is located on the indicator particles, on other treatment materials, or in a separate location within an absorbent article. For example, in the case of coelenterazine, a luciferin that may exhibit low water solubility, the greater the surface area treated with coelenterazine, the more accessible the reactant becomes to luciferase. Porous media can provide a larger surface area than non-porous and low-porosity materials. Furthermore, hydrophilic porous materials can also facilitate water transport to the reaction site for the light-generating reaction.

[0104] Unexpectedly, it has been found that porous transport agents provide benefits in some embodiments in which binders are used. As discussed above, some binders function by forming a coating or film over the surface of a substrate material, retaining the chemiluminescent component to the material, but also resisting penetration by an aqueous system that solubilizes and / or releases the chemiluminescent component for transport to the site of chemiluminescence. This may manifest, for example, as a delay in the visibility of chemiluminescence after ingestion into the absorbent article, lower chemiluminescence intensity upon ingestion, such as the first ingestion, etc. However, in some such embodiments, the presence of a porous transport agent has been found to hasten or facilitate material transport by improving the aforementioned effects of some binders. That is, functionally speaking, porous transport agents have been found in some embodiments to provide benefits similar to those of release agents such as PVPA and HPBC.

[0105] Porous and hydrophilic media have been found to be generally suitable for use as porous transport agents. A non-exclusive list of porous transport agents suitable for such use includes starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers. Due to their ability to promote mass transport, some embodiments may include porous transport agents even in the absence of a binder.

[0106] Within the aforementioned parameters, the indicator particles may have any desired size, shape, and / or morphology. The particles may be produced by cutting or splitting a sheet of cellulose pulp, in which case the thickness and basis weight of the particle may be that of the sheet from which the particle is cut. For example, a Henion dicer may be used to dice a sheet of cellulose pulp into generally hexagonal particles such as those shown in FIG. 6A , which have two opposing surfaces 402, a thickness of approximately 1 mm, four sides 404 that are approximately 2 mm long, and two sides 406 that are approximately 3 mm long. Due to the splitting method used, some variation in shape and / or dimensions may exist.

[0107] FIG. 6B shows another example indicator particle 400' in the form of an elongated strip that is 1 mm thick, about 2 mm wide, and about 350 mm long. As will be explained below, the indicator The various forms of the particles can be customized to suit their expected use in absorbent articles and desired length (and other physical dimensions).

[0108] 6A and 6B are exemplary in nature. Thus, particles 400, 400′ are shown as having, for example, flat, planar sides and straight edges. Particles having these morphologies can include and exhibit various irregularities as a result of the material from which the particles are produced, the production method, etc. For example, particles 400 and 400′ may exhibit some twists and / or kinks and / or may appear worn along their edges, etc.

[0109] For convenience, the two main forms of indicator particles discussed herein can be distinguished by their aspect ratio, i.e., the ratio of the particle's length to its width. Particles having an aspect ratio of less than about 1.5, such as indicator particle 400 in FIG. 6A, are referred to herein as "flakes," while particles having an aspect ratio of about 1.5 or greater, such as indicator particle 400' in FIG. 6B, are referred to herein as "strips." This distinction can be useful in some applications, for example, when a particular particle shape is preferred over another, although the principles of use are generally otherwise the same. In some embodiments, a flake, as in particle 400, will have a width greater than its thickness and a length greater than its width. Particle 400 has two opposing faces, each of which has an area (e.g., the product of its length and width) of about 14 mm in the illustrated example. 2 For example, in some embodiments, the area of such particles is less than 0.1 mm 2 ~300mm 2In some embodiments, the area of such particles ranges between 1 mm 2 ~10mm 2 In some embodiments, the area of such particles ranges between 8 mm 2 ~30mm 2 In some embodiments, the area of such particles ranges between 30 mm 2 ~150mm 2 In some embodiments, the area of such particles ranges between 50 mm 2 ~150mm 2 In some embodiments, the area of such particles ranges between 100 mm 2 ~300mm 2 Similarly, the shape of the flakes may vary from that shown in FIG. 6A. For example, the shape may be square, circular, regular or irregular polygonal, etc. The dimensions and shape of the strips may vary as well. For example, the width of particle 400' (strip) is 2 mm in the example shown, but in some embodiments varies from about 0.5 mm to 2.5 mm. The thickness is 1 mm, but in some embodiments varies from about 0.05 mm to 2.0 mm. The cross section may be about 2 mm. 2 However, in some embodiments, it is about 0.01 mm 2 ~200mm 2 The length can also vary from about 1 mm to about 800 mm. 350 mm is roughly the standard diaper length, although longer lengths up to and even exceeding 800 mm (e.g., for larger diapers and adult incontinence products) may be used. Also, while the cross-sectional dimension is shown as being constant along the length of strip 400', the strip may include a non-constant cross-section along its length, as well as kinks or twists.

[0110] Any suitable dividing method may be used depending on the desired size and shape. Any suitable material incorporating hydrogen-bonded cellulose pulp fibers may be used. For example, a pulp sheet having a basis weight ranging from 10 to 850 gsm may be used. In some embodiments, the material also incorporates synthetic fibers having a fiber diameter ranging from 1 micron to 100 microns.

[0111] Somewhat similar to the treated tissue compositions according to the present disclosure, some embodiments of indicator particles can be customized for their use, specifically the manner(s) in which they are incorporated into absorbent articles. An example use of particle 400 (flakes) is shown in Figure 4E, which is similar to that shown in Figures 4C and 4D, but in which the particle 400 is incorporated into an absorbent article. 1 shows a cross section 200" of an example diaper 100 featuring a plurality of flakes 400 arranged in a single layer between the absorbent material 110 and the backsheet 104, where the absorbent material 110 is shown disposed between the backsheet 104 and the topsheet 102. A similar example embodiment (not shown) uses one or more of the particles 400' (strips) placed parallel to the length of the diaper in a single layer between the absorbent material 110 and the backsheet 104. In yet another example embodiment, the plurality of flakes 400 are uniformly distributed throughout the absorbent material 110.

[0112] Like the treated tissue composition, the indicator particle (or multiple indicator particles) can be incorporated into the absorbent article in various ways other than those shown. For example, the indicator particle can be placed in other locations in the diaper, such as in another layer or location between the topsheet and the backsheet, depending on, for example, whether the particle incorporates luciferin, luciferase, or both; the desired location in the diaper for the chemiluminescent reaction to occur upon excretion (for example, whether the chemiluminescent component(s) incorporated in the particle are transported to a different location by fluid excretion, or whether another chemiluminescent component is transported to the particle); the desired intensity of the chemiluminescence; the desired shape of the chemiluminescent area (for example, a strip, or multiple strips, can show chemiluminescence as corresponding glowing stripes), etc. The flake form of the particle can be useful not only as a substrate material for the chemiluminescent component, but also in terms of absorption function. For example, as disclosed in U.S. Patent No. 9,617,687, pseudoprismatic pulp particles can be used as or in an ADL for diapers. Patent No. '687 explains that when such particles are distributed as a layer within the ADL, they can maintain space between the ADL's topsheet and its storage layer, with the interstices and void spaces between adjacent particles forming channels through which fluid can flow to the storage layer. In a somewhat similar manner, flakes 400 can be incorporated into ADLs for absorbent articles, while also providing one or more components of a chemiluminescent system.

[0113] The indicator particles 400 may incorporate a wide range of concentrations of the component(s) of the chemiluminescent composition, with the suitable concentration determined by the factors discussed above with respect to the treated tissue composition 300.

[0114] In one embodiment of particle 400 (flake), the reactive component is coelenterazine, a luciferin, and the particle comprises a concentration of the component less than 0.50 weight percent. In one embodiment of particle 400, the reactive component is Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase, and the particle comprises a concentration of the component less than 0.01 total weight percent. In one embodiment of particle 400' (strip), the reactive component is coelenterazine, a luciferin, and the particle comprises a concentration of the component less than 0.50 weight percent. In one embodiment of particle 400', the reactive component is Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase, and the particle comprises a concentration of the component less than 0.01 total weight percent. However, in either (or any other) form, the indicator particles may contain 0.00002 to 20.0 weight percent coelenterazine and / or 0.003 to 10.0 weight percent Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase, and / or a suitable amount of one or more luciferins and / or luciferases. Some sample weight percent ranges for coelenterazine in such particles include 0.00002 to 0.01, 0.01 to 0.20, 0.20 to 5.0, and 5.0 to 20, or any range within any of these ranges, and all other possible subranges. The Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase in such particles may be present in a range of 0.00002 to 0.01, 0.01 to 0.20, 0.20 to 5.0, and 5.0 to 20, or any range within any of these ranges, and all other possible subranges. Some sample weight percents of luciferase, and / or Metridia luciferase, total amount include 0.0003-0.001, 0.001-0.1, 0.1-2.0, and 2.0-10, or any range within any of these ranges, and all other possible subranges.

[0115] The concentration or amount of the component(s) in the indicator particle is not particularly limited other than by the volume of the particle itself. In general, it is usually economically preferable to use only the amount of component(s) required to generate the desired intensity or duration of chemiluminescence. However, the present disclosure is not so limited, as it may be desirable to incorporate larger amounts of one or more components, such as to ensure sufficient amounts remain reactive even after extended storage. Another way to express the range of concentration or amount of the reactive component(s) of the chemiluminescence system on the indicator particle is by the total amount of the component(s) used in the absorbent article. In one embodiment, an absorbent article (in the form of a diaper) includes a plurality of approximately 65 particles of similar size and dimensions to particle 400, or particles with a total weight of approximately 0.7 g, collectively containing approximately 1.0 mg of coelenterazine and approximately 0.25 mg of Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase. In other variations, the multiple indicator particles used in the absorbent article may collectively contain a total amount of coelenterazine in the range of 0.0001 to 20.0 mg and / or a total amount of Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase in the range of 0.00003 to 20.0 mg. In other variations, the plurality of indicator particles used in the absorbent article may collectively contain a total amount of coelenterazine in the range of 0.0001 to 20.0 mg, 0.001 to 20.0 mg, 0.01 to 20.0 mg, 0.1 to 20.0 mg, or 1 to 20.0 mg, and / or a total amount of Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase in the range of 0.00003 to 20.0 mg, 0.0003 to 20.0 mg, 0.003 to 20.0 mg, 0.03 to 20.0 mg, or 0.3 to 20.0 mg.

[0116] While the absorbent articles discussed above incorporate a plurality of similarly configured indicator particles, the disclosure is not so limited, as variations of absorbent articles according to the present disclosure may include a plurality of particles that are not all similarly configured, such as an absorbent article including particles of two or more different forms, sizes, or shapes, and / or particles that separately incorporate different components of a chemiluminescence system, for example, a first plurality of particles that incorporate luciferin and a second plurality that incorporate luciferase.

[0117] It will be apparent that multiple treatment materials and / or multiple types of treatment materials, such as the treated tissue compositions and indicator particles described above, may be incorporated into an absorbent article. For example, one component of a chemiluminescence system may be provided by a treated tissue composition and another component may be provided by indicator particles and disposed in a diaper such that upon discharge into the diaper by an aqueous system, one component is transferred to the other component, initiating a chemiluminescence-producing reaction between the components.

[0118] One illustrative example of such a configuration is shown in Figure 4F, which shows a cross section 200''' of a diaper 100 similar to that shown in Figures 4C-4E, but featuring an absorbent core 112 disposed between the topsheet 102 and the backsheet 104, with the absorbent core formed from absorbent material 110 encased in a treated tissue composition 300. This example also shows a layer of particles 400 (flakes) arranged in a single layer between the absorbent core 112 and the backsheet 104. During use, fluid exudates, which generally travel from the topsheet 102 toward the backsheet 104, encounter the treated tissue composition 300 and migrate toward the backsheet, where they are immersed in the chemiluminescent component disposed on the treated tissue composition. to transfer the reactive component to the particle 400, initiating the chemiluminescence reaction when it reaches the particle 400. In variations of such a configuration, one or more of the structural elements (i.e., the tissue sheet and the indicator particle) may include more than one reactive component to more reliably ensure that transfer of one reactive component to the other occurs under various conditions, initiating chemiluminescence, etc.

[0119] Optionally, indicator particles according to the present disclosure may include other additive materials, such as releasing agents, photoluminescent compounds, pH buffers, etc., as described elsewhere herein. Treated absorbent core As mentioned above, advances in SAP technology have enabled the design of absorbent core configurations in which fluff pulp contributes less to the core's absorbent capacity and more to providing a fibrous structure for fluid distribution and / or to stably hold the SAP in place. These functions may, in some cases, be provided by synthetic fibers, leading to the development of absorbent cores that partially or even completely replace historically used natural (e.g., cellulose) fibers. Accordingly, in another embodiment of a treatment material according to the present disclosure, an article is provided that includes synthetic fibers and at least one of luciferin and luciferase. In some embodiments, the synthetic fibers form a nonwoven absorbent matrix, and thus the article may be suitable for use in or as an absorbent core (such as a fluffless absorbent core) for an absorbent article.

[0120] 7 shows an example embodiment of such an article 500 in the form of an absorbent core 502. As shown in a partial cutaway view, the absorbent core 502 includes synthetic fibers 504 arranged to form an absorbent matrix and sandwiched between two sheets of material 506, 508, thereby forming an integral component suitable for incorporation into an absorbent article. The two sheets may be of the same or different materials, but will typically be fluid-permeable materials such as nonwoven webs or sheets, such as tissue sheets. In some embodiments, one of the sheets 506, 508 will be a liquid-permeable topsheet, and the other will be a liquid-impermeable backsheet, or the like.

[0121] A wide variety of synthetic fibers may be used. For example, synthetic fibers may include fibers composed of one or more of polypropylene or other thermoplastic polymers, bicomponent fibers, elastomeric polymer fibers, and mixtures thereof. Some example synthetic fiber materials suitable for use are disclosed in U.S. Patent Application Publication No. 2007 / 0142803 to Soerens et al., the complete disclosure of which is incorporated herein by reference. Some embodiments additionally include natural fibers (e.g., cellulose fibers) along with synthetic fibers, for example, in the same fibrous matrix or in a blend of two types of fibers arranged separately, such as in discrete layers or sections. In some embodiments, such as within a fluffless core, the fibers are entirely synthetic.

[0122] Article 500 incorporates at least one component of a chemiluminescence system selected from luciferin and luciferase. In the form of absorbent core 502, the chemiluminescent component may be disposed on the surface of one or both sheets 506, 508, on and / or between the synthetic fibers, or on SAP particles that may be incorporated into one or both sheets 506, 508 or distributed throughout the synthetic fibers. Absorbent core 502 may include additional structural elements, such as a distribution layer disposed between one of sheets 506, 508 and synthetic fibers 504, the distribution layer including the chemiluminescent component disposed on or within such layer. In some embodiments of article 500, the chemiluminescent component is a luciferin selected from coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, furimazine, and combinations thereof. For example, in some such embodiments, the component is coelenterazine. In some embodiments, the chemiluminescent component is a luciferase selected from Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase. For example, in some such embodiments, the component is Gaussia luciferase. For example, in some such embodiments, the component is Renilla luciferase. For example, in some such embodiments, the component is Metridia luciferase. In some embodiments, the article incorporates both luciferin and luciferase such that a light-generating reaction is initiated when the article is contacted by liquid excrement. For example, in some such embodiments, the luciferin is coelenterazine and the luciferase is Gaussia luciferase, Renilla luciferase, or Metridia luciferase, and combinations thereof. In one embodiment taking the form of an absorbent core as shown in Figure 7, the luciferin and luciferase are disposed in different locations on the absorbent core or within different materials of the absorbent core, such as with luciferin disposed on the surface of the synthetic fibers and luciferase distributed throughout the synthetic fibers. In another such embodiment, the luciferase is distributed throughout the synthetic fibers and the luciferin is disposed on or incorporated within one or both of sheets 506, 508. The concentration and / or amount of chemiluminescent component(s) incorporated into article 500 is not particularly limited and may be consistent with those described with respect to other treatment materials herein, such as per diaper.

[0123] Optionally, articles (such as absorbent cores) according to the present disclosure may include other additive materials as described elsewhere herein, such as photoluminescent compounds, pH buffers, binders, porosity transport agents, release agents, and the like. Encapsulation Chemistry In some variations of the embodiments of the treatment materials discussed above, a composition includes at least one component of a chemiluminescence system as an encapsulated particle. That is, in such embodiments, particles containing one component of a chemiluminescence system (such as particles of one or more materials treated with the chemiluminescence component and / or the chemiluminescence component itself in particulate form) each have a coating covering the entire surface of the particle, and the coating is water-soluble and / or water-permeable. In a non-limiting illustrative example, luciferase in particulate form (such as a powder or other pulverized form) is encapsulated, for example, as a water-soluble capsule and / or microcapsule in a coating material such as sugars and polysaccharides (e.g., starch, dextrin, etc.), gums, water-soluble polymers (e.g., PVOH), gelatin and other amino acid- or protein-based materials, superabsorbent materials, porous media, etc. In another non-limiting illustrative example, luciferin-treated particles, such as the aforementioned dice, or even smaller particles of treated substrate material, are encapsulated, for example, using one or more of the aforementioned coating materials. In compositions according to the present disclosure, the encapsulated particles collectively comprise a predetermined amount of a first chemiluminescent component and further comprise a predetermined amount of a second chemiluminescent component, such that the predetermined amount of each component is sufficient to generate light of a desired intensity in the presence of an aqueous system. In some such compositions, both the first and second chemiluminescent components are encapsulated, e.g., separately encapsulated. Encapsulation of one or both chemiluminescent components can provide chemical stability and / or longevity in some applications and / or can provide ease of handling when incorporating the component(s) into absorbent articles and the like. In some embodiments, such compositions may allow end users to incorporate the chemiluminescent system into standard absorbent articles and the like.

[0124] Such compositions of partially or fully encapsulated chemiluminescent systems may be incorporated into absorbent articles in various ways, such as dispersing the encapsulated component in an absorbent material such as a fibrous matrix, with other chemiluminescent components disposed elsewhere in the absorbent article, such as in or on a treatment material or structural element, according to other embodiments discussed herein, in a similar manner where, for example, particulate SAP is dispersed in a fibrous matrix. In two-component chemiluminescent systems where both components are encapsulated, both may be dispersed throughout the same fibrous matrix, etc. Other processing materials Consistent with the concepts and principles discussed above and elsewhere herein, other treated materials and structural elements are within the scope of the present disclosure. For example, in some embodiments, a poly backsheet is treated with one or more chemiluminescent components in a manner conceptually similar to the treated tissue compositions discussed above. In some embodiments, a fluid-permeable material may be treated with one or more chemiluminescent components to produce a carrier substrate for component(s) for inclusion in an absorbent article during production, such as in a manner that incorporates the inclusion of a treated carrier substrate in a standard production process for absorbent articles.

[0125] The manner in which a chemiluminescent system is disposed in or on such treatment materials and / or structural elements may take into account factors such as, for example, the nature of the intended use of the absorbent article incorporating the treatment material or element, the application technique used, user safety, efficient and / or economical manufacturing principles, etc.

[0126] 9A-9J show different example embodiments (not shown in full outline) of representative structural elements suitable for incorporation into absorbent articles. Each shows a simplified, somewhat schematic, top view of one embodiment of structural element 900. While structural element 900 itself is shown as a rectangle and is described in the form of an absorbent core of suitable size and dimensions, the following description applies to materials and / or other structural elements that may be incorporated into absorbent articles, such as topsheets, backsheets, tissue sheets, treatment layers of liquid-permeable material, etc., which may have other shapes / dimensions or may be similar to those shown.

[0127] Structural element 900 includes a first surface 902, which includes a treated area 904, which has been treated with at least one component of a chemiluminescent system adapted to react in the presence of an aqueous system to produce light. The treated area need not necessarily be visually distinguishable from the remaining untreated portion(s) of the first surface, but is shown as such for purposes of illustration. The treated area may be generated in any manner disclosed herein, such as by application of at least one component to the surface by printing, streaming, etc.

[0128] The treated area may have any desired configuration. For example, the treated area may cover all, a portion, or a portion of the surface. However, in many applications, certain areas of the surface may not correspond to the target area where fluid excretion is expected, so a significant portion of the surface may not be utilized. Also, because many absorbent articles transport fluid received from excretion, it may not be necessary to treat the entire area corresponding to the target area to trigger the light-generating reaction, because it can be expected that the fluid front from excretion can wick toward the treated area and then encounter the treated area.

[0129] Thus, the treatment area may be sized and shaped to provide the desired effect during use while reducing the amount of chemiluminescent material(s) used. The example embodiment shown in Figure 9A shows the treatment area 904 as a continuous shape, specifically in the form of a strip 906 that runs the length of the element 900. Because the width of the strip is significantly narrower than the width of the surface 902, such a configuration is less costly than a configuration in which the entire surface 902 is treated. , which can result in corresponding cost savings. In a variation of this example configuration, a first chemiluminescent material (i.e., a component such as either luciferin and / or luciferase) is applied to surface 902 within strip 906, and a second chemiluminescent material (i.e., a component such as the other or both of luciferin or luciferase) is applied to the entire surface 902, to another area of surface 902 (not shown), to the material comprising structural element 900, or to another structural element (not shown). FIG. 9B shows another example embodiment in which treatment area 904 is shown as a pattern of discrete portions, specifically as a discontinuous strip 908 spanning a portion of the length of element 900. A discontinuous strip having the same width as a continuous strip may require relatively less chemiluminescent material, and even less chemiluminescent material may be required if the overall length of the strip is shorter. In such an example, the arrangement of a first chemiluminescent material (i.e., a component such as either luciferin and / or luciferase) may be applied to surface 902 in discontinuous strips 908, and a second chemiluminescent material (i.e., a component such as the other or both of luciferin or luciferase) may be applied to the entire surface 902, to another area of surface 902 (not shown), to the material that makes up structural element 900, to another structural element (not shown). In some embodiments, such as that shown in FIG. 9B, the luciferin component and the luciferase component may be applied together or separately in the same discrete portion of a non-continuous strip 908 and in the same treatment area 904, or may be applied individually so that adjacent discrete portions have different components, with or without all of the material of the surface 902 or another structure being treated with at least one chemiluminescent material (i.e., a component such as either luciferin and / or luciferase).

[0130] 9A and 9B, the treatment area is much smaller than the area of the surface. Moreover, in FIG. 9B, the treatment area is proportionally smaller than the treatment area of FIG. 9A. In these and the following embodiments, the treatment area may optionally be configured to cover a total area that is smaller than the area of the first surface. For example, the treatment area may be any of 1-99% of the area of the surface, such as 1-2%, 1-10%, 5-20%, 1-25%, 10-50%, 20-90%, or any range within any of these ranges, and all other possible subranges.

[0131] A treatment area consisting of a pattern of discrete portions may allow for covering a large portion of surface 902 while using less chemiluminescent material than complete, continuous treatment of an area of the same size. One example of such a configuration is shown in the example embodiment depicted in FIG. 9C , where treatment area 904 is in the form of an array of shapes—specifically, an array of star shapes 910—that extend across most of the area of surface 902 (as shown) or across only the target area of structural element 900 (not shown). Other shapes or patterns, including a mixture of different shapes and / or irregular patterns, may be utilized within treatment area 904. The number of individual shapes may be as desired, for example, to correspond to the amount of fluid suitable for triggering light generation. Individual chemiluminescent components may be disposed within shapes 910 as described above with respect to the discrete portions of FIG. 9B or as described above.

[0132] The configuration of the treatment area may take into account the nature and expected use of the absorbent article in which the structural element 900 is to be used. For example, in the case of a diaper or adult incontinence pad, these articles generally have limited movement relative to the wearer, so there are typically localized areas where fluid discharge may be expected during use. The diaper 100 shown in FIG. 4B illustrates this schematically with target areas 108. Thus, the treatment area of a structural element 900 suitable for a diaper 100 (e.g., as shown in FIG. 9A or 9B ) may correspond to the size and / or shape of the target area 108, or a portion thereof, or a portion of one or more structural elements that overlie or are positioned near the target area 108.

[0133] In some embodiments, a diaper or similar absorbent article may be configured to handle multiple insults (e.g., two or three sequential insults, or more than three sequential insults) before replacement is required, such as by incorporating an absorbent core of appropriate construction. Generally, fluid from an exudate spreads laterally outward from the initial point of insult through the absorbent core before being stored due to the wicking capabilities of the materials used in the absorbent core. Fluid fronts from subsequent insults then wick further away from the initial point of insult until they reach unused SAP within the absorbent core. Thus, the target area in such multiple-use configurations may be considered to include multiple generally annular concentric regions.

[0134] Thus, the array of treatment areas may be configured to indicate not only that the absorbent article has been used, but also the extent to which the absorbent article has been used, or not used. 9D, in which the surface 902 of one embodiment of a structural element 900 includes a target area 912, which corresponds to the area where one or more fluid discharges are expected during use of an absorbent article in which the structural element is incorporated. For simplicity, the target area 912 is shown to consist of three concentric regions (914, 916, 918), each corresponding to the area where the fluid front from three sequential discharges is expected to wick. The treatment area 904, in the form of a non-continuous strip, is shown to partially overlap the target area and further includes discrete portions or segments 920 corresponding to each of the three concentric regions.

[0135] Although the boundaries of the concentric regions will vary depending on the absorbent article design, intended user, etc., the treatment zone is configured so that the fluid front from successive insults first encounters the inner pair of segments 920 in the treatment zone, and then the outer pair of segments, and thus the resulting chemiluminescence pattern can visually indicate whether the diaper has been subjected to one, two, three, or even more insults.

[0136] 9D , where each portion of the treatment zone overlaps only a corresponding portion of the target area, different portions of the treatment zone 904 may be configured to produce visual light that differs from one another in at least one visual respect. For example, outer segments may be configured to produce light of a different (e.g., higher) intensity and / or a different color, duration, etc., compared to inner segments, such as by varying the chemistry applied to different portions of the treatment zone 904 in accordance with the methods disclosed herein (e.g., by using a photoluminescent compound, different concentrations of at least one chemiluminescent component, treatment coat weight, or buffers that affect the efficiency of the chemiluminescent reaction). For example, the rate and / or intensity of the chemiluminescent reaction can be manipulated by varying the concentration of at least one chemiluminescent component, such as luciferase or luciferin, within the treatment zone 904 or from treatment zone 904 to treatment zone 904 as you progress through the concentric regions. This arrangement allows for a high degree of precision in the amount and / or duration of light production visible to the caregiver, for example, early / fast onset (articles requiring immediate replacement), slower / later onset (articles designed for longer wear periods), shorter duration (articles more likely to be detected by the caregiver), and longer duration (articles more likely to be detected by the caregiver or to signal that full capacity has been reached). The difference in at least one chemiluminescent component per treated area can be, but is not limited to, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, and 1:99, or any range within any of these ranges, and all other possible subranges, from 1:1 to 1:100 and all ranges therebetween. Such variations can improve the properties of the luminescent indicator, which may allow the caregiver to more easily determine the condition of the absorbent article. Alternatively, in some embodiments, segments 920 may be disposed in only one or two concentric regions (e.g., only in region 918 (see FIG. 9H , which includes segment 934), or only in region 916 (see FIG. 91 , which includes segment 936), or in both regions 916 and 918) depending on the desired pattern of discharge / wetness indication. Similarly, individual chemiluminescent components may be disposed in segments 920, 934, and 936 as described above with respect to the discrete portions of FIG. 9B , the shape of FIG. 9C , or as described above.

[0137] Another configuration suitable for multiple-use absorbent articles is shown in Figure 9E, in which the surface 902 of one embodiment of a structural element 900 also includes a target area 912 having multiple concentric regions, but includes a treatment area 904 of two discrete portions 922, each shaped to have a surface area that increases with the expected wicking distance of the fluid front from multiple insults, thus allowing for increasingly larger areas of luminescence as the absorbent article undergoes successive insults. Unlike the configurations shown in Figures 9D, 9H, and 9I, the portions 922 are shown to overlap all of the multiple concentric regions and thus may be suitable for embodiments where the boundaries of the regions are not deterministic and / or predictable. Individual chemiluminescent components may be disposed within the discrete portions 922 as described above for the discrete portions of Figure 9B, the shape of Figure 9C, or as described above.

[0138] In some applications, it may be preferable to position the treatment area (or portions thereof) away from the target area where one or more fluid excretions are expected. For example, absorbent articles such as bed pads are designed to cover a large area rather than being worn. Positioning the treatment area away from the target area may reduce the likelihood that the user's body will block the chemiluminescent signal resulting from an excretion. Furthermore, positioning the treatment area near the edge of the absorbent article may also allow a caregiver to more easily determine whether an excretion has occurred on the bed pad, for example, by lifting an edge or corner of the bed cover and inspecting the treatment area. A configuration suitable for such situations is shown in FIG. 9F, in which one embodiment of a structural element 900 includes a treatment area 904 on a surface 902 that includes multiple discrete portions 924 that do not overlap the target area 926 but rather are positioned away from the target area 926. Individual chemiluminescent components may be disposed within the discrete portions 924 as described above for the discrete portions of FIG. 9B, the shape of FIG. 9C, or as described above.

[0139] In some applications, it may be difficult to predict the target area where fluid discharge may be expected. In the case of a bed pad or pet pad, the location of fluid discharge may vary depending on the relative position of the user, which may change during sleep, bed rest, or other use of the absorbent article, and therefore fluid discharge may occur anywhere in relation to the absorbent article. Therefore, a configuration featuring a pattern consisting of multiple discrete treated portions extending over a large area of the surface of the structural element 900 may be appropriate, for example, as shown in Figure 9C.

[0140] In any of the foregoing example embodiments, at least one component (also described herein as the chemiluminescent material, the first component, the component, etc.) may be luciferin or luciferase, according to the various species and concentration ranges detailed herein.

[0141] Alternatively, at least one component may be both luciferin and luciferase, in accordance with the application techniques disclosed herein for applying two reactive components of a chemiluminescence system to the same substrate material described above in alternative embodiments, such as to the same or overlapping portion(s) / surface(s) of the substrate material (see, e.g., Figures 5D, 5E, and 5G).

[0142] However, in some applications, both luciferin and luciferase are used as structural elements, However, it may be preferable to incorporate it to avoid the challenges of application to the same or overlapping portions of the substrate material.

[0143] As described in more detail below, various application techniques may be suitable for producing various example embodiments of the structural element 900 discussed herein. For example, a method for producing a structural element for incorporation into an absorbent article that has been treated with at least one component of a chemiluminescence system that reacts to generate light in the presence of an aqueous system may include applying a formulation to a predetermined area of a first surface of the structural element, the formulation including at least one component, the at least one component being selected from luciferin and luciferase. As mentioned above, the predetermined area may at least partially overlap one or more target areas where fluid discharge may be expected during use of an absorbent article in which the structural element is incorporated, as described above, and may take any form. Certain application techniques, for example, inkjet printing techniques such as continuous inkjet printing, may allow for increased speed and / or accuracy of application, which may allow for the construction of treated areas in which two or more reactive components are applied in close proximity to one another, including overlapping patterns. Thus, in some applications, a treatment zone may incorporate both luciferin and luciferase, such as in a configuration with components applied to non-overlapping portions of the treatment zone. A configuration illustrating such an arrangement is shown in FIG. 9G, in which an embodiment of a structural element 900 includes a treatment zone 904 on a surface 902 similar to that shown in FIG. 9E, but with discrete portions 928 each consisting of non-overlapping segments in which the two components are separately applied. By "non-overlapping," we mean that at least a shortest distance separates the two segments such that the chemiluminescent components disposed therein are not in fluid communication after application and before at least the first fluid discharge. More specifically, each discrete portion 928 includes two segments 930 that may be treated with one of the components, flanking a segment 932 that may be treated with the other of the components. In such a configuration, the treatment zone may overlap the target area (not shown for clarity).During use, in the presence of fluid excretion, one or both of the reactive components, when in "fluid communication" with the other or both, can be transported to the other as the fluid wicks, initiating a light-generating reaction.

[0144] In addition to limiting the treated area 928 of FIG. 9G (by way of example, but not limitation) to the area of the surface 902 expected to encounter fluid exudates at a given time, treating adjacent areas 930 and 932 with any of the individual components can enable significant raw material savings in many of the embodiments described herein by reducing or eliminating areas (such as the surface 902 of the structural element 900, materials within the absorbent core, or other structures within the article) that are extensively treated with at least one of the components. The pattern and / or shape of the adjacent treated areas is not limiting. A non-limiting example is shown in FIG. 9J with two adjacent, non-overlapping star-and-moon shapes on the surface 902 of the structural element 900. The inner star 940 includes a treated area containing one component of a chemiluminescence system (e.g., luciferin or luciferase). The outer star 942 includes the other component. Inner moon 941 includes a treated area containing one component of a chemiluminescence system (e.g., luciferin or luciferase). Outer moon 943 contains the other component. In this illustrative example, outer star 942 and outer moon 943 are discontinuous lines (i.e., dashed lines), while inner star 940 and inner moon 941 are patterned with continuous lines. Additional non-overlapping shapes and / or patterns may be incorporated inside or outside these shapes (not shown). Colored inks or pigments may also be incorporated into any or all of the shapes to achieve color effects in illuminated conditions and / or alter the observed color emitted by the chemiluminescence reaction (not shown), for example, when printed onto an impermeable poly backsheet 900.

[0145] Additionally, to manipulate the intensity and duration of the observed light emission of the chemiluminescence reaction, the coat weight, concentration of the component(s) used, and / or the distance between the inner shapes 940, 941 and the outer shapes 942, 943 can be varied within the structural elements (including overlapping patterns). For example, a constant distance between star shapes 940 and 942, which are relatively close to each other, will result in faster transport and availability of each component, assuming all other variables are equal. In comparison, moon shapes 941 and 943 have both close and far dimensions between them, which will allow for a more sustained reaction and light emission characteristics. The light emission characteristics can be further modified by changing the distance between the shapes, such as by placing star shapes 940 and 942 closer to each other when placed farther from the expected area of excretion, or further apart when placed closer to the expected area of excretion. Alternatively, or in conjunction, the coat weight or concentration of one or both of the components in the inner and outer shape-treated regions can be varied overall on the surface 902 or in advantageous zones (e.g., concentric regions). The constant or variable availability (e.g., spatial or concentration) of excipients with response-enhancing or response-inhibiting activity can similarly control the duration and / or intensity of light emission from the chemiluminescence reaction (not shown). Spatial separation for delayed response of the components of a chemiluminescence system can also be achieved by individually arranging the components within distinct, separate structural elements 900 (e.g., luciferin printed within star shapes 940 on a poly backsheet and luciferase scattered throughout absorbent core fluff pulp), or as shown in Figures 9H and 9I.

[0146] As discussed above, application of one or both chemiluminescent components can produce treated areas that are visually indistinguishable from untreated areas. In some embodiments, it may be desirable to have visually distinct treated areas, for example, to quality check the application process, to provide a visual wetness indicator other than chemiluminescence, etc. This may be achieved by various means, one example of which is to also apply a non-chemiluminescent wetness indicator to the first surface. The non-chemiluminescent wetness indicator may be applied as desired, such as to at least partially overlap the target area but not the treated area. Continuous inkjet printing, optionally in conjunction with other application techniques, may be used to produce embodiments that also incorporate a non-chemiluminescent wetness indicator.

[0147] In still other embodiments of treatment materials or structural elements according to the present disclosure, one or more chemiluminescent components may be provided as discrete amounts in the form of a fluid, gel, powder, etc., such as for incorporation into a pre-made absorbent article (e.g., to convert such absorbent article into one incorporating a chemiluminescent system) or pre-made structural element therefor. In some of such embodiments, an end user may incorporate one or more chemiluminescent components into a pre-made absorbent article or the like. absorbent articles As discussed above, it will be apparent that multiple types of treatment materials according to the present disclosure may be incorporated into an absorbent article. One illustrative example is shown in Figure 4F, which incorporates a treated tissue composition 300 and a layer of indicator particles 400, each of which incorporates a different chemiluminescent component, such that an aqueous system in the form of fluid waste moving through the absorbent article will transfer a first chemiluminescent component to a second chemiluminescent component, such as to initiate a light-generating reaction.

[0148] As another illustrative example, certain embodiments of absorbent articles incorporate the absorbent core 502 discussed further herein with respect to Figure 7, along with a layer of indicator particles 400 arranged between the absorbent core and the backsheet of the diaper in a manner structurally similar to the configuration shown in Figure 4F. In embodiments where particles 400 are treated with a second chemiluminescent component, fluid exudates moving through the diaper will transfer one chemiluminescent component to the other chemiluminescent component.

[0149] However, in a more general sense, absorbent articles produced in accordance with the present disclosure may, but need not, incorporate the various treatment materials described herein. Rather, absorbent articles produced in accordance with the present disclosure may incorporate a chemiluminescent system by having the chemiluminescent components of the chemiluminescent system separately disposed in (or on) the various structural elements used in the absorbent article (which may include one or more of the aforementioned treatment materials).

[0150] That is, an absorbent article constructed according to the present disclosure includes a liquid-permeable topsheet, a liquid-impermeable backsheet, an absorbent material (such as fluff pulp and / or synthetic fibers) disposed between the topsheet and the backsheet, a liquid-permeable tissue sheet, and one or more structural elements selected from the group including particles formed from or including hydrogen-bonded cellulose pulp fibers, and a chemiluminescent system adapted to react and produce light in the presence of an aqueous system. In some embodiments, the liquid-permeable tissue sheet includes fibers selected from cellulose fibers, synthetic fibers, and combinations thereof. The components of the chemiluminescent system in such an absorbent article are separately disposed in (or on) the topsheet, backsheet, absorbent material, and structural element(s) in a configuration in which a first chemiluminescent component is transferred to a second chemiluminescent component by an aqueous system moving through the absorbent article.

[0151] Thus, the exemplary configurations shown in Figures 4D, 4E, and 4F are all example embodiments of such absorbent articles. In some embodiments, one of the chemiluminescent components is disposed within an absorbent material (e.g., fluff pulp, synthetic fibers, SAP, etc.). In some such embodiments, another chemiluminescent component is disposed within a liquid-permeable tissue sheet, such as the treated tissue compositions discussed above, e.g., as shown in FIG. 4D. In some examples of this configuration, the chemiluminescent system includes a luciferin disposed on the tissue sheet and a luciferase disposed within the absorbent material. In certain embodiments, the luciferase is Gaussia luciferase and the luciferin is coelenterazine. In certain embodiments, the luciferase is Renilla luciferase and the luciferin is coelenterazine. In certain embodiments, the luciferase is Metridia luciferase and the luciferin is coelenterazine. In certain embodiments, the absorbent material treated with the chemiluminescent component comprises cellulose fibers.

[0152] Incorporation of a chemiluminescent system into an absorbent article as discussed herein is generally performed by the producer of the absorbent article and / or the manufacturer(s) of the treatment material(s) or structural element(s) incorporated into the absorbent article. However, it is within the scope of the present disclosure that an end user (or, for example, another individual) may apply one or more chemiluminescent components into the absorbent article. For example, in some embodiments according to this aspect of the present disclosure, the absorbent article includes a liquid-permeable topsheet, a liquid-impermeable backsheet, an absorbent material disposed between the topsheet and the backsheet, and a first chemiluminescent component disposed between the topsheet and the backsheet. Such embodiments also include a measured amount of a second chemiluminescent component suitable for reacting with the first chemiluminescent component in the presence of an aqueous system to produce light of a predetermined duration and / or intensity. In such embodiments, which may be provided, for example, as a kit for an end user, a liquid formulation, gel, or the like may be prepared for application to the absorbent article, etc. The measured amount may be provided in any suitable form, such as a roll, powder, or in particulate form, such as a processing die or strip disclosed herein, encapsulated particles, or the like. In such embodiments, the absorbent article may be configured to allow for the application of the measured amount, such as by incorporating a portion that can be selectively opened and reclosed. In one exemplary embodiment, the backsheet includes a flap that can be selectively flipped and then replaced to allow for the application of a measured amount of the second chemiluminescent component to the absorbent article's internal structure. Furthermore, some embodiments may be configured to allow existing (e.g., pre-made) absorbent articles to be modified to include the chemiluminescent system, such as by applying a measured amount of the chemiluminescent component to the absorbent article, such as by an end user or third-party manufacturer.

[0153] Regardless of the form or method in which the chemiluminescent system, or its components, are incorporated into the absorbent article, the total amount can vary considerably, depending, for example, on the construction and use of the absorbent article. As one illustrative and non-limiting example, an embodiment such as a standard baby diaper may contain 0.00001-100.0 mg of luciferin and 0.00001-100.0 mg of luciferase. In some embodiments, the absorbent article comprises 0.00001 to 100.0 mg, 0.0001 to 100 mg, 0.001 to 100 mg, 0.01 mg to 100 mg, 0.1 to 100 mg, or 1 to 100 mg of luciferin and 0.00001 to 100.0 mg, 0.0001 to 100 mg, 0.001 to 100 mg, 0.01 mg to 100 mg, 0.1 to 100 mg, or 1 to 100 mg of luciferase, or any range within any of these ranges, and all other possible sub-ranges.

[0154] Some such embodiments include a total amount of coelenterazine in the range of 0.0001 to 20.0 mg and a total amount of luciferase (Gaussia luciferase, Renilla luciferase, Metridia luciferase, or a combination thereof) in the range of 0.00003 to 20.0 mg. Some such embodiments include a total amount of coelenterazine in the range of 0.01 to 100.0 mg and a total amount of luciferase (Gaussia luciferase, Renilla luciferase, Metridia luciferase, or a combination thereof) in the range of 0.2 to 40.0 mg. Of course, baby diapers may include smaller and larger amounts, and other absorbent articles may include different amounts and / or ranges of each component. Treatment Formulation For example, a formulation useful for applying a chemiluminescence system to a substrate material in the production of a treatment material and / or absorbent article disclosed herein includes at least one component of the chemiluminescence system selected from luciferin and luciferase in a liquid carrier. Depending on factors such as its solubility in the liquid carrier, the reactive component may be dispersed and / or dissolved in the liquid carrier. Thus, the term "formulation" as used herein encompasses mixtures (e.g., dispersions, suspensions, etc.) as well as solutions. For example, in certain exemplary embodiments, the liquid carrier is a suitable solvent (e.g., ethanol) in which the luciferin is dissolved. In certain exemplary embodiments, the liquid carrier is water in which the luciferase is dissolved, while when the solvent is ethanol (e.g., in the form of a ground powder), the luciferase is dispersed.

[0155] Formulations according to the present disclosure include one-component formulations, ie, incorporating either luciferin or luciferase, and two-component formulations, ie, incorporating both luciferin and luciferase.

[0156] As noted above, chemiluminescent systems, and specifically their components, react to produce light in the presence of water. Absorbent articles, and / or materials or structural elements for absorbent articles. One challenge in incorporating a reactive component into a substrate is to do so in a way that the reaction does not begin prematurely, such as during production. One way to address this challenge is by providing the components in separate materials or structural elements and / or in different locations within the absorbent article, although in some applications it may be appropriate to incorporate both components into the same substrate material. Thus, in such applications, the challenge can be to produce a substrate material that does not begin to prematurely initiate chemiluminescence. One way to address this challenge is to provide a two-component formulation in which the components do not react with each other. For example, in one exemplary embodiment of a two-component formulation, the liquid carrier is a suitable non-aqueous solvent (e.g., ethanol) in which luciferin is dissolved and luciferase is dispersed.

[0157] Various solvents are suitable for use in or as the liquid carrier for either one-component or two-component formulations. Suitable solvents for luciferin include, for example, ethanol, isopropanol, n-butanol, isobutanol, ethyl acetate, methyl acetate, isopropyl acetate, acetone, pentanone, methyl ethyl ketone, and n-butyl acetate. Combinations of the aforementioned solvents may also be used, illustrative examples of which include ethanol and isopropyl acetate, ethanol and acetone, pentanone and ethanol, and the like. The aforementioned solvents and combinations are also suitable media in which luciferase may be dispersed. The choice of solvent may be determined by several factors, including the solubility of the particular luciferin(s) in the solvent, whether other substances (e.g., luciferase, binders, porous transport agents, viscosity modifiers, photoluminescent compounds, pH buffers, etc.) will be included in the formulation, process considerations such as the method of application of the formulation, and the substrate material(s) to which the formulation will be applied.

[0158] The concentration of the chemiluminescent component(s) in the formulation is not particularly limited in a general sense, other than by the solubility limit of the liquid carrier solvent, which may be suitable for the particular application.

[0159] However, it has been found that even in some situations where the chemiluminescent component is not particularly soluble in the solvent, its solubility can be enhanced through the use of an excipient—i.e., a compound that functions to promote the solubility of the chemiluminescent component in the solvent. One example of this is the case with some luciferins, such as coelenterazine, which are poorly soluble in water. However, for various reasons (e.g., handling requirements, regeneration / recovery / disposal costs, raw material costs, capacity of existing manufacturing facilities, etc.), water may be a more desirable solvent than, for example, the aforementioned organic solvents. Suitable excipients for coelenterazine generally include polar protic solvents other than water, including some of the aforementioned organic solvents suitable for luciferins (e.g., ethanol, butanol, propanol, isopropanol, pentanone), as well as other materials, such as hydroxypropyl-β-cyclodextrin (HPBC), and combinations thereof. In some embodiments, the use of a solvent as an excipient in a partially aqueous formulation may be a suitable approach to reduce the amount that would otherwise be used in the formulation.

[0160] Thus, in some embodiments, a partially aqueous formulation comprises luciferin and a solvent for dissolving the luciferin, the solvent comprising water and an excipient that promotes the solubility of the luciferin in water. In certain embodiments, a partially aqueous formulation comprises luciferin and a solvent for dissolving the luciferin, the solvent comprising 40-99 weight percent water and 1-60 weight percent excipient adapted to promote the solubility of the luciferin in water, and optionally a binder adapted to bind the luciferin to a substrate material. In certain embodiments, a partially aqueous formulation comprises 40-99, 50-99, 60-99, 70-99, 80-99, 90-99, or 95-99 weight percent water, or any range within any of these ranges, and all other possible subranges. In certain embodiments, a partially aqueous formulation comprises 1-60, 5-60, 10-60, 12-14, 16-18, 18-20, 19-21, 20-22, 21-23, 22-24, 23-25, 24-26, 25-26, 26-27, 27-28, 28-29, 29-30, 30-31, 31-32, 32-33, 34-35, 35-36, 37-38, 38-39, 39-40, 41-42, 43-44, 45-46, 47-48, 48-49, 49-50, 50-51, 51-52, 52-53, 53-54, 54-55, 55-56, 56-57, 57-58, 58-59, 59-60, Including 0, 20-60, 30-60, 40-60, 50-60 weight percent or more of excipient, or any range within any of these ranges, and all other possible sub-ranges.

[0161] In some such embodiments, the excipient is one or more of hydroxypropyl-β-cyclodextrin, ethanol, butanol, propanol, isopropanol, and pentanone. The effect of some excipients may be additive in their contribution to luciferin solubility. In such embodiments, the solvent is generally at least 40 weight percent water, and the concentration of the excipient may be determined by the desired concentration of luciferin dissolved in the solvent. For example, in embodiments in which HPBC is used as the excipient, a concentration of about 45-50 mM HPBC can promote the dissolution of coelenterazine in water up to a concentration of about 3.7 mM (corresponding to about 1.57 g of coelenterazine per liter of water).

[0162] Thus, in some embodiments of formulations according to the present disclosure, the liquid carrier comprises a solvent in which luciferin is dissolved, and the formulation composition ranges from 40 to 99 weight percent solvent and 0.01 to 20 weight percent luciferin. In some embodiments, the formulation comprises 40 to 80 weight percent, 45 to 85 weight percent, 50 to 90 weight percent, 60 to 95 weight percent, or 70 to 99 weight percent solvent, or any range within any of these ranges and all other possible subranges. In some embodiments, the formulation comprises 0.01 to 20, 0.1 to 10, 0.1 to 15, 1 to 15, 5 to 15, or 5 to 20 weight percent luciferin, or any range within any of these ranges and all other possible subranges. In some such embodiments, the solvent is selected from ethanol, isopropanol, n-butanol, isobutanol, ethyl acetate, methyl acetate, isopropyl acetate, acetone, pentanone, methyl ethyl ketone, n-butyl acetate, and combinations thereof. In exemplary such embodiments, the solvent comprises ethanol. In some non-limiting examples of such embodiments, the solvent is ethanol and the formulation comprises between 80 and 99 weight percent ethanol. In some non-limiting examples of such embodiments, the solvent is ethanol and the formulation comprises between 45 and 50 weight percent ethanol. In some of the foregoing embodiments, the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, furimazine, and combinations thereof. In some non-limiting examples of such embodiments, the luciferin is coelenterazine and the formulation comprises between 0.1 and 0.3 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine and the formulation comprises between 0.2 and 0.5 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine and the formulation comprises 0.5 to 0.9 weight percent luciferin.In some non-limiting examples of such embodiments, the luciferin is coelenterazine and the formulation comprises 0.9 to 2.0 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine and the formulation comprises 2.0 to 10 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine and the formulation comprises 10 to 20 weight percent luciferin.

[0163] The luciferin-containing formulation may further comprise a luciferase in embodiments where the liquid carrier is non-aqueous (and therefore the chemiluminescent component does not react). Thus, in some embodiments of formulations according to the present disclosure, the non-aqueous liquid carrier comprises a solvent in which the luciferin is dissolved, and the composition of the formulation is between 40 and 99 weight percent solvent, between 0.01 and 20 weight percent luciferin, and between 0.01 and 20 weight percent luciferase. The luciferase ranges between 0.05 and 0.2 percent by weight. In such embodiments, the solvent and luciferin may be as described above. In some such embodiments, the luciferase is selected from Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase. In some non-limiting examples of such embodiments, the luciferase is Gaussia luciferase, Renilla luciferase, Metridia luciferase, and combinations thereof, and the formulation comprises 0.05 to 0.2 percent by weight of the luciferase. In some non-limiting examples of such embodiments, the luciferase is Gaussia luciferase, Renilla luciferase, Metridia luciferase, and / or combinations thereof, and the formulation comprises 0.2 to 0.6 percent by weight of the luciferase. In some non-limiting examples of such embodiments, the luciferase is Gaussia luciferase, Renilla luciferase, Metridia luciferase, and / or combinations thereof, and the formulation comprises 0.1 to 1.0 weight percent luciferase. In some non-limiting examples of such embodiments, the luciferase is Gaussia luciferase, Renilla luciferase, Metridia luciferase, and / or combinations thereof, and the formulation comprises 1.0 to 10.0 weight percent luciferase. In some non-limiting examples of such embodiments, the luciferase is Gaussia luciferase, Renilla luciferase, Metridia luciferase, and / or combinations thereof, and the formulation comprises 10.0 to 20.0 weight percent luciferase.

[0164] Embodiments in which the liquid carrier / solvent is aqueous or partially aqueous are generally one-component formulations because the chemiluminescent components react to produce light in the presence of water. Formulations according to the present disclosure, such as any of the formulations discussed above, may include one or more of a variety of other substances in addition to the liquid carrier / solvent and chemiluminescent component(s). As noted above, one example is a binder, as described above with respect to treatment materials produced according to the present disclosure, to aid in the retention of the chemiluminescent component(s) on the substrate material to which the formulation is to be applied, for example. Suitable binders are discussed above and include ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane. While not required for all embodiments, the binder may act as a water barrier and / or sustained-release agent, as discussed above. Another example is a porous transport agent, as also described above with respect to various embodiments of the treatment materials. Porous transport agents incorporated into the formulations disclosed herein can provide benefits after application of the formulation to the substrate material. In particular, when the treated substrate material is subsequently contacted with an aqueous system, the porous transport agent can facilitate the transport of the chemiluminescent component(s) and / or the aqueous system relative to the substrate material to which the formulation is applied. Thus, as discussed above, porous transport agents can ameliorate the tendency of some binders to reduce the availability of chemiluminescent components in the presence of aqueous systems. Suitable porous transport agents are discussed above and include starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers. In some embodiments, the formulation contains about 0.01 weight percent to about 52 weight percent of the porous transport agent. In some embodiments, the formulation contains about 0.01 to about 5 weight percent, about 0.1 to about 10 weight percent, about 1 to about 20 weight percent, about 5 to about 40 weight percent, or about 10 to about 52 weight percent of the porous transport agent, or any range within any of these ranges and all other possible subranges.

[0165] Yet another example of an optional additive is a viscosity modifier, which aids in the application of the formulation to the substrate material by any of a variety of methods (e.g., streaming, printing, coating, etc.). They may be used to adjust the viscosity of the formulation to a desired level, such as a viscosity suitable for fabrics. While technically any additive, soluble or insoluble in the solvent, can function to alter the rheological properties of the solvent, the term "viscosity modifier" as used herein refers to a substance that imparts a measurable change to the viscosity of the formulation. Thus, suitable viscosity modifiers include substances that can also be suitable binders, such as ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane, as well as substances that can also be suitable porous media.

[0166] The inclusion of one or more of the foregoing additives, their selection, their concentrations, etc. may be determined by several factors, such as the intended application method for the formulation, the substrate material(s) to which the formulation will be applied, interactions between other substances in the formulation, etc.

[0167] For example, formulations that include a binder may contain high levels of binder, e.g., when the substrate material would otherwise not retain the chemiluminescent component(s) well or at all. In contrast, even low levels of binder have been found to improve retention in some applications. While this is not intended to be limiting, generally, suitable concentrations of binder in formulations according to the present disclosure have been found to range from 0.01 to 15 weight percent of the formulation. For example, in some such embodiments, the binder concentration ranges from about 8.0 to about 12.5 weight percent. In some such embodiments, the binder concentration ranges from about 0.01 to 1.2 weight percent. In some such embodiments, the binder concentration ranges from about 1.2 to 8.0 weight percent. In some embodiments, the binder concentration is in the range of about 0.01 to about 1 weight percent, about 0.1 to about 5 weight percent, about 1 to about 10 weight percent, or about 1 to about 15 weight percent, or any range within any of these ranges, and all other possible subranges.

[0168] Similarly, formulations containing viscosity modifiers are not particularly limited in the amount of agent used, but generally, suitable concentrations of viscosity modifiers in formulations according to the present disclosure have been found to range from 0.01 to 30 weight percent of the formulation. In certain embodiments, the viscosity modifier has a concentration in the range of 0.01 to 30, 0.1 to 10, 1 to 15, 5 to 30 weight percent of the formulation, or any range within any of these ranges, and all other possible subranges. One factor that may determine suitability is the application method for the formulation (discussed below).

[0169] As mentioned above, porous transfer agents can improve the tendency of some binders, when contacted with an aqueous system, to resist release of the chemiluminescent component from the substrate material in which it is incorporated. However, even in the absence of such binders, the porous transfer agent can promote the availability of the chemiluminescent component in the presence of an aqueous system. In such situations, even small amounts can be beneficial. On the other hand, because many porous transfer agents are suspended or dispersed in the formulation rather than dissolved, larger amounts of porous transfer agent can be used to produce thicker, more viscous formulations, for example, to limit the mobilization or flow of the formulation relative to the substrate material after it is applied. This can be useful, for example, in applications where it is desirable to have the chemiluminescent component(s) localized or even limited to one or more specific areas on the substrate material, or in applications where the substrate material may be less able to limit the free flow of the formulation once applied (e.g., poly backsheet). This can also be useful for reducing drying time after application. In general, suitable concentrations of porous transport agents in formulations according to the present disclosure have been found to range between 0.01 and 52 weight percent of the formulation, depending on the application. For example, in some such embodiments, the porous transport agent concentration ranges between about 3.0 and about 6.0 weight percent. In some such embodiments, the porous transfer agent concentration ranges from about 10 to about 25 weight percent. In some such embodiments, the porous transfer agent concentration ranges from about 40 to about 52 weight percent.

[0170] While some specific embodiments are discussed more thoroughly in the "Examples" section of this specification, the following summarizes various illustrative and non-exclusive example formulations according to the present disclosure. In a non-limiting example, the component is luciferin, wherein the luciferin comprises coelenterazine, and the liquid carrier comprises a solvent in which the coelenterazine is dissolved and which comprises ethanol, wherein the formulation comprises 40 to 90 weight percent ethanol, 0.1 to 5.0 weight percent coelenterazine, 0.01 to 15 weight percent binder, and 9 to 52 weight percent porous transport agent.

[0171] In a first simple example, a "one-component" formulation, coelenterazine ("CTZ") is dissolved in ethanol. A sample composition of such a formulation is 89 weight percent ethanol and 11.0 weight percent crude CTZ (approximately 50% pure). This formulation was found to be suitable for the effective application of CTZ to cellulosic tissue sheets. When incorporated into an absorbent article with luciferase-treated fluff pulp, chemiluminescence generated during testing of the construct was visible in a dark room without light. This indicates that CTZ of relatively low purity can be used in such applications.

[0172] Variations of the aforementioned formulation also included one or more binders dissolved in the solution. A sample composition, also using crude CTZ of approximately 50% purity, contained 87.39 weight percent ethanol, 0.88 weight percent ethyl cellulose (binder), 0.33 weight percent polyurethane (also a binder), 0.40 weight percent cornstarch, and 11.0 weight percent crude CTZ. This formulation also effectively applied CTZ to tissue sheets. When incorporated into absorbent articles and tested as described above, chemiluminescence was similarly visible, although there were some differences in the observed intensity after successive excretions. Specifically, in this application, the presence of the binder and starch release agent in the formulation was associated with stronger light generation after fewer excretions and dimmer light generation after more excretions. The addition of PVPA as a release agent or in place of a binder leads to stronger light production after fewer excretions and dimmer light production after more excretions (see Figure 15A). In contrast, the use of treated fluff pulp containing 2% aluminum (see Figure 16) or the addition of hydroxypropyl-β-cyclodextrin in the luciferin application formulation acts as a binder to limit the availability of luciferin, both of which delay light production until after more excretions.

[0173] In a non-limiting example, the formulation is a two-component formulation, wherein the luciferin comprises coelenterazine, the luciferase comprises Gaussia luciferase, Renilla luciferase, and / or Metridia luciferase, the solvent comprises ethanol, and the formulation comprises 50 to 99 weight percent ethanol, 0.1 to 5.0 weight percent coelenterazine, 0.1 to 5.0 total weight percent luciferase, optionally 0.01 to 30 total weight percent of one or more of a binder adapted to hold at least one component onto a substrate material to which the formulation is applied and a viscosity modifier, and optionally 0.1 to 10 weight percent of a porous transport agent.

[0174] In a first simple example, a "two-component" formulation, CTZ and ethyl cellulose are dissolved in ethanol, and Gaussia luciferase ("GLuc") is dispersed in the solution. A sample composition of such a formulation was 89.8 weight percent ethanol. The formulation is composed of 8.6 weight percent ethylcellulose, 2.0 weight percent or less of CTZ, and 2.0 weight percent or less of GLuc. This formulation has been found to be suitable for effective application of both chemiluminescent components to a polybacksheet suitable for diapers. The formulation has a viscosity suitable for application by line streaming.

[0175] Variations of the aforementioned formulations included a porous transport agent dispersed in the solution. A sample composition using cornstarch as the porous transport medium consisted of 82.5 weight percent ethanol, 8.8 weight percent ethyl cellulose, 3.3 weight percent polyurethane (another binder), less than 1.0 weight percent CTZ, less than 2.0 weight percent GLuc, and 4.0 weight percent cornstarch. Another sample composition replaced the cornstarch with synthetic amorphous silica but was otherwise identical. Both of these formulations were found to be equally suitable for the effective application of both chemiluminescent components to a polypropylene backsheet suitable for diapers. However, when tested, the chemiluminescence exhibited by backsheets treated with the formulation containing the porous medium was significantly stronger than that exhibited by backsheets treated with the formulation that did not contain the porous medium. Such formulations also had a viscosity suitable for line streaming application.

[0176] Notably, compositional variations in the formulations summarized herein (e.g., the inclusion of binders, release agents, porous media, or other additive materials, and their concentration ranges) may instead include only one chemiluminescent component in applications where it is desired to produce a material or article treated with only one chemiluminescent component, such as, for example, in absorbent article configurations where the chemiluminescent component is separately disposed within the absorbent article's structure (e.g., among different materials and / or structural elements of the absorbent article). The converse—that one-component formulations may be modified in accordance with the present disclosure to include more than one chemiluminescent component, such as both luciferin and luciferase—is also true, at least in embodiments where the solvent or liquid carrier does not prematurely initiate a reaction between the chemiluminescent components or in the dry formulation application. For example, the CTZ in ethanol formulation described above may also include luciferase.

[0177] An example formulation demonstrating the breadth of additive materials in the formulation contains a relatively high content of porous transport agent compared to those described above, with a composition of 47.10 weight percent ethanol, 1.49 weight percent ethyl cellulose, less than 1.0 weight percent polyurethane, less than 0.50 weight percent CTZ, and 50.67 weight percent cornstarch. Despite its high porous media content, the formulation was found to be flowable and suitable for effective application of CTZ to poly diaper backsheets. Once applied, the formulation was found to substantially remain in place on the substrate material, resisting migration / flow to other areas, and, when assembled into a diaper-like structure containing an absorbent material containing luciferase, exhibited effective bioluminescence when subjected to an excretion test. While this example formulation is a "one-component" formulation, variations may also contain luciferase, since the solvent would not trigger the light-generating reaction between the two chemiluminescent components.

[0178] In one example "one-component" formulation, coelenterazine at a concentration of up to 3.7 mM (about 1.57 g per liter) is dissolved in an aqueous solution of 45-50 mM hydroxypropyl-β-cyclodextrin. In another example, coelenterazine at a desired concentration of up to about 11 weight percent is dissolved in 1-30% ethanol or isopropanol (or a combination thereof). Variations of these examples also include up to 15 weight percent binder and / or porous transport agent. Thus, such partially aqueous luciferases are well known. The luciferin formulation may be suitable for application to various substrate materials discussed herein, such as absorbent materials such as fluff pulp, synthetic fibers, or combinations thereof. In another example, a solvent-soluble excipient, such as poly(1-vinylpyrrolidone-co-vinyl acetate (PVPA)), may be added to a 1-30% ethanol or isopropanol partial solvent system. The solvent-soluble PVPA, for example, has a concentration of 0.2% in the partial solvent system. The addition of 0.2% PVPA has a dramatic effect on the availability of luciferin after fewer voids of aqueous solution (see Figure 15A).

[0179] In the "one-component" formulations described above, and following the principles and concepts disclosed herein, one skilled in the art will be able to determine the appropriate combination of factors for any configuration of absorbent article with only reasonable experimentation. In embodiments where the reactive component is coelenterazine with luciferin, the treated tissue composition may comprise 0.00002 to 20 weight percent coelenterazine. For example, in one such embodiment, the treated tissue composition comprises 1 to 6 weight percent coelenterazine. Processing method Generally, the formulations according to one embodiment of the present disclosure and their variants may be applied to or incorporated into substrate materials using various methods, such as those disclosed in the aforementioned U.S. patent application Ser. No. 14 / 516,255, which describes several methods for incorporating chemiluminescent systems into fluff pulp, such as coating, rinsing, dipping, or spraying one or more non-aqueous solutions of the respective chemiluminescent component(s) onto the fluff pulp sheet prior to the airlaid process.

[0180] In one aspect of the present disclosure, additional methods and techniques are provided relating to the treatment of substrate materials with one or more reactive components of a chemiluminescence system. In such embodiments, the substrate material is treated with one or both reactive components of a bioluminescence system—i.e., luciferin and luciferase. Such methods may be used in addition to, or instead of, standard methods and / or methods described in the aforementioned '255 application for fluff pulp and / or other substrate materials and / or structural elements, such as those suitable for use in absorbent articles.

[0181] As one illustrative, non-exclusive example of such a method according to the present disclosure, a method for producing a fluff pulp composition may be performed during an airlaid process, such as when a fluff pulp sheet is fiberized in a hammer mill. Such a method includes fiberizing a sheet of fluff pulp fibers in air to produce a dispersion of individualized fluff pulp fibers, and spraying a formulation of at least one component of a chemiluminescent system into the dispersion. In such a method, the spraying step is configured to deposit an amount of the chemiluminescent component(s) onto the individualized fluff pulp fibers, corresponding to a concentration of the component between 0.0003 and 10 weight percent. The formulation in such a method is not particularly limited and may take any of the forms described herein, for example. The spraying step may occur at various locations within the process. For example, in some embodiments, the fiberizing step is performed within a chamber of a hammer mill, and the formulation is sprayed into the chamber of the hammer mill. In some embodiments where the fiberizing step is carried out in the chamber of a hammer mill, the fiber dispersion is then pneumatically conveyed from the hammer mill, and the formulation is sprayed into the dispersion during and / or after it is pneumatically conveyed from the chamber.

[0182] Another illustrative, non-exclusive example of a method for producing a treated fluff pulp composition comprises applying to a portion of a fluff pulp sheet a non-aqueous solution containing luciferin and an aqueous solution containing luciferase. The method includes separately applying the luciferase and luciferase components to the luciferin solution. In some embodiments of this method, the portions are non-overlapping, such as on opposing surfaces of the fluff pulp sheet. Optionally, the non-overlapping portions may be on the same surface of the fluff pulp sheet. In one example, the separately applied components may overlap by substantially drying an aqueous application of the luciferase component before or after application of the luciferin component (where substantially dried means that there is insufficient water to consume more than 5% of one or both components in the treated area in a chemiluminescence reaction without adding more water).

[0183] Of course, several treated materials and structural elements in addition to treated fluff pulp have been described above, examples of which include treated tissue compositions, indicator particles of various sizes and shapes, absorbent cores and similar articles comprising absorbent materials such as SAP and synthetic fibers and / or cellulose (e.g., fluff pulp) fibers, other structural elements (liquid-permeable topsheets, liquid-permeable backsheets, etc.) and portions thereof, etc.

[0184] Also described above are several formulations for producing a treatment material or for applying one or more chemiluminescent components to a substrate material. Developing a suitable method for applying a treatment formulation to a substrate material or structural element can face several challenges, some of which are described above. For example, one challenge can be incorporating reactive components into the material and / or absorbent article such that the photogenerating reaction does not begin prematurely, such as during production or storage, but only during use of the absorbent article. One challenge can be ensuring retention of the chemiluminescent component(s) on the substrate material after application. A related challenge can be limiting the mobility of the chemiluminescent component(s) relative to the substrate material after application.

[0185] As explained above, some challenges may be addressed by including one or more additives in the formulation, such as a binder, e.g., to improve retention, and / or a porous medium, e.g., to limit mobility. Some challenges may be addressed by disposing the reactive components separately within the absorbent article - such as on two or more separate materials or structural elements of the absorbent article - so that one reactive component is transferred to the other reactive component during use, such as by an aqueous system that migrates through the absorbent article.

[0186] Additional challenges may exist, such as scaling up a coating method from laboratory and / or pilot scale to commercial scale. Some challenges are presented by existing equipment configurations, e.g., in incorporating a coating method into existing machinery such as a tissue coating machine or printing press. Some challenges are presented by the desire to use a single coating method for a variety of different substrate materials or structural elements. There is also a continuing goal of achieving better process efficiency. These and other challenges may be addressed (alternatively or additionally) by coating methods or techniques.

[0187] As an example, it is often desirable to increase the overall speed of a production process, however, application of a formulation to a substrate material generally requires consideration of subsequent removal of the liquid carrier (e.g., water, organic solvent, etc.) from the material, which is often accomplished by a heating or drying step.

[0188] Many materials suitable for incorporation into absorbent articles have the capacity to retain a threshold level of bound water after the free water has been removed. This capacity, in cellulosic materials, is called the "fiber saturation point" and represents the point at which only water bound within the cell walls remains ("free water" being all other water not so bound). The fiber saturation point of fluff pulp can vary considerably depending on factors such as composition, species, etc., but generally ranges between about 15 and 25 weight percent. The threshold moisture level of synthetic materials is generally lower, e.g., polythene. will generally have a threshold level of moisture of around 5 weight percent, but this can be as high as 10 weight percent.

[0189] It has been found that this property can also be utilized in one method of applying a chemiluminescent component to a substrate material to reduce or eliminate the need for a drying step after application. Thus, in some embodiments, a method of applying luciferase to a substrate material includes applying a formulation comprising luciferase dispersed in an aqueous liquid to the surface of the substrate material such that the moisture level of the substrate material is not elevated above its threshold moisture level.

[0190] In certain embodiments, the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0191] The luciferase formulation may have any desired concentration within a suitable range, taking into account factors such as the initial moisture content of the substrate material, the threshold moisture content of the substrate material, the amount of formulation applied to the substrate material, and the desired concentration of luciferase on the substrate material. A typical concentration range for luciferase on the substrate material for such methods is between 0.01 and 20 mg per gram of substrate material. To achieve this, the concentration range of luciferase in the formulation, in some embodiments, is between about 5.0 and 30 weight percent.

[0192] In some embodiments, the substrate material has a moisture threshold level of up to 25 weight percent. In some embodiments, the substrate material is a fluff pulp sheet having a moisture threshold level (or fiber saturation point) of at least 15 weight percent. In some such embodiments, the luciferase formulation is applied to the surface at a rate that increases the moisture level of the fluff pulp sheet by less than 10 weight percent. In some embodiments, the substrate material is a poly sheet having a moisture threshold level of up to 10 weight percent.

[0193] The following illustrative example considers a sheet of fluff pulp having a moisture content of 7.5% at ambient conditions and a fiber saturation point of approximately 15%. The following table shows an exemplary range of application levels of a 15 weight percent aqueous luciferase formulation to achieve a final pulp moisture content below the fiber saturation point. Fluff pulp sheets treated in this manner can reduce or eliminate the need for a post-application drying step due to the absence of free water in the treated material.

[0194] [Table 2]

[0195] Similar calculations can be performed for other concentrations of luciferase formulations, such as to achieve a desired concentration of luciferase in the substrate material without exceeding a threshold level of moisture in the material. Another application method according to the present disclosure applies two reactive components of the chemiluminescent system to the same substrate material, such as the same or overlapping portion(s) / surface(s) of the substrate material. As mentioned above, in many applications, it is preferable to place the reactive components of the chemiluminescent system in different or separate materials or structural elements of the absorbent article—such as luciferase in the absorbent material (e.g., fluff pulp, synthetic fiber, SAP, etc.) and luciferin in another structural element (e.g., treated tissue composition, poly backsheet, flake, strip, etc.). Such a configuration can better ensure that the chemiluminescent components do not unintentionally react, such as due to ambient moisture or humidity, before use, such as during production, transportation, or storage.

[0196] Regardless, in some situations, it may be desirable to incorporate more than one reactive component (e.g., both luciferin and luciferase) into the same material or structural element. As noted above, this may be accomplished through the use of a non-aqueous formulation incorporating both luciferin and luciferase. However, it has been discovered that this may also be accomplished using application methods in which luciferase and luciferin are separately applied to the same substrate material—particularly to the same area or surface of the substrate material. Such methods also take advantage of the capacity of the substrate material to bind moisture up to a maximum threshold level such that there is no, or insufficient, free water available to initiate the light-generating reaction.

[0197] Thus, in some embodiments, a method for applying a chemiluminescence system to a substrate material includes a luciferase treatment step in which an area on the surface of the substrate is treated with a luciferase formulation comprising a luciferase dissolved in an aqueous liquid, and a luciferin treatment step in which the area is treated with a luciferin formulation comprising a luciferin dissolved in a non-aqueous solvent. In such methods, the luciferase treatment step does not increase the moisture content of the substrate material above a moisture threshold level. Therefore, because the moisture content will not exceed the moisture threshold level of the substrate material, there will be no free water available to initiate the reaction of the chemiluminescence component.

[0198] In certain embodiments, the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine. In certain embodiments, the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase. luciferase, copepod luciferase, and firefly luciferase.

[0199] In such methods, the luciferin formulation contains a non-aqueous solvent, which does not initiate a reaction between the chemiluminescent components—rather, for aqueous luciferase formulations, moisture level is a more important consideration. As noted above, the luciferase formulation may have any desired concentration within a suitable range, taking into account factors such as the initial moisture content of the substrate material, the threshold moisture content of the substrate material, the amount of formulation applied to the substrate material, the concentration of luciferin on the substrate material, and the like. Such a range is generally between about 5.0 and 30 weight percent. The illustrative example formulation application levels for a 15 weight percent luciferase formulation shown in Table 2 also apply to this method, and similar calculations can be performed for luciferase formulations of other concentrations, such as to achieve a desired concentration of luciferase in the substrate material without exceeding the material's moisture threshold level.

[0200] The aforementioned application methods, which take advantage of the substrate material's ability to bind a certain amount of water, provide one approach to reducing or avoiding the need for a subsequent step to remove the liquid carrier (such as a drying step). However, alternative application methods according to the present disclosure may be suitable for substrate materials with lower threshold moisture levels, such as poly backsheets or similar structural elements incorporating synthetic materials.

[0201] Such methods produce a liquid-impermeable backsheet structure that has been treated with at least one component of a chemiluminescent system. In one exemplary embodiment of such a method, a formulation is applied to the surface of the liquid-impermeable backsheet, the formulation including luciferin and / or luciferase, a liquid carrier, and a binder adapted to hold the chemiluminescent component(s) to the backsheet. At least a portion of the liquid carrier is then removed from the backsheet.

[0202] The formulation in such a method can be among those described herein. One example formulation described above includes luciferin as the chemiluminescent component dissolved in ethanol, with the composition comprising 40 to 90 weight percent ethanol, 0.1 to 5.0 weight percent luciferin, 0.01 to 15 weight percent binder, and 9 to 52 weight percent porous transport agent. As noted above, materials used in or as liquid-impermeable backsheets, such as synthetic materials, can present certain challenges, such as relatively low retention of the chemiluminescent component applied thereto, migration or flow of the formulation relative to the material after application, etc. The incorporation of a binder can address retention issues, and, as noted above, a greater amount of porous media in the formulation can address migration issues. Thus, in some embodiments of such methods, the formulation includes a reduced amount of liquid carrier and an increased amount of porous media. One specific, non-limiting example of such a formulation is described above as containing 47.10 weight percent ethanol, 1.49 weight percent ethyl cellulose, less than 1.0 weight percent polyurethane, less than 0.5 weight percent CTZ, and 50.67 weight percent cornstarch. However, variations of this method may include all manner of modifying the formulation according to the principles discussed above, including varying the amount of binder and / or porous medium to impart a desired viscosity to the formulation, all of which are considered within the scope of this disclosure. In some embodiments of this method, the viscosity of the formulation is suitable for application to the backsheet by streaming, which refers to a process in which a stream of the formulation is applied to the surface through a nozzle. The viscosity suitable for streaming application may vary depending on the nozzle design and configuration (e.g., the proximity of the nozzle to the surface, etc.). In some embodiments, any viscosity at which the formulation remains flowable is suitable.

[0203] As described above, the method includes subsequently removing at least a portion of the liquid carrier from the backsheet. In some embodiments of the method, this removing step includes heat treating the formulation-treated surface of the backsheet. However, in some embodiments, the removing step includes contacting the backsheet with an absorbent material adapted to wick the liquid carrier from the surface of the backsheet. In some such embodiments, the absorbent material is in the form of an absorbent core comprising absorbent fibers and / or SAP. In some such embodiments, the absorbent material has been treated with luciferase.

[0204] In a non-limiting example of such an application method using a wicking technique to remove the liquid carrier, the luciferin-in-ethanol formulation from the above example was first streamed onto the surface of a polybacksheet. Immediately after application, a diaper core assembly formed from SAP dispersed in luciferase-treated pulp was placed on top of the treated area. The diaper core assembly wicked away excess solvent (in this case, ethanol) more quickly than air-drying.

[0205] Thus, the above-described wicking techniques may be incorporated into the diaper manufacturing process, in some cases reducing or even eliminating the need for a post-application drying step before assembling the diaper structure using a treated backsheet. Furthermore, as described above, when another chemiluminescent component is disposed within the wicking material (such as the diaper core assembly) or elsewhere within the diaper structure, the result is a diaper incorporating two reactive chemiluminescent components separately disposed within the diaper structure such that upon liquid exudation, one reactive chemiluminescent component transfers to the other reactive chemiluminescent component.

[0206] Variations of this method may include alternative or additional approaches to one or more of the aforementioned problems. For example, some embodiments of the method may include applying a formulation to the surface of the backsheet followed by applying a coating over the treated surface, where the coating is water-soluble or water-permeable. In one example, to form a thin, water-permeable coating of ethylcellulose, a solvent-soluble coating such as ethylcellulose may be sprayed and dried on a formulation layer already deposited on the backsheet. In another example, to form a water-soluble film of carboxymethylcellulose (CMC), an aqueous-soluble coating such as CMC may be sprayed and dried on a formulation layer already deposited on the backsheet. Other example coating (i.e., encapsulating) materials include sugars and polysaccharides (e.g., starch, dextrin, etc.), gums, water-soluble polymers (e.g., PVOH), gelatin and other amino acid- and / or protein-based materials, superabsorbent materials, and porous media. Such coatings can help retain the chemiluminescent component on the backsheet and / or reduce the tendency of the formulation to migrate or flow. The water-soluble / water-permeable nature of the coating will not significantly interfere with the transport of the chemiluminescent component(s) through aqueous systems, such as during use of an absorbent article containing the treated backsheet.

[0207] Other application / production methods according to the present disclosure may be used to produce the treatment materials described herein, such as treated tissue compositions, and indicator particles, etc. For example, an exemplary method for producing indicator particles such as those shown in Figures 6A and 6B may include a combination of techniques and other concepts described elsewhere herein, such as dividing a fluff pulp sheet into particles having a desired shape and size, applying a suitable chemiluminescent component formulation to the particles (e.g., by spraying, soaking, etc.), and removing the solvent and / or liquid carrier (e.g., by drying). The order of these operations may be varied; for example, a variation of such a method may include, after application of the chemiluminescent component formulation and removal of the solvent and / or liquid carrier, The method may include dividing a fluff pulp sheet into particles. In embodiments in which particles are treated with both luciferin and luciferase, the formulation may include both components, or variations of the method may include sequential treatment of the fluff pulp sheet and / or particles with two different formulations of each component, etc. Such methods may be incorporated into the production of absorbent articles, such as by mixing indicator particles with absorbent material (e.g., fluff pulp, synthetic fibers, SAP, etc.). In some embodiments of this method, luciferin-treated particles may be mixed with luciferase-treated particles, or all of the indicator particles may be treated with the same chemiluminescent component, absorbent material treated with different chemiluminescent components, etc., so that both chemiluminescent components are incorporated into the absorbent article.

[0208] Variations in the method of producing absorbent articles using indicator particles include delivering the indicator particles to the diaper structure as it is being produced, for example, to the surface of the absorbent core intended to face the backsheet so that the indicator particles are disposed in the diaper between the absorbent core and the backsheet; or to the inner surface of the backsheet before final assembly of the diaper; or within the absorbent core as performed for SAP, etc. Thus, in one embodiment, the method of producing an absorbent article includes the steps of producing an encapsulating material comprising particles including one of two reactive components of a chemiluminescent system configured to generate light upon contact with an aqueous system, along with one or more of a water-permeable and water-soluble material, and producing an absorbent article comprising disposing the encapsulating material between a liquid-permeable topsheet and a liquid-impermeable backsheet, and disposing the other reactive component of the chemiluminescent system within a structural element of the absorbent article.

[0209] As another example, in one exemplary method of producing a treated tissue composition, a formulation is applied to the surface of a liquid-permeable tissue sheet, the formulation including luciferin and a solvent that the luciferin is dissolved in. At least a portion of the solvent is then removed from the tissue sheet, retaining the luciferin on the tissue sheet.

[0210] Somewhat similar to the exemplary method for producing a treated backsheet, embodiments of the exemplary method for producing a treated tissue composition include one or more various aspects and variations thereof spanning a wide range of application techniques. For example, tissue printing is one technique in which inks and similar formulations can be applied to a continuous tissue sheet, such as in a tissue coater (one example of such a machine is the MirWec μCoater™ 350), and formulations suitable for application to a tissue sheet via delivery by a tissue coater are within the scope of the present disclosure. To be suitable, such formulations would be customized to the capabilities of the machine. This may include adjusting the viscosity of the formulation to an appropriate level, incorporating suitable additives, etc. Typically, a tissue coater applies the ink or formulation using one or more cylinders over which the tissue sheet is conveyed, followed by a heating and / or drying step in which the liquid carrier is removed. Typically, the tissue sheet to which the formulation is applied is a continuous tissue sheet.

[0211] Alternatively, in some embodiments, the formulation is applied by streaming the formulation onto the surface of the tissue sheet, such as by a streaming device where the tissue sheet is moving relative to the streaming device. In some such embodiments, the streaming device includes one or more nozzles positioned in close proximity to and / or contact with the moving surface. The tissue sheet, in such embodiments, may be a continuous tissue sheet.

[0212] In accordance with one aspect of the present disclosure, an example stream suitable for use in such an embodiment is: Schematic diagrams of a streaming apparatus are shown in FIGS. 8A and 8B. In FIG. 8A, streaming apparatus 600 is shown to include two pivot points in the form of rollers 602, 604 over which a continuous tissue sheet 606 is moved in the direction indicated by arrow A. The tissue sheet 606 is thereby suspended or floated above a zone defined by the rollers, shown in FIG. 8A as a tissue floating zone 608. Streaming apparatus 600 includes a nozzle 610 positioned to deliver a formulation to the upper surface of the tissue sheet 606, such as by streaming the formulation provided from a reservoir 612 onto the tissue sheet surface as the tissue sheet moves. Streaming apparatus 600 is also shown to include a heating element at 614, which provides a hot air zone 616 through which the treated tissue sheet is conveyed to evaporate the solvent by thermal treatment. FIG. 8B shows an exemplary alternative configuration of streaming apparatus 600′, in which rollers 602, 604 have a different arrangement. A streaming apparatus having a configuration similar to that shown in Figures 8A and 8B was used to produce treated tissue compositions such as that shown as tissue composition 300 in Figure 5A, where the longitudinal strips may be discontinuous, dotted, dashed, straight, curved, one or more shapes, etc. In some embodiments, the ambient temperature of the application environment provides sufficient thermal energy to dry the liquid carrier of the formulation.

[0213] Several other variations in the configuration of the streaming device are within the scope of this disclosure. For example, multiple nozzles may be held stationary and selectively activated to generate a predetermined pattern or shape by activating and deactivating each nozzle at timed intervals. The roller may be a non-rotating cylinder. The formulation may be delivered by an array of multiple nozzles. One or more nozzles may move relative to the tissue sheet, such as transversely to the direction in which the tissue sheet is moved, such as to generate treatment zones that take the form of a desired shape or pattern. To further facilitate this capability, one or more nozzles may be configured to stream the formulation intermittently and / or continuously, such as to generate continuous or discontinuous treatment zones on the tissue sheet. Thus, various embodiments of the present method include applying a formulation to a tissue sheet so that the treated areas are of any desired width, e.g., longitudinal strips ranging from 0.1 mm to the width of the tissue sheet (e.g., about 235 mm, the width of a standard diaper) in any desired arrangement or pattern (e.g., the treated areas may be in the form of strips running perpendicular or perpendicular to the longitudinal direction of the tissue sheet, continuous or discontinuous (e.g., dotted or dashed), straight or curved, or may include curved and / or straight portions, shapes or other configurations, etc.). The treated areas may range from 0.003 to 100% of the total area of the tissue sheet. As noted above, the treated areas may, in total, be any of 1 to 99% of the surface area, e.g., 1 to 2%, 1 to 10%, 5 to 20%, 1 to 25%, 10 to 50%, 20 to 90%, or any range within any of these ranges, and all other possible subranges.

[0214] Method embodiments incorporating such streaming devices may offer several potential advantages over the use of a tissue press. For example, a tissue floating zone may reduce the likelihood of the formulation bleed-through the tissue sheet to the cylinder(s) of the tissue press. Floating the tissue may also allow for greater contact with ambient air to dry the tissue, reducing the extent of heat treatment required to remove the solvent.

[0215] The formulations applied by embodiments of the present method are not particularly limited, and some components and examples are discussed above, including sample compositions described as suitable for the effective application of coelenterazine to cellulosic tissue sheets. Thus, in some embodiments, the formulation comprises 40-99 weight percent solvent and 0.01-20 weight percent The formulation comprises a luciferin as a chemiluminescent light-generating agent. In some such embodiments, the luciferin is coelenterazine. In some such embodiments, the solvent is or includes ethanol. In some such embodiments, the solvent is or includes ethanol and is or includes an excipient that promotes dissolution of the luciferin deposited on the treated tissue or backsheet surface for the chemiluminescent light-generating reaction upon excretion. In some such embodiments, the solvent includes water and an excipient that promotes solubility of the luciferin in water. In some embodiments, the formulation includes a binder and / or viscosity modifier, such as to adjust the viscosity to a desired level. In certain embodiments, the formulation includes 0.01 to 30 weight percent binder. One of the sample formulations mentioned above contained 87.39 weight percent ethanol, 0.88 weight percent ethyl cellulose (binder), 0.33 weight percent polyurethane (also a binder), 0.40 weight percent corn starch, and 11.0 weight percent crude CTZ (about 50% pure).

[0216] Embodiments of the method include applying a formulation to a tissue sheet at a rate that achieves a desired concentration of chemiluminescent component(s) on the tissue sheet. As noted above, the concentration is not particularly limited and can be expressed in various ways, such as weight percent of the tissue sheet, mass per unit length of the tissue sheet, etc. For example, in some embodiments where the formulation includes luciferin, the formulation is applied at a rate that achieves a luciferin concentration on the tissue sheet of 0.00002 to 20 weight percent. In some embodiments where the formulation includes coelenterazine, the formulation is applied at a rate that achieves a coelenterazine concentration on the tissue sheet of 0.01 mg to 25 grams of coelenterazine per 12 inches (30.48 cm) length of the tissue sheet. In some embodiments where the formulation includes coelenterazine, the formulation is applied at a rate that achieves a coelenterazine concentration on the tissue sheet of 0.01 to 1.0 grams of coelenterazine per 12 inches (30.48 cm) length of the tissue sheet. In some embodiments where the formulation includes coelenterazine, the formulation is applied at a rate that achieves a coelenterazine concentration on the tissue sheet of 0.1 to 100 mg of coelenterazine per 12 inch length of tissue sheet.

[0217] Some embodiments of the method according to the present disclosure include additional steps, such as dividing the treated tissue sheet into discrete lengths following application of the formulation. A related method for producing an absorbent core for incorporation into an absorbent article includes producing a treated tissue composition according to the above and incorporating the treated tissue composition into the absorbent core, such as by using the treated tissue composition as a wrapper for the absorbent material—i.e., by partially or completely surrounding the absorbent material with the treated tissue composition. As discussed further herein, in certain embodiments, such treated tissue compositions can include fibers, such as fibers selected from the group consisting of cellulosic fibers, synthetic fibers, and combinations thereof. As noted above, application of the formulations disclosed herein to various substrate materials can be carried out by any of a variety of methods, including streaming, printing, coating, spraying, rinsing, soaking, dipping, and the like. The above discussion describes the principles of customizing formulations for such applications and example composition ranges for exemplary applications. As noted above, one factor that may determine suitability for a particular application method is the viscosity of the formulation, which may be adjusted, for example, by incorporating one or more of the additive materials discussed herein (e.g., binders, porous media, release agents, other viscosity modifiers, etc.) Viscosity ranges appropriate for particular applications may differ or overlap.

[0218] Ink suitable for various ink application methods, e.g. streaming, printing, coating, etc. The formulations according to the present disclosure may be configured as inks. The following simplified explanations illustrate the differences between several application methods: Streaming, for example, refers to a process in which a stream of formulation is applied to a surface by one or more nozzles (moving or fixed). Printing generally refers to a process in which an ink formulation is deposited onto a substrate material.

[0219] For example, in intaglio printing techniques such as gravure and rotogravure, the image to be printed is engraved into an image carrier, which is then supplied with an ink formulation. The ink in the recessed portion(s) forming the image is transferred to a substrate material pressed against the inked image carrier. In letterpress printing techniques such as letterpress and flexography, the image to be printed is raised (rather than recessed), supplied with ink, which is then transferred to a substrate material pressed against a relief plate. In screen printing, a mesh is used to transfer the ink onto the substrate except in areas made impermeable to the ink, such as by a blocking stencil. Various coating methods, such as slot-die coating and ultra-strand coating, apply a formulation, usually containing molten material, onto a substrate material.

[0220] In inkjet printing techniques, droplets of ink are propelled toward a substrate material. Most consumer and commercial / industrial inkjet printers use drop-on-demand ("DOD") techniques, in which droplets are ejected from one or more ink chambers in response to pulses of electrical current. However, advances in inkjet printing have produced several techniques that can enable very fast application of various ink formulations to substrate materials and / or structural elements according to the present disclosure, such as the ink formulations discussed herein. In some methods of continuous inkjet ("CIJ") printing, for example, the printer imparts a controlled, variable electrostatic charge to individual ink droplets in a continuously generated stream. CIJ printing therefore differs from DOD printing in that the droplets are ejected continuously, which can provide greater speed in printing compared to DOD techniques. The CIJ droplets then travel through a magnetic field generated within the printhead. The droplets are deflected toward the substrate material with a degree of deflection determined by their electrostatic charge, and uncharged droplets are collected (e.g., in a printhead) and circulated back into the ink supply, thus printing characters or other images or patterns onto the substrate material.

[0221] 9A-9I, an exemplary method for producing a structural element treated with one or more components of a chemiluminescent system, such as those shown in Figures 9A-9I, includes applying a formulation to a predetermined area of a first surface of the structural element, the formulation comprising one or more components. Accordingly, in certain embodiments, such methods include a method for producing a structural element for incorporation into an absorbent article that has been treated with at least one component of a chemiluminescent system that reacts in the presence of an aqueous system to produce light, the method comprising applying a formulation to a predetermined area of a first surface of the structural element, the formulation comprising at least one component, the at least one component being selected from luciferin and luciferase.

[0222] In some embodiments, the predetermined area at least partially overlaps an area in which one or more fluid discharges are expected during use of the absorbent article in which the structural element is incorporated, as discussed further herein with respect to Figures 9A-9J. Such a predetermined area can define a continuous shape. Accordingly, the predetermined area can include two or more discrete portions.

[0223] The formulation applied to the structural element can include a formulation of the present disclosure, which includes at least one component of a chemiluminescent system. In some embodiments, at least one The component is a luciferase. In one embodiment, the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase. In one embodiment, at least one component is a luciferin and a luciferase. In one embodiment, the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine, and / or the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0224] In some such methods, the formulation is an ink formulation, and the application comprises printing, e.g., inkjet printing, such as CIJ printing. In some such methods, both luciferin and luciferase are applied, for example, in separate formulations and / or to different portions of a predetermined area, such as by CIJ or other inkjet printing. As noted above, the other of one or more components (i.e., the other of luciferin or luciferase) may be applied to the material of the structural element by a separate application method. The electrostatic charge of the ink formulation may be adjusted by the addition of organic or inorganic salts, including salts of luciferin.

[0225] Additionally, versatile application techniques, such as CIJ printing, may be used to apply multiple formulations, such as ink formulations, to a substrate material. In certain embodiments, applying a formulation includes applying at least two formulations, where one of the at least two formulations includes luciferin and another of the at least two formulations includes luciferase. Such application of at least two formulations may include applying a formulation, including separately applying the at least two formulations. In this regard, at least two formulations may be applied to non-overlapping portions of a predetermined area. As described throughout, overlapping portions of a predetermined area may be treated with two formulations to minimize or avoid reacting the two components of the chemiluminescence system by more than 5% prior to the addition of an external source of water (i.e., fluid waste).

[0226] As noted above, it may be desirable in some applications to apply other materials, such as non-chemiluminescent wetness indicators, to the substrate material or structural element in addition to the chemiluminescent material. Such variations are considered within the scope of this disclosure.

[0227] A method for producing a structural element according to certain embodiments of the present disclosure can include, for example, applying a non-chemiluminescent wetness indicator to a first surface. Such a non-chemiluminescent wetness indicator can be applied so as to at least partially overlap a predetermined area. Similarly, a non-chemiluminescent wetness indicator can be applied so as not to overlap the predetermined area.

[0228] It is therefore apparent that these example application methods may have different requirements for suitable formulations. However, formulations according to the present disclosure may be customized to a particular application method, such as by incorporating suitable additives (e.g., to achieve a desired viscosity, composition, thermal stability, rheological behavior, etc.), while still effectively delivering the chemiluminescent component(s) of the formulation to the substrate material. [Example]

[0229] The following paragraphs provide a description of exemplary ways in which treated materials with incorporated chemiluminescence systems can be manufactured and tested. The results demonstrate the benefits of chemiluminescence systems for wetness detection in the dark. Chemiluminescence can be seen through absorbent articles and clothing that incorporate the chemiluminescence system. The examples are illustrative and not limiting.

[0230] Chemiluminescence intensity in many of the examples is assessed by visibility to the human eye in low light or in a dark room, but some examples generally discuss relative light units (RLU) analysis performed with a luminometer for comparative purposes. In such RLU analysis, chemiluminescence is measured without the use of any light filters. Roughly speaking, values of 10,000,000 to 15,000,000 RLU correspond to the lower threshold of visibility by the human eye in a dark room. However, higher RLU levels may be required or lower RLU levels may be tolerated for visibility by some individuals. Porous Transport Agent Example 1: Preparation and Testing of Two-Component Formulations A solvent solution containing coelenterazine ("CTZ") and Gaussia luciferase (GLuc) was prepared using a binder (ethyl cellulose (EC 4 cP, Sigma)) in ethanol. Sample formulations are shown in the table below.

[0231] [Table 3]

[0232] 20 μl of the above solvent solution was pipetted onto a poly backing sheet as a rounded dot, and the poly sheet was dried at 80° C. for 30 seconds. Once dry, the treated area was drained with 0.2 ml of phosphate buffered saline ("PBS") (pH 7.5). PBS is a water-based buffer solution that can be used to simulate urine in absorbent article testing. The PBS formulation used in the examples herein contains 137 mM sodium chloride, 2.7 mM potassium chloride, 10 mM dibasic sodium phosphate, 1.8 mM monobasic potassium phosphate, 1.0 mM calcium chloride, and 0.5 mM magnesium chloride. Very weak bioluminescence was observed, consistent with slow or reduced release of CTZ and / or GLuc from the poly sheets. Porous Transport Agent Example 2: Preparation and Testing of Two-Component Formulations Containing Porous Media Solvent solutions containing CTZ and GLuc were prepared in ethanol using various binders, such as ethyl cellulose (EC 4 cP, Sigma) and polyurethane (Versamid PUR 1120, BASF). Porous media, such as cornstarch (Sigma Cat. No. S4180) and synthetic amorphous silica (SAS), were also added. Two sample formulations, identical except for the porous media used, are shown in the table below. Sample formulation "A" contained cornstarch. Sample formulation "B" contained SAS.

[0233] [Table 4]

[0234] Each solvent solution was tested by pipetting 20 μl of the solvent solution onto a poly backing sheet, creating a rounded dot, which was then dried at 80° C. for 30 seconds.

[0235] Once dry, each treated area was drained with 0.2 ml of pH 7.5 PBS. In both cases, extremely strong bioluminescence was observed, consistent with uninhibited or assisted release of CTZ and / or GLuc from the poly sheets. Tissue Example 1: Preparation of Treated Tissue Sheets Using a laboratory-scale embodiment of the floating tissue streaming design shown schematically in Figures 8A and 8B, a formulation of coelenterazine ("CTZ") was streamed by a nozzle onto a continuous, moving tissue sheet suspended between two pivot points to produce a treatment area in the form of a longitudinal strip. Two sample formulations are shown in the table below. Sample formulation "A" contained no binder. Sample formulation "B" was prepared using the binders ethyl cellulose (EC 4 cP, Sigma) and polyurethane (Versamid PUR 1120, BASF), and corn starch.

[0236] [Table 5]

[0237] The formulation was streamed at a rate of 1.0 mg of CTZ (equivalent to 100% purity) applied per 12 inches of length. To simulate a hot air zone, the streamed tissue was dried in an incubator at 80 °C for 15 s. Higher temperatures can significantly reduce drying times.

[0238] The configuration shown schematically in Figures 8A and 8B has been successfully tested using a similar formulation on a MirWec μCoater™ 350. Other tissue coating / printing equipment may also be suitable. Tissue Example 2: Diaper Assembly with Treated Tissue Sheets and Excretion Testing A size 4 baby diaper was cut open and modified to include a diaper core containing SAP and luciferase-treated fluff pulp. A streamed tissue sample prepared in Tissue Example 1 was placed between the backsheet and the modified diaper core. The diaper was reassembled, and 45 ml of pH 7.5 PBS was voided into the diaper. At T=0 time, after the diaper had completely absorbed the exudates, the chemiluminescence generated by the chemistry within the modified diaper was observed and imaged in a dark room without light. Chemiluminescence was visible after the exudation. At T=2, 4, 6, and 8 hours, the same dose of PBS-buffered saline was subsequently voided into the modified diaper. Chemiluminescence was visible after each exudation. Tissue Example 3: Relative Light Units (RLU) Analysis Reassembled diapers modified to contain streamed tissue samples prepared using both sample formulations from Example 1 were die cut with a 2.54 cm (1 inch) diameter die to produce mini-diapers, which were subjected to four consecutive 1.5 hour intervals of 0.63 ml doses of pH 7.5 PBS, equivalent to 45 ml of pH 7.5 PBS for a full diaper discharge dose. Bioluminescence relative light units (RLU) were measured in a GloMax® Discover System Luminometer (Promega, Madison, WI). The RLU plot for the analysis shown in Figure 10 shows the level of chemiluminescence at and after each discharge. The plot is based on the average of triplicate tests. The Sample A formulation sample shows weaker light production at the second excretion but much stronger light production at the fourth excretion, while the Sample B formulation sample shows brighter light at the second excretion but dimmer light at the fourth excretion. Tissue Example 4: Graded bioluminescence design using treated tissue sheets Using a laboratory-scale implementation of the floating tissue streaming design as implemented in Tissue Example 1, two formulations of coelenterazine ("CTZ") were applied by a nozzle onto a continuously moving tissue sheet suspended between two pivot points to create treatment areas in the form of two rigid longitudinal strips. The two sample formulations contained a binder and were identical except for the concentration of CTZ and the remainder of the solvent (sample formulation "C" had approximately 0.9% by weight of CTZ, approximately 50% pure; sample formulation "D" had approximately twice the CTZ concentration of formulation C). Sample formulation C was applied to the tissue sheet in a line approximately three times wider than the line of sample formulation D, and the same volume of each was applied. The tissue sample was wetted with a sufficient amount of luciferase-containing solution (approximately 2 mL with a GLuc concentration of 1 mg / mL) to mimic excretion. At T=0, the "C" stream glowed brightly, while the "D" stream did not (not shown). At T=2 hours, the "C" stream continued to glow with minimal loss of intensity, while the "D" stream had only diffuse emission around the line (not shown). At T=4 hours, the "C" stream continued to glow with significant loss of intensity, while the "D" stream had increased intensity in the area of the line (not shown). Flake Particle Example 1: Preparation of Indicator Flakes Pulp flakes with a hexagonal shape are used to prepare pulp-based indicator flakes. The hexagonal pulp flakes have a thickness of 1 mm and four sides of 2 mm and two sides of 3 mm. Each flake weighs approximately 11 mg and has a moisture content of approximately 7%. International Paper produces 750 g / m 2 Flakes were prepared from CF416 pulp board.

[0239] Various binders, such as ethyl cellulose (EC 4 cP, Sigma) and A solvent solution containing coelenterazine ("CTZ") and Gaussia luciferase (GLuc) was prepared using polyurethane (Versamid PUR 1120, manufactured by BASF). To facilitate dispersion, the GLuc was milled before being added to the solution. A sample formulation is shown in the table below.

[0240] [Table 6]

[0241] The solution was yellow. Once well mixed, the solution was added to each flake. A total of 0.7 g of pulp hexagonal flakes (approximately 65 flakes) was treated and used for each diaper application. After treatment, the pulp flakes were dried with hot air in an oven at 80°C for 2 minutes.

[0242] In this example, the dried flakes contained less than 0.50% by weight of CTZ and less than 0.01% by weight of GLuc. 0.7 g of dried flakes contained a total of 1.0 mg of CTZ and 0.025 mg of GLuc. Flake Particle Example 2: Diaper Assembly Containing Indicator Flakes A long rectangular section of the backsheet of a size 4 baby diaper was cut open and turned up without interrupting the diaper core structure. The flakes were uniformly distributed in a single, discontinuous layer on the inner surface of the backsheet section. The backsheet section was then sealed with transparent tape placed over the cut edge and replaced in the diaper. Flake particle example 3: Repeated diaper excretion with PBS The diaper of Example 2 was voided with 60 ml of pH 7.5 PBS.

[0243] At T=0 hours, after the excrement was completely absorbed by the diaper, the chemically generated chemiluminescence on the treated pulp flakes was observed and imaged in a dark room without light. The chemiluminescence was very visible after the excrement. By T=1.5 hours, the chemiluminescence was no longer visible. A second excrement was applied at T=1.5 hours, and the chemiluminescence was again very visible. By T=2.0 hours, the chemiluminescence was no longer visible. A third excrement was applied at T=3.0 hours, and the chemiluminescence was again visible, but not as visible as after the first and second excrements. By T=4.0 hours, the chemiluminescence was no longer visible. Flake Particle Example 4: Relative Light Unit (RLU) Analysis A 2.54 cm (1 inch) diameter disk was punched from the diaper. The backsheet was removed, and five treated hexagonal pulp flakes, treated according to Example 1, were placed in a row between the backsheet and the diaper core. Four consecutive urinations of pH 7.5 PBS were performed at 1.5 hour intervals. Chemiluminescence was monitored with a GloMax® Discover System Luminometer (Promega, Madison, WI). The RLU plot for the analysis, shown as Figure 11, shows the level of chemiluminescence at and after each urination. The results show that luminescence intensity (RLU) increased significantly after the first urination. During the second excretion, the spike is much higher and then drops off, remaining higher in intensity than the first spike until after the fourth excretion the intensity gradually decreases. Strip Particle Example 1: Preparation of Indicator Strips Pulp strips measuring 1 mm x 2 mm x 350 mm were cut and used to prepare pulp-based indicator strips. Each strip weighed approximately 0.7 g. 750 g / m2 from International Paper. 2 CF416 pulp board was used to prepare the strips.

[0244] Solvent solutions containing coelenterazine ("CTZ") and suspended Gaussia luciferase (GLuc) were prepared using various binders, such as ethyl cellulose (EC 4 cP, Sigma) and polyurethane (Versamid PUR 1120, BASF). To facilitate dispersion, the GLuc was milled before being added to the solution. Sample formulations are shown in the table below.

[0245] [Table 7]

[0246] The solution was yellow in color. Once well mixed, the solution was added to each strip. After treatment, the pulp strips were dried in an oven at 80°C with hot air for 2 minutes. In this example, each dry strip contained less than 0.50% by weight of CTZ and less than 0.10% by weight of GLuc, for a total of 1.0 mg of CTZ and 0.025 mg of GLuc. Strip Particle Example 2: Diaper Assembly Including Indicator Strips A long rectangular section of the backsheet of a size 4 baby diaper was cut open and turned up without interrupting the diaper core structure. A single strip was placed longitudinally in the center of the inner surface of the backsheet section. The backsheet section was then sealed back into the diaper with transparent tape placed over the cut edge. Strip particle example 3: Repeated diaper excretion with PBS The diaper of Example 2 was voided with 60 ml of pH 7.5 PBS.

[0247] At T=0 hours, after the excrement was completely absorbed by the diaper, the chemically generated chemiluminescence on the treated pulp flakes was observed and imaged in a dark room without light. Chemiluminescence was very visible after excrement. By T=1.5 hours, chemiluminescence was faintly visible. A second excrement was applied at T=1.5 hours, and chemiluminescence was again very visible. By T=2.0 hours, chemiluminescence was faintly visible. A third excrement was applied at T=3.0 hours, and chemiluminescence was again visible, but significantly weaker than after the second excrement. By T=4.0 hours, chemiluminescence was no longer visible. Strip Particle Example 4: Relative Light Units (RLU) Analysis A 2.54 cm (1 inch) diameter disk was punched from the diaper. The backsheet was removed, and a 2.54 cm (1 inch) treated pulp strip treated according to Example 1 was placed between the backsheet and the diaper core. Four consecutive urinations of pH 7.5 PBS were performed at 1.5 hour intervals. Chemiluminescence was monitored with a GloMax® Discover System Luminometer (Promega, Madison, WI). The RLU plot shown as Figure 12 shows the level of chemiluminescence during and after each urination. The results show that the luminescence intensity (RLU) rises after the first urination and then gradually drops. During the second urination, there is a much higher spike, then a drop, maintaining the intensity higher than the first spike until the intensity gradually decreases after the fourth urination. From T = 2.0 h (after the spike after the second excretion) to T = 4.0 h, the chemiluminescence was fairly stable and visible to the human eye in the dark. Strip particle example 5: Production of CTZ-treated indicator strips of various dimensions CF416 pulp board (weight 750g / m 2Pulp (International Paper) was processed in a Crumbler® rotary shear system (Forest Concepts, LLC) equipped with a 1.8 mm blade cutter and a 0.8 mm blade cutter to produce strips of pulp having various widths. The strips were trimmed lengthwise into long strips (e.g., longer than 20 mm) and short strips (10-20 mm). The apparent density or bulk of the 1.8 mm strips was 0.0886 cc / g, and the apparent density or bulk of the 0.8 mm strips was 0.145 cc / g. Strips of various sizes were used to test aspects of the production process, such as speed and efficiency, and to determine whether smaller strips could also be efficiently produced. Smaller strips would be easier to air transport and therefore more suitable for use in standard diaper fluff core forming equipment.

[0248] Solvent solutions containing coelenterazine ("CTZ") were prepared using various binders, such as ethyl cellulose (EC 4 cP, Sigma) and polyurethane (Versamid PUR 1120, BASF). Cornstarch was also added (Sigma catalog number S4180). Sample formulations are shown in the table below. One gram of sample composition contains 2.0 mg of CTZ.

[0249] [Table 8]

[0250] Once well mixed, the solution was applied to the strips by mixing 2.0 g of the solution with 2.0 g of the various pulp strips in a small beaker. After treatment, the pulp strips were dried with hot air in an oven at 80°C for 2 minutes. Strip Particle Example 6: Diaper Core Assembly with CTZ-Treated Indicator Strips and Excretion Testing One gram of CTZ-treated strips of the aforementioned size (containing a total of 2.0 mg of CTZ per gram) on the back of the diaper core containing luciferase-treated fluff pulp. (at a concentration of approximately 0.56 mg of luciferase per gram of fluff, or approximately 5.6 mg of luciferase per diaper core). The diaper core assembly was then sandwiched between a liquid-impermeable poly backsheet and a liquid-permeable topsheet, with the CTZ-treated strip positioned adjacent to the backsheet.

[0251] 60 ml of pH 7.5 PBS waste was added to the diaper core. Chemiluminescence was observed and imaged. Chemiluminescence was quite visible through the backsheet in the dark and under dim light. Backsheet Example 1: CTZ Formulation for Backsheet Application Solvent solutions containing coelenterazine ("CTZ") were prepared using various binders, such as ethyl cellulose (EC 4 cP, Sigma) and polyurethane (Versamid PUR 1120, BASF). The binder was diluted in ethanol, and then CTZ was added. Once dissolved, cornstarch was added. The mixture was mixed by vortexing. Sample formulations are shown in the table below.

[0252] [Table 9]

[0253] Cornstarch was found to exhibit no clumping in ethanol, and similar formulations with up to 52 weight percent starch remained flowable. Backsheet Example 2: Application and Wicking-Promoting Drying Using a small syringe (1 ml), the formulation from Example 1 was streamed in a 6 inch line across a poly backsheet (XP-1943SX Polyfilm, Berry Global Inc., Evansville, IN), thus applying 64 mg of formulation per inch of backsheet (approximately 0.05-0.30 mg of CTZ per inch).

[0254] Immediately after application, a diaper core made of fluff pulp and SAP treated with luciferase at a concentration of less than 1.0 weight percent was placed over the streamed line on the backsheet.

[0255] The fluff core wicked the solvent (ethanol in this case) faster than air drying. Backsheet Example 3: Chemiluminescence Test (1) The treated backsheet and diaper core assembly and (2) the diaper core only sample were dosed with pH 7.5 PBS. The treated backsheet and diaper core assembly sample exhibited strong bioluminescence. The diaper core only sample also exhibited some bioluminescence, indicating that some of the CTZ had diffused into the diaper core when used to wick the solvent. Backsheet Example 4: Relative Light Units (RLU) Analysis A standard diaper topsheet containing an acquisition distribution layer (ADL) was applied to the exposed side of the diaper core of the assembly from Example 3, sandwiching the diaper core between the topsheet / ADL and the treated backsheet. Six 2.54 cm (1-inch) diameter disks were die-cut from this assembly to produce six "mini-diaper" assemblies. These were placed in a six-sample test cassette designed for bioluminescence testing in a GloMax® Discover System Luminometer (Promega, Madison, WI). Each mini-diaper was dosed with 0.84 ml of pH 7.5 PBS buffer solution (an amount proportional to the 60 ml of waste delivered to a medium-sized diaper). Successive urinations were performed at 1.5-hour intervals. The RLU plot for the analysis, shown as Figure 13, shows the chemiluminescence levels during and after each urination. The results show that luminescence intensity (RLU) rises after the first excretion (at T=0) and then gradually declines. There is a sharp rise after each successive excretion, followed by successively slower declines. The results indicate that the presence of more liquid is associated with more intense light in this application.

[0256] Additionally, chemiluminescence was observed to be visible in the dark after the fourth bowel movement, despite the relatively small treated area (a 1-inch line within each mini-diaper) compared to a fully treated baby diaper core. SAP Level Example: Varying the amount of superabsorbent polymer affects water availability in aqueous systems Diaper cores were made with different superabsorbent polymer (SAP) contents: 0, 6, 12, 18, 24, and 36 weight percent based on the total cellulose fiber (fluff) in the core. The cellulose fibers were treated with luciferase (GLuc). The tissues were streamed with a blend of coelenterazine (CTZ) (approximately 50% purity) in ethanol containing 0.88 wt% ethyl cellulose (EC 4 cP), 0.33 wt% polyurethane (PUR), and 0.40 wt% cornstarch to have a concentration of less than 1.0 mg of pure CTZ.

[0257] Diaper cores containing luciferase (GLuc)-containing cellulose fibers and different SAP contents were modified to contain tissue treated with a CTZ formulation. In each case, the treated tissue was placed between the diaper core and the diaper backsheet. The modified diapers were cut with a 2.54 cm (1 inch) diameter die to produce mini-diapers, which were then subjected to four consecutive 2-hour voids of 0.63 ml of pH 7.5 PBS, equivalent to 45 ml of pH 7.5 PBS for a full diaper voiding dose. Bioluminescence relative light units (RLU) were measured in a GloMax® Discover System Luminometer (Promega, Madison, WI). RLU plots are shown in Figure 14A for 0, 6, and 12 weight percent SAP contents and in Figure 14B for 18, 24, and 36 weight percent SAP contents. Example of inorganic salt application PBS buffer was used as a carrier solution for treating the pulp strips with aluminum chloride. Each strip of pulp was treated with its weight of PBS buffer containing aluminum chloride. For example, if it was desired to have a pulp treated with 1% aluminum chloride, PBS buffer containing 1% aluminum chloride was used. If it was desired to have a pulp treated with 2% aluminum chloride, PBS buffer containing 2% aluminum chloride was used, etc.

[0258] After treatment, the pulp strips were dried and then fiberized in a Kamas hammer mill. 7.4g of fiber was mixed with 4.2g of BASF T A pad was formed by mixing with 9400 SAP, and the pad was then pressed at 0.34 MPa (50 psi) for 20 seconds.

[0259] Addition of aluminum and magnesium inorganic salts was found to suppress reaction conditions due to an (unfavorable) drop in pH after the initial excretion. Further excretion buffers or raises the pH, which then favors reaction conditions, resulting in a stronger light production peak after several excretions (see Figure 16).

[0260] The addition of other inorganic salts that do not lower the pH will counteract the effect of SAP, for example by increasing the osmotic pressure within the fluff pulp, thus making more free water available for the aqueous system to initiate the chemiluminescence reaction. Conclusion and Illustrative Embodiments The various exemplary ranges set forth for the components and materials discussed herein are each intended to encompass the upper and / or lower limits of the given range examples, as well as all subranges within the given ranges, without explicitly reciting such subranges. Similarly, the various exemplary combinations of the components, steps, processes, materials, concepts, and principles discussed above, e.g., in various processing materials, absorbent articles, formulations, processing methods, production methods, etc., are intended to encompass all combinations thereof that would be apparent to those skilled in the art in light of this disclosure, without explicitly reciting such combinations. Thus, while exemplary embodiments have been illustrated and described, it will be understood that various changes can be made therein without departing from the spirit and scope of the present disclosure.

[0261] As used herein, the term "about," when referring to a quantity, refers to a number within a range of slight variations above and below a stated reference number. For example, "about" can refer to a number within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% above or below the stated reference number. In some embodiments, "about" refers to a number within 5% above or below the stated reference number. In some embodiments, "about" refers to a number within 10% above or below the stated reference number. In some embodiments, "about" refers to a number within 1% above or below the stated reference number. The present specification includes the following aspects of the invention. [1] A structural element for incorporation into an absorbent article, comprising: a first surface having a treated area, the treated area being treated with at least one component of a chemiluminescent system adapted to react in the presence of an aqueous system to produce light; the at least one component is selected from luciferin and luciferase; A structural element, wherein the treated area is smaller than the area of the first surface. [2] the first surface includes a target area corresponding to an area where one or more fluid discharges are expected during use of an absorbent article in which the structural element is incorporated; 10. The structural element according to claim 1, wherein the treatment area at least partially overlaps the target area. [3] the target areas include two or more areas corresponding to areas of expected sequential fluid discharge during use of the absorbent article; [2] The structural element according to [2], wherein the treatment area includes two or more discrete portions that at least partially overlap the two or more regions. [4] The structural element described in [3], wherein a first portion of the two or more discrete portions is configured to generate visible light that differs in at least one visual aspect from a second portion of the two or more discrete portions. [5] The structural element of [4], wherein the first portion is configured to provide a different intensity of visible light than the second portion. [6] The structural element according to [4], wherein the first portion is configured to provide visible light of a different color than the second portion. [7] The structural element of [4], wherein the first portion of the treatment area is configured to provide visible light of a different duration than the second portion. [8] A structural element according to any one of [3] to [7], wherein each of the two or more portions of the treatment area overlaps only with a corresponding area of each of the two or more regions. [9] The structural element according to [4], wherein the first and second portions of the two or more discrete portions overlap the corresponding regions to different degrees.

[10] A structural element according to any one of [3] to [9], wherein at least two of the two or more regions are substantially concentric.

[11] The target areas include two or more areas corresponding to areas of expected sequential fluid discharge during use of the absorbent article; [2] The structural element according to [2], wherein the treated area at least partially overlaps one of the two or more regions but does not overlap another of the two or more regions.

[12] A structural element according to any one of [1] to

[10] , wherein the treated area is in the form of a continuous shape.

[13] A structural element according to

[12] , wherein the treated area is in the form of a longitudinal strip.

[14] A structural element according to

[12] or

[13] , wherein the first surface has a length and the longitudinal strip has a length that is shorter than the length of the first surface.

[15] A structural element according to any one of [1] to

[10] , wherein the treated area is in the form of a pattern including two or more discrete portions.

[16] A structural element according to

[15] , wherein the pattern is in the form of discontinuous longitudinal strips.

[17] A structural element according to

[15] or

[16] , wherein the first surface has a length and the longitudinal strip has a length that is shorter than the length of the first surface.

[18] The structural element according to

[15] , wherein the pattern is in the form of an array of shapes.

[19] The structural element of

[15] or

[18] , wherein the pattern extends over an area that is smaller than the total area of the first surface.

[20] The structural element according to any one of [1] to

[19] , wherein the at least one component is luciferin.

[21] The structural element according to

[20] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogues, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[22] The structural element according to any one of [1] to

[19] , wherein the at least one component is luciferase.

[23] The structural element according to

[22] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[24] The structural element according to any one of [1] to

[19] , wherein the at least one component is luciferin and luciferase.

[25] The luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine; 24. The structural element according to claim 23, wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[26] A structural element according to

[24] or

[25] , wherein the treated areas comprise separate areas, one area treated with luciferin and another area treated with luciferase.

[27] The structural element according to

[26] , wherein the separate areas are adjacent to each other.

[28] The structural element according to

[26] , wherein the separate regions overlap.

[29] A structural element described in any of [1] to

[28] , wherein the treated area is a first treated area and the first surface further comprises a second treated area treated with a non-chemiluminescent wetness indicator.

[30] The structural element according to

[29] , wherein the first and second treatment areas do not overlap.

[31] A structural element according to any one of [1] to

[30] , wherein the treated area is approximately 1 to 99% of the area of the first surface, or any range therein.

[32] The structural element according to any one of [1] to

[31] , which is in a form selected from the group consisting of an absorbent core, a layer of material used within the absorbent core, a liquid-permeable sheet, a liquid-impermeable sheet, a tissue sheet, and a backsheet.

[33] An absorbent article incorporating a structural element according to any one of [1] to

[32] , wherein the absorbent article is in a form selected from the group consisting of a baby diaper, a wearable adult incontinence product, a feminine hygiene product, a pet pad, and a bed pad.

[34] A method for producing a structural element according to any one of [1] to

[32] , comprising a step of applying a formulation to the first surface of the structural element to form the treated area, the formulation comprising at least one component of the chemiluminescence system.

[35] The method of

[34] , wherein the formulation is an ink formulation, and applying the formulation comprises applying the ink formulation by printing.

[36] The method of

[35] , wherein the printing comprises inkjet printing.

[37] The method of

[36] , wherein the inkjet printing comprises continuous inkjet printing.

[38] A method of producing a structural element for incorporation into an absorbent article that has been treated with at least one component of a chemiluminescent system that reacts in the presence of an aqueous system to produce light, comprising: applying a formulation to a predetermined area of a first surface of a structural element, said formulation comprising said at least one component, said at least one component being selected from luciferin and luciferase.

[39] The method of

[38] , wherein the predetermined area at least partially overlaps an area where one or more fluid discharges are expected during use of an absorbent article in which the structural element is incorporated.

[40]

[38] or

[39] , wherein the predetermined area is in the form of a continuous shape. The method described.

[41] The method according to any one of

[38] to

[40] , wherein the predetermined area includes two or more discrete portions.

[42] The method of

[41] , wherein the predetermined area is in the form of a pattern comprising two or more discrete portions.

[43] The method according to any one of

[37] to

[42] , wherein the at least one component is luciferin.

[44] The method according to

[43] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogues, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[45] The method according to any one of

[38] to

[42] , wherein the at least one component is luciferase.

[46] The method according to

[45] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[47] The method according to any one of

[38] to

[42] , wherein the at least one component is luciferin and luciferase.

[48] The method of

[47] , wherein the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine, and / or the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[49] The method of

[47] , wherein the step of applying a formulation comprises applying at least two formulations, one of the at least two formulations containing the luciferin and another of the at least two formulations containing the luciferase.

[50] The method of

[49] , wherein the step of applying the at least two formulations comprises applying the at least two formulations separately.

[51] The method according to

[49] or

[50] , wherein the at least two formulations are applied to non-overlapping portions of the predetermined area.

[52] The method according to any one of

[38] to

[51] , wherein the formulation is an ink formulation, and the step of applying the formulation comprises applying the ink formulation by printing.

[53] The method of

[52] , wherein the printing comprises inkjet printing.

[54] The method of

[53] , wherein the inkjet printing comprises continuous inkjet printing.

[55] The method according to any one of

[38] to

[54] , further comprising the step of applying a non-chemiluminescent wetness indicator to the first surface.

[56] The method of

[55] , wherein the non-chemiluminescent wetness indicator is applied so as to at least partially overlap the predetermined area.

[57] The method of

[55] , wherein the non-chemiluminescent wetness indicator is applied to the predetermined area so as not to overlap.

[58] A liquid-permeable tissue sheet comprising cellulosic fibers and having two opposing surfaces. 1. A treated tissue composition comprising: At least one of the two opposing surfaces is treated with at least one component of a chemiluminescence system adapted to react in the presence of an aqueous system to produce light. It has been the at least one component is selected from luciferin and luciferase; A treated tissue composition, wherein said at least one component is retained on said at least one surface.

[59] The treated tissue composition of

[58] , wherein the at least one component is luciferin.

[60] The treated tissue composition of

[59] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[61] The treated tissue composition according to

[59] , wherein the luciferin is coelenterazine.

[62] The treated tissue composition of

[61] , comprising about 0.00002 to about 20 weight percent coelenterazine.

[63] The treated tissue composition of

[61] , comprising about 0.00002 to about 0.01 weight percent coelenterazine.

[64] The treated tissue composition of

[61] , comprising about 0.01 to about 2 weight percent coelenterazine.

[65] The treated tissue composition of

[61] , comprising about 2 to about 10 weight percent coelenterazine.

[66] The treated tissue composition of

[61] , comprising about 1 to about 6 weight percent coelenterazine.

[67] The treated tissue composition of

[61] , comprising about 10 to about 20 weight percent coelenterazine.

[68] The treated tissue composition of

[61] , wherein the liquid-permeable tissue sheet is about 0.1 to 235 mm wide and contains about 0.01 mg to 25 g of coelenterazine per 12 inches of length, which is less than or equal to the weight of an untreated tissue sheet having a length of 12 inches.

[69] The treated tissue composition of

[61] , wherein the liquid-permeable tissue sheet is about 0.1 to 235 mm wide and contains about 0.1 to 100 mg of coelenterazine per 12 inches of length, the weight of coelenterazine per 12 inches of length being less than or equal to the weight of an untreated 12-inch tissue sheet.

[70] The treated tissue composition according to any one of

[58] to

[69] , wherein the at least one component is held on the at least one surface by a binder.

[71] The treated tissue composition of

[70] , wherein the binder comprises one or more binders selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[72] The tissue sheet has a density of about 10 to 1500 g / m 2 The treated tissue composition according to any one of

[58] to

[71] , having a basis weight of

[73] The treated tissue composition according to any one of

[58] to

[72] , wherein the tissue sheet further contains synthetic fibers.

[74] The treated tissue composition according to any one of

[58] to

[73] , wherein the treated area of the at least one surface treated with the at least one component has a width equal to or less than the width of the liquid-permeable tissue sheet.

[75] The treated tissue composition of

[74] , wherein the treated area is in the form of a longitudinal strip.

[76] The treated tissue composition of

[75] , wherein the longitudinal strip is a continuous longitudinal strip.

[77] The treated tissue composition of

[75] , wherein the longitudinal strip is a discontinuous longitudinal strip.

[78] The treated tissue composition of

[77] , wherein the longitudinal strips are one or more of dotted line longitudinal strips and dashed line longitudinal strips.

[79] The treated tissue composition according to any one of

[75] to

[78] , wherein the longitudinal strip is a straight longitudinal strip.

[80] The treated tissue composition according to any one of

[75] to

[78] , wherein the longitudinal strip includes one or more curved portions.

[81] The treated tissue composition according to any one of

[75] to

[78] , wherein the longitudinal strip includes one or more straight portions.

[82] The treated tissue composition of

[74] , wherein the treated area is in the form of one or more shapes.

[83] The treated tissue composition according to

[74] , wherein the total treated area is about 0.003 to 100% of the area of the liquid-permeable tissue sheet.

[84] The treated tissue composition of

[58] , wherein the at least one component is luciferase.

[85] The treated tissue composition of

[84] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[86] The treated tissue composition according to any one of

[58] to

[85] , wherein the at least one component is luciferin and luciferase.

[87] The treated tissue composition of

[86] , wherein the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine, and the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[88] The treated tissue composition of

[86] or

[87] , wherein the luciferin is coelenterazine and the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase.

[89] The treated tissue composition described in any of

[58] to

[88] , further comprising a release agent adapted to promote the release of the at least one component from the at least one surface in the presence of an aqueous system.

[90] The treated tissue composition according to any one of

[58] to

[89] , which comprises at least two liquid-permeable layers, one of which is the liquid-permeable tissue sheet.

[91] The treated tissue composition of

[90] , comprising first and second liquid-permeable tissue sheets, at least one surface of each tissue sheet being treated with a different component of the chemiluminescent system.

[92] The treated tissue composition of

[90] or

[91] , wherein the liquid-permeable tissue sheet is sandwiched between two liquid-permeable layers.

[93] An absorbent core for an absorbent article, comprising the treated tissue composition according to any one of

[58] to

[92] .

[94] An absorbent core according to

[93] , comprising an absorbent structure at least partially surrounded by the treated tissue composition according to any one of

[58] to

[92] .

[95] The absorbent core according to

[94] , wherein the absorbent structure is an absorbent pad.

[96] An absorbent article comprising an absorbent core according to

[94] or

[95] .

[97] The treated tissue composition according to any one of

[58] to

[92] 1. An absorbent core for an absorbent article comprising an absorbent structure partially surrounded by a treated tissue composition, the treated tissue composition comprising luciferin and the absorbent structure comprising luciferase.

[98] An indicator particle comprising hydrogen-bonded cellulose pulp fibers and at least one component of a chemiluminescence system adapted to react in the presence of an aqueous system to produce light, the at least one component is selected from luciferin and luciferase; Indicator particles, wherein said at least one component is held on said hydrogen-bonded cellulose pulp fibers.

[99] The indicator particle according to

[98] , wherein the at least one component is disposed on the hydrogen-bonded cellulose fibers on at least one surface of the indicator particle.

[0100] An indicator particle as described in

[98] , wherein the at least one component is disposed on the hydrogen-bonded cellulose pulp fibers throughout the indicator particle.

[0101] Indicator particles described in

[98] , wherein the at least one component is luciferin.

[0102] An indicator particle described in

[0101] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogues, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[0103] The indicator particle described in

[98] , wherein at least one component is luciferase.

[0104] The indicator particle described in

[0103] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0105] An indicator particle described in

[0103] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase. the at least one component comprises both luciferin and luciferase; the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine; The indicator particle according to

[98] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0107] An indicator particle described in

[0106] , wherein the luciferin is coelenterazine and the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase.

[0108] Indicator particles according to

[0107] , comprising approximately 0.00002 to 20.0 weight percent coelenterazine.

[0109] Indicator particles according to

[0107] , comprising approximately 0.00002 to 0.01 weight percent coelenterazine.

[0110] Indicator particles according to

[0107] , comprising about 0.01 to 0.20 weight percent coelenterazine.

[0111] Indicator particles according to

[0107] , comprising about 0.2 to 5.0 weight percent coelenterazine.

[0112] Containing about 5.0 to 20.0 weight percent coelenterazine, The indicator particle according to claim 1.

[0113] An indicator particle described in any one of

[98] to

[0112] , which contains approximately 0.0003 to 10.0 weight percent luciferase.

[0114] An indicator particle according to

[0113] , comprising approximately 0.001 to 0.10 weight percent luciferase.

[0115] An indicator particle according to

[0113] , comprising approximately 0.10 to 2.0 weight percent luciferase.

[0116] An indicator particle according to

[0113] , comprising approximately 2.0 to 10 weight percent luciferase.

[0117] An indicator particle described in

[0106] , comprising approximately 0.00002 to 20.0 weight percent coelenterazine and approximately 0.0003 to 10.0 weight percent luciferase, wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase.

[0118] having a length, a width, and a thickness, the length is equal to or greater than the width, The indicator particle according to any one of

[98] to

[0117] , wherein the width is equal to or greater than the thickness.

[0119] An indicator particle as described in

[0118] , wherein the ratio of the length to the width is less than about 1.5.

[0120] The product of the length and the width is about 0.1 to 300 mm2 Indicator particles according to

[0118] , which are between:

[0121] The product of the length and the width is about 8 to 30 mm 2 Indicator particles according to

[0118] , which are between:

[0122] An indicator particle as described in

[0118] , wherein the ratio of the length to the width is about 1.5 or more.

[0123] The cross-sectional area of the indicator particle is about 0.01 to 200 mm 2 Indicator particles according to

[0122] , which are within the range of

[0124] Indicator particles described in

[0122] or

[0123] , wherein the length is within the range of approximately 1 to 800 mm.

[0125] Indicator particles described in

[0122] or

[0123] , wherein the length is within the range of approximately 1 to 350 mm.

[0126] Indicator particles described in any one of

[0121] to

[0125] , wherein the width is within the range of approximately 0.5 to 2.5 mm and the thickness is within the range of approximately 0.05 to 2.0 mm.

[0127] Indicator particles described in any one of

[98] to

[0126] , further containing synthetic fibers.

[0128] Indicator particles described in

[0127] , wherein the fiber diameter of the synthetic fibers is within the range of approximately 1 to 100 microns.

[0129] The indicator particles have a density of about 10 to 850 g / m 2 The indicator particles according to any one of

[98] to

[0128] , having a basis weight within the range of

[0130] An indicator particle described in any of

[98] to

[0129] , further comprising a binder, the binder being configured to hold the at least one component on the hydrogen-bonded cellulose pulp fibers.

[0131] Indicator particles described in

[0130] , wherein the binder comprises one or more binders selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[0132] An indicator particle described in

[0131] , wherein at least one component is luciferin.

[0133] When the indicator particles are in contact with an aqueous system, the indicator particles are adapted to promote the transport of the at least one component and / or the aqueous system relative to the indicator particles. The indicator particles according to any one of

[98] to

[0132] , further comprising a porous transfer agent incorporated therein.

[0134] An indicator particle described in

[0133] , wherein the porous transport agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

[0135] An indicator particle described in any of

[98] to

[0134] , further comprising a release agent adapted to promote the release of at least one component from the hydrogen-bonded cellulose pulp fibers in the presence of an aqueous system.

[0136] An absorbent article comprising a plurality of indicator particles according to any one of

[98] to

[0135] .

[0137] further comprising a liquid permeable topsheet, a liquid impermeable backsheet, and an absorbent material disposed between the topsheet and the backsheet; An absorbent article as described in

[0136] , wherein the indicator particles are disposed between the top sheet and the back sheet.

[0138] An absorbent article described in

[0136] or

[0137] , wherein the indicator particles are disposed between the absorbent material and the back sheet.

[0139] An absorbent article described in any one of

[0136] to

[0138] , wherein each of the plurality of indicator particles contains both luciferin and luciferase. the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine; The absorbent article described in

[0139] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase. wherein the luciferin is coelenterazine and the luciferase is one or more of Gaussia luciferase, Renilla luciferase, and Metridia luciferase; An absorbent article as described in

[0140] , wherein the plurality of indicator particles collectively contain approximately 0.0001 to 20.0 mg of coelenterazine and a total of approximately 0.00003 to 20.0 mg of luciferase.

[0142] synthetic fibers; at least one component of a chemiluminescent system adapted to react in the presence of an aqueous system to produce light; wherein the at least one component is selected from luciferin and luciferase.

[0143] An article described in

[0142] , wherein the synthetic fibers form an absorbent matrix.

[0144] An article described in

[0143] , wherein the absorbent matrix comprises synthetic fibers.

[0145] An article described in any of

[0142] to

[0144] , wherein at least one of the components is luciferin.

[0146] The article described in

[0145] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogues, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[0147] An article described in any of

[0142] to

[0146] , wherein at least one component is luciferase.

[0148] The article described in

[0147] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0149] The article described in

[0148] , wherein the luciferase is Gaussia luciferase.

[0150] The article described in

[0148] , wherein the luciferase is Renilla luciferase.

[0151] The article described in

[0148] , wherein the luciferase is Metridia luciferase.

[0152] The article described in

[0148] , wherein the luciferase comprises two or more luciferases selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase. the chemiluminescence system comprises both luciferin and luciferase; the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine; An article described in any one of

[0142] to

[0144] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0154] The article described in

[0153] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase.

[0155] An article described in any of

[0142] to

[0154] configured as an absorbent core for use in an absorbent article.

[0156] An article described in

[0155] , wherein the synthetic fiber is at least partially surrounded by a liquid-permeable material.

[0157] An article described in

[0156] , wherein the liquid-permeable material is a tissue sheet.

[0158] An article described in

[0157] , wherein the tissue sheet comprises fibers selected from the group consisting of cellulose fibers, synthetic fibers, and combinations thereof.

[0159] An article described in any one of

[0142] to

[0157] , wherein at least one component is held on the synthetic fiber.

[0160] An article described in

[0159] , further comprising a binder, the binder configured to hold the at least one component on the synthetic fibers.

[0161] An article described in

[0160] , wherein the binder comprises one or more binders selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[0162] An article described in any of

[0159] to

[0161] , further comprising a release agent adapted to promote the release of at least one component from the synthetic fiber in the presence of an aqueous system.

[0163] An absorbent article incorporating an article described in any one of

[0142] to

[0162] .

[0164] An absorbent article, a liquid permeable topsheet; a backsheet that is liquid impermeable; an absorbent material disposed between the topsheet and the backsheet; at least one structural element selected from the group consisting of a liquid-permeable tissue sheet and particles comprising hydrogen-bonded cellulose pulp fibers; a chemiluminescent system adapted to react in the presence of an aqueous system to produce light; wherein the first component of the chemiluminescent system is transferred to the second component of the chemiluminescent system by the aqueous system moving through the absorbent article, an absorbent article, wherein luminescent components are separately disposed in or on two or more of the group consisting of the absorbent material, the topsheet, the backsheet, and the at least one structural element.

[0165] An absorbent article as described in

[0164] , wherein the first component is disposed within the absorbent material.

[0166] An absorbent article as described in

[0165] , further comprising a liquid-permeable tissue sheet at least partially surrounding the absorbent material, the second component being disposed on at least one surface of the liquid-permeable tissue sheet.

[0167] the chemiluminescence system comprises luciferin and luciferase; the luciferase is disposed within the absorbent material; An absorbent article as described in

[0166] , wherein the luciferin is disposed on the liquid-permeable tissue sheet. the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine; The absorbent article described in

[0167] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0169] An absorbent article described in

[0167] or

[0168] , wherein the luciferin is coelenterazine and the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase.

[0170] An absorbent article as described in

[0165] , wherein the absorbent material comprises fibers treated with the first component of the chemiluminescence system.

[0171] An absorbent article as described in

[0170] , wherein the treated fibers include cellulosic fibers.

[0172] An absorbent article, a liquid permeable topsheet; a backsheet that is liquid impermeable; a fibrous absorbent material comprising luciferase-treated fibers; a tissue sheet comprising at least one surface treated with luciferin; wherein the tissue sheet and the absorbent material are disposed between the topsheet and the backsheet in a configuration in which one of the luciferin and the luciferase is transferred to the other by an aqueous system moving through the absorbent article.

[0173] An absorbent article as described in

[0172] , wherein the tissue sheet at least partially surrounds the absorbent material to form an absorbent core. the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine; An absorbent article described in

[0172] or

[0173] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0175] An absorbent article described in any one of

[0172] to

[0174] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase, and the luciferin is coelenterazine.

[0176] An absorbent article according to

[0175] , comprising approximately 0.00001 to 100.0 mg of coelenterazine and approximately 0.00001 to 100.0 mg of total luciferase.

[0177] An absorbent article according to

[0175] , comprising approximately 0.0001 to 20.0 mg of coelenterazine and approximately 0.00003 to 20.0 mg of total luciferase.

[0178] An absorbent article according to

[0175] , comprising approximately 0.01 to 100.0 mg of coelenterazine and approximately 0.2 to 40 mg of total luciferase. at least one component of a chemiluminescence system adapted to react in the presence of an aqueous system to produce light, wherein the at least one component is selected from luciferin and luciferase; A liquid carrier A formulation comprising:

[0180] The formulation described in

[0179] , wherein at least one of the components is luciferin. the liquid carrier comprises a solvent in which the luciferin is dissolved; The formulation described in

[0180] , wherein the formulation comprises about 40 to 99 weight percent of a solvent and about 0.01 to 20 weight percent of a luciferin.

[0182] The formulation described in

[0181] , wherein the solvent is selected from the group consisting of ethanol, isopropanol, n-butanol, isobutanol, ethyl acetate, methyl acetate, isopropyl acetate, acetone, pentanone, methyl ethyl ketone, n-butyl acetate, and combinations thereof.

[0183] A formulation described in

[0181] or

[0182] , wherein the solvent comprises ethanol.

[0184] A formulation described in

[0181] or

[0182] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogues, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[0185] A formulation described in any of

[0180] to

[0184] , wherein the luciferin is coelenterazine.

[0186] A formulation described in

[0185] , comprising approximately 0.1 to 0.3 weight percent coelenterazine.

[0187] A formulation described in

[0185] , comprising approximately 0.2 to 0.5 weight percent coelenterazine.

[0188] A formulation described in

[0185] , comprising about 0.5 to 0.9 weight percent coelenterazine.

[0189] A formulation described in

[0185] , comprising approximately 0.9 to 2.0 weight percent coelenterazine.

[0190] A formulation described in

[0185] , comprising approximately 2.0 to 10 weight percent coelenterazine.

[0191] A formulation described in

[0185] , comprising approximately 10 to 20 weight percent coelenterazine.

[0192] A formulation described in any of

[0180] to

[0185] , wherein the liquid carrier is non-aqueous and the formulation further comprises approximately 0.01 to 20 weight percent luciferase.

[0193] A formulation described in any of

[0179] to

[0192] , further comprising a binder adapted to hold at least one component on a substrate material to which the formulation is applied.

[0194] The formulation of

[0192] , comprising about 0.1 to 30 weight percent of said binder.

[0195] A formulation described in

[0192] or

[0193] , wherein the binder is selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[0196] Further comprising a viscosity modifier in an amount sufficient to impart a desired viscosity to said formulation. A formulation described in any one of

[0179] to

[0195] .

[0197] A formulation according to

[0196] , comprising about 0.1 to 15 weight percent of the viscosity modifier.

[0198] A formulation described in

[0196] or

[0197] , wherein the desired viscosity is a viscosity suitable for application of the formulation by streaming.

[0199] A formulation described in

[0196] or

[0197] , wherein the desired viscosity is a viscosity suitable for applying the formulation by printing.

[0200] A formulation described in

[0196] or

[0197] , wherein the desired viscosity is suitable for application of the formulation by coating.

[0201] A formulation described in any of

[0196] to

[0200] , wherein the viscosity modifier is selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[0202] A formulation described in any of

[0180] to

[0201] , further comprising a porous transfer agent adapted to promote the transfer of at least one component and / or the aqueous system compared to the substrate material when the substrate material treated with the formulation comes into contact with an aqueous system.

[0203] A formulation according to

[0202] , comprising 0.01 to 52 weight percent of a porous transport agent.

[0204] A formulation described in

[0202] or

[0203] , wherein the porous transport agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

[0205] A formulation described in

[0179] , wherein the chemiluminescence system includes both luciferin and luciferase.

[0206] The formulation described in

[0205] , wherein the liquid carrier comprises a solvent in which the luciferin is dissolved, and the luciferase is dispersed in the liquid carrier.

[0207] A formulation described in

[0206] , comprising approximately 40 to 99 weight percent of a solvent, approximately 0.01 to 20 weight percent of a luciferin, and approximately 0.01 to 20 weight percent of a luciferase.

[0208] The formulation described in

[0206] , wherein the luciferin comprises coelenterazine and the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase.

[0209] A formulation described in

[0206] , comprising about 0.05 to about 0.2 weight percent luciferase.

[0210] A formulation described in

[0208] containing approximately 0.2 to 0.6 weight percent luciferase.

[0211] A formulation described in

[0208] containing approximately 0.1 to 1.0 weight percent luciferase.

[0212] A formulation described in

[0208] containing approximately 1.0 to 10 weight percent luciferase.

[0213] A formulation described in

[0208] containing approximately 10 to 20 weight percent luciferase.

[0214] The luciferin comprises coelenterazine, the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase, the solvent comprises ethanol, and the formulation is Approximately 50 to 99 weight percent ethanol; about 0.1 to 5.0 weight percent coelenterazine; about 0.1 to 5.0 percent luciferase by total weight; Optionally, about 0.01 to 30 total weight percent a binder adapted to hold the at least one component onto a substrate material to which the formulation is applied; and Viscosity modifier and one or more of Optionally, about 0.1 to 10 weight percent of a porous transport agent; A formulation according to

[0205] or

[0206] , comprising:

[0215] The formulation described in

[0214] , wherein the binder is selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[0216] The formulation described in

[0214] , wherein the viscosity modifier is selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[0217] A formulation described in any of

[0205] to

[0216] , further comprising a porous transport agent, wherein the porous transport agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

[0218] The component is luciferin, the luciferin comprises coelenterazine, the liquid carrier comprises a solvent in which the coelenterazine is dissolved and comprises ethanol, and the formulation is Approximately 40 to 90 weight percent ethanol; about 0.1 to 5.0 weight percent coelenterazine; about 0.01 to 15 weight percent of a binder; about 9 to 52 weight percent porous transport agent; The formulation described in

[0179] , comprising:

[0219] A formulation described in

[0218] further containing luciferase.

[0220] A formulation described in

[0218] or

[0219] , wherein the binder is selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

[0221] A formulation described in any of

[0218] to

[0220] , wherein the porous transport agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

[0222] A partially aqueous formulation for applying luciferin to a substrate material, comprising luciferin, a solvent configured to dissolve the luciferin, the solvent comprising about 40 to 99 weight percent water and about 1 to 60 weight percent of an excipient adapted to promote solubility of the luciferin in water, and optionally a binder adapted to bind the luciferin to the substrate material.

[0223] A partially aqueous formulation according to

[0222] , wherein the excipient comprises a polar protic solvent other than water.

[0224] A partially aqueous formulation according to

[0222] or

[0223] , wherein the excipient is selected from the group consisting of hydroxypropyl-β-cyclodextrin, ethanol, butanol, propanol, isopropanol, pentanone, and combinations thereof.

[0225] A partially aqueous formulation described in any of

[0222] to

[0224] , further comprising a binder, the binder comprising up to 15 weight percent of a binder selected from the group consisting of ethyl cellulose, methyl cellulose, and polyurethane.

[0226] A partially aqueous formulation according to

[0225] , comprising from about 0.01 to about 1.2 weight percent of a binder.

[0227] A partially aqueous formulation according to

[0225] , comprising from about 1.2 to about 8.0 weight percent of a binder.

[0228] A partially aqueous formulation according to

[0225] , comprising from about 8.0 to about 12.5 weight percent of a binder.

[0229] A partially aqueous formulation described in any one of

[0222] to

[0225] , further comprising a porous transport agent.

[0230] The porous transport agent according to

[0229] , wherein the porous transport agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers. The partially aqueous formulation described above.

[0231] A partially aqueous formulation described in any of

[0222] to

[0230] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogues, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[0232] A partially aqueous formulation described in

[0231] , wherein the luciferin is coelenterazine.

[0233] A partially aqueous formulation according to

[0232] , wherein the excipient comprises hydroxypropyl-β-cyclodextrin at a concentration of about 45-50 mM, and the luciferin at a concentration of up to about 3.7 mM.

[0234] A partially aqueous formulation according to

[0232] , comprising up to 11 weight percent coelenterazine in solution. 1. A method of applying luciferase to a substrate material capable of retaining moisture up to a maximum threshold level after free water has been removed, comprising: applying a formulation comprising luciferase dispersed in an aqueous liquid to the surface of the substrate material to achieve a luciferase concentration in the substrate of about 0.01 to 20 mg per gram of substrate material; wherein the applying step does not increase the moisture level of the substrate material above the threshold level of moisture.

[0236] The method described in

[0235] , wherein the substrate material is a fluff pulp sheet having a threshold moisture level of at least about 15 weight percent.

[0237] A method as described in

[0236] , wherein the composition is applied to the surface at a rate that increases the moisture level of the fluff pulp sheet by less than about 10 percent by weight.

[0238] The method described in

[0235] , wherein the substrate material has a threshold moisture level of up to about 25 weight percent.

[0239] A method described in any of

[0235] to

[0238] , wherein the luciferase formulation has a luciferase concentration of approximately 5.0 to 30 weight percent.

[0240] A method described in any of

[0235] to

[0239] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase.

[0241] The method described in

[0240] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, and Metridia luciferase. A method of applying a chemiluminescent system that reacts to produce light in the presence of free water to a substrate material that is capable of retaining moisture up to a maximum threshold level after the free water has been removed, comprising: a luciferase treatment step in which an area on the surface of the substrate is treated with a luciferase formulation comprising luciferase in an aqueous liquid; a luciferin treatment step in which the area is treated with a luciferin formulation comprising luciferin dissolved in a non-aqueous solvent; wherein the luciferase treatment step does not increase the moisture content of the substrate material above the threshold level of moisture.

[0243] The method described in

[0242] , wherein the substrate is a fluff pulp sheet having a threshold moisture level of at least about 15 weight percent.

[0244] The method described in

[0243] , wherein the luciferase formulation is applied to the surface at a rate that increases the moisture level of the fluff pulp sheet by less than about 10 weight percent.

[0245] The method described in

[0242] , wherein the threshold level of moisture is up to about 25 weight percent.

[0246] A method described in any of

[0242] to

[0245] , wherein the luciferase formulation has a luciferase concentration of approximately 5.0 to 30 weight percent. the luciferin is selected from the group consisting of coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine; The method according to any one of

[0243] to

[0246] , wherein the luciferase is selected from the group consisting of Gaussia luciferase, Renilla luciferase, Metridia luciferase, Oplophorus luciferase, dinoflagellate luciferase, copepod luciferase, and firefly luciferase. A method of producing a treated tissue composition for incorporation into an absorbent article, comprising: applying a formulation to a surface of a liquid-permeable tissue sheet, the formulation comprising luciferin and a solvent in which the luciferin is dissolved, the luciferin being retained on the liquid-permeable tissue sheet upon application of the formulation; subsequently removing said solvent from said liquid-permeable tissue sheet.

[0249] The method described in

[0248] , wherein the applying step includes streaming the formulation onto the surface.

[0250] The formulation is streamed by a streaming device; The method described in

[0249] , wherein the applying step further comprises the step of moving the liquid-permeable tissue sheet relative to the streaming device.

[0251] The method described in

[0250] , wherein the streaming device includes one or more nozzles through which the formulation is streamed, the one or more nozzles being positioned so as to contact the surface.

[0252] A method according to

[0250] or

[0251] , wherein the surface of the tissue sheet onto which the formulation is streamed is suspended between two fixed points.

[0253] A method according to any one of

[0248] to

[0251] , wherein the liquid-permeable tissue sheet is a continuous sheet.

[0254] A method according to any one of

[0248] to

[0253] , wherein the step of removing the solvent includes a step of heating the surface of the liquid-permeable tissue sheet treated with the formulation.

[0255] A method described in any of

[0248] to

[0254] , wherein the liquid-permeable tissue sheet comprises cellulosic fibers and the formulation further comprises a binder adapted to hold the luciferin on the cellulosic fibers.

[0256] The method described in

[0255] , wherein the liquid-permeable tissue sheet further comprises synthetic fibers.

[0257] A method according to any one of

[0248] to

[0256] , wherein the formulation comprises about 40 to 99 weight percent of a solvent and about 0.01 to 20 weight percent of luciferin.

[0258] The method described in

[0257] , wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogues, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

[0259] The method of

[0258] , wherein the luciferin is coelenterazine and the formulation is applied at a rate that produces the treated tissue composition having a coelenterazine concentration of about 0.00002 to about 20 weight percent.

[0260] The method of

[0257] or

[0258] , wherein the formulation is applied at a rate that produces the treated tissue composition having a luciferin concentration of about 0.001 to 10 weight percent.

[0261] Any one of

[0257] to

[0260] , wherein the solvent comprises ethanol. How to do it.

[0262] A method described in any of

[0257] to

[0261] , wherein the solvent comprises approximately 40 to 99 weight percent water and approximately 1 to 60 weight percent of an excipient configured to promote solubility of the luciferin in water.

[0263] A method according to any one of

[0257] to

[0262] , wherein the formulation further comprises about 0.01 to 30 weight percent of a binder adapted to hold the luciferin on the cellulosic fibers.

[0264] The method of

[0263] , wherein the amount of binder is selected to give the formulation a desired viscosity.

[0265] A method according to any one of

[0248] to

[0264] , wherein the formulation is applied to the surface in the form of a longitudinal strip having a width equal to or less than the width of the tissue sheet.

[0266] The method described in

[0265] , wherein the longitudinal strip is a continuous longitudinal strip.

[0267] The method described in

[0266] , wherein the longitudinal strip is a discontinuous longitudinal strip.

[0268] The method described in

[0267] , wherein the longitudinal strip is one or more of a dotted longitudinal strip and a dashed longitudinal strip.

[0269] A method according to any one of

[0265] to

[0268] , wherein the longitudinal strip is straight.

[0270] A method according to any one of

[0265] to

[0268] , wherein the longitudinal strip includes one or more curved portions.

[0271] A method according to any one of

[0265] to

[0268] , wherein the longitudinal strip includes one or more straight portions.

[0272] A method according to any one of

[0248] to

[0264] , wherein the formulation is applied to the surface in the form of one or more shapes.

[0273] A method described in any of

[0248] to

[0272] , wherein the formulation further contains luciferase.

[0274] A method according to any one of

[0248] to

[0273] , which is carried out at least in part on a tissue printing machine.

[0275] A method according to any one of

[0248] to

[0274] , wherein the luciferin is coelenterazine and the formulation is applied at a rate that produces the treated tissue composition having about 0.01 mg to 25 g of coelenterazine per 30.48 cm (12 inches) length of tissue sheet.

[0276] The method of claim 275, wherein the formulation is applied at a rate that produces the treated tissue composition having about 0.01 to 100 mg of coelenterazine per 12 inch length of tissue sheet.

[0277] The method of claim 272, wherein the formulation is applied at a rate that produces the treated tissue composition having about 0.01 to 1.0 g of coelenterazine per 12 inch length of tissue sheet.

[0278] The method according to any one of

[0275] to

[0277] , wherein the liquid-permeable tissue sheet to which the formulation is applied is continuous, and further comprising a step of dividing the liquid-permeable tissue sheet into discrete lengths following the step of applying the formulation.

[0279] 1. A method of producing an absorbent core for incorporation into an absorbent article, comprising: Producing a treated tissue composition according to any of the methods described ...

Claims

1. 1. A method for producing a liquid impervious backsheet structure for incorporation into an absorbent article comprising an absorbent material that has been treated with at least one component of a chemiluminescent system that reacts in the presence of an aqueous system to produce light, said method comprising: applying a formulation to the surface of the liquid impervious backsheet that contacts the absorbent material, the formulation comprising: said at least one component; A liquid carrier; a binder adapted to hold the at least one component on the liquid impermeable backsheet; and and subsequently removing at least a portion of the liquid carrier or at least a portion of the formulation from the liquid impervious backsheet; Including, the at least one component is luciferin, the liquid carrier comprises a solvent in which the luciferin is dissolved and which comprises ethanol; and The formulation comprises: 40 to 90 weight percent ethanol; 0.1 to 5.0 weight percent luciferin; 0.01 to 15 weight percent of a binder; 9 to 52 weight percent of a porous transport agent; The above method, comprising:

2. 10. The method of claim 1, wherein the porous transport agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

3. 3. The method of claim 1 or 2, wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, bulgurin, and furimazine.

4. The method of claim 3 , wherein the luciferin comprises coelenterazine.

5. The method of any one of claims 1 to 4, wherein the binder is selected from the group consisting of ethyl cellulose, methyl cellulose, nitrocellulose, and polyurethane.

6. 6. The method of any of claims 1 to 5, wherein the amount of one or more of the binder and the porous transfer agent is configured to provide the formulation with a viscosity that allows the formulation to remain flowable.

7. The method of any preceding claim, wherein applying the formulation to the surface comprises streaming the formulation onto the surface.

8. 8. The method of any of claims 1 to 7, further comprising applying a coating over the surface of the liquid impervious backsheet that has been treated with the formulation, wherein the coating is one or more of a water-soluble coating or a water-permeable coating.

9. The method of any of claims 1 to 8, wherein removing the liquid carrier comprises heating the surface of the liquid impervious backsheet that has been treated with the formulation.

10. 10. The method of any of claims 1 to 9, wherein removing the liquid carrier comprises contacting the surface of the liquid impervious backsheet that has been treated with the formulation with the absorbent material adapted to wick the liquid carrier from the surface of the liquid impervious backsheet.

11. The method of claim 10, wherein the absorbent material is treated with luciferase.

12. 12. The method of claim 11, wherein the absorbent material is in the form of an absorbent core comprising one or more of absorbent fibers and superabsorbent polymers.

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