CN112638339B

CN112638339B - Chemiluminescent wetness indicator for absorbent products

Info

Publication number: CN112638339B
Application number: CN201980057071.6A
Authority: CN
Inventors: 布伦特·A·彼得森; 约翰韦·高; 丹尼诗·马丁; 盖瑞·尼可雷特
Original assignee: International Paper Co
Current assignee: International Paper Co
Priority date: 2018-06-29
Filing date: 2019-06-28
Publication date: 2023-07-18
Anticipated expiration: 2039-06-28
Also published as: CN117017624A; EP3813753A2; CN117017623A; CN112638339A

Abstract

Disclosed herein are materials and structural elements for absorbent articles that incorporate at least one component of a chemiluminescent system configured to generate light upon contact with an aqueous system. The present disclosure also relates to absorbent articles incorporating the material or structural element. The present disclosure also relates to formulations and methods for treating materials or structural elements with one or more components of a chemiluminescent system. Representative absorbent articles include disposable diapers and adult incontinence products. Representative chemiluminescent systems include bioluminescent systems.

Description

Chemiluminescent wetness indicator for absorbent products

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional application No. 62/753,024 filed on 10 months and 30 days of 2018 and U.S. provisional application No. 62/692,502 filed on 6 months and 29 days of 2019 and U.S. patent application No. 16/457,732 filed on 28 days of 2019, each of which is incorporated herein by reference in its entirety.

Technical Field

Some chemiluminescent systems react in the presence of an aqueous system to produce light. Some of such chemiluminescent systems include components that react in the presence of an aqueous system to generate light, such as bioluminescent systems that include luciferin and luciferase. The present disclosure relates to materials or structural elements for absorbent articles that are treated or otherwise integrated with at least one component of such chemiluminescent systems. The present disclosure also relates to absorbent articles comprising such chemiluminescent systems, for example, in the above-described 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

Personal care absorbent products, such as infant diapers, adult incontinence pads, and feminine care products, and related absorbent articles that are not typically worn, such as absorbent mattresses, absorbent pet pads, and the like, typically comprise a fluid absorbent core comprising one or more absorbent materials. While many configurations exist, many absorbent articles include a fluid-absorbent core disposed between a topsheet and a backsheet. The topsheet is typically formed of a fluid permeable material adapted to facilitate transfer of fluid into the absorbent core, such as when contaminated with liquid, the topsheet typically having minimal fluid retention. One absorbent material commonly used in absorbent cores is southern pine fluff pulp, which is typically in the form of a fibrous matrix, sometimes in combination with superabsorbent polymers (SAP) dispersed throughout the fibrous matrix. Fluff pulp is known worldwide as the first fiber of absorbent products based on its high fiber length, fiber coarseness and its relative ease of handling from wet and dry pulp sheets to air-laid. The feedstock for this type of cellulosic fluff pulp is southern pine (e.g., loblolly pine, pinus taeda l.). The feedstock is renewable and the slurry is prone to biodegradation. These fibers are less expensive by mass than SAP, but are more expensive per unit of liquid retention. These fluff pulp fibers are mostly absorbed in the interstices between the fibers. For this reason, the fibrous matrix easily releases the obtained liquid when pressure is applied. During use of an absorbent product comprising a core formed solely of cellulosic fibres, the tendency to release the obtained liquid can lead to a significant wetting of the skin. Such products also tend to leak the liquid obtained, since the liquid is not effectively retained in such fibrous absorbent cores.

SAPs are water-swellable, typically water-insoluble, absorbent materials that have a high absorption capacity for fluids. They are used in absorbent articles such as infant diapers or adult incontinence products to absorb and retain body fluids. Upon absorbing a fluid, the SAP swells and becomes a gel, whose holding capacity exceeds the weight of its fluid. The most commonly used SAPs are derived from acrylic acid. Acrylic-based polymers also comprise a significant part of the cost structure of diapers and incontinence pads. SAP is designed to have high gel strength (as evidenced by high absorbency under load or AUL). The high gel strength (upon swelling) of the SAP particles currently used helps them to maintain a large amount of void space between the particles, which helps to quickly absorb fluids. However, this high "void volume" simultaneously results in a large amount of interstitial (between particles) liquid in the product in a saturated state. When interstitial liquid is present, the "rewet" value or "wet feel" of the absorbent product is compromised.

Advances in SAP technology have allowed for the design of absorbent core constructions in which fluff pulp contributes less to the absorbent capacity of the core, while contributing more to the provision of a matrix structure in which SAP is stably maintained. Fluff pulp fibers also provide a fluid distribution function to direct fluid to the SAP. However, it has been found that these structural and fluid distribution functions can be provided by synthetic fibers in some constructions, resulting in the development of absorbent cores comprising fluff pulp fibers and synthetic fibers, even "fluff-free" absorbent cores without fluff pulp fibers. These configurations may provide the advantage of a smaller physical volume without sacrificing absorbency.

Regardless of construction, the absorbent core is an absorbent structure that includes one or more materials suitable for absorbing fluid insults. In some constructions, the absorbent core is a self-contained component that is placed into the absorbent article during production. In such a configuration, the absorbent material of the absorbent core (e.g., fluff pulp, synthetic fibers, SAP, etc.) may be enclosed or at least partially encased in a fluid-permeable material such as a tissue sheet.

Some absorbent articles, such as diapers or adult incontinence pads, also include an Acquisition and Distribution Layer (ADL) for acquisition and even timely distribution of fluid from the fluid insult to the absorbent core. The ADL is typically placed between the topsheet and the absorbent core and is typically in the form of a composite web. In an exemplary configuration, the top third of such a fabric also has a low density (higher denier fibers), has relatively large voids and a high void volume to effectively collect the provided fluid, even at relatively high discharge rates. The middle third of the ADL composite fabric is typically made of higher density (low denier) fibers with smaller voids, while the lower third of the fabric is made of higher density (lower and smaller denier) but finer void fibers. The higher density portion of the composite fabric has more and finer capillaries and thus creates more capillary pressure to move a larger volume of fluid to the outer region of the structure, allowing the fluid to be properly directed and distributed in a uniform manner, allowing the absorbent core to absorb all liquid insult in a time-limited manner to retain the SAP within the absorbent core and gel the insult neither too slowly nor too quickly. ADLs provide faster liquid acquisition (minimizing overflow in the target area) and ensure faster fluid transport and thorough distribution into the absorbent core.

As noted above, regardless of configuration, the absorbent core functions to retain fluid and thus may be comprised of one or more layers (e.g., layers for acquisition, distribution, and/or storage of fluid). In many cases, a matrix of cellulosic fibers, for example in the form of an airlaid pad and/or nonwoven web, is used in (or as) the absorbent core of an absorbent article. In some cases, the different layers may be composed of one or more different types of cellulose fibers, such as crosslinked cellulose fibers. In some cases, synthetic fibers with or without cellulosic fibers may be used. The absorbent core may also include one or more fluid retaining agents or other absorbent materials, such as one or more SAPs, which are typically distributed as particles throughout the fibrous matrix.

The backsheet is typically formed of a fluid impermeable material to form a barrier to prevent the retained fluid from escaping.

Regardless of the construction, when the absorbent article is wetted with one or more liquid insults, the chance of liquid contacting the skin is greatly increased, which if left unchanged for an extended period of time can cause problems with infant diaper rash or adult dermatitis, thus constituting a skin health hazard. However, in general, the only way to know whether an absorbent article is dry or wet is to physically inspect it. This may not cause significant problems during the day, as the caregiver may check the wearing article (e.g., diaper or adult incontinence product) or other article (e.g., mattress) as many times as desired. On the other hand, examination at night may cause discomfort to infants and adults, thereby affecting their sleep. Furthermore, frequent night checks, such as several checks in one night, may disrupt the sleep pattern of the wearer, which constitutes a health hazard for both infants and adult users. In addition, for wearing articles such as diapers or incontinence pads, garments such as pants, pajamas and/or undergarments are often worn on absorbent articles. With articles such as mattresses or pet pads, the position of the user (human or animal) on the pad can obstruct the view of the caretaker. Thus, even absorbent articles incorporating different types of wetness and/or moisture indicators have difficulty finding soil in time.

As a result, there is typically a period of time between the soil and the discovery thereof. If this period of time is prolonged, diaper rash, skin irritation and/or skin peeling may occur. These conditions can be very painful for the affected person. This is especially true for infants and adults in caregivers facilities, and for night soil, which may result in longer times before absorbent articles are replaced.

While these problems may not be as urgent for absorbent products that are not typically worn against the body (e.g., absorbent mattresses), maintaining the hygiene and comfort of the user remains an important goal.

Previous wetness indicators incorporated into absorbent articles use color changes as a visual indicator of wetness detection. Ink that appears or disappears based on contact with liquid is a common mechanism for detecting humidity. Fluorescence has also been used for humidity detection, for example by binding compounds that fluoresce in the presence of a liquid. The mechanisms of such indicators generally fall into three broad categories: (1) Printing a moisture indicating pattern on one of the sheets of the absorbent article; (2) A discrete wetness indicator or layer incorporated between the layers of the absorbent article; and (3) a discrete (i.e., not part of the construction of the absorbent article) indicator strip secured to the interior of the absorbent article immediately prior to use.

Regardless of the mechanism, these visual indicators are inadequate in low light (e.g., nighttime) situations. The presence or absence of ink must be detected directly visually, requiring the caregiver to directly view the absorbent product. In low light situations, this may require both a light source (e.g., overhead light or flashlight) and the removal of a covering garment (e.g., pajamas or undergarments). Fluorescent indicators suffer from similar problems because they require an external light source to excite the fluorescent compound. Such excitation is typically provided by exposing the indicator to ultraviolet light (which has an effect on the health of the wearer and caretaker) and must be in direct optical communication with the fluorescent compound, and then removing the overlying garment, blanket, etc. is required. Thus, the use of visual indicators previously used to detect wetness in absorbent garments has a number of drawbacks in low light conditions that greatly reduce the usefulness of their indication mechanisms.

Each of these solutions for wetness detection of absorbent articles is insufficient to meet the need for night soil detection. First, all techniques do not trigger reliably, and even if triggered, direct luminous visual inspection is required for detection.

Accordingly, conventional absorbent articles are inadequate when alerting caregivers to the creation of soil at night and/or under clothing.

U.S. patent application Ser. No. 14/516,255, the entire disclosure of which is incorporated herein by reference, discloses fluff pulp compositions treated with a chemiluminescent system configured to generate visible light upon contact with an aqueous system, and absorbent articles incorporating such treated fluff pulp compositions.

Disclosure of Invention

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.

In one aspect of the disclosure, materials treated with one or more reactive components of a chemiluminescent system are provided. Generally, two-component systems, such as bioluminescent systems, are discussed, including luciferin and luciferase. In such embodiments, the treated material includes at least one reactive component of such a chemiluminescent system. However, these components react in the presence of an aqueous system to produce light. Thus, one challenge is to incorporate the reactive components into the material and/or absorbent article in a manner that does not prematurely initiate the luminescent reaction, for example, during production or storage, but only during use of the absorbent article, in particular, when the absorbent article receives fluid insult.

Thus, some materials are treated with only one reactive component. In use, embodiments in which the treated material comprises only one reactive component will typically be incorporated into the absorbent article in an arrangement with the other reactive components disposed elsewhere in the absorbent article (e.g., in another treated material or layer), wherein when the absorbent article receives fluid insult, such as when the aqueous fluid of the insult moves from the topsheet to the backsheet (for example), one reactive component will transfer to the other, thereby reacting and initiating a luminescent reaction. However, in some embodiments, the treated material includes two components that react with each other to produce light. In use, the reaction is typically initiated when the aqueous system contacts the treated material.

Materials are those materials that are commonly incorporated into absorbent articles. The material may be an absorbent or non-absorbent material.

In some embodiments, the treated 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 in a manner that the components remain on the surface. The treated tissue composition may be incorporated into an absorbent article, for example as a material that encapsulates the absorbent core. In some embodiments, the material is formed from hydrogen bonds An indicator particle formed from synthetic cellulose pulp fibers treated with one or more of luciferin and luciferase retained on the surface of the particle and/or throughout the particle. In such embodiments, the indicator particles may take a variety of physical forms. For example, the indicator particles may be in the form of flakes having two opposing faces and an aspect ratio (length to width ratio) of less than 1.5, wherein one or both of the faces has an area of 0.1 to 300mm ² . As another example, the indicator particles may be in the form of elongated strips having an aspect ratio of greater than or equal to 1.5 and a cross-sectional area of 0.01-200mm ² The length is 1-800mm. In use, one or more indicator particles may be incorporated into the absorbent article, such as being disposed or distributed within the absorbent core, or between the absorbent core and the backsheet. The physical form of the particles may vary for a particular configuration and/or size of the absorbent core or absorbent article.

In another aspect of the disclosure, an article includes a synthetic fiber 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 (e.g., a fluff-free absorbent core) of an absorbent article.

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, an absorbent article includes a liquid permeable topsheet, a liquid impermeable backsheet, an absorbent material disposed therebetween, and a chemiluminescent system, the reactive components of which are independently disposed within the absorbent article in a configuration wherein the reactive components are transferred to one another by an aqueous system moving through the absorbent article. In such embodiments, the reactive component is disposed in or on a different structural element of the absorbent article, such as an absorbent material, a topsheet, a backsheet, a liquid permeable tissue sheet, treated indicator particles, or the like. In an illustrative and non-limiting example of such an embodiment, the chemiluminescent system includes luciferin and luciferase, the luciferase being disposed within the fibrous absorbent material, and the luciferin being disposed on a sheet of tissue that may form a wrapper of the absorbent material such that the absorbent material and the sheet of tissue together form an absorbent core. In this example, when the absorbent article receives fluid insults, fluid flowing through the absorbent article toward the absorbent core will encounter the luciferin on the tissue sheet and transfer it to the luciferase in the absorbent material (and vice versa), thereby initiating a luminescent reaction. In some embodiments incorporating a fluff-free absorbent core, the chemiluminescent system includes luciferin and luciferase, the luciferase being disposed in an absorbent material comprising superabsorbent material, and the luciferin being disposed on a sheet of tissue, which may form a wrapper of the absorbent material. In some embodiments incorporating a fluff-free absorbent core, the chemiluminescent system is disposed within the core material or other structure(s) without tissue wrapping. In some embodiments, a structural element for incorporation into an absorbent article includes a first surface having a treated region treated with at least one component of a chemiluminescent system, wherein the total treated area is less than the area of the first surface.

In yet another aspect of the present disclosure, a formulation is provided for treating a matrix material with one or more reactive components of a chemiluminescent system, particularly luciferin and luciferase. 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 of such embodiments include a binder adapted to retain the reactive components on the matrix material. Some of such embodiments include a viscosity modifier to impart a desired viscosity to the formulation, for example, a viscosity suitable for application processes such as flow coating, printing, coating, and the like. Some of such embodiments include a porous transfer agent. The porous transfer agent is adapted to facilitate transfer of the reaction component(s) and/or the aqueous system relative to the matrix material after contacting the matrix material treated with the formulation through the aqueous system. In other embodiments, at least one component of the chemiluminescent system is applied to one or more substrates as a dry formulation within a dry carrier material. The dry carrier material may include any inert material to allow for the application of flowable or dispersible formulations in machinery such as, but not limited to, sugars, minerals or salts thereof, starches, silica, clays, talc, micronized wood or other cellulose, gelatin, agar and SAP.

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 a solvent and the luciferase is dispersed in a liquid carrier.

In some embodiments, particularly for applying luciferin to a matrix material, a partial aqueous formulation is used. Such examples include luciferins, solvents that dissolve luciferins, including water, and excipients suitable for promoting the solubility of luciferins in water (e.g., hydroxypropyl-beta-cyclodextrin, ethanol, water soluble polymers such as 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, salts thereof, and the like. Some of such embodiments include a binder adapted to bind the luciferin to the matrix material. Some excipients, while inert to chemiluminescent reactions, provide additional benefits. For example, such additional benefits include the effect on the solubility of a given component of the chemiluminescent system in various aqueous and non-aqueous solvent systems, the effect on the water availability in the absorbent article, the retention of one or both components of the chemiluminescent system on various substrates (e.g., binders), the release of one or both components of the chemiluminescent system (e.g., porous transfer agents), and the like. Some such excipients may have a variety of these or other functions. Thus, excipient usage in the present teachings is not limited to partially aqueous formulations.

Within these broad parameters, formulations according to the present disclosure may include components and their relative amounts suitable for a variety of applications. In illustrative and non-limiting examples of such embodiments, formulations suitable for applying coelenterazine (luciferin) to a liquid impermeable backsheet typically formed of a synthetic material include ethanol, coelenterazine, a binder, and a porous transfer agent. In another illustrative and non-limiting example, a formulation suitable for applying coelenterazine and luciferase to a cellulosic substrate material includes ethanol, coelenterazine, luciferase (e.g., gaussia, renilla, and/or Metridia luciferase), a binder and/or viscosity modifier, and a porous transfer agent. As explained in more detail herein, the nature of the matrix material of the applied formulation is a factor for determining whether the binder is suitable. For example, the binder may be beneficial for a formulation to be applied to a matrix material comprising synthetic fibers, whereas the binder may not be needed in a formulation to be applied to a matrix material consisting of cellulosic fibers.

In yet another aspect of the present disclosure, a method of treating a host material with one or more reactive components of a chemiluminescent system is provided. As described above, these components react in the presence of an aqueous system to produce light. Thus, one challenge in incorporating reactive components into materials and/or absorbent articles is to do so in a manner that does not unduly initiate a luminescent reaction. In some embodiments, a method includes applying a luciferase formulation dispersed in an aqueous liquid to a matrix material sufficient to achieve a desired luciferase concentration on the matrix material, but not increasing the moisture content of the matrix material above a threshold level of moisture. Such a method may provide the advantage of reducing the need for a subsequent drying step, for example if luciferin is also applied to the matrix material. In some embodiments, a method includes separate luciferase and luciferin treatment steps, wherein the areas on the surface of the matrix material are treated with a luciferase formulation including a luciferase dispersed in an aqueous liquid and separately with a luciferin formulation including luciferin dissolved in a non-aqueous solvent.

In yet another aspect, a method for producing an absorbent article or a structural element for incorporation into an absorbent article is provided, for example using one or more of the treated materials described above. In some embodiments, the treated tissue composition may be produced by applying a formulation comprising luciferin dissolved in a solvent to a liquid permeable tissue sheet, for example by flow coating the formulation to a surface, followed by removal of the solvent from the tissue sheet. In some of such embodiments, the sheet of tissue may be a continuous sheet that moves relative to one or more nozzles of the flow-coating formulation, with the surface of the sheet of tissue to which the formulation is applied hanging between two fixed points. In such embodiments, the solvent may be removed by subsequently thermally treating the treatment surface, for example by moving the treatment surface through a heated zone.

In yet another aspect, a chemiluminescent system is provided in a form suitable for use in an absorbent article, or in one or more materials and/or structural elements thereof. In some embodiments, the composition includes an encapsulating material comprised of particles including a predetermined amount of a first component of the chemiluminescent system and a predetermined amount of a second component of the chemiluminescent system, the particles having a water permeable or water soluble coating covering the entire surface of the particles. Such a composition may be suitable for incorporation into an absorbent article or a component thereof, for example, by an end user during production or prior to use of the absorbent article. Some embodiments may be in the form of a kit comprising an absorbent article having incorporated therein a first component of a chemiluminescent system, and a measured amount of a second component of the chemiluminescent system adapted to react with the first component to produce light of a predetermined duration and/or intensity. In some of such embodiments, the measured quantity may be in the form of a liquid formulation, gel, powder, or the like, for example, that is applied to the absorbent article by an end user of the absorbent article prior to use of the absorbent article.

Representative absorbent articles include disposable diapers and adult incontinence products.

Drawings

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:

FIG. 1 shows, by photograph, an exemplary absorbent article incorporating a chemiluminescent fluff pulp composition.

FIG. 2A is a chemical structure of a representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 2B is a chemical structure of a representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 2C is a chemical structure of another representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 2D is a chemical structure of another representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 2E is a chemical structure of another representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 2F is a chemical structure of another representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 2G is a chemical structure of another representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 2H is a chemical structure of another representative luciferin compound that may be used in a chemiluminescent system according to embodiments disclosed herein;

FIG. 3 graphically illustrates spectral properties of representative luciferins, in accordance with embodiments disclosed herein;

FIG. 4A shows a perspective view of a non-limiting representative example of an absorbent article (in the form of a diaper) according to embodiments disclosed herein;

FIG. 4B is a top plan view of the absorbent article of FIG. 4A;

FIG. 4C illustrates an exemplary cross section of the absorbent article of FIG. 4A according to an embodiment of the present disclosure;

FIG. 4D illustrates an exemplary cross section of the absorbent article of FIG. 4A according to an embodiment of the present disclosure;

FIG. 4E illustrates an exemplary cross section of the absorbent article of FIG. 4A according to an embodiment of the present disclosure;

FIG. 4F illustrates an exemplary cross section of the absorbent article of FIG. 4A in accordance with embodiments of the present disclosure;

FIG. 5A shows a perspective view of a non-limiting representative example of a treated tissue composition according to embodiments disclosed herein;

fig. 5B shows a perspective view of a non-limiting representative example of another treated tissue composition in accordance with embodiments disclosed herein;

Fig. 5C shows a perspective view of a non-limiting representative example of another treated tissue composition in accordance with embodiments disclosed herein;

FIG. 5D illustrates a cross-sectional view of a non-limiting representative example of a treated tissue composition according to an embodiment of the present disclosure;

fig. 5E illustrates a cross-sectional view of another non-limiting representative example of a treated tissue composition in accordance with an embodiment of the present disclosure;

FIG. 5F illustrates a cross-sectional view of another non-limiting representative example of a treated tissue composition according to an embodiment of the present disclosure;

FIG. 5G illustrates a cross-sectional view of another non-limiting representative example of a treated tissue composition according to an embodiment of the present disclosure;

FIG. 6A shows a non-limiting representative example of an indicator particle according to embodiments disclosed herein;

FIG. 6B shows a non-limiting representative example of another indicator particle according to embodiments disclosed herein;

FIG. 7 shows a non-limiting representative example of an article in the form of an absorbent core according to embodiments disclosed herein;

fig. 8A schematically illustrates a non-limiting representative example of a flow coating apparatus suitable for producing a treated tissue composition according to embodiments disclosed herein;

Fig. 8B schematically illustrates a non-limiting representative example of a flow coating apparatus suitable for producing a treated tissue composition according to embodiments disclosed herein;

FIG. 9A shows a non-limiting representative example of structural elements for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9B shows a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9C shows a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9D illustrates a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9E shows a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9F shows a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9G illustrates a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9H illustrates a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9I illustrates a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 9J illustrates a non-limiting representative example of another structural element for incorporation into an absorbent article according to embodiments disclosed herein;

FIG. 10 graphically illustrates the change in chemiluminescent intensity exhibited by a representative exemplary treated material according to embodiments disclosed herein;

FIG. 11 graphically illustrates the change in chemiluminescent intensity exhibited by a representative exemplary treated material according to embodiments disclosed herein;

FIG. 12 graphically illustrates the change in chemiluminescent intensity exhibited by a representative exemplary treated material according to embodiments disclosed herein;

FIG. 13 graphically illustrates the change in chemiluminescent intensity exhibited by a representative exemplary treated material according to embodiments disclosed herein;

FIG. 14A graphically illustrates the change in chemiluminescent intensity exhibited by a representative exemplary treated material according to embodiments disclosed herein;

FIG. 14B graphically illustrates a representative exemplary treated material exhibiting a change in chemiluminescent intensity over time in accordance with embodiments disclosed herein;

FIG. 15A graphically illustrates a representative exemplary treated material exhibiting a change in chemiluminescent intensity over time in accordance with embodiments disclosed herein;

FIG. 15B graphically illustrates a representative exemplary treated material exhibiting a change in chemiluminescent intensity over time in accordance with embodiments disclosed herein; and

FIG. 16 graphically illustrates the change in chemiluminescent intensity exhibited by a representative exemplary treated material according to embodiments disclosed herein.

Detailed Description

Although illustrative embodiments have been shown and described, it should be understood that various changes may 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 incorporating such materials and structural elements for absorbent articles, formulations, compositions, and methods of treatment and production associated with chemiluminescent systems and use thereof in absorbent articles. The chemiluminescent system is configured to produce light upon contact with the aqueous system. The reactive components of the chemiluminescent system are typically disposed in one or more treated materials and/or compositions incorporated into the absorbent article. Representative absorbent articles include disposable diapers and adult incontinence products. Representative chemiluminescent systems include bioluminescent systems.

Chemiluminescence is produced by chemical reactions that produce light, thus providing a luminescent indication of moisture in low and/or no light and visible through clothing. Furthermore, chemiluminescence does not require 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 ability of the absorbent article to indicate the presence of soil in dark conditions (e.g., at night) is greatly enhanced in combination with a chemiluminescent system. Moreover, by generating light that is detectable through the garment, the caregiver can confirm the presence of the insult without having to move or interfere with the infant or adult wearer of such absorbent articles, for example, during sleep. Thus, the various compositions and articles provided herein may provide unique advantages of night time and indication of soiling through clothing, which may reduce or even eliminate the need for a caregiver to interfere with the sleep of the wearer of such absorbent articles in order to test for soiling (e.g., by taking off the clothing and/or illuminating a light). Furthermore, since visible light (i.e., light in the visible spectrum) is generated by the chemiluminescent system disclosed herein, there is no need to expose the absorbent article and/or wearer in which the system is incorporated to ultraviolet light in order to determine whether dirt has occurred, allowing for the avoidance of health problems associated with ultraviolet radiation.

Dim light detection provided by a chemiluminescent system, particularly by certain embodiments of absorbent articles incorporating such systems, is discussed in applicant's co-pending U.S. patent application Ser. No. 14/516,255 and shown in some of the figures herein. For example, FIG. 1 reproduced from the' 255 application is a photograph of an absorbent article (diaper) incorporating an absorbent core comprising a chemiluminescent fluff pulp composition (fluff pulp treated with luciferase and luciferin). In fig. 1, a simulated soil (saline solution) is applied and an image is captured showing chemiluminescence through the diaper backsheet and lightweight cotton fabric for easy visual detection under low light conditions. A comparative absorbent article formed using fluorescent rather than chemiluminescent fluff cannot function through diaper material due to blocked excitation via an external light source (see, e.g., fig. 9A of the' 255 application). Activating the fluorescent wetness indicator requires removing clothing, etc., and applying an excitation light (e.g., ultraviolet light) to visually detect the soil. Chemiluminescence requires neither removal of clothing nor excitation light.

Because of the reduced interruption required, the absorbent articles disclosed herein can more easily detect soil, and thus caregivers can check for soil as needed (e.g., more frequently). More frequent inspection may allow the insult to be detected earlier and the absorbent article to be replaced shortly after the insult, thereby reducing the time for the insult to contact the wearer's skin and reducing the likelihood of fluid from multiple insults contacting the wearer's skin. When the length of time that the fluid is in contact with the skin is reduced, the skin health and overall comfort of the wearer may be improved.

In one aspect, a material treated with one or more reactive components of a chemiluminescent system is provided that reacts in the presence of an aqueous system to produce visible light. The term "visible light" herein refers to light in the visible spectrum. Materials are those materials that are commonly incorporated into absorbent articles. The material may be an absorbent or non-absorbent material.

Chemiluminescent system

The 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 reaction components to produce light. The chemiluminescent system is adapted to react in the presence of an aqueous system to produce light. In a preferred embodiment, the light produced is visible light that can be observed by humans. In some embodiments, only a single reaction component selected from luciferin and luciferase is present in a given structural element within the article, as described herein. In such embodiments, the chemiluminescent system is configured to generate light in the presence of the aqueous system and another reactive component. In a preferred embodiment, the light produced is visible light that can be observed by humans. In some embodiments, an aqueous system is used to transfer one reaction component to another, thereby initiating a luminescent reaction. As used herein, the term "aqueous system" refers to water or an aqueous composition. In the context of the present disclosure, such aqueous compositions are typically in the form of body fluids, such as urine, menses, feces, and the like. The occurrence of bodily fluid (or fluid itself) release is referred to herein as "soil", "liquid soil" or "fluid soil". Thus, the chemiluminescent system of the present disclosure produces light on the soil of the article in which the reactive components of the chemiluminescent system are incorporated.

Since configured to generate visible light upon contact with the aqueous system, one of the reactive components of the chemiluminescent system emits light when the reactive components react in the presence of the aqueous system. In some embodiments, water is a component of an aqueous system that initiates the luminescent reaction. In these embodiments, the reactive components do not react in the absence of an aqueous system. In these embodiments, the reactive components do not emit light independently.

Representative chemiluminescent systems comprising two or more reactive components include bioluminescent systems, such as systems comprising luciferin and luciferase.

Bioluminescence is light produced by a chemical reaction that occurs in the body or in the secretions of some type of organism. Bioluminescence involves a combination of two species in a luminescent reaction: luciferin and luciferase. Luciferin is a compound that emits light in nature (i.e., generates light). Luciferases are enzymes that catalyze reactions. In some cases, luciferases are proteins known as photoproteins, and the luminescence process requires charged ions (e.g., cations such as calcium) to activate the reaction. In general, bioluminescence processes require the presence of a substance such as oxygen or Adenosine Triphosphate (ATP) to initiate the oxidation reaction. The rate of reaction of luciferin is generally controlled by the enzyme luciferase. The luciferin-luciferase reaction may also produce byproducts such as inactivated oxidized luciferin and water.

Luciferin and luciferase are common names and not specific materials. For example, luciferin coelenterazine (in its natural form) is common in marine bioluminescence, but variants can be chemically synthesized, and these various forms are collectively referred to as luciferin. Several synthetic methods of coelenterazine are disclosed in U.S. provisional application No. 62/692,485, the entire contents of which are incorporated herein by reference.

The mechanism by which light is generated by chemical reactions distinguishes bioluminescence from other optical phenomena such as fluorescence or phosphorescence.

For example, fluorescent molecules do not themselves emit light. They require an external photon source to excite their electrons to a higher energy state. Upon relaxation from a high energy state to its natural ground state, they release the energy they acquire as a light source, but typically at a longer wavelength. Since excitation and relaxation occur simultaneously, fluorescence is only visible upon illumination (excitation).

The term phosphorescence technically refers to a special case of photoexcited luminescence emission, wherein, unlike fluorescence, relaxation from the excited state to the ground state does not occur immediately, photon emission can last from seconds to minutes after original excitation.

In practice, the technical distinction between bioluminescence and fluorescence is sometimes obscured, but technically they are two different phenomena. In most cases, bioluminescence may be autofluorescent, but this is not the case for fluorescence. The latter still requires photon excitation to emit light. In some cases, the bioluminescent spiny, crustacean or fish may comprise a fluorescent protein, such as Green Fluorescent Protein (GFP), and the light emitted by the bioluminescence will serve as photons that excite GFP. GFP in turn emits light in a relaxed state at a wavelength (most likely a higher wavelength) different from that of the bioluminescence it has received as photons. In this example, GFP may be excited by blue light (wavelength 470 nm) from bioluminescence, but emits green light (wavelength 510nm to 520 nm) in its relaxed state.

The bioluminescence system can be incorporated into the absorbent article in any manner that produces the desired chemiluminescence. Several are disclosed herein.

In some embodiments, the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, and furazine. With respect to coelenterazine, there are many analogs or variants in nature, any of which may be used in the embodiments and methods disclosed herein. For clarity, the term "coelenterazine analog" refers to a substance, such as methyl coelenterazine, 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 hep, while "coelenterazine" refers to natural coelenterazine. Thus, in some embodiments, the coelenterazine can be one or more of natural coelenterazine and coelenterazine analogs. By way of example, the coelenterazine may be one or more of natural coelenterazine, coelenterazine 400a, methyl coelenterazine, coelenterazine f, coelenterazine cp, coelenterazine fcp, and coelenterazine hep. As yet another example, coelenterazine may be one or more of coelenterazine 400a, methyl coelenterazine, and coelenterazine fcp. As yet another example, the coelenterazine may be one or more of coelenterazine 400a, methyl coelenterazine, and coelenterazine hep. In yet another example, the coelenterazine can be one or more of coelenterazine 400a and coelenterazine hep.

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, copepodia luciferase, and Marine (vargula) luciferase. Certain embodiments of luciferases according to the present disclosure include one or more of Gaussia luciferase, renilla luciferase, dinoflagellate luciferase and firefly luciferase. As another example, the luciferase may 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.

In some embodiments, the chemiluminescent system comprises coelenterazine and/or Gaussia, renilla and Metridia luciferases as luciferin, or a combination thereof.

Natural forms of coelenterazine and analogs thereof have different luminescence properties due to the variation of the moieties thereof. Some are good substrates for luciferase and some are not, considering the structural changes of the coelenterazine family. The following is a brief description of natural coelenterazine and representative analogs.

Coelenterazine (in its native form) shown in fig. 2A is the luciferase matrix of Renilla (Renillaformis) luciferase (RLuc). Renilla luciferase/coelenterazine has also been used as a bioluminescence donor in bioluminescence resonance transfer (BRET) studies. The term "coelenterazine" as used herein refers to coelenterazine in its natural form unless otherwise specified.

Coelenterazine 400a shown in fig. 2B includes derivatives of coelenterazine and is a good substrate for Renilla luciferase (RLuc), but is not well oxidized by Gaussia luciferase (GLuc). It is the preferred substrate for BRET (bioluminescence resonance energy transfer) because its maximum emission at 400nm has minimal interference with GFP emission.

Fluorescence Resonance Energy Transfer (FRET), BRET, resonance Energy Transfer (RET) and Electron Energy Transfer (EET) are mechanisms describing energy transfer between two photosensitive molecules (chromophores), and generally define that one luminescent chemical interferes with energy transfer of another luminescent chemical, thus reducing the energy states that the latter can adopt, which is crucial for releasing relaxation energy back to the ground state. The donor chromophore initially in an electronically excited state may transfer energy to the acceptor chromophore via non-radiative dipole-dipole coupling. The efficiency of this energy transfer is inversely proportional to the sixth power of the distance between donor and acceptor, making FRET extremely sensitive to small changes in distance. The 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.

For example, comparing BRET of coelenterazine 400a in the presence of Renilla luciferase (RLuc) with coelenterazine (native form) and clearly shows minimal interference with GFP emission, as shown in fig. 2A and 2B, where "hRluc" is the Renilla luciferase and coelenterazine h bioluminescence system; "FLuc" is the Renilla luciferase and natural coelenterazine system; "luciron" is a luciferase and luciferin system, GFP2 acting as a photon acceptor that fluoresces due to the emission of the hrlick bioluminescence; and "GFP 2" is a green fluorescent protein (second generation).

The coelenterazine cp shown in fig. 2C is a coelenterazine-jellyfish complex, producing a 15-fold higher luminous intensity than coelenterazine (in its native form).

The luminescence intensity of coelenterazine f (coelenterazine-aequorin complex) shown in fig. 2D is 20-fold higher than coelenterazine in its native form, while its maximum emission is about 8nm longer than in its native form.

Coelenterazine fcp shown in fig. 2E is an analog in which the o-phenyl structure in the elentazine portion of the coelenterazine f structure is replaced with a cyclic pentane (similar to coelenterazine cp). Coelenterazine fcp emits light 135-fold more intense than coelenterazine (in its natural form).

Coelenterazine fcp complexes with jellyfish to form a coelenterazine fcp-jellyfish photoprotein complex and as a matrix for jellyfish the luminous intensity of which is 135 times that of natural coelenterazine. However, coelenterazine fcp is a poor substrate for Renilla luciferase.

Other representative analogs of coelenterazine as substrates for Renilla luciferases are coelenterazine e, H and n shown in fig. 2F, 2G and 2H, respectively. Although these three analogs are good substrates for Renilla luciferases, they are poor substrates for aequorin.

The luminescent properties of coelenterazine analogs vary. For example, some analogs emit less light (measured in lumens) but have higher luminous intensities (lumens/steradian). Table 1 lists the luminescence properties of coelenterazine (in its natural form) and its analogs with Renilla luciferase. The luminous intensity is reported as% initial intensity. For example, an analog with an initial strength of 900% is 20 times greater than the natural coelenterazine with an initial strength of 45%.

Table 1: luminescent properties of selected coelenterazine analogs with Renilla luciferase

Analogues	λ _em (nm)	Total light%	Initial Strength (%)
				Natural material	475	100	45
cp	470	23	135
				e	418，475	137	900
f	473	28	45
				h	475	41	135
n	475	47	900

The emission spectra (normalized) of coelenterazine e (20-fold higher luminescence intensity than native coelenterazine) and native coelenterazine are shown in fig. 3. In FIG. 3, coelenterazine e (solid line) and native coelenterazine (dashed line) are measured in the presence of recombinant Renilla luciferase (RLuc). It should be noted that coelenterazine e has two intensity peaks, one at 418nm (k _em ) At wavelength, the other at 475 nm.

Visible light (i.e., light in the visible spectrum) is produced by a chemiluminescent system. The light may be visually detected by the caregiver in the dark and through the garment and/or cover, and thus have a wavelength, intensity and duration that provide the necessary indication. These spectral characteristics of the chemiluminescent system can be tailored based on one or more chemiluminescent compounds. For example, in a bioluminescent system, luciferin and luciferase may be selected to produce a desired light characteristic. Depending on the bioluminescence system used, different spectral characteristics may occur. Coelenterazine can also emit light independently of the oxidation of the enzyme (luciferase) in the presence of superoxide anions and/or a nitrile peroxide compound, a process known as self-luminescence.

The chemiluminescent system can be customized to produce visible light of a particular color. As described in table 1 above, the emission wavelength can range from about 400nm (violet) to about 475nm (blue-green), even in the coelenterazine family.

With respect to duration, the duration of light emission can be controlled by selecting coelenterazine (luciferin) (both in its natural form and its analogues) and enzymes (luciferases) (e.g., gaussia and Renilla). The ratio and concentration of luciferin and luciferase used may also vary the duration of luminescence. To give an illustrative and non-limiting example, the luciferin analogue coelenterazine e has 130% total light and 900% initial intensity compared to the natural coelenterazine (see fig. 3). By judicious selection of the concentrations of coelenterazine and Renilla luciferase, the time to emit visible light can last up to 8 to 10 hours.

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 may have a duration of 1-2 hours, 1-3 hours, 1-4 hours, 1-5 hours, 1-6 hours, or any of these ranges, as well as all other possible subranges.

Regarding intensity, the quantum efficiency of chemiluminescence contributes to the intensity, depth and hue of the emitted color.

Quantum Efficiency (QE) is the fraction of photon flux used to excite a luminescent chemical species to raise it to a higher energy state. Quantum efficiency is one of the most important parameters for assessing detector quality, commonly referred to as "spectral response" to reflect its wavelength dependence. Which is defined as the number of signal electrons produced per incident photon. In some cases, it may exceed 100% (e.g., when each incident photon produces more than one electron). If the spectral response exceeds 100%, the intensity and depth of the emitted color is vivid, but depending on the state of the primary electronic excited state, the duration of the emission will be determined (e.g., the higher the excited state, the longer it takes to return to the base (standard) state).

Spectral responsivity is a similar measure but with different units. The unit of measure is amperes or watts (i.e., how much current each incident photon of a given energy and wavelength flows from the device).

Both quantum efficiency and spectral responsivity are functions of photon wavelength. For example, in the case of luciferin coelenterazine, the latter not only has a high light intensity, but also 30% more light energy than the former is emitted between one of the natural forms and its analogs, because the latter produces two electrons when excited by a given quantum (hv) of incident photons, and the primary electron at wavelength 475 has the same emission intensity as the natural coelenterazine, but a lumen intensity 20 times greater than the natural product. Thus, the stimulated coelenterazine analog will emit twenty times brighter light than the native form, but 130% of the total light energy will last longer than the native form.

The wavelength determines the color of the emitted visible light.

The chemiluminescent system of the present disclosure generally comprises two reactive components, such as luciferin and luciferase, sometimes referred to herein as a "luciferin component" and a "luciferase component", respectively. The treated material according to aspects of the present disclosure includes at least one, and in some embodiments, two reactive components. Absorbent articles according to another aspect of the present disclosure typically combine the two reactive components described above, for example by including one or more materials treated with the reactive components. The term "combined" when referring to reactive components means that the components are included in the absorbent article in some way. In some embodiments, one or more components are held on or within the surface of certain materials or structural elements of the absorbent article, such as on cellulose and/or other fibers of the treated material, such as by a binder or otherwise through chemical or mechanical interactions. In some embodiments, one or more components (e.g., in particulate, powder, or other particulate form) are distributed on or throughout some materials, such as within a cellulosic and/or synthetic fiber matrix. In some embodiments, at least one component of the chemiluminescent system is applied to one or more substrates as a dry formulation within a dry carrier material. The dry carrier material may include any inert material to allow the application of flowable or dispersible formulations within the machine, such as, but not limited to, sugars, minerals or salts thereof, starches, silica, clays, talc, micronized wood or other cellulose, gelatin, agar, and SAP. In one embodiment, an absorbent article includes a liquid permeable topsheet, a liquid impermeable backsheet, a fibrous absorbent material including fibers treated with a luciferase enzyme, and a tissue sheet treated with a luciferin, wherein the absorbent material and tissue sheet are disposed between the topsheet and backsheet in a configuration wherein one of the chemiluminescent components is transferred to the other by an aqueous system moving from the topsheet to the backsheet. For example, the treated tissue sheet may form a wrapper for an absorbent core comprising the treated absorbent material.

Photoluminescent compounds

The chemiluminescent system can interact with a photoluminescent (e.g., fluorescent and/or phosphorescent) compound having a photoluminescent absorption wavelength range that overlaps with a chemiluminescent emission wavelength range of the chemiluminescent system, wherein the photoluminescent compound has a photoluminescent emission wavelength range that is different from the chemiluminescent emission wavelength range. Thus, photoluminescent compounds can be used to "shift" the emission wavelength of the chemiluminescent system. For example, photoluminescence may be used to change or otherwise tailor the color (or other spectral quality) of the generated light.

When the chemiluminescent system produces light, the chemiluminescent itself need not necessarily be in the visible spectrum. Chemiluminescence produces electromagnetic radiation in some wavelength ranges, but the disclosed embodiments are not limited to chemiluminescent emission in the visible range. Thus, in certain embodiments, the chemiluminescent system may produce chemiluminescent emissions that are not in the visible wavelength range. In such embodiments, photoluminescent compounds may be used to shift the emission spectrum into the visible range.

The photoluminescent compound may be selected from fluorescent compounds and phosphorescent compounds. Fluorescent compounds may include, but are not limited to, xanthene derivatives such as luciferin, rhodamine, oregon green, eosin and texas red; cyanine derivatives such as indocyanine; a cycloalkane derivative; 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 porphyrins; bilirubin; phosphorescent compounds such as silver activated zinc sulfide and doped strontium aluminate; etc.

The photoluminescent compound may 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. It is important that the photoluminescent compound be in optical communication with the chemiluminescent light (at the emission and excitation wavelengths). For example, the photoluminescent compound may be disposed on a backsheet of the absorbent article.

pH buffering agent

The pH buffering agent may be present in the material and/or the absorbent article. The pH buffer may be configured to modify a spectral property, such as the intensity of the chemiluminescent system. For example, pH control can be used to improve the efficiency of chemiluminescence.

Exemplary improvements in chemiluminescent efficiency include extending or otherwise altering the duration of emission to provide a caregiver with a desired amount of time to detect soil. Thus, the pH buffer may be configured to increase the efficiency of visible light from the chemiluminescent system upon contact with the aqueous system.

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

The pH buffering agent may 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. It is important that the pH buffer be in contact with the chemiluminescent system when contaminated. Thus, the pH buffer should be disposed in the absorbent article such that it is carried into contact with the chemiluminescent system when contaminated.

Treated material and structural element

In one aspect of the disclosure, materials and structural elements treated with one or more reactive components of a chemiluminescent system are provided. In such embodiments, the treated material or structural element comprises one or both of the reactive components of the bioluminescent system, namely luciferin and luciferase.

Materials are those materials that are commonly incorporated into absorbent articles. The material may be an absorbent or non-absorbent material. Representative absorbent articles include child or infant diapers, adult diapers and incontinence products, feminine hygiene products, absorbent pads, bandages and other wound care dressing articles, absorbent mattresses and absorbent pet pads.

For purposes of illustrating exemplary materials, a representative absorbent article is shown in fig. 4A and 4B as a diaper 100, with fig. 4B showing a simplified and somewhat schematic top view of the diaper in a flattened form. However, the following description applies to all types of absorbent articles. The diaper includes a topsheet, generally indicated at 102, and a backsheet, generally indicated at 104. The topsheet 102 is formed of a fluid permeable material adapted to facilitate transfer of fluid to the interior of the diaper, typically with minimal topsheet fluid. Exemplary materials include nonwoven fibrous sheets incorporating synthetic and/or cellulosic fibers. In contrast, the backsheet 104 is made of a fluid impermeable material to prevent any fluid leakage from the interior of the diaper. Sometimes also referred to as "multiple sheets," exemplary backsheet includes polyethylene sheets or films. Each of the topsheet and backsheet may be a composite material and/or be formed of one or more materials or layers that function together or independently to provide the fluid permeable or fluid impermeable characteristics of the sheet.

The interior of the diaper includes an absorbent region 106 and a target region 108 that generally indicates the area intended to be contaminated. The exact boundaries of the regions 106 and 108 will vary with the design of the diaper or absorbent article.

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

A chemiluminescent system is also provided in the diaper 100.

In some embodiments, the chemiluminescent system comprises a luciferin component and a luciferase component that are adapted to react with each other in the presence of an aqueous system to generate light. In some such embodiments, the components are independently disposed within the diaper in a configuration in which one component is transferred to the other by, for example, an aqueous system (e.g., fluid insult) moving from the topsheet to the backsheet. The components may be disposed on, in, and/or throughout two or more materials incorporated into the diaper structure.

Exemplary materials include absorbent materials (e.g., materials that are typically incorporated into an absorbent core) and non-absorbent materials (e.g., materials that are typically incorporated elsewhere in the structure of an absorbent article), and combinations thereof. Examples of absorbent materials include fluff pulp, SAP, synthetic fibers, and the like. Examples of non-absorbent materials include topsheet 102, backsheet 104, tissue sheets or compositions, one or more layers of materials used in Acquisition and Distribution Layers (ADLs), and the like.

As described above, applicant's co-pending et.s. patent application No. 14/516,255 discloses fluff pulp compositions treated with a chemiluminescent system configured to generate visible light upon contact with an aqueous system that may be incorporated into absorbent articles, for example, as an absorbent material.

Treated tissue compositions

In one embodiment of a treated material according to the present disclosure, a treated tissue composition is provided. Fig. 5A shows an example of such a tissue composition 300 that includes a liquid permeable tissue sheet 302. The tissue sheet comprises fibers, such as fibers selected from the group consisting of cellulosic fibers, synthetic fibers, and combinations thereof, and may have any configuration and arrangement suitable for incorporation into an absorbent article, such as a wrapper for an absorbent core.

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 the chemiluminescent system selected from luciferin and luciferase, which component remains on the treated surface. In some embodiments, the component is a luciferin selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, furazine, and combinations thereof. For example, in some such embodiments, the component is coelenterazine. In some embodiments, the component is a luciferase selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase, and firefly luciferase. For example, in some such embodiments, the component is a Gaussia luciferase, a Renilla luciferase, and/or a Metridia luciferase. In some embodiments, the treated tissue composition binds both luciferin and luciferase such that a luminescent reaction will be initiated when the liquid insult is contacted with the treated tissue composition. 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 a Metridia luciferase.

Although not required, binders may optionally be used to help retain the chemiluminescent components on the tissue sheet, for example, on the fibers of the tissue sheet. In general, an adhesive is any material or substance that holds or attracts other materials together to mechanically, chemically form an adhesive whole by bonding or cohesion. It has been found that although cellulose fibres are able to retain luciferin applied to their surface primarily by molecular interactions, some synthetic fibres and/or surfaces are less or even unable to do so. In such cases, it was found that one or more binders may promote the retention of luciferin on such materials, and that binders may provide similar benefits even on matrix materials capable of retaining luciferin. When the component is luciferin, suitable binders may include ethylcellulose, methylcellulose, nitrocellulose, polyurethane, and the like, as well as various combinations thereof. Thus, in some embodiments, the components of the chemiluminescent system are held on the surface of the tissue sheet by a suitable adhesive.

Some binders function by forming a coating or film on the surface of the matrix material that holds the chemiluminescent components to the material, but also resists penetration by the aqueous system to dissolve and/or release the chemiluminescent components for transfer to the chemiluminescent sites. For example, this may be manifested as a delay after the absorbent article is contaminated before chemiluminescence is visible, a lower chemiluminescence intensity at a contaminant such as a first contaminant, and so on. In some embodiments, such a delay may be used as a time release mechanism. However, in many applications, it is preferable to make the chemiluminescence visible as soon as possible after contamination. In some such embodiments, the presence of a release agent may accelerate or otherwise facilitate the release of the chemiluminescent component held by the binder. Suitable release agents include poly (1-vinylpyrrolidone-CO-vinyl acetate) (PVPA), hydroxypropyl-P-cyclodextrin (HPBC), and the like. Thus, some embodiments that include one or more binders also include one or more release agents.

Some embodiments include luciferin, aqueous or non-aqueous solvents that solubilize the luciferin, and excipients suitable to promote the solubility of luciferin in water (e.g., hydroxypropyl-beta-cyclodextrin; ethanol; water soluble polymers selected from the group consisting of polyethylene glycol, polyvinyl alcohol, partially hydrolyzed polyvinyl 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, salts thereof, and the like. Some of such embodiments include a binder adapted to bind the luciferin to the matrix material. Some excipients, while inert to chemiluminescent reactions, provide additional benefits. For example, such additional benefits include the effect on the solubility of a given component of the chemiluminescent system in various aqueous and non-aqueous solvent systems, the effect on the water availability in the absorbent article, the retention of one or both components of the chemiluminescent system on various substrates (e.g., binders), the release of one or both components of the chemiluminescent system (e.g., porous transfer agents), and the like. Some such excipients may have a variety of these or other functions.

Some non-limiting examples within the scope of the present disclosure are provided herein. In a first example, the excipient may be selected for its ability to affect the degree of water utilization within the absorbent article. Changing the relative amount of superabsorbent material (e.g., SAP) in the diaper structure will affect the amount of free water that can be used to activate the chemiluminescent system by binding the two components (i.e., luciferase and luciferin) together or otherwise allowing the reaction to begin in an aqueous environment. The SAP binds water while less SAP allows more free water and earlier peak photon generation in absorbent articles without SAP, staggered peak photon generation with 12-24wt% SAP, or later peak photon generation with 36wt% SAP (see fig. 14A and 14B; note that the components of the chemiluminescent system and all other variables are constant). In a second example, the excipient may be selected for its ability to modulate the effect of the binder excipient upon exposure to the aqueous system, thereby releasing one or more components of the chemiluminescent system for reaction within the absorbent article. Variations in the amount or type of such porous transfer agent excipients in the diaper structure will affect the usability of the combined components. In diapers where luciferin (coelenterazine) is disposed on the absorbent core tissue wrap, the inclusion of hydroxypropyl-beta-cyclodextrin in the application formulation (see FIGS. 15A and 15B; "HPBC") reduces the availability of luciferin that reacts with the luciferase enzyme disposed in the fluff pulp of the core (Gaussia), thereby delaying peak production and allowing longer lasting photon production (right shoulder of the figure). hydroxypropyl-P-cyclodextrin also aids in the solubility of coelenterazine in aqueous solutions for application to tissue core wrap structures. However, the inclusion of poly (1-vinylpyrrolidone-CO-vinyl acetate) in the application formulation (see fig. 15A; "PVPA") provides a robust availability of luciferin, which is shown in bright early reaction with aqueous systems after contamination, which is reduced in each subsequent contamination due to exhaustion of the reactants. In a third example, the excipient may be selected for its ability to inhibit the reaction conditions of the chemiluminescent system. After contamination of the absorbent article, changing the amount and type of salt treatment of the absorbent material can affect the pH of the resulting aqueous system. By providing a detrimental reaction environment on the addition of multivalent minerals and/or salts thereof (see fig. 16; aluminum and magnesium salts), the reaction is inhibited unless and until the pH conditions change over time (e.g., increase with the addition of buffer components or urine soil).

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

Several aspects of the treated tissue composition may be tailored to suit its use, particularly the manner in which the treated tissue composition is incorporated into an absorbent article. As described above, embodiments in which the treated tissue composition includes one reactive component will typically be incorporated into the absorbent article in an arrangement with another reactive component disposed elsewhere in the absorbent article (e.g., in another treated material or layer), wherein when the absorbent article receives fluid insult, such as when the aqueous fluid of the insult moves from the topsheet to the backsheet (for example), one reactive component will transfer to the other, thereby reacting and initiating a luminescent reaction.

As an example of such an absorbent article, another reactive component may be disposed in the absorbent material of the absorbent article.

As noted above, in some diaper constructions, the absorbent core is a self-contained component that is placed into the diaper during manufacture. Thus, for one exemplary use of the treated tissue composition, the absorbent material of the absorbent core (e.g., fluff pulp, synthetic fibers, SAP, etc.) may be encapsulated or at least partially contained in the treated tissue composition. In such a configuration, the fluid insult will transfer the first reactive component from the absorbent core to the second reactive component, e.g., located in the treated tissue composition (or from another location to the treated tissue component or other location of the second reactive component) to initiate chemiluminescence.

Thus, fig. 4D shows an exemplary cross-section 200' similar to the diaper 100 shown in fig. 4C, but featuring an absorbent core 112 disposed between the topsheet 102 and the backsheet 104. In the absorbent core 112, the treated tissue composition 300 is shown enveloping the absorbent material 110.

The treated tissue composition may be incorporated into the absorbent article in a variety of ways other than that shown. For example, instead of (or in addition to) being used as a wrapper for the absorbent core, a layer of treated tissue composition may be placed in the diaper structure adjacent to or at least partially surrounding the absorbent core 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 a treated tissue composition that binds luciferin, wherein the absorbent structure binds luciferase. In other constructions, the treated tissue composition (e.g., one or more layers, or discrete pieces) may be placed in the diaper upstream of where another component of the chemiluminescent system is located, as desired, in a manner such that soil moving through the diaper will encounter the treated tissue composition and transfer the reactive components of the tissue sheet to the other components, where the components react and chemiluminescent. In yet other variations, the treated tissue composition may be placed in the diaper downstream of the other component such that the other component is transferred to the treated tissue composition by fluid insult. In some variations, the treated tissue composition is placed near or beside the backsheet to optimize the visibility of the chemiluminescence. While the usual path for fluid insult in an absorbent article is from the topsheet toward the backsheet, this is not always the case (e.g., the fluid insult may traverse 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.

Thus, the treated tissue sheet 302 may have any suitable size. Standard infant diapers, discussed herein as dimensional references, are about 235mm wide and about 350mm long. However, it should be understood that while several dimensional aspects of the materials and structural elements disclosed herein are discussed with reference to a standard infant diaper, such references are provided merely as illustrative and non-exclusive examples of absorbent articles and are not limiting in terms of such dimensions. Moreover, although reference is made to standard infant diaper sizes, the size and size range of infant diapers is quite large, and this range varies from manufacturer to manufacturer. In addition, other absorbent articles within the scope of the present disclosure may be larger than infant diapers (e.g., adult incontinence products, pet pads, mattresses), smaller than infant diapers (e.g., feminine hygiene products), have different dimensional aspects, and so forth. Thus, while some embodiments of the treated tissue sheet 302 (and other treated materials) discussed have certain size ranges, such ranges are provided as non-limiting examples only.

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

Moreover, the treated tissue sheet 302 may have any suitable thickness or basis weight, although generally thin and flexible. For example, in some embodiments, the tissue sheet may have a basis weight in the range of 10-1500g/m ² (also denoted as "gsm"). In an embodiment, the tissue sheet has a basis weight of about 10g/m ² To about 50g/m ² About 25g/m ² To about 100g/m ² About 50g/m ² To about 250g/m ² About 100g/m ² To about 500g/m ² About 250g/m2 to about 1000g/m ² About 500g/m ² To about 1500g/m ² Or any of these ranges, as well as all other possible subranges.

The treated tissue composition 300 may incorporate a wide range of concentrations of the components of the chemiluminescent composition, with the appropriate concentration being determined by factors such as the surface area of the tissue sheet treated with the reactive component, the portion of the treated surface area that is expected to be exposed to fluid insult, the desired light intensity and/or duration, the nature of the other reactive components of the chemiluminescent system that have been or are to be incorporated into the diaper, and the like. In light of the principles and concepts disclosed herein, a skilled artisan will be able to determine, through reasonable experimentation, the appropriate combination of factors for any configuration of absorbent articles. In some embodiments in which the reactive component is luciferin coelenterazine, the treated tissue composition may include 0.00002 to 20wt% coelenterazine based on standard diaper dimensions with 235mm wide tissue sheets as the core wrap, wherein the tissue sheets have a mass of 1.32 grams. For example, in one such embodiment, the treated tissue composition includes from 1 to 6 percent by weight coelenterazine. In one embodiment, the treated tissue composition includes from 0.00002 to 0.01wt% coelenterazine. In one embodiment, the treated tissue composition includes from 10 to 20 percent by weight coelenterazine. In one embodiment, the treated tissue composition includes from 0.01 to 2 percent by weight coelenterazine. In one embodiment, the treated tissue composition includes from 2 to 10 percent by weight coelenterazine.

The concentration of the components in the treated tissue composition 300 is not particularly limited except for the capacity of the tissue sheet. In general, it is generally economically preferable to use only as many components as are needed to produce the desired intensity or duration of chemiluminescence. However, the present disclosure is not so limited as it may be desirable to incorporate greater amounts of one or more components to ensure that there will be a sufficient amount of reaction even after prolonged storage. Another way of indicating the concentration range of one or more reactive components of the chemiluminescent system on the tissue sheet is by means of the weight or mass of the components per surface area of the tissue sheet. Typically, tissue sheets are formed into continuous rolls that are cut to standard lengths, such as 12 inches long, typically from about 0.1mm to about 235mm wide for standard diapers, and larger for larger diapers and incontinence products. In embodiments in which the reactive component is luciferin coelenterazine, the treated tissue composition may include 0.01mg to 25g coelenterazine per 12 inch length, with the weight of coelenterazine per 12 inch length being less than or equal to the weight of the untreated tissue sheet that is 12 inches long. In another embodiment, wherein the reactive component is luciferin coelenterazine, the treated tissue composition may include up to 0.1-100mg coelenterazine per 12 inch length, with the weight of coelenterazine per 12 inch length being less than or equal to the weight of the untreated tissue sheet that is 12 inches long.

The tissue sheet 302 may have any suitable construction or composition. In one variation, the tissue sheet is composed entirely of cellulosic fibers. In another variation, the tissue sheet comprises synthetic fibers.

Furthermore, although the treatment region 306 of the surface 304 is shown as a longitudinal strip, the treatment region(s) may have any desired form and size, such as a desired pattern, such that the chemiluminescence takes the form of such a pattern. For example, the treatment zone may be in the form of a strip extending perpendicular or otherwise transverse to the longitudinal direction of the tissue sheet. The strip may be continuous or discontinuous (e.g. dotted or dashed), straight or curved or comprise curved and/or straight portions. The treatment area may be in the form of one or more shapes or other forms, etc.

Moreover, the total treated surface area may be any size relative to the surface area of the tissue sheet, e.g., in the range of about 0.003-100% of the tissue sheet area, with the lower limit representing a single point of concentration sufficient to react to produce light and the upper limit representing complete coverage of the tissue sheet surface. In this regard, the total treatment area may be 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 these ranges, as well as all other possible subranges.

The treated tissue sheet 302 is shown in fig. 5A as having only one treated surface 304, but the disclosure is not so limited as the opposite surface may also be treated, for example, with the same or different components. Further, in some embodiments, the surface 304 may be treated with two components, such as in non-overlapping areas.

The treated tissue composition 300 is shown in fig. 5A as a single ply of the treated tissue sheet 302, but the disclosure is not so limited, as the treated tissue composition may incorporate multiple plies, for example, where one ply is a multi-ply structure of the treated tissue sheet. Fig. 5B illustrates an exemplary embodiment of a treated tissue composition 300' that is shown as including two tissue sheets 302a, 302B treated with different components of a chemiluminescent system such that upon contact of liquid insult with the treated tissue composition, a luminescent reaction will be initiated (an effect similar to an embodiment in which a single tissue sheet is treated with more than one reactive component). In variations of this configuration, multiple plies of the tissue sheet may be processed with the same or different components of the chemiluminescent system. Fig. 5C illustrates another exemplary 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 (e.g., untreated plies of tissue sheet). The multi-layered embodiments may be incorporated into absorbent articles according to the principles described above.

In some embodiments, the overlapping area on surface 302 may be treated by applying one or both components under substantially non-aqueous combining conditions. Non-limiting examples of such embodiments include:

applying one of the components to the surface 302 in a water-based solution to create a first treated region 306a, allowing the solution to substantially dry (i.e., insufficient water to allow greater than 5% of one or both of the components in the treated region to be consumed in the chemiluminescent reaction without further addition of water), and applying the other of the components to the surface 302 in any manner without water to create a second treated region 306b (see fig. 5D); applying one of the components to the surface 302 in a non-aqueous solvent-based solution to create a first treated region 306c, substantially drying the solution, and applying the other of the components to the surface 302 in a manner that limits water utilization (i.e., by flash drying or a non-aqueous solvent system) to create a second treated region 306d (see fig. 5E); and

both components are applied to the surface 302 in a non-aqueous solvent based solution to create a single treated region 306e (see fig. 5F).

The processing regions 306a-D may have any desired size and the sizes need not match (as shown in fig. 5D and 5E). Conversely, in some embodiments, the first processing region 306f may have a larger size than the second processing region 306G (see fig. 5G). One and/or another component of the chemiluminescent system may include an applied material that forms the first treatment region 306f and the second treatment region 306 g. The first processing region 306f and the second processing region 306G may completely overlap (as shown by the second processing region 306G in fig. 5G), may partially overlap (not shown) or any other pattern. Furthermore, in some embodiments, one and/or another component of the chemiluminescent system may be included in a different absorbent article structural element 300 '", for example, where the structural element 300'" is a fluff pulp core and the structural element 300 is a sheet of tissue. Any structural element within the absorbent article may be implemented as structural element 300 and structural element 300' "depending on the application method used to treat the chemiluminescent component. It should be noted that fig. 5D-5G are shown in two-dimensional cross-sectional schematic views.

Optionally, the treated tissue compositions according to the present disclosure may include other additive materials described elsewhere herein, such as photoluminescent compounds, pH buffers, porous transfer agents, and the like.

Indicator particles

In another embodiment of a treated material according to the present disclosure, indicator particles are provided. Fig. 6A shows an example of such a particle 400 formed from hydrogen bonded cellulose pulp fibers and incorporating at least one component of a chemiluminescent system selected from luciferin and luciferase, which component remains on the fibers. The component may be disposed on one or more surfaces 402 of the particle, and/or on the fibers of the entire particle. In some embodiments, the component is a luciferin selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, furazine, and combinations thereof. For example, in some such embodiments, the component is coelenterazine. In some embodiments, the component is a luciferase selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase, and firefly luciferase. For example, in some such embodiments, the component is a Gaussia luciferase, a Renilla luciferase, and/or a Metridia luciferase. In some embodiments, the indicator particles bind both luciferin and luciferase such that a luminescent reaction will be initiated when the liquid soil contacts the indicator particles. 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 a Metridia luciferase.

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 ethylcellulose, methylcellulose, nitrocellulose, polyurethane, and the like, as well as various combinations thereof. Thus, in some embodiments, the components of the chemiluminescent system are held on the surface of the tissue sheet by a suitable adhesive.

Although not required, a porous transfer agent may be incorporated into the indicator particles. It has been found that in some applications some porous media function to assist in the mass transfer of the reactive component and/or the aqueous system, such as those applications in which the reactive component is disposed in a separate location, on an indicator particle, on other treated materials, or otherwise disposed in an absorbent article. For example, in the case of luciferin coelenterazine exhibiting low water solubility, the greater the surface area treated with coelenterazine, the greater the availability of reactants to the luciferase. Porous media can provide a larger surface area than non-porous and less porous materials. In addition, the hydrophilic porous material can also promote water transfer to reaction sites for luminescence reactions.

Unexpectedly, it was found that the porous transfer agent provides benefits in some embodiments using a binder. As described above, some binders function to form a coating or film on the surface of the matrix material that holds the chemiluminescent components on the material, but also resists penetration by the aqueous system to dissolve and/or release the chemiluminescent components for transfer to the chemiluminescent sites. For example, this may be manifested as a delay after the absorbent article is soiled before chemiluminescence is visible, a lower chemiluminescence intensity at the time of soiling such as the first soiling, and so on. However, it was found that in some such embodiments, the presence of porous transfer agents accelerates or promotes mass transfer by improving the above-described effects of certain binders. In other words, functionally, in some embodiments, porous transfer agents are found to have similar benefits as release agents such as PVPA and HPBC.

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

The indicator particles may have any desired size, shape and/or form within the parameters described above. The particles may be produced by cutting or otherwise dividing a cellulose pulp sheet, in which case the thickness and basis weight of the particles may be the thickness and basis weight of the sheet cut therefrom. For example, a Henion dicer may be used to cut the cellulose pulp sheet into generally hexagonal particles, such as shown in fig. 6A, having two opposing surfaces 402, a thickness of about 1mm, four sides 404 of about 2mm in length, and two sides 406 of about 3mm in length. The shape and/or size may vary due to the segmentation method used.

Fig. 6B shows another exemplary indicator particle 400' in the form of an elongated strip having a thickness of 1mm, a width of about 2mm and a length of about 350mm. As described below, the various forms of indicator particles can be tailored according to their intended use in the absorbent article and the desired length (and other physical dimensions).

Fig. 6A and 6B are illustrative in nature. Thus, the particles 400, 400' are shown, for example, as having flat, planar sides and linear edges. Particles having these forms may include and exhibit various irregularities due to materials, production methods, and the like of the particles. For example, the particles 400 and 400' may exhibit some curl and/or twist, and/or appear to wear along their edges, and so forth.

For convenience, the two main forms of indicator particles discussed herein may be distinguished by their aspect ratio or the ratio of the length of the particles to their width. Particles having an aspect ratio of less than about 1.5, such as indicator particle 400 in fig. 6A, are referred to as "flakes", while particles having an aspect ratio of greater than or equal to about 1.5, such as indicator particle 400' in fig. 6B, are referred to as "ribbons". This distinction may be useful in certain applications, for example, if particles of a particular shape are preferred over another shape, although the principle of use is generally otherwise the same. In some embodiments, as in particle 400, the sheet will have a width greater than its thickness and a length greater than its width. The particle 400 has two opposing faces, each of which has an area (e.g., product of length and width) of about 14mm in the illustrated example ² But may vary over a considerable range. For example, in some embodiments, the area of such particles is 0.1mm ² -300mm ² Between them. In some embodiments, the area of such particles is 1mm ² -10mm ² Between them. In some embodiments, the area of such particles is 8mm ² -30mm ² Between them. In some embodiments, the area of such particles is 30mm ² -150mm ² Between them. In some embodiments, the area of such particles is 50mm ² -150mm ² Between them. In some embodiments, the area of such particles is 100mm ² -300mm ² Between them. Similarly, the shape of the sheet may be different from that shown in fig. 6A. For example, the shape may be square, circular, regular or irregular polygonal, and the like. The size and shape of the strips may similarly vary. For example, in the example shown, particles 400' (barsThe band) is 2mm wide, but in some embodiments is about 0.5mm-2.5mm. The thickness is 1mm, but in some embodiments is about 0.05mm to 2.0mm. A cross section of about 2mm ² But in some embodiments is about 0.01mm ² -200mm ² . The length may also be from about 1mm to about 800mm. Although 350mm is about the length of a standard diaper, longer lengths (e.g., up to or even exceeding 800mm for larger diapers and adult incontinence products) may be used. Also, the cross-sectional dimension is shown as being constant along the length of the strip 400', but the strip may include a non-constant cross-section and be twisted or curled along its length.

Any suitable segmentation method may be used, depending on the desired size and shape. Any suitable material that binds hydrogen bonded cellulose pulp fibers may be used. For example, a pulp sheet having a basis weight of 10-850gsm may be used. In some embodiments, the material also incorporates synthetic fibers having fiber diameters in the range of 1 micron to 100 microns.

Similar somewhat to the treated tissue compositions according to the present disclosure, several aspects of the indicator particles may be tailored to their use, specifically the manner in which they are incorporated into the absorbent article. One exemplary use of particles 400 (flakes) is shown in fig. 4E, which shows an exemplary cross-section 200 "of a diaper 100 similar to that shown in fig. 4C and 4D, but featuring a plurality of flakes 400 arranged in a single layer between an absorbent material 110 and a backsheet 104, wherein the absorbent material 110 is shown disposed between the backsheet 104 and a topsheet 102. Similar exemplary embodiments (not shown) employ one or more particles 400' (strips) disposed in a single layer between the absorbent material 110 and the backsheet 104, parallel to the length of the diaper. In yet another exemplary embodiment, the plurality of flakes 400 are uniformly distributed throughout the absorbent material 110.

Similar to the treated tissue composition, the indicator particle(s) may be incorporated into the absorbent article in a variety of ways other than that shown. For example, the indicator particles may be disposed elsewhere in the diaper, such as in another layer or location between the topsheet and the backsheet, e.g., depending on whether the particles bind luciferin, luciferase, or both; the desired location in the diaper where the chemiluminescent reaction occurs upon contamination (e.g., whether the chemiluminescent component incorporated into the particle is transferred to another location by the fluid insult or another chemiluminescent component is to be transferred to the particle); a desired intensity of chemiluminescence; the desired shape of the chemiluminescent region (e.g., a stripe or stripes may exhibit chemiluminescence as the corresponding luminescent stripe); etc. The flake form of the particles can be used not only as a matrix material for the chemiluminescent component, but also in terms of absorption function. As disclosed in us patent No. 9,617,687, for example, pseudo-cylindrical pulp particles may be used as or for ADLs for diapers. The' 687 patent explains that when such particles are distributed as a layer within an ADL, the particles may maintain a certain space between the top sheet of the ADL and its storage layer, with the gaps and interstices between adjacent particles forming channels through which fluid may flow to the storage layer. In a somewhat similar manner, the sheet 400 may be incorporated into an ADL for an absorbent article while also providing one or more components of a chemiluminescent system.

The indicator particles 400 may incorporate a wide concentration range of the components of the chemiluminescent composition and the appropriate concentration is determined by the factors discussed above with respect to the treated tissue composition 300.

In one embodiment of the particle 400 (flake), the reactive component is luciferin coelenterazine and the particle includes a component at a concentration of less than 0.50 weight percent. In one embodiment of the particle 400, the reaction component is Gaussia luciferase, renilla luciferase, and/or Metridia luciferase, and the particle comprises a component at a concentration of less than 0.01 total weight percent. In one embodiment of particle 400' (strip), the reactive component is luciferin coelenterazine and the particle includes a component at a concentration of less than 0.50 weight percent. In one embodiment of the particle 400', the reaction component is Gaussia luciferase, renilla luciferase, and/or Metridia luciferase, and the particle comprises a component at a concentration of less than 0.01 total weight percent. However, in any (or any other) form, the indicator particles may comprise from 0.00002 to 20.0 weight percent coelenterazine and/or from 0.003 to 10.0 weight percent Gaussia luciferase, renilla luciferin and/or metrdia luciferase, and/or suitable amounts of one or more luciferins and/or luciferases. Some sample weight percent ranges of coelenterazine in such particles include 0.00002-0.01,0.01-0.20,0.20-5.0, and 5.0-20, or any of these ranges, as well as all other possible subranges. Some sample weight percentages of the total amount of Gaussia luciferase, renilla luciferase and/or Metridia luciferase in such particles are 0.0003-0.001,0.001-0.1,0.1-2.0 and 2.0-10, or within any of these ranges, as well as all other possible subranges.

The concentration or amount of the components in the indicator particles is not particularly limited, except for the capacity of the particles themselves. In general, it is generally economically preferable to use only as many components as are needed to produce the desired intensity or duration of chemiluminescence. However, the present disclosure is not so limited as it may be desirable to incorporate greater amounts of one or more components to ensure a sufficient amount that will react even after prolonged storage. Another way of indicating the concentration or amount range of the reactive components of the chemiluminescent system on the indicator particles is by means of the total amount of components used in the absorbent article. In one embodiment of an absorbent article (in the form of a diaper) comprising a plurality of about 65 particles having a size and dimensions similar to particle 400, or about 0.7g of the total weight of the particles, together comprise about 1.0mg coelenterazine, and about 0.25mg Gaussia luciferase, renilla luciferase, and/or Metridia luciferase. In other variations, the plurality of indicator particles used in the absorbent article may collectively comprise coelenterazine in a total amount ranging from 0.0001 to 20.0mg and/or Gaussia luciferase, renilla luciferin and/or Metridia luciferase in a total amount ranging from 0.00003 to 20.0 mg. In other variations, the plurality of indicator particles used in the absorbent article may collectively comprise a total amount ranging from 0.0001 to 20.0mg, from 0.001 to 20.0mg, from 0.01 to 20.0mg, from 0.1 to 20.0mg, or from 1 to 20.0mg coelenterazine, and/or a total amount ranging from 0.00003 to 20.0mg, from 0.0003 to 20.0mg, from 0.003 to 20.0mg, from 0.03 to 20.0mg, or from 0.3 to 20.0mg of Gaussia luciferase, renilla luciferase, and/or Metridia luciferase.

Although the absorbent article discussed above incorporates a plurality of similarly configured indicator particles, the present 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 of similar configuration, such as absorbent articles that include two or more different forms, sizes, or shapes of particles, and/or particles that independently bind different components of a chemiluminescent system, such as a first plurality of particles that bind luciferin and a second plurality of particles that bind luciferase, and so forth.

Obviously, a plurality of treated materials and/or a plurality of types of treated materials, such as the treated tissue compositions and indicator particles described above, may be incorporated into the absorbent article. For example, one component of the chemiluminescent system may be provided by the treated tissue composition, while the other component may be provided by the indicator particles and disposed in the diaper such that when the diaper is contaminated with an aqueous system, one component is transferred to the other to initiate a chemiluminescent reaction between the components.

An illustrative example of such a configuration is provided in fig. 4F, which shows a cross-section 200' "similar to the diaper 100 shown in fig. 4C-4E, but is characterized by an absorbent core 112 disposed between the topsheet 102 and the backsheet 104, wherein the absorbent core is formed of an absorbent material 110 enclosed by a treated tissue composition 300. This example also shows a layer of particles 400 (flakes) disposed in a single layer between the absorbent core 112 and the backsheet 104. In use, fluid insults that normally move from the topsheet 102 to the backsheet 104 will encounter the treated tissue composition 300 and, as it continues to move, will transfer the chemiluminescent components disposed on the treated tissue composition toward the backsheet to initiate a chemiluminescent reaction when it reaches the particles 400. In variations of such a configuration, one or more of the structural elements (i.e., the tissue sheet and the indicator particles) may include more than one reactive component to better ensure that the transfer of one reactive component to another will occur under a variety of conditions to induce chemiluminescence.

Optionally, indicator particles according to the present disclosure may include other additive materials described elsewhere herein, such as release agents, photoluminescent compounds, pH buffers, and the like.

Treated absorbent core

As mentioned above, advances in SAP technology have allowed for the design of absorbent core constructions in which the fluff pulp contributes less to the absorbent capacity of the core, while more provides a fibrous structure for fluid distribution and/or for stably retaining SAP. In some cases, these functions may be provided by synthetic fibers, resulting in the development of an absorbent core that replaces historically used natural (e.g., cellulosic) fibers partially or even entirely with synthetic fibers. Thus, in another embodiment of a treated material according to the present disclosure, there is provided an article comprising 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 (e.g., fluff-free absorbent core) of an absorbent article.

Fig. 7 shows an exemplary embodiment of such an article 500 in the form of an absorbent core 502. The absorbent core 502 is shown in partial cross-section comprising synthetic fibers 504 arranged to form an absorbent matrix and sandwiched between two sheets of material 506, 508, thereby forming a self-contained component suitable for incorporation into an absorbent article. The two sheets may be of the same material or of 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 panels 506, 508 will be a liquid permeable topsheet, while the other will be a liquid impermeable backsheet, and so on.

A wide variety of synthetic fibers may be used. For example, the synthetic fibers may include fibers composed of one or more of polypropylene or other thermoplastic polymers, bicomponent fibers, elastomeric polymer fibers, and mixtures thereof. Several exemplary synthetic fiber materials suitable for use are disclosed in U.S. publication No. 2007/0142803 to Soerens et al, the entire disclosure of which is incorporated herein by reference. Some embodiments additionally include natural fibers (e.g., cellulosic fibers) as well as synthetic fibers, such as in a blend of two types of fibers in the same fibrous matrix, or disposed in discrete layers or portions, respectively, and so forth. In some embodiments, such as in a fluff-free core, the fibers are fully synthetic fibers.

Article 500 incorporates at least one component of a chemiluminescent system selected from luciferin and luciferase. In the form of an absorbent core 502, the chemiluminescent component may be disposed on and/or between the synthetic fibers, on or integrated into the surface of one or both of the sheets 506, 508, disposed on SAP particles that may be distributed throughout the synthetic fibers, and so forth. The absorbent core 502 may include additional structural elements such as a distribution layer disposed between one of the sheets 506, 508 and the synthetic fibers 504, chemiluminescent components disposed on or within such layers, and the like. In some embodiments of article 500, the chemiluminescent component is a luciferin selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, furazine, and combinations thereof. For example, in some such embodiments, the component is coelenterazine. In some embodiments, the chemiluminescent component is a luciferase selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophos luciferase, dinoflagellate luciferase, copepodia 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 a Metridia luciferase. In some embodiments, the article binds both luciferin and luciferase such that a luminescent reaction will be initiated when liquid soil contacts the article. 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 an embodiment in the form of an absorbent core as shown in fig. 7, the luciferin and the luciferase are provided in different locations or materials of the absorbent core, e.g. the luciferin is provided on the surface of the synthetic fibers and the luciferase is distributed over the whole synthetic fibers. In another such embodiment, the luciferases are distributed throughout the synthetic fiber and the luciferins are disposed on or integrated within one or both of the sheets 506, 508. The concentration and/or amount of chemiluminescent components incorporated into the article 500 is not particularly limited and may be consistent with those described herein with respect to other treated materials, for example, on a diaper-by-diaper basis.

Optionally, articles (e.g., absorbent cores) according to the present disclosure may include other additive materials described elsewhere herein, such as photoluminescent compounds, pH buffers, binders, porous transfer agents, release agents, and the like.

Encapsulation chemistry

In variations of some embodiments of the treated materials discussed above, the composition includes at least one component of the chemiluminescent system as an encapsulated particle. In other words, in such embodiments, the particles comprising one component of the chemiluminescent system (e.g., particles of one or more materials that have been treated with the chemiluminescent component, and/or the chemiluminescent component itself is in particulate form) each have a coating that covers the entire surface of the particle, the coating being water soluble and/or water permeable. In a non-limiting illustrative example, luciferase in particulate form (e.g., in powder or other milled form) is encapsulated in a coating material, e.g., as water-soluble capsules and/or microcapsules, such as sugars and polysaccharides (e.g., starches, dextrins, etc.), gums, water-soluble polymers (e.g., PVOH), gelatin and other amino acid or protein-based materials, superabsorbent materials, porous media, and the like. In another non-limiting illustrative example, a treated matrix material of luciferin treated particles (e.g., the above-described cut pieces) or even smaller particles is encapsulated, for example, using one or more of the above-described coating materials. In the 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 the respective component is sufficient to produce a desired intensity of light in the presence of the aqueous system. In some such compositions, both the first and second chemiluminescent components are encapsulated, e.g., individually encapsulated. Encapsulation of one or both chemiluminescent components may provide chemical stability and/or longevity in some applications and/or ease of handling when incorporating one or more components into an absorbent article. In some embodiments, such compositions may allow an end user to incorporate a chemiluminescent system into standard absorbent articles, and so forth.

According to other embodiments discussed herein, such compositions of partially or fully encapsulated chemiluminescent systems may be incorporated into absorbent articles in a variety of ways, such as dispersing the encapsulated component into an absorbent material such as a fibrous matrix, e.g., in a similar manner as dispersing particulate SAP into a fibrous matrix, with other chemiluminescent components disposed elsewhere in the absorbent article, e.g., in or on the treated material or structural element. In a two-component chemiluminescent system in which both components are encapsulated, both may be dispersed throughout the same fibrous matrix, and so on.

Other treated materials

Other processed materials and structural elements are within the scope of the present disclosure consistent with the concepts and principles discussed above and elsewhere herein. For example, in some embodiments, the polyester backsheet is treated with one or more chemiluminescent components in a manner conceptually similar to the treated tissue compositions described above. In some embodiments, the fluid permeable material may be treated with one or more chemiluminescent components to produce a carrier matrix for components included in the absorbent article during production, for example, in a manner that integrates the treated carrier matrix into a standard production process for absorbent articles.

The manner in which the chemiluminescent system is disposed in or on the treated material and/or structural element may take into account factors such as the nature of the intended use of the absorbent article in combination with the treated material or element, the application technique employed, user safety, principles of efficient and/or economical manufacture, and the like.

For illustration, fig. 9A-9J illustrate various exemplary embodiments (full profile not shown) of representative structural elements suitable for incorporation into an absorbent article. Each depicts a simplified and somewhat schematic top view of an embodiment of a structural element 900. The structural element 900 itself is shown as rectangular and described in the form of an absorbent core of suitable size and dimensions, but the following description applies to materials and/or other structural elements that may be incorporated into an absorbent article, such as topsheets, backsheets, tissue sheets, treated layers of liquid permeable material, etc., which may have other shapes/dimensions or be similar to those shown.

The structural element 900 comprises a first surface 902, which in turn comprises a treatment area 904, wherein the treatment area has been treated with at least one component of a chemiluminescent system adapted to react in the presence of an aqueous system to generate light. Although it may not be necessary to visually distinguish the treated area from the remaining untreated portion of the first surface, this is shown for illustration purposes. The treatment area may be created in any of the ways disclosed herein, for example, via application of at least one component to the surface by printing, flow coating, or the like.

The treatment area may have any desired configuration. For example, the treatment area may cover all or a portion of the surface. However, in many applications, a substantial portion of the surface may not be utilized, as certain areas of the surface may not correspond to target areas where fluid contamination is expected. In addition, since many absorbent articles transfer fluid received from a insult, it may not be necessary to treat the entire area corresponding to the target area, as it is contemplated that the front of the fluid from the insult may be attracted to and subsequently encounter the treated area in order to trigger a luminescent reaction.

Thus, the treatment region may be sized and shaped to provide a desired effect during use while reducing the amount of chemiluminescent material used. The exemplary embodiment shown in fig. 9A shows the treatment area 904 as a continuous shape, in particular in the form of a strip 906 extending along the length of the element 900. Because the width of the strip is substantially less than the width of the surface 902, such a configuration may represent a corresponding cost savings relative to a configuration that processes the entire surface 902. In an exemplary variation of this configuration, a first chemiluminescent material (i.e., a component such as luciferin and/or luciferase) is applied to the surface 902 in the 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, another region (not shown) of the surface 902, the material comprising the structural element 900, or another structural element (not shown). Fig. 9B illustrates another exemplary embodiment in which the treatment region 904 is shown as a pattern of discrete portions, particularly discontinuous strips 908 extending along a portion of the length of the element 900. Discontinuous strips having the same width as the continuous strips may require relatively less chemiluminescent material, and less if the overall length of the strip is shorter. In such an example, an arrangement of a first chemiluminescent material (i.e., a component such as luciferin and/or luciferase) may be applied to the surface 902 in the discontinuous strip 908, and a second chemiluminescent material (i.e., a component such as another one or both of luciferin and/or luciferase) applied to the entire surface 902, another region (not shown) of the surface 902, the material comprising the structural element 900, another structural element (not shown). In some embodiments as shown in fig. 9B, the luciferin and luciferase components may be applied together or separately in the same treatment region 904 as the same discrete portion of the discontinuous strip 908, or separately, such that adjacent discrete portions have different components, all of the material or another structure of the surface 902 being treated with or without at least one chemiluminescent material (i.e., components such as luciferin and/or luciferase).

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

The treated areas composed of the pattern of discrete portions may allow for coverage of a substantial portion of the surface 902 while using less chemiluminescent material than a complete, continuous treatment of the same sized area. An example of such a configuration is shown in the exemplary embodiment shown in fig. 9C, wherein the treatment area 904 is an arrangement of shapes extending over a majority of the area of the surface 902 (as shown) or only over a target area (not shown) of the structural element 900, in particular an arrangement of stars 910. Other shapes or patterns may be utilized in the processing region 904, including a mixture of different shapes and/or irregular patterns. The number of individual shapes may be desirable, for example, to correspond to the amount of fluid suitable to trigger the luminescence. The individual chemiluminescent components may be provided in shape 910 as described above for the discrete portions of fig. 9B or otherwise as described above.

The configuration of the treatment area may take into account the nature and intended use of the absorbent article in which the structural element 900 is used. For example, in the case of diapers or adult incontinence pads, there are often localized areas where fluid contamination may be expected during use, as these articles are often restricted from moving relative to the wearer. The diaper 100 shown in fig. 4B schematically illustrates this as a target area 108. Thus, a treatment area (e.g., as shown in fig. 9A or 9B) suitable for the structural element 900 of the diaper 100 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 overlap the target area 108 or are disposed proximate the target area 108.

In some embodiments, a diaper or similar absorbent article may be configured to handle multiple insults (e.g., two or three consecutive insults, or more than three) before a change is desired, such as by incorporating an appropriately configured absorbent core. Typically, due to the wicking ability of the material used in the absorbent core, fluid from the insult diffuses laterally outward through the absorbent core from the point of origin of the insult before it is stored. The fluid front from the subsequent insult will then wick away from the point of origin of the insult until it reaches the unused SAP in the absorbent core. Thus, the target region in such a multiple use configuration may be considered to comprise a plurality of concentric, generally annular regions.

The arrangement of the treatment zones may accordingly be configured to indicate not only that the absorbent article has been used, but also the extent or lack thereof.

An example of such a configuration is shown in fig. 9D, where a surface 902 of an embodiment of a structural element 900 includes a target region 912 corresponding to a region where one or more fluid insults are expected during use of the absorbent article into which the structural element is incorporated. For simplicity, the target region 912 is shown to consist of three concentric regions (914, 916, 918) that respectively correspond to the extent to which fluid fronts from three consecutive insults are expected to wick. The treatment region 904 is shown as partially overlapping the target region in the form of a discontinuous strip and further includes discrete portions or segments 920 corresponding to each of the three concentric regions.

While the boundaries of the concentric zones will vary with the design of the absorbent article, the intended user, etc., the treated zones are configured such that the fluid front from the continuous insult will first encounter the pair of inner sections 920 of the treated zone and then the pair of outer sections. Thus, the resulting chemiluminescent pattern may visually indicate whether the diaper has received one, two, three or more insults.

In a configuration similar to that shown in fig. 9D, where each portion of the treatment region overlaps only a corresponding portion of the target region, different portions of the treatment region 904 may be configured to produce visual light that differs from each other in at least one visual aspect. For example, the outer segment can be configured to produce light of a different (e.g., greater) intensity, and/or different color, duration, etc., than the inner segment, such as by varying the chemistry applied to different portions of the treatment region 904 according to the methods disclosed herein (e.g., by using photoluminescent compounds, different concentrations of at least one chemiluminescent component, treating the coating weight, or buffers that affect the efficiency of the chemiluminescent reaction). For example, the speed and/or intensity of the chemiluminescent reaction may be manipulated by varying the concentration of at least one chemiluminescent component (e.g., luciferase or luciferin) in the treatment region 904 or from the treatment region 904 through concentric regions. This arrangement allows for accuracy in the amount and/or duration of illumination, such as early/fast illumination (articles that require immediate replacement), slow/late illumination (articles designed for longer wear times), shorter durations (articles that are more easily detected by the caregivers), and longer durations (articles that are more easily detected by the caregivers or that have reached full signal capacity), for example, as seen by the caregivers. The variation of the at least one chemiluminescent component from the treatment area to the treatment area may be 1:1 to 1:100 and all ranges therebetween, including but 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, as well as all other possible subranges. Such variations may enhance the properties of the luminescent indicator, which may allow a caregiver to more easily determine the status of the absorbent article. Alternatively, in some embodiments, the segments 920 may be disposed in only one or both of the concentric regions (e.g., only in region 918 (see fig. 9H with segments 934), or only in region 916 (see fig. 9I with segments 936), or in both regions 916 and 918), depending on the desired pattern of soil/wetness indication. Similarly, individual chemiluminescent components may be disposed in segments 920, 934, and 936 as described above for discrete portions of fig. 9B, the shape of fig. 9C, or otherwise.

Another configuration of an absorbent article suitable for multiple use is shown in fig. 9E, wherein the surface 902 of an embodiment of the structural element 900 further comprises a target region 912 having a plurality of concentric regions, but comprising a treated region 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 a plurality of insults, which may thus create an increasingly larger light emitting area as the absorbent article receives a continuous insult. Unlike the configuration shown in fig. 9D, 9H, and 9I, portion 922 is shown overlapping all of the plurality of concentric regions, and thus may be suitable in embodiments in which the boundaries of the regions may not be deterministic and/or predictable. The individual chemiluminescent components may be disposed in the discrete portion 922 as described above for the discrete portion of fig. 9B, the shape of fig. 9C, or otherwise.

In some applications, it may be preferable to locate the treatment region (or portion thereof) away from the target region where one or more fluid contaminants are expected. For example, absorbent articles such as mattresses are designed to cover large areas rather than wearing articles. Positioning the treatment region away from the target region may reduce the likelihood that the user's body will block chemiluminescent signals due to contamination. Furthermore, positioning the treatment area close to the edge of the absorbent article may also allow a caregiver to check the treatment area by lifting the edge or corner of the bed cover, thereby making it easier to determine whether, for example, the mattress is contaminated. A configuration suitable for this is shown in fig. 9F, where an embodiment of a structural element 900 includes a treatment region 904 on a surface 902 that includes a plurality of discrete portions 924 that do not overlap a target region 926, but are positioned away from the target region 926. The individual chemiluminescent components may be disposed in the discrete portions 924 as described above for the discrete portions of fig. 9B, the shape of fig. 9C, or otherwise.

In some applications, it may be difficult to predict a target area where fluid contamination may be expected. In the case of a mattress or pet pad, the location of the fluid insult may vary with the relative location of the user, which may vary during sleep or bed rest or other use of the absorbent article, such that the fluid insult may occur anywhere relative to the absorbent article. The configuration of a pattern consisting of a plurality of discrete processing portions characterized by extension over a large area of the surface of the structural element 900 may thus be suitable, for example, as shown in fig. 9C.

In any of the above-described exemplary embodiments, the at least one component (also described herein as a chemiluminescent material, a first component, a component, etc.) may be luciferin or luciferase, depending on the various species and concentration ranges detailed herein.

Alternatively, according to the application techniques disclosed herein for applying two reactive components of a chemiluminescent system to the same matrix material as described above in alternative embodiments, e.g., the same or overlapping portions/surfaces of the matrix material (see, e.g., fig. 5D, 5E and 5G), at least one component may be both luciferin and luciferase.

However, in some applications, it may be preferable to incorporate both luciferin and luciferase into the structural element, but in a manner that avoids challenges imposed on the same or overlapping portions of the matrix material.

As explained in more detail below, various application techniques may be suitable for producing the various exemplary embodiments of the structural element 900 discussed herein. For example, a method of producing a structural element for incorporation into an absorbent article treated with at least one component of a chemiluminescent system that reacts in the presence of an aqueous system to generate light may include applying a formulation to a predetermined area of a first surface of the structural element, wherein the formulation includes the at least one component, and wherein the at least one component is selected from luciferin and luciferase. As described above, the predetermined region may at least partially overlap with one or more target regions where fluid insult is expected during use of the absorbent article in which the structural element is incorporated, and may take any form, as described above. Certain application techniques, such as inkjet printing techniques, e.g., continuous inkjet printing, may allow for increased application speeds and/or precision, which in turn may allow for the configuration of treatment areas in which two or more reactive components are applied in close proximity to each other, including overlapping patterns. Thus, in some applications, for example in configurations comprising components that are applied to non-overlapping portions of the treatment region separately, the treatment region may bind luciferin and luciferase. A configuration illustrating such an arrangement is shown in fig. 9G, where an embodiment of a structural element 900 includes a treated area 904 on a surface 902 that is similar to the area shown in fig. 9E, but where the discrete portions 928 are each comprised of a non-overlapping portion to which two components are applied independently. By "non-overlapping" is meant that at least the minimum distance separates the two segments such that the chemiluminescent components disposed in each segment are not in fluid communication after application and at least prior to the first fluid insult. More specifically, the discrete portions 928 each include two segments 930 that may be treated with one component on either side of the segment 932, and the segment 932 may be treated with another component. In such a configuration, the treatment region may overlap with a target region (not shown for clarity). In use, when fluid soil is present, one or both of the reactive components may be transferred as a fluid core to the other to initiate a luminescent reaction when in "fluid communication" with the other or both.

In addition to limiting the treatment area 928 of fig. 9G to areas of the surface 902 where fluid insult is expected to be encountered at a given time, treating adjacent areas 930 and 932 with any separate component may allow substantial raw material savings in many embodiments described herein by reducing or eliminating a wide treatment area with at least one of the components (e.g., the surface 902 of the structural element 900, material within the absorbent core, or other structures in the article). The pattern and/or shape of adjacent processing regions is not limited. A non-limiting example is shown in two shapes in fig. 9J, two adjacent and non-overlapping star-moon shapes on the surface 902 of the structural element 900. The inner star 940 includes a treatment region that includes one component of a chemiluminescent system (e.g., luciferin or luciferase). Outer star 942 includes another component. Inner month 941 includes a treatment region that includes one component of a chemiluminescent system (e.g., luciferin or luciferase). The outer month 943 includes another component. In this illustrative example, outer star 942 and outer month 943 are in discontinuous (i.e., virtual) lines, while inner star 940 and inner month 941 are patterned in continuous lines. Other non-overlapping shapes and/or patterns may be incorporated within or outside of these shapes (not shown). Additionally, colored inks or pigments can be incorporated in any or all shapes to provide a coloring effect (not shown) under light conditions and/or by observed color changes emitted by chemiluminescent reactions, such as printing on the impermeable polymer backsheet 900.

In addition, the coating weight, concentration of the components employed and/or the distance between the inner shapes 940, 941 and the outer shapes 942, 943 may be varied within the structural element (including overlapping patterns) to manipulate the observed luminescence intensity and duration of the chemiluminescent reaction. For example, assuming that all other variables are equal, a relatively close fixed distance like stars 940 and 942 will result in faster transfer and availability of each component. In contrast, the shapes 941 and 943 have approaching and separating dimensions therebetween, which will allow for longer lasting response and luminescence characteristics. The light emission characteristics may be further changed by changing the distance between the shapes, for example, the stars 940 and 942 are close to each other when they are farther from the intended soil region and are spaced apart when they are closer to the intended soil region. Alternatively or in combination, the coating weight or concentration of one or both components within the inner and outer shape treatment zones may be varied throughout or in advantageous areas (e.g., concentric areas) on the surface 902. The fixation or variable availability (e.g., space or concentration) of excipients with reaction enhancing or inhibiting activity may similarly control the duration and/or intensity of luminescence (not shown) of the chemiluminescent reaction. The spatial separation of the delayed reaction of the components of the chemiluminescent system can also be achieved by disposing the components separately in separate and distinct structural elements 900 (e.g., luciferin printed in a star 940 on a polyester backsheet, and luciferase dispersed throughout the absorbent core fluff pulp), or as shown in fig. 9H and 9I.

As described above, the application of one or both chemiluminescent components may produce a treated region that is visually indistinguishable from an untreated region. In some embodiments, it may be desirable to have visually distinct treatment areas, such as in a quality check application process, provide visual wetness indicators other than chemiluminescence, and so forth. This may be accomplished by various means, one example of which is also to apply a non-chemiluminescent wetness indicator to the first surface. Non-chemiluminescent wetness indicators may be applied to at least partially overlap the target area, but not the treatment area, etc., as desired. Continuous inkjet printing, optionally in combination with other application techniques, can be used to create embodiments that also incorporate non-chemiluminescent wetness indicators.

In still other embodiments of treated materials or structural elements according to the present disclosure, one or more chemiluminescent components may be provided in discrete amounts in a fluid, gel, powder, or the like, for incorporation into or use in a preformed absorbent article (e.g., converting such absorbent article into an absorbent article incorporating a chemiluminescent system). In some such embodiments, the end user may incorporate one or more chemiluminescent components into a preformed absorbent article or the like.

Absorbent article

As noted above, it is apparent that various types of treated materials according to the present disclosure may be incorporated into absorbent articles. An illustrative example is provided in fig. 4F, which combines a treated tissue composition 300 and a layer of indicator particles 400, each of which combines a different chemiluminescent component such that the first chemiluminescent component is transferred to the second chemiluminescent component by an aqueous system in the form of a fluid insult that moves through the absorbent article, thereby initiating a luminescent reaction.

As another illustrative example, an embodiment of an absorbent article incorporates an absorbent core 502 as further discussed herein with respect to fig. 7, and a layer of indicator particles 400 disposed between the absorbent core and the backsheet of the diaper, similar in structure to the configuration shown in fig. 4F. In such embodiments where the absorbent core 502 incorporates a first chemiluminescent component and the particles 400 are treated with a second chemiluminescent component, fluid insult moving through the diaper transfers one chemiluminescent component to another.

However, in a more general sense, absorbent articles produced according to the present disclosure may, but need not, incorporate the various treated materials described herein. Rather, absorbent articles produced in accordance with the present disclosure can incorporate chemiluminescent systems by disposing their chemiluminescent components independently in (or onto) a variety of structural elements used in absorbent articles (which may include one or more of the treated materials described above).

In other words, an absorbent article constructed in accordance with the present disclosure includes a liquid permeable topsheet, a liquid impermeable backsheet, an absorbent material (e.g., fluff pulp and/or synthetic fibers) disposed between the topsheet and backsheet, and one or more structural elements selected from the group consisting of liquid permeable tissue sheets and particles formed from or otherwise including hydrogen bonded cellulose pulp fibers, and a chemiluminescent system adapted to react in the presence of an aqueous system to produce light. In embodiments, the liquid permeable tissue sheet comprises fibers selected from the group consisting of cellulosic fibers, synthetic fibers, and combinations thereof. In such absorbent articles, the components of the chemiluminescent system are independently disposed in (or on) the topsheet, backsheet, absorbent material and structural element in a configuration in which the first chemiluminescent component is transferred to the second chemiluminescent component by the aqueous system moving through the absorbent article.

Thus, the illustrative constructions shown in fig. 4D, 4E, and 4F are all exemplary 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 in a liquid permeable tissue sheet, such as the treated tissue composition described above, and is shown, for example, in fig. 4D. In some examples of this configuration, the chemiluminescent system includes luciferin and a luciferase, wherein the luciferase is disposed within the absorbent material and the luciferin is disposed on a sheet of tissue. In a particular embodiment, the luciferase is a Gaussia luciferase and the luciferin is coelenterazine. In a particular embodiment, the luciferase is a Renilla luciferase and the luciferin is coelenterazine. In a particular embodiment, the luciferase is a Metridia luciferase and the luciferin is coelenterazine. In particular embodiments, the absorbent material treated with the chemiluminescent component comprises cellulosic fibers.

Incorporation of the chemiluminescent system into the absorbent articles discussed herein is typically accomplished by the manufacturer of the absorbent article and/or the manufacturer of the treated material or structural element incorporated into the absorbent article. However, it is within the scope of the present disclosure that an end user (or another person, for example) may apply one or more chemiluminescent components to the absorbent article. For example, in some embodiments according to this aspect of the disclosure, an 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 second chemiluminescent component adapted to react 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 to an end user as a kit, for example, the measured amount may be provided in any suitable form (e.g., liquid formulation, gel, powder, particulate form, such as the treated cut pieces or strips disclosed herein, encapsulated particles, etc.), for application to an absorbent article. In such embodiments, the absorbent article may be configured to allow the application of a measured quantity, for example by incorporating selectively openable and resealable portions. In one illustrative embodiment, the backsheet includes a flap that can be selectively peeled away to allow a measured amount of the second chemiluminescent component to be applied to the interior structure of the absorbent article and then replaced. Further, some embodiments may be configured to allow existing (e.g., prefabricated) absorbent articles to be modified to include a chemiluminescent system, for example, by an end user or third party manufacturer, such as by applying a measured amount of chemiluminescent component to the absorbent article.

Regardless of the form or method of incorporating the chemiluminescent system or its components into the absorbent article, the total amount may vary significantly depending on, for example, the construction and use of the absorbent article. As an illustrative and non-limiting example, an embodiment such as an infant standard diaper may include 0.00001-100.0mg of luciferin and 0.00001-100.0mg of luciferase. In embodiments, the absorbent article comprises 0.00001-100.0mg,0.0001-100mg,0.001-100mg,0.01mg-100mg,0.1-100mg or 1-100mg of luciferin and 0.00001-100.0mg,0.0001-100mg,0.001-100mg,0.01mg-100mg,0.1-100mg or 1-100mg of luciferase, or any range within these ranges, as well as all other possible subranges.

Some of such embodiments include coelenterazine in a total amount ranging from 0.0001-20.0mg and luciferase (Gaussia luciferase, renilla luciferase, metridia luciferase, or combinations thereof) in a total amount ranging from 0.00003-20.0 mg. Some of such embodiments include coelenterazine in a total amount ranging from 0.01-100.0mg and luciferase (Gaussia luciferase, renilla luciferase, metridia luciferase, or a combination thereof) in a total amount ranging from 0.2-40.0 mg. Of course, infant diapers may include either less or more amounts, and other absorbent articles may also include different amounts and/or ranges of corresponding components.

Treatment formulation

Formulations for applying a chemiluminescent system to a matrix material, such as in the production of the treated materials and/or absorbent articles disclosed herein, include at least one component of the chemiluminescent system selected from luciferin and luciferase in a liquid carrier. Depending on factors such as its solubility in the liquid carrier, the reactive components may be dispersed and/or dissolved in the liquid carrier, and so forth. Thus, the term "formulation" as used herein encompasses mixtures (e.g., dispersions, suspensions, etc.) as well as solutions. For example, in an illustrative embodiment, the liquid carrier is a suitable solvent (e.g., ethanol) in which the luciferin is dissolved. In an exemplary embodiment, the liquid carrier is water in which the luciferase is dissolved; however, where the solvent is ethanol (e.g., in the form of a ground powder), the luciferase is dispersed.

Formulations according to the present disclosure include one-component formulations (i.e., incorporating luciferin or luciferase) and two-component formulations (i.e., incorporating both luciferin and luciferase).

As described above, the chemiluminescent system, and in particular its components, react in the presence of water to produce light. One challenge in incorporating reactive components into absorbent articles and/or materials or structural elements of absorbent articles is to do so in a manner that does not initiate the reaction in advance, for example, during production. While one way to address this challenge is by providing the components in separate materials or structural elements and/or at different locations in the absorbent article, in some applications it may be appropriate to incorporate both components into the same matrix material. In such applications, the challenge may therefore be to produce a host material in a manner that does not unduly trigger 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 an illustrative embodiment of a two-component formulation, the liquid carrier is a suitable non-aqueous solvent (e.g., ethanol) in which the luciferin is dissolved and in which the luciferase is dispersed.

A variety of solvents are suitable for use in or as a liquid carrier for one-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, n-butyl acetate. Combinations of the above solvents may also be used, illustrative examples of which include ethanol and isopropyl acetate, ethanol and acetone, pentanone and ethanol, and the like. The foregoing solvents and combinations are also suitable mediums in which the luciferase may be dispersed. The choice of solvent may be determined by a variety of factors including the solubility of the particular luciferin in the solvent, whether other materials (e.g., luciferases, binders, porous transfer 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, the matrix material to which the formulation is to be applied, etc.

The concentration of the chemiluminescent component in the formulation is not particularly limited in a general sense, except for the solubility limit of the solvent of the liquid carrier, and may be suitable for a particular application.

However, it was found that even in some cases where the chemiluminescent component is not particularly soluble in a solvent, its solubility can be promoted by using an excipient (i.e., a compound having a function of promoting the solubility of the chemiluminescent component in the solvent). One example of this is some luciferins, such as coelenterazine, which are not very soluble in water. However, water may be a more desirable solvent than the organic solvents described above for various reasons (e.g., operational requirements, recycle/recovery/disposal costs, raw material costs, capacity of existing manufacturing equipment, etc.). Suitable excipients for coelenterazine generally include polar protic solvents other than water, including some of the above-described suitable organic solvents for luciferin (e.g., ethanol, butanol, propanol, isopropanol, pentanone), and other materials such as hydroxypropyl-beta-cyclodextrin (HPBC), and the like, as well as combinations thereof. In some embodiments, using a solvent as an excipient in a portion of an aqueous formulation may be a suitable method of reducing the amount of additional use in the formulation.

Thus, in some embodiments, the partially aqueous formulation comprises luciferin and a solvent that dissolves the luciferin, including water and an excipient that promotes the solubility of the luciferin in water. In an embodiment, the portion of the aqueous formulation comprises luciferin, a solvent to dissolve the luciferin comprising 40-99 weight percent water and 1-60 weight percent of an excipient adapted to promote the solubility of the luciferin in water, and optionally a binder adapted to bind the luciferin to the matrix material. In embodiments, a portion of the aqueous formulation includes a solvent that includes 40-99, 50-99, 60-99, 70-99, 80-99, 90-99, or 95-99 weight percent water, or any of these ranges, as well as all other possible subranges. In embodiments, a portion of the aqueous formulation includes 1-60, 5-60, 10-60, 20-60, 30-60, 40-60, 50-60, or more weight percent excipient, or any of these ranges, as well as all other possible subranges.

In some such embodiments, the excipient is one or more of hydroxypropyl-beta-cyclodextrin, ethanol, butanol, propanol, isopropanol, and pentanone. The effects of some excipients may be additive in terms of aiding the solubility of luciferin. In such embodiments, the solvent is typically at least 40 weight percent water, and the concentration of excipient may be determined by the desired concentration of luciferin to be dissolved in the solvent. For example, in embodiments using HPBC as an excipient, an HPBC concentration of about 45-50mM can promote dissolution of coelenterazine in water to a concentration of about 3.7mM (which is associated with about 1.57g of coelenterazine per liter of water).

Thus, in some embodiments of the formulation according to the present disclosure, the liquid carrier includes a solvent in which the luciferin is dissolved, the composition of the formulation ranging from 40 to 99 weight percent solvent, 0.01 to 20 weight percent luciferin. In embodiments, the formulation includes 40-80 weight percent, 45-85 weight percent, 50-90 weight percent, 60-95 weight percent, or 70-99 weight percent solvent, or any of these ranges, as well as all other possible subranges. In embodiments, the formulation includes 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 of these ranges, as well as all other possible subranges. In some such embodiments, 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. In an example of such an embodiment, the solvent comprises ethanol. In some non-limiting examples of such embodiments, the solvent is ethanol and the formulation includes 80-99 weight percent ethanol. In some non-limiting examples of such embodiments, the solvent is ethanol and the formulation includes 45-50 weight percent ethanol. In some of the foregoing embodiments, the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, furazine, and combinations thereof. In some non-limiting examples of such embodiments, the luciferin is coelenterazine, and the formulation includes 0.1 to 0.3 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine, and the formulation includes 0.2 to 0.5 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine, and the formulation includes 0.5 to 0.9 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine, and the formulation includes 0.9 to 2.0 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine, and the formulation includes 2.0 to 10 weight percent luciferin. In some non-limiting examples of such embodiments, the luciferin is coelenterazine, and the formulation includes 10 to 20 weight percent luciferin.

In embodiments in which the liquid carrier is non-aqueous (and thus in which the chemiluminescent components will not react), the luciferin-containing formulation may further comprise a luciferase. Thus, in some embodiments of the formulation according to the present disclosure, the non-aqueous liquid carrier comprises a solvent in which the luciferin is dissolved, the composition of the formulation ranges from 40 to 99 weight percent solvent, from 0.01 to 20 weight percent luciferin, and from 0.01 to 20 weight percent luciferase. In such embodiments, the solvent and luciferin may be as described above. In some such embodiments, the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase, and firefly luciferase. In some non-limiting examples of such embodiments, the luciferase is a Gaussia luciferase, a Renilla luciferase, a Metridia luciferase, and combinations thereof, and the formulation includes 0.05 to 0.2 weight percent of the luciferase. In some non-limiting examples of such embodiments, the luciferase is a Gaussia luciferase, a Renilla luciferase, a Metridia luciferase, and/or combinations thereof, and the formulation includes 0.2 to 0.6 weight percent luciferase. In some non-limiting examples of such embodiments, the luciferase is a Gaussia luciferase, a Renilla luciferase, a Metridia luciferase, and/or combinations thereof, and the formulation includes 0.1 to 1.0 weight percent of the luciferase. In some non-limiting examples of such embodiments, the luciferase is a Gaussia luciferase, a Renilla luciferase, a Metridia luciferase, and/or combinations thereof, and the formulation includes 1.0 to 10.0 weight percent of the luciferase. In some non-limiting examples of such embodiments, the luciferase is a Gaussia luciferase, a Renilla luciferase, a Metridia luciferase, and/or combinations thereof, and the formulation includes 10.0 to 20.0 weight percent luciferase.

Embodiments in which the liquid carrier/solvent is aqueous or partially aqueous are typically one-component formulations in that the chemiluminescent components react in the presence of water to produce light.

In addition to the liquid carrier/solvent and chemiluminescent components, formulations according to the present disclosure, such as those discussed above, may include one or more of a variety of other substances. As described above, one example is a binder, for example to help retain the chemiluminescent component on the matrix material to which the formulation is to be applied, as described above with respect to the treated material produced according to the present disclosure. Suitable binders include ethylcellulose, methylcellulose, nitrocellulose, and polyurethane, as described above. Although not required in all embodiments, the adhesive may be used as a water blocking barrier and/or a time release agent, as described above. Another example is a porous transfer agent, also as described above with respect to various embodiments of the treated material. The porous transfer agents incorporated into the formulation as disclosed herein may provide benefits after application of the formulation to a matrix material. In particular, the porous transfer agent may facilitate transfer of the chemiluminescent component and/or aqueous system relative to the matrix material upon which the formulation is applied upon subsequent contact of the treated matrix material with the aqueous system. As described above, when an aqueous system is present, the porous transfer agent may thus improve the tendency of some binders to reduce the utilization of the chemiluminescent component. Suitable porous transfer agents are also discussed above and include starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers. In embodiments, the formulation includes from about 0.01 weight percent to about 52 weight percent of the porous transfer agent. In embodiments, the formulation includes from about 0.01 to about 5 weight percent, from about 0.1 to about 10 weight percent, from about 1 to about 20 weight percent, from about 5 to about 40 weight percent, or from about 10 to about 52 weight percent of the porous transfer agent, or within any of these ranges, as well as all other possible subranges.

Another example of an alternative additive material is a viscosity modifier that can be used to modify the viscosity of the formulation to a desired level, such as a viscosity suitable for application of the formulation to a matrix material by any of a variety of methods (e.g., flow coating, printing, coating, etc.). Although technically any soluble or insoluble additive to a solvent may function to alter the hydrodynamic properties of the solvent, the term "viscosity modifier" is used herein to refer to a substance that produces a non-negligible change in the viscosity of the formulation. Thus, suitable viscosity modifiers include materials that may also be suitable binders, such as ethylcellulose, methylcellulose, nitrocellulose and polyurethane, materials that may also be suitable porous media, and the like.

The choice of one or more of the above additives, the concentration thereof, etc. may be determined by a variety of factors, such as the intended method of application of the formulation, the matrix material to which the formulation is to be applied, interactions between other substances in the formulation, etc.

For example, a formulation containing a binder may include a high level of binder, for example if the matrix material is otherwise not good or does not retain the chemiluminescent component at all. On the other hand, it was found that even low levels of binder in some applications would enhance retention. Although this is not intended to be limiting, suitable concentrations of binder in formulations according to the present disclosure are generally found in the range between 0.01 and 15 weight percent of the formulation. For example, in some such embodiments, the binder concentration is in a range between about 8.0 to about 12.5 weight percent. In some such embodiments, the binder concentration is in a range between about 0.01 to 1.2 weight percent. In some such embodiments, the binder concentration is in a range between about 1.2 to 8.0 weight percent. In 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 of these ranges, as well as all other possible subranges.

Similarly, the amount of formulation including the viscosity modifier used is not particularly limited, but it is generally found that a suitable concentration of the viscosity modifier in the formulation according to the present disclosure is in the range between 0.01 and 30 weight percent of the formulation. In embodiments, the concentration of the viscosity modifier is in the range of 0.01 to 30,0.1 to 10,1 to 15,5 to 30 weight percent of the formulation, or in any of these ranges, as well as all other possible subranges. One factor determining suitability is the method of application of the formulation (discussed below).

As described above, the porous transfer agent may improve the tendency of some binders to resist the release of chemiluminescent components from the matrix material to which it is bound when contacted with an aqueous system. However, even in the absence of such a binder, the porous transfer agent may promote the utilization of the chemiluminescent component when an aqueous system is present. In such cases, even small amounts may be beneficial. On the other hand, since many porous transfer agents are suspended or dispersed in the formulation rather than dissolved, a large amount of porous transfer agent can be used to produce a thicker viscous formulation, for example, to limit the movement or flow of the formulation relative to the matrix material after it is applied. For example, this may be useful in applications where it is desired to locate or even limit the chemiluminescent component to one or more specific areas on the matrix material, applications where the matrix material has less ability to restrict free flow of the formulation after application (e.g., polyester backsheet), and the like. It may also be useful to reduce the drying time after application. In general, suitable concentrations of the porous transfer agent in the formulations according to the present disclosure are found to be in the range of 0.01 to 52 weight percent of the formulation, depending on the application. For example, in some such embodiments, the concentration of the porous transfer agent is in the range of about 3.0 to about 6.0 weight percent. In some such embodiments, the concentration of the porous transfer agent is in the range of about 10 to about 25 weight percent. In some such embodiments, the concentration of the porous transfer agent is in the range of about 40 to about 52 weight percent.

While several specific embodiments are discussed more fully in the "examples" section herein, various illustrative and non-exclusive examples in accordance with the present disclosure are summarized below.

In a non-limiting example, the component is luciferin, wherein the luciferin comprises coelenterazine, and wherein the liquid carrier comprises a solvent in which the coelenterazine is dissolved and which comprises ethanol; and wherein the formulation comprises: 40-90 weight percent ethanol; 0.1-5.0 weight percent coelenterazine; 0.01-15 weight percent of a binder; and 9-52 weight percent of a porous transfer agent.

In a first simple exemplary "one-component" formulation, coelenterazine ("CTZ") is dissolved in ethanol. The sample composition of this formulation was 89 weight percent ethanol and 11.0 weight percent crude CTZ (purity about 50%). The formulation was found to be suitable for effective application of CTZ to cellulosic tissue sheets. When incorporated into absorbent articles with luciferase-treated fluff pulp, the chemiluminescence produced when the structures were tested was visible in dark chambers without light, indicating that lower purity CTZ could be used in such applications.

Variants of the foregoing formulation also include one or more binders dissolved in the solution. Sample compositions also using crude CTZ having a purity of about 50% included 87.39 weight percent ethanol, 0.88 weight percent ethylcellulose (binder), 0.33 weight percent polyurethane (also binder), 0.40 weight percent cornstarch and 11.0 weight percent crude CTZ. The formulation is also effective in applying CTZ to tissue sheets. When incorporated into an absorbent article and tested as described above, chemiluminescence was similarly visible, with some differences in the intensity observed after successive insults. In particular, in this application, the presence of binders and starch releasing agents in the formulation is associated with higher luminescence after less soil and lower luminescence after more soil. The addition of PVPA as a release agent or in place of a binder resulted in higher luminescence with less soil and lower luminescence with more soil (see FIG. 15A). In contrast, the availability of luciferin is limited in a luciferin application formulation by using treated fluff pulp containing 2% alum (see figure 16) or adding hydroxypropyl-beta-cyclodextrin as a binder. Both will delay the illumination until after more dirt.

In a non-limiting example, the formulation is a two-component formulation, wherein the luciferin comprises coelenterazine, the luciferase comprises Gaussia luciferase, renilla luciferin and/or Metridia luciferase, and the solvent comprises ethanol; and wherein the formulation comprises: 50-99 weight percent ethanol; 0.1-5.0 weight percent coelenterazine; alternatively, 0.1 to 5.0 total weight percent luciferase; optionally, 0.01-30 total weight percent of one or more of the following: a binder adapted to hold at least one component on a matrix material to which the formulation is applied; and a viscosity modifier; and optionally, 0.1 to 10 weight percent of a porous transfer agent.

In a first simple exemplary "two-component" formulation, CTZ and ethylcellulose are dissolved in ethanol, and Gaussia luciferase ("GLuc") is dispersed in solution. The sample composition of this formulation was 89.8 weight percent ethanol, 8.6 weight percent ethylcellulose, CTZ at a concentration of less than 2.0 weight percent, and GLuc at a concentration of less than 2.0 weight percent. The formulation was found to be suitable for effectively applying both chemiluminescent components to a polyester backsheet suitable for diapers and to have a viscosity suitable for application by wire flow coating.

Variants of the foregoing formulation include a porous transfer agent dispersed in a solution. Sample compositions using cornstarch as the porous transfer medium were 82.5 weight percent ethanol, 8.8 weight percent ethylcellulose, 3.3 weight percent polyurethane (another binder), CTZ at a concentration of less than 1.0 weight percent, GLuc at a concentration of less than 2.0 weight percent, and cornstarch at a concentration of 4.0 weight percent. Another sample composition replaces corn starch with synthetic amorphous silica, but is otherwise identical. Both formulations were also found to be suitable for the effective application of both chemiluminescent components to polyester backsheets suitable for diapers. However, when tested, the backsheet treated with the formulation including the porous medium exhibited much more chemiluminescence than the backsheet treated with the formulation not including the porous medium. Such formulations also have a viscosity suitable for application by wire flow coating.

Other composition variations in the formulations summarized herein (e.g., including binders, release agents, porous media or other additive materials, and concentration ranges thereof) are that a "two-component" formulation may include only one chemiluminescent component, such as in applications where it is desirable to produce a material or article treated with only one chemiluminescent component, such as in absorbent article construction, where the chemiluminescent component is disposed independently within the structure of the absorbent article (e.g., in a different material and/or structural element of the absorbent article). Vice versa, i.e. consistent with the present disclosure, a one-component formulation may be modified to include more than one chemiluminescent component, e.g. both luciferin and luciferase, at least in embodiments wherein the solvent or liquid carrier does not prematurely initiate a reaction between the chemiluminescent components or in dry formulation applications. For example, the preparation of CTZ in ethanol as described above may also include luciferase.

An exemplary formulation illustrating the breadth of the additive material range in the formulation is one that includes 47.10 weight percent ethanol, 1.49 weight percent ethylcellulose, polyurethane at a concentration of less than 1.0 weight percent, CTZ at a concentration of less than 0.50 weight percent, and 50.67 weight percent cornstarch relative to the higher levels of the porous transfer agent described above. The formulation was found to be flowable even in high levels of porous media, and was also found to be suitable for efficient application of CTZ to polyester backsheet of diapers. Once applied, the formulation was found to remain substantially on the matrix material and resist migration/flow to other areas, and was found to exhibit effective bioluminescence when assembled into a diaper-like structure with an absorbent material comprising luciferase when subjected to soil testing. Although this exemplary formulation is a "one-component" formulation, variants may also include luciferase, as the solvent does not trigger a luminescent reaction between the two chemiluminescent components.

In an exemplary "one-component" formulation, coelenterazine at a concentration of up to 3.7mM (about 1.57g per liter) is dissolved in an aqueous solution of 45-50mM hydroxypropyl-P-cyclodextrin. In another example, the desired concentration of coelenterazine 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 transfer agent. Such partially aqueous luciferin formulations are therefore suitable for application of luciferin to a variety of matrix materials discussed herein, such as absorbent materials, e.g. fluff pulp, synthetic fibres or combinations thereof. In another example, a solvent-soluble excipient, such as poly (1-vinylpyrrolidone-CO-vinyl acetate) (PVPA) or the like, may be added to a portion of the solvent system of 1-30% ethanol or isopropanol. For example, the concentration of the solvent-soluble PVPA in the partial solvent system is 0.2%. The addition of 0.2% PVPA after less fouling of the aqueous solution had a significant effect on the luciferin utilization (see fig. 15A).

In the above "single component" formulation, the skilled artisan will be able to determine, in accordance with the principles and concepts disclosed herein, the appropriate combination of factors for any configuration of absorbent articles by no more than reasonable experimentation. In embodiments in which the reactive component is luciferin coelenterazine, the treated tissue composition may include 0.00002 to 20 weight percent coelenterazine. For example, in one such embodiment, the treated tissue composition includes from 1 to 6 weight percent coelenterazine.

Treatment method

In general, formulations according to one aspect of the present disclosure and variants thereof may be applied or incorporated into a matrix material using a variety of methods, such as those disclosed in the above-identified U.S. patent application Ser. No. 14/516,255, which describe several methods of incorporating a chemiluminescent system into fluff pulp, such as coating, rinsing, dipping or spraying one or more non-aqueous solutions of chemiluminescent components onto fluff pulp sheets prior to air-laying.

In one aspect of the present disclosure, additional methods and techniques are provided relating to treating a host material with one or more reactive components of a chemiluminescent system. In such embodiments, the matrix material is treated with one or both of the reactive components of the bioluminescent system (i.e., luciferin and luciferase). Such a process may be used in addition to or in lieu of the standard process and/or the process described in the aforementioned' 255 application for fluff pulp and/or other matrix materials and/or structural elements, such as those suitable for use in absorbent articles.

As an illustrative and non-exclusive example of such a method according to the present disclosure, the method of producing a fluff pulp composition may be performed during an air-laying process, such as when fiberizing fluff pulp sheets in a hammer mill. Such a method includes fiberizing a sheet of fluff pulp fibers to produce a dispersion of individualized fluff pulp fibers in air, 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 chemiluminescent component onto the individualized fluff pulp fibers, corresponding to a concentration of 0.0003 to 10 weight percent of the component. The formulation in this method is not particularly limited and may take any of the forms described herein, for example. The spraying step may be performed at various locations in the process. For example, in some embodiments, the fiberizing is performed in a chamber of a hammer mill and the formulation is sprayed into the chamber of the hammer mill. In some embodiments, in which fiberization is performed in the chamber of the hammermill, the dispersion of fibers is then transported from the hammermill air and the formulation is sprayed into the dispersion as and/or after transporting the formulation from the chamber air.

Another illustrative and non-exclusive example of a method of producing a treated fluff pulp composition includes independently applying a non-aqueous solution including luciferin and an aqueous solution including luciferase to portions of a fluff pulp sheet. In some embodiments of the method, the portions are non-overlapping, such as on opposite surfaces of the fluff pulp sheet. Alternatively, the non-overlapping portions may be on the same surface of the fluff pulp sheet. In one example, by substantially drying the aqueous application of the luciferase component before or after application of the luciferase component, the separately applied components may overlap (where substantially drying means that water is insufficient to allow more than 5% of one or both components in the treatment area to be consumed in the chemiluminescent reaction without further addition of water).

Of course, several treated materials and structural elements are described above, examples of which include treated tissue compositions, indicator particles of various sizes and shapes, absorbent cores and similar articles, which include absorbent materials such as SAP and synthetic fibers and/or cellulosic (e.g., fluff pulp) fibers, other structural elements (liquid permeable topsheets, liquid permeable backsheets, etc.), portions thereof, and the like.

Several formulations for producing the treated material or otherwise applying one or more chemiluminescent components to the matrix material are also described above.

Developing a suitable method of applying a treatment formulation to a matrix material or structural element may present some challenges, some of which are mentioned above. For example, one challenge may be to incorporate reactive components into the material and/or absorbent article in a manner that does not unduly initiate a luminescent reaction, such as during production or storage, but only during use of the absorbent article. One challenge may be to ensure that the chemiluminescent component remains on the matrix material after application. A related challenge may be to limit the mobility of the chemiluminescent component relative to the matrix material after application.

As described above, some challenges may be addressed by including one or more additives in the formulation (e.g., such as binders to enhance retention, and/or porous media to limit mobility, for example). Some challenges may be addressed by providing the reactive components separately in the absorbent article, such as on two or more separate materials or structural elements of the absorbent article, such that one is transferred to the other during use, such as by an aqueous system moving through the absorbent article.

Additional challenges may exist, such as scaling up the application process from laboratory and/or pilot scale to commercial scale. Existing equipment configurations present challenges such as integrating the application method into existing machines, such as tissue coating or printing machines. The need to use a single application method for a plurality of different matrix materials or structural elements presents some challenges. There is also a continuing goal to achieve better process efficiency. These and other challenges may be addressed (alternatively or additionally) according to application methods or techniques.

As one example, it is often desirable to increase the overall speed of the production process. However, application of the formulation to the matrix material typically requires consideration of subsequent removal of the liquid carrier (e.g., water, organic solvent, etc.) from the material, which is typically accomplished by a heating or drying step.

Many materials suitable for incorporation into absorbent articles have a capacity to retain a threshold level of bound water after removal of any free water. In cellulosic materials, this capacity is referred to as the "fiber saturation point" and refers to the point at which only water bound in the cell wall is retained ("free water" is any other moisture not so bound). The fiber saturation point of fluff pulp can vary significantly depending upon factors such as composition, type, and the like, but is typically in the range of between about 15-25 weight percent. The threshold level of moisture for the synthetic material is typically low, for example, the polyester chips will typically have a moisture threshold level of about 5 weight percent, but this may be as high as 10 weight percent.

It has been found that this property can be exploited in a method of applying a chemiluminescent component to a matrix material to reduce or eliminate the need for a drying step after application. Thus, in some embodiments, a method of applying a luciferase to a matrix material includes applying a formulation including a luciferase dispersed in an aqueous liquid to a surface of the matrix material such that the moisture content of the matrix material does not increase above its moisture threshold content.

In certain embodiments, the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase, and firefly luciferase.

The luciferase formulation may have any desired concentration within a suitable range that takes into account factors such as the initial moisture content of the matrix material, the threshold moisture content of the matrix material, the amount of formulation applied to the matrix material, the desired concentration of luciferase on the matrix material, and the like. For this method, a representative concentration of luciferase on the matrix material ranges between 0.01-20mg per gram of matrix material. To this end, in some embodiments, the concentration of luciferase in the formulation ranges between about 5.0-30 weight percent.

In some embodiments, the matrix material has a moisture threshold content of up to 25 weight percent. In some embodiments, the matrix material is fluff pulp sheet having a moisture threshold content (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 content of the fluff pulp sheet by less than 10 weight percent. In some embodiments, the matrix material is a polyester sheet having a threshold moisture content of up to 10 weight percent.

The following illustrative examples consider fluff pulp sheets having a moisture content of 7.5% and a fiber saturation point of about 15% at ambient conditions. The following table shows an exemplary range of application levels of 15 weight percent aqueous luciferase formulation to achieve a final slurry moisture content less than the fiber saturation point. Fluff pulp sheets treated in this manner can reduce or eliminate the need for post-application drying steps due to the lack of free water in the treated material.

Table 2: exemplary final slurry moisture content Using different application levels of 15% luciferase formulation

Similar calculations may be performed for other concentrations of the luciferase formulation to achieve a desired luciferase concentration in the matrix material without exceeding the moisture threshold content of the material.

Other application methods according to the present disclosure apply two reactive components of a chemiluminescent system to the same matrix material, e.g., the same or overlapping portions/surfaces of the matrix material. As described above, in many applications it is preferred to locate the reactive components of the chemiluminescent system in a different or separate material or structural element of the absorbent article, such as with the luciferase in the absorbent material (e.g., fluff pulp, synthetic fibers, SAP, etc.) and the luciferin in another structural element (e.g., treated tissue composition, polyester backsheet, sheet, strip, etc.). Such a configuration may better ensure that the chemiluminescent component does not react accidentally, for example, due to ambient moisture or humidity, prior to use, such as during production, transportation or storage.

Regardless, in some cases, it may be desirable to incorporate more than one reaction component (e.g., luciferin and luciferase) into the same material or structural element. As described above, this can be accomplished by using a non-aqueous formulation that binds luciferin and luciferase. However, it was found that this could also be accomplished using an application method in which the luciferase and luciferin are applied separately to the same matrix material, in particular to the same region or surface of the matrix material. Such methods also utilize the capacity to bind moisture to a threshold level of matrix material such that no or insufficient free water is available to initiate the luminescent reaction.

Thus, in some embodiments, a method of applying a chemiluminescent system to a substrate material comprises a luciferase treatment step in which a region on a 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 region is treated with a luciferin formulation comprising a luciferin dissolved in a non-aqueous solvent. In such a method, the luciferase treatment step does not increase the moisture content of the matrix material above a threshold moisture content. Thus, the moisture content will not exceed the moisture threshold content of the matrix material, so no free water is available to initiate the reaction of the chemiluminescent components.

In certain embodiments, the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, and furazine. In certain embodiments, the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase, and firefly luciferase.

In such methods, the luciferin formulation comprises a non-aqueous solvent which will not initiate a reaction between the chemiluminescent components, but rather, aqueous luciferase formulations are a more important consideration in terms of moisture content. As previously mentioned, the luciferase formulation may have any desired concentration within a suitable range taking into account factors such as the initial moisture content of the matrix material, the threshold moisture content of the matrix material, the amount of formulation applied to the matrix material, the concentration of luciferin on the matrix material, and the like. Such ranges are typically between about 5.0-30 weight percent. The illustrative example formulation application levels of 15 weight percent of the luciferase formulation shown in table 2 are also applicable to the method, and similar calculations may be made for other concentrations of the luciferase formulation, for example to achieve a desired concentration of luciferase in the matrix material without exceeding the moisture threshold content of the material.

The above-described application method that utilizes the ability of the matrix material to bind a certain amount of water provides a solution that reduces or avoids the need for a subsequent step (e.g., a drying step) to remove the liquid carrier. However, alternative application methods according to the present disclosure may be applicable to matrix materials having lower threshold moisture content, such as polyester backsheets or similar structural elements incorporating synthetic materials.

Such a method produces a liquid impermeable backsheet structure that is treated with at least one component of a chemiluminescent system. In an illustrative embodiment of such a method, a formulation is applied to a surface of a liquid impermeable backsheet, the formulation comprising luciferin and/or luciferase, a liquid carrier, and a binder adapted to hold a chemiluminescent component to the backsheet. At least some of the liquid carrier is then removed from the backsheet.

Formulations in such methods may be in those described herein. One exemplary formulation described above includes luciferin dissolved in ethanol as a chemiluminescent component, the composition including 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 transfer agent. As noted above, materials used in or as liquid impermeable backsheets, such as synthetic materials, may present certain challenges, such as relatively low retention of chemiluminescent components applied thereto, migration or flow of the formulation relative to the material after application of the material, and so forth. The binding of the binder may solve the retention problem and, as mentioned above, a higher number of porous media in the formulation may solve the migration problem. Thus, in some embodiments of such methods, the formulation includes a reduced amount of liquid carrier and an increased amount of porous medium. Specific non-limiting examples of such formulations are described above as comprising 47.10 weight percent ethanol, 1.49 weight percent ethylcellulose, polyurethane at a concentration of less than 1.0 weight percent, CTZ at a concentration of less than 0.5 weight percent, and 50.67 weight percent cornstarch. However, variations of the method may include all variations of the formulation according to the principles described above, including varying the amount of binder and/or porous medium to impart a desired viscosity to the formulation, all of which are considered to be within the scope of the present disclosure. In some embodiments of the method, the viscosity of the formulation is suitable for application to the backsheet by flow coating, which refers to a process in which a flow of the formulation is applied to a surface through a nozzle. Suitable viscosities for flow coating applications may vary depending on the design and configuration of the nozzle (e.g., proximity of the nozzle to the surface, etc.). In some embodiments, any viscosity at which the formulation remains flowable is suitable.

As described above, the method includes subsequently removing at least some of the liquid carrier from the backsheet. In some embodiments of the method, the removing step comprises heat treating the surface of the backsheet treated with the formulation. However, in some embodiments, the removing step includes contacting the backsheet with an absorbent material suitable for wicking 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 is treated with luciferase.

In a non-limiting example of such an application method using wicking techniques to remove the liquid carrier, the above-described exemplary formulation of luciferin in ethanol is first flow coated onto the surface of the polyester backsheet. Immediately after application, a diaper core assembly formed of SAP dispersed in a luciferase-treated slurry was placed on the treatment area. The diaper core assembly wicks excess solvent (in this case ethanol) faster than it dries.

Thus, the wicking techniques described above may be integrated into the diaper manufacturing process, in some cases reducing or even eliminating the need for a post-application drying step prior to assembling the diaper structure using the treated backsheet. Furthermore, as described above, if another chemiluminescent component is disposed in the wicking material (e.g., diaper core component) or elsewhere in the diaper structure, the result is a diaper that combines two reactive chemiluminescent components separately disposed in the diaper structure so that one can transfer to the other upon receipt of liquid insult.

Variations of the method may include alternatives or additions to one or more of the foregoing challenges. For example, some embodiments of the method may include, after applying the formulation to the surface of the backsheet, applying a coating on the treated surface, wherein the coating is water-soluble or water-permeable. In one example, a solvent-soluble coating agent such as ethylcellulose may be sprayed on top of the formulation layer that has been deposited on the backsheet and dried to form a thin water-permeable coating of ethylcellulose. In another example, a water-soluble coating agent such as carboxymethyl cellulose (CMC) may be sprayed on top of a formulation layer that has been deposited on the backsheet and dried to form a water-soluble film of CMC. Other exemplary coating (i.e., encapsulating) materials include sugars and polysaccharides (e.g., starches, dextrins, etc.), gums, water-soluble polymers (e.g., PVOH), gelatin and other amino acid and/or protein based materials, superabsorbent materials, and porous media. Such a coating may help retain the chemiluminescent component on the backsheet and/or reduce the tendency of the formulation to migrate or flow. The water solubility/permeability of the coating does not significantly hinder the transfer of chemiluminescent components by the aqueous system, such as during use of the absorbent article including the treated backsheet.

Other application/production methods according to the present disclosure may be used to produce the treated materials described herein, such as treated tissue compositions and indicator particles, and the like.

For example, illustrative methods for producing indicator particles, such as those shown in fig. 6A and 6B, may include a combination of techniques and other concepts described elsewhere herein, such as separating fluff pulp sheets into particles of a desired shape and size, applying a suitable chemiluminescent component formulation to the particles (e.g., by spraying, dipping, etc.), and removing solvent and/or liquid carrier (e.g., by drying). The order of these operations may vary; for example, variations of this method may include separating the fluff pulp sheet into particles after application of the chemiluminescent component formulation and removal of the solvent and/or liquid carrier. In embodiments in which the particles are treated with both luciferin and luciferase, the formulation may comprise two components, or a variation of the method may comprise sequential treatment of fluff pulp sheets and/or particles with two different formulations of the respective components, and so on. Such a method may be integrated into the production of an absorbent article, for example, by mixing the indicator particles with absorbent materials (e.g., fluff pulp, synthetic fibers, SAP, etc.). In some embodiments of the method, the luciferin-treated particles may be mixed with the luciferin-treated particles, or all indicator particles may be treated with the same chemiluminescent component, the absorbent material treated with another chemiluminescent component, etc., such that both chemiluminescent components are integrated into the absorbent article.

Variations of the method of producing an absorbent article using indicator particles include delivering the indicator particles to a diaper structure at the time of production, such as delivering the particles to a surface of an absorbent core intended to face a backsheet such that the indicator particles will be disposed in the diaper between the absorbent core and the backsheet; or delivering the particles to the inner surface of the backsheet prior to final assembly of the diaper; or within the absorbent core as performed in SAP; etc. Thus, in an embodiment, a method of producing an absorbent article includes producing an encapsulating material composed of particles comprising one of two reactive components of a chemiluminescent system configured to produce light upon contact with an aqueous system, with a material of one or more of water permeable and water soluble; the absorbent article is produced by disposing an encapsulant material between a liquid permeable topsheet and a liquid impermeable backsheet and disposing other reactive components of a chemiluminescent system in a structural element of the absorbent article.

As another example, in an illustrative method of producing a treated tissue composition, a formulation is applied to a surface of a liquid permeable tissue sheet, wherein the formulation includes luciferin and a solvent in which the luciferin is dissolved. At least some of the solvent is then removed from the tissue sheet while the luciferin remains on the tissue sheet.

Somewhat similar to the illustrative method of producing a treated backsheet, embodiments of the illustrative method for producing a treated tissue composition include one or more of various aspects and variations thereof, covering a wide range of application techniques. For example, tissue printing can be performed, for example, in a tissue coater (an example of such a machine is the MirWec pCoater ^TM 350 A technique for applying ink and similar formulations to a continuous tissue sheet, and formulations suitable for application to a tissue sheet by transport through a tissue coater are within the scope of the present disclosure. For the sake of suitability, such formulations will be tailored to the capabilities of the machine, which may include adjusting the viscosity of the formulation to an appropriate level, incorporating suitable additives, and the like. Typically, tissue applicators use one or more cylinders on which the tissue sheet is carried to apply the ink or formulation, 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 sheet of tissue.

Alternatively, in some embodiments, the formulation is applied by flow coating the formulation onto the tissue sheet surface, for example by means of a flow coating device, wherein the tissue sheet moves relative to the flow coating device. In some such embodiments, the flow coating device includes one or more nozzles positioned proximate to and/or in contact with the moving surface. In such embodiments, the tissue sheet may be a continuous tissue sheet.

In accordance with one aspect of the present disclosure, a schematic diagram of an exemplary flow coating apparatus suitable for use in such an embodiment is shown in fig. 8A and 8B. In fig. 8A, the flow coating apparatus 600 is shown to include two pivot points in the form of rollers 602, 604 over which a continuous sheet of tissue 606 moves in the direction indicated by arrow a. Whereby the sheet 606 hangs or floats over the area defined by the rollers, indicated in fig. 8A as tissue floating area 608. The flow coating apparatus 600 includes a nozzle 610 configured to deliver a formulation to the top surface of the tissue sheet 606, for example, by flow coating the formulation supplied from a reservoir 612 to the tissue sheet surface as the tissue sheet is moved. The flow coating apparatus 600 is also shown to include a heating element at 614 that provides a hot air zone 616 through which the treated tissue sheet is conveyed to evaporate the solvent by the heat treatment. Fig. 8B shows an illustrative alternative configuration of a flow coating apparatus 600' in which the rollers 602, 604 have different arrangements. A flow coating apparatus having a configuration similar to that shown in fig. 8A and 8B is used to produce a treated tissue composition, such as that shown in fig. 5A as tissue composition 300, e.g., the longitudinal strips are discontinuous, dotted, dashed, straight, curved, according to one or more shapes, and so forth. In some embodiments, the ambient temperature of the application environment provides sufficient thermal energy to dry the liquid carrier of the formulation.

Several other variations of the configuration of the flow coating apparatus are within the scope of the present disclosure. For example, a plurality of nozzles may be held stationary and selectively activated to produce 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 via an arrangement of a plurality of nozzles. The one or more nozzles may be moved relative to the tissue sheet, e.g., transversely to the direction of movement of the tissue sheet, to create a treatment area in the desired shape or pattern. To enhance this capability, one or more nozzles may be configured to intermittently and/or continuously flow-coat the formulation, thereby creating continuous or discontinuous treatment zones on the tissue sheet. Thus, various embodiments of the method include applying the formulation to the tissue sheet such that the treatment area has any desired width, such as a longitudinal strip ranging from 0.1mm to the width of the tissue sheet (e.g., about 235mm, the width of a standard diaper), in any desired arrangement or pattern (e.g., the treatment area may be in the form of a strip extending perpendicular or otherwise transverse to the longitudinal direction of the tissue sheet, continuous or discontinuous (e.g., dotted or dashed), straight or curved or including curved and/or straight portions, including shapes or other forms, etc.). The treated area may range from 0.003-100% of the total area of the tissue sheet. As noted above, the total treatment area may be 1% to 99% of the surface area, such as 1-2%,1-10%,5-20%,1-25%,10-50%,20-90%, or any range within these ranges, as well as all other possible subranges.

Embodiments of the method incorporating such a flow coating apparatus may provide potential advantages over the use of tissue printers. For example, the tissue suspension area may reduce the likelihood of the formulation penetrating through the tissue sheet into the cylinder of the tissue printer. Moreover, suspending the tissue may allow more contact with ambient air to dry the tissue, thereby reducing the degree of heat treatment required to remove the solvent.

The formulation applied by the examples of the method is not particularly limited and several components and examples are discussed above, including sample compositions described as suitable for effective application of coelenterazine to cellulosic tissue sheets. Thus, in some embodiments, the formulation comprises 40 to 99 weight percent solvent and 0.01 to 20 weight percent luciferin. 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 an excipient that promotes dissolution of the deposited luciferin on the treated tissue or backsheet surface to perform a chemical-biological reaction at the soil. In some such embodiments, the solvent comprises water and an excipient that promotes the solubility of the luciferin in water. In some embodiments, the formulation includes a binder and/or viscosity modifier to adjust the viscosity to a desired level. In embodiments, the formulation includes 0.01-30 weight percent binder. One of the foregoing sample formulations included 87.39 weight percent ethanol, 0.88 weight percent ethylcellulose (binder), 0.33 weight percent polyurethane (also binder), 0.40 weight percent cornstarch and 11.0 weight percent crude CTZ (purity about 50%).

Embodiments of the method include applying the formulation to the tissue sheet at a rate that achieves a desired chemiluminescent component concentration on the tissue sheet. As described above, the concentration is not particularly limited, and may be expressed in various manners, such as a weight percentage of the thin paper sheet, a mass per unit length of the thin paper sheet, and the like. For example, in some embodiments where the formulation includes luciferin, the formulation is applied at a rate such that the concentration of luciferin on the sheet of paper reaches 0.00002 to 20 weight percent. In some embodiments, wherein the formulation includes coelenterazine, the formulation is applied at a rate such that the coelenterazine concentration on the tissue sheet reaches 0.01mg to 25 grams of coelenterazine per 12 inch length of the tissue sheet. In some embodiments, wherein the formulation includes coelenterazine, the formulation is applied at a rate such that the coelenterazine concentration on the tissue sheet reaches 0.01 to 1.0 grams of coelenterazine per 12 inch length of the tissue sheet. In some embodiments, wherein the formulation includes coelenterazine, the formulation is applied at a rate such that the coelenterazine concentration on the tissue sheet reaches 0.1-100mg of coelenterazine per 12 inch length of the tissue sheet.

Some embodiments of methods according to the present disclosure include additional steps, such as dividing the treated tissue sheet into discrete lengths after the formulation is applied. A related method of producing an absorbent core for incorporation into an absorbent article comprises producing a treated tissue composition according to the above, and incorporating the treated tissue composition into the absorbent core, for example by using the treated tissue composition as a wrapper for the absorbent material, i.e. by partly or completely surrounding the absorbent material with the treated tissue composition. As further discussed herein, in embodiments, such treated tissue compositions may include fibers, such as fibers selected from the group consisting of cellulosic fibers, synthetic fibers, and combinations thereof. As noted above, the formulations disclosed herein may be applied to a variety of substrate materials by any of a variety of methods, including flow coating, printing, coating, spraying, rinsing, soaking, dip coating, and the like. The above discussion sets forth the principles of tailoring the formulation to such applications, as well as the exemplary compositional ranges for illustrative 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 additive materials discussed herein (e.g., binders, porous media, release agents, other viscosity modifiers, etc.). Viscosity ranges suitable for certain applications may be different or overlapping.

Formulations according to the present disclosure may be formulated as inks suitable for various ink application methods (e.g., flow coating, printing, coating, etc.). The following simplified description illustrates the differences between some of the application methods. For example, flow coating refers to a process in which a stream of formulation is applied to a surface through one or more nozzles (moving or stationary). Printing generally refers to a process in which an ink formulation is deposited onto a substrate material.

For example, in gravure printing techniques, such as gravure printing and rotogravure printing, an image to be printed is engraved into an image carrier, and then an ink formulation is provided thereto; the ink in the recessed areas forming the image is transferred to a matrix material that is pressed against the ink image carrier. In relief printing techniques, such as flexography and flexography, the image to be printed is raised (rather than recessed) and supplied with ink, which is then transferred to the substrate material against the relief. In screen printing, the mesh is used to transfer ink to the substrate material except in areas where the ink is impermeable (e.g., by blocking the stencil). Various coating methods, such as slot die coating and super-chain coating, apply a formulation, typically comprising a molten material, to a substrate material.

In inkjet printing technology, ink droplets are pushed towards a substrate material. Most consumer and commercial/industrial inkjet printers use drop on demand ("DOD") technology in which ink droplets are ejected from one or more ink chambers in response to current pulses. However, advances in inkjet printing have resulted in several techniques that can allow for very rapid application of a variety of ink formulations to matrix materials and/or structural elements according to the present disclosure, such as the ink formulations discussed herein. For example, in some methods of continuous inkjet ("CU") printing, a printer applies a controlled variable electrostatic charge to individual droplets of a continuously generated stream. Therefore, CU printing is different from DOD printing in that ink droplets are continuously ejected, and a higher printing speed can be provided as compared with DOD technology. The CIJ ink drops are then propelled by the magnetic field generated in the printhead. The ink drops deflect toward the substrate material to an extent determined by their electrostatic charge, and the uncharged ink drops are collected (e.g., inside the printhead) and circulated back into the ink supply and in this manner print characters or other images or patterns onto the substrate material.

As described above, an illustrative method of producing a structural element (such as those shown in fig. 9A-9I) treated with one or more components of a chemiluminescent system includes applying a formulation to a predetermined area of a first surface of the structural element, wherein the formulation includes the one or more components. Thus, in an embodiment, such a method includes a method of producing a structural element treated with at least one component of a chemiluminescent system incorporated into an absorbent article, the at least one component reacting in the presence of an aqueous system to produce light, the method comprising: applying a formulation to a predetermined area of the first surface of the structural element, wherein the formulation comprises at least one component, and wherein the at least one component is selected from luciferin and luciferase.

In an embodiment, the predetermined region at least partially overlaps with a region where one or more fluid insults are expected during use of the absorbent article into which the structural element is incorporated, as discussed further herein with respect to fig. 9A-9J. Such predetermined areas may define a continuous shape. Accordingly, the predetermined area may include two or more discrete portions.

The formulation applied to the structural element may include a formulation of the present disclosure that includes at least one component of the chemiluminescent system. In embodiments, at least one component is a luciferase. In embodiments, the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase, and firefly luciferase. In embodiments, at least one component is luciferin and luciferase. In embodiments, the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine, and/or wherein the luciferases are selected from Gaussia luciferases, renilla luciferases, metridia luciferases, oplophorus luciferases, dinoflagellate luciferases, copepodiums luciferases and firefly luciferases.

In some such methods, the formulation is an ink formulation and the applying comprises printing, such as inkjet printing, e.g., CIJ printing. In some such methods, both luciferin and luciferase are applied, e.g., by CIJ or other inkjet printing, to separate formulations, and/or to separate portions of a predetermined area. As described above, the other of the one or more components (i.e., the other of luciferin or luciferase) may also 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 either organic or inorganic salts, including salts of luciferin.

In addition, common application techniques such as CLJ printing may be used to apply a variety of formulations (such as ink formulations) to the matrix material. In an embodiment, applying the formulation comprises applying at least two formulations, wherein one of the at least two formulations comprises luciferin, and wherein the other of the at least two formulations comprises luciferase. Such application of at least two formulations may include application of the formulations, including application of at least two formulations independently. In this regard, at least two formulations may be applied to non-overlapping portions of the predetermined area, respectively. As provided throughout, the overlapping portion of the predetermined area may be treated with the two formulations in a manner that minimizes or avoids more than 5% of the reaction of the two components of the chemiluminescent system prior to the addition of an external water source (e.g., fluid soil).

As noted above, it may be desirable in some applications to apply other materials besides chemiluminescent materials to a matrix material or structural element, such as a non-chemiluminescent wetness indicator. Such variations are considered to be within the scope of the disclosure.

Methods of producing a structural element according to embodiments of the present disclosure may include, for example, applying a non-chemiluminescent wetness indicator to a first surface. Such non-chemiluminescent wetness indicators may be applied to at least partially overlap the predetermined area. Similarly, a non-chemiluminescent wetness indicator is applied so as not to overlap a predetermined area.

Thus, it is apparent that these exemplary methods of application may have different requirements for suitable formulations. However, formulations according to the present disclosure may be tailored to a particular application method, for example, by incorporating appropriate additives (e.g., to achieve a desired viscosity, composition, thermal stability, rheological behavior, etc.), while still effectively delivering the chemiluminescent components of the formulation to the matrix material.

Example

The following paragraphs provide a description of illustrative ways in which the treated materials incorporating the chemiluminescent system are manufactured and tested. The results demonstrate the benefit of chemiluminescent systems to detect humidity in the dark. Chemiluminescence can be seen through the absorbent article incorporated therein and through the garment. The examples are illustrative and not limiting.

While the chemiluminescent intensity in many examples is assessed by the visibility of the human eye in dim light or darkroom, some examples generally discuss Relative Light Unit (RLU) analysis performed by a photometer for comparison purposes. In this RLU analysis, chemiluminescence can be measured without any filter. Roughly speaking, a value of 10,000,000 to 15,000,000RLU corresponds to a lower threshold visible to the human eye in a darkroom. However, some individuals may require or allow higher or lower RLU levels.

Porous transfer agent example 1: preparation and testing of two-component formulations

A solvent solution containing coelenterazine ("CTZ") and Gaussia luciferase (GLuc) was prepared with a binder (ethylcellulose (E-C4 cP, from Sigma)) in ethanol. Sample formulations are shown in the table below.

Table 3: formulation examples for two-component (binder-containing) testing

Component (A)	wt.％
		Ethanol	89.8
E-C 4cP	8.6
		CTZ	＜2.0
Gluc	＜2.0

Mu.l of the above solvent solution was pipetted and discharged as a round point onto a polyester backsheet, and the polyester sheet was dried at 80℃for 30 seconds.

Once dried, the treated area was contaminated with 0.2ml 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. PBS formulations used in the examples herein included 137mM sodium chloride, 2.7mM potassium chloride, 10mM disodium hydrogen phosphate, 1.8mM monopotassium phosphate, 1.0mM calcium chloride, and 0.5mM magnesium chloride. Very low bioluminescence was observed, consistent with slow or reduced release of CTZ and/or GLuc from the polyester sheet.

Porous transfer agent example 2: preparation and testing of two-component formulations with porous media

Solvent solutions containing CTZ and GLuc were prepared with various binders, such as ethylcellulose in ethanol (E-C4 cP from Sigma) and polyurethane (Versamid PUR 1120 from BASF). Porous media such as corn starch (Sigma cat.no. s 4180) and Synthetic Amorphous Silica (SAS) were also added. Two sample formulations are shown in the table below, except that the porous media used are identical. Sample formulation "a" comprises corn starch. Sample formulation "B" contained SAS.

Table 4: exemplary formulations for two-component (with binder and porous Medium) testing

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The solvent solution was tested by pipetting 20 μl of the solution and discharging it as a round spot onto the polyester backsheet. The polyester chips were then dried at 80℃for 30 seconds.

Once dried, each treatment area was contaminated with 0.2ml of PBS pH 7.5. In both cases, very strong bioluminescence was observed, consistent with non-inhibited or auxiliary release of CTZ and/or GLuc from the polyester sheet.

Tissue example 1: preparation of treated tissue sheets

Using a laboratory scale embodiment of a suspension tissue flow coating design as schematically shown in fig. 8A and 8B, a formulation of coelenterazine ("CTZ") was flow coated through a nozzle onto a continuous, moving sheet of tissue suspended between two pivot points to create a treatment zone 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 with the binders ethylcellulose (E-C4 cP from Sigma) and polyurethane (Versamid PUR 1120 from BASF) and corn starch.

Table 5: exemplary formulations for CTZ flow coating onto tissue

The formulation was flow coated at a rate of 1.0mg CTZ (100% purity equivalent) per 12 inch length.

The flow coated tissue was dried in an incubator at 80 ℃ for 15 seconds to simulate a hot air zone. Higher temperatures can significantly reduce drying times.

The configuration schematically shown in FIGS. 8A and 8B is in the MirWec pCoater ^TM Trial was performed successfully with similar formulations at 350. Other tissue coating/printing devices are also suitable.

Tissue example 2: diaper assembly and soil test with treated tissue sheets

Infant diaper # 4 was cut and modified to include a diaper core containing SAP and luciferase treated fluff pulp. The flow-coated tissue sample prepared in tissue example 1 was placed between the backsheet and the modified diaper core. The diaper was reassembled and contaminated with 45ml of PBS pH 7.5. After the soil was completely absorbed by the diaper, at t=0 hours, the chemiluminescence produced by the chemicals in the modified diaper was observed and imaged in the dark room without light. Chemiluminescence was visible after contamination. The modified diapers were then contaminated with the same dose of PBS buffered saline at t=2, 4, 6 and 8 hours. Chemiluminescence was visible after each contamination.

Tissue example 3: relative Light Unit (RLU) analysis

The reassembled diaper was cut with a 1 inch diameter die to produce a mini-diaper modified to include flow coated tissue samples prepared with the two sample formulations from example 1, the mini-diaper was contaminated four times consecutively at 1.5 hour intervals with a 0.63ml dose of pH 7.5 dose of PBS corresponding to 45ml pH 7.5 of the full diaper soil dose. At the position ofBioluminescence Relative Light Units (RLU) were measured in a Discover System photometer (Promega, madison, wis.). The RLU plot for analysis as shown in fig. 10 shows the chemiluminescent levels at and after each contamination. The graph is based on the average of three replicates. Sample a formulation samples had lower luminescence at the second contamination but much higher luminescence at the 4 th contamination, while sample B formulation samples had more luminescence at the 2 nd contamination and less luminescence at the 4 th contamination.

Tissue example 4: staged bioluminescence design of treated tissue sheets

Using the laboratory scale embodiment of the suspension tissue flow coating design completed in tissue example 1, two formulations of coelenterazine ("CTZ") were applied through a nozzle onto a continuously moving sheet of tissue suspended between two pivot points to create a treated area in the form of two solid longitudinal strips. Both sample formulations contained a binder and were identical except for the concentration of CTZ and the balance of the solvents (sample formulation "C" had about 0.9wt% CTZ, purity was about 50%, and the CTZ concentration of sample formulation "D" was about twice that of formulation C). Sample preparation C was applied to the tissue sheet in a line of width approximately three times the width of the line of sample preparation D, the same amount of each volume being applied. The tissue sample was wetted with a sufficient amount of luciferase-containing solution (about 2mL, gluc concentration of 1 mg/mL) to simulate soil. At t=0, the "C" stream brightly emits light, while the "D" stream does not emit light (not shown). At t=2 hours, the "C" stream continues to emit light with minimal loss of intensity, while the "D" stream diffuses only at the periphery of the line (not shown). At t=4 hours, the "C" stream continued to emit light with a significant decrease in intensity, while the "D" stream had an increased intensity in the line area (not shown).

Flake particle example 1: preparation of an indicator sheet

Pulp sheets having a hexagonal shape are used to prepare pulp-based indicator sheets. The thickness of the hexagonal pulp sheet was 1mm, four sides 2mm and two sides 3mm. Each sheet was about 11mg and had a moisture content of about 7%. From 750g/m of International Paper ² CF416 pulp sheet preparation flakes.

Solvent solutions containing coelenterazine ("CTZ") and Gaussia luciferase (GLuc) were prepared with various binders, such as ethylcellulose (E-C4 cP, from Sigma) and polyurethane (Versamid PETR 1120, from BASF). GLuc is finely ground and then added to the solution to facilitate dispersion. Sample formulations are shown in the table below.

Table 6: exemplary formulations for treating slurry-based indicator sheets

The solution was yellow. After thorough mixing, the solution was added to each sheet. A total of 0.7g of six deformed flakes (about 65 flakes) were treated and used for each diaper application. After the treatment, the pulp sheet was dried in an oven at 80 ℃ for 2 minutes with hot air.

In this example, the dry flakes include CTZ at a concentration of less than 0.50wt% and GLuc at a concentration of less than 0.01 wt%. 0.7g of dry flakes together comprise 1.0mg of CTZ and 0.025mg of GLuc.

Flake particle example 2: diaper assembly with indicator tab

The longitudinal rectangular section of the backsheet of the baby diaper No. 4 was cut and peeled away without interrupting the diaper core structure. The flakes are uniformly distributed in a single discontinuous layer on the inner surface of the backsheet section. The sections of backsheet are then sealed back to the diaper with a clear adhesive tape placed over the cut edges.

Flake particle example 3: repeated diaper soiling with PBS

The diaper of example 2 was soiled with 60ml of pH 7.5 PBS.

After complete absorption of the soil by the diaper, at t=0 hours, chemiluminescence from the chemicals on the treated pulp sheet was observed and imaged in a dark room without light. Chemiluminescence was very pronounced after contamination. Chemiluminescence was no longer visible until t=1.5 hours. The second soil was applied at t=1.5 hours and chemiluminescence was again very pronounced. Chemiluminescence was no longer visible until t=2.0 hours. At t=3.0 hours a third soil was applied, the chemiluminescence was again visible, but less after the first and second soil. Chemiluminescence was no longer visible until t=4.0 hours.

Flake particle example 4: relative Light Unit (RLU) analysis

A one inch diameter disc was punched from the diaper. The negative film was removed and 5 treated according to example 1 were to be treated The hexagonal pulp sheets are placed in rows between the backsheet and the diaper core. Four consecutive contaminations of PBS at pH 7.5 were performed at 1.5 hour intervals. By passing throughThe Discover System photometer (Promega, madison, wis.) monitors chemiluminescence. The RLU diagram for analysis as shown in fig. 11 shows the chemiluminescent levels at and after each contamination. The results show that the luminescence intensity (RLU) peaks after the first contamination and then gradually decreases. At the second contamination, the spike is much higher and then decreases and remains at a higher intensity than the first contaminated spike until the intensity gradually decreases after the fourth contamination.

Stripe particle example 1: preparation of indicator strips

A1 mm by 2mm by 350mm slurry strip was cut and used to prepare a slurry-based indicator strip. Each strip weighed about 0.7g. 750g/m from International Paper was used ² CF416 pulp sheet strips were prepared.

Solvent solutions containing coelenterazine ("CTZ") and suspended Gaussia luciferase (GLuc) were prepared with various binders, such as ethylcellulose (E-C4 cP, from Sigma) and polyurethane (Versamid PETR 1120, from BASF). GLuc is finely ground and then added to the solution to facilitate dispersion. Sample formulations are shown in the table below.

Table 7: exemplary formulations for treating slurry-based indicator particles

Component (A)	wt.％
		Ethanol	98.449
E-C 4cP	0.535
		PUR	0.203
CTZ	＜1.0
		Gluc	＜1.0
Corn starch	0.242

The solution was yellow. After thorough mixing, the solution was added to each strip. After treatment, the pulp strips were dried in an oven with hot air at 80 ℃ for 2 minutes.

In this example, the dry strips each include CTZ at a concentration of less than 0.50wt% and GLuc at a concentration of less than 0.10 wt%. Each dry band included a total of 1.0mg CTZ and 0.025mg GLuc.

Stripe particle example 2: diaper assembly with indicator strip

The longitudinal rectangular section of the backsheet of the baby diaper No. 4 was cut and peeled away without interrupting the diaper core structure. The individual strips are placed longitudinally in the center of the inner surface of the backsheet section. The sections of backsheet are then sealed back to the diaper with a clear adhesive tape placed over the cut edges.

Stripe particle example 3: repeated diaper soiling with PBS

The diaper of example 2 was soiled with 60ml of pH 7.5 PBS.

After complete absorption of the soil by the diaper, at t=0 hours, chemiluminescence from the chemicals on the treated pulp sheet was observed and imaged in a dark room without light. Chemiluminescence was very pronounced after contamination. Chemiluminescence was weakly visible before t=1.5 hours. The second soil was applied at t=1.5 hours and chemiluminescence was again very pronounced. Chemiluminescence was weakly visible before t=2.0 hours. At t=3.0 hours a third soil was applied, the chemiluminescence was again visible, but significantly less after the second soil. Chemiluminescence was no longer visible until t=4.0 hours.

Stripe particle example 4: relative Light Unit (RLU) analysis

A one inch diameter disc was punched from the diaper. The backsheet was removed and a 1 inch treated pulp strip treated according to example 1 was placed between the backsheet and the diaper core. Four consecutive contaminations of PBS at pH 7.5 were performed at 1.5 hour intervals. By passing throughThe Discover System photometer (Promega, madison, wis.) monitors chemiluminescence. The RLU plot as shown in fig. 12 shows the chemiluminescent levels at and after each contamination. The results show that the luminescence intensity (RLU) increases after the first contamination and then gradually decreases. At the second contamination, the spike is much higher and then decreases and remains at a higher intensity than the first contaminated spike until the intensity gradually decreases after the fourth contamination. From t=2.0 hours (after the spike after the second contamination) to t=4.0 hours, the chemiluminescence was quite stable and visible to the human eye in the dark room.

Stripe particle example 5: production of CTZ-treated indicator strips of various sizes

CF416 pulp sheet (basis weight 750g/m ² International Paper) inA rotary shearing system (Forest notes) was treated with a 1.8mm blade cutter and a 0.8mm blade cutter to produce pulp strips having the respective widths. The strips are classified by length into long strips (e.g., longer than 20 mm) and short strips (10-20 mm). The apparent density or volume of the 1.8mm strip was 0.0886cc/g and the apparent density or volume of the 0.8mm strip was 0.145cc/g. Testing a production process using strips of various sizes Such as speed and efficiency, and to determine whether smaller strips can be produced efficiently. Smaller strips may be more pneumatically conveyed and thus more suitable for use in standard diaper fluff core forming devices.

Solvent solutions containing coelenterazine ("CTZ") were prepared with various binders, such as ethylcellulose (E-C4 cP, from Sigma) and polyurethane (Versamid PUR 1120, from BASF). Corn starch (Sigma catalog number S4180) was also added. Sample formulations are shown in the table below. One gram of the sample composition contained 2.0mg CTZ.

Table 8: exemplary formulations for treating slurry-based indicator strips

Component (A)	wt.％
		Ethanol	98.19
E-C 4cP	0.88
		PUR	0.33
CTZ	＜0.50
		Corn starch	＜0.50

Once thoroughly mixed, the solution was applied to the strips by mixing a 2.0g portion of the solution with 2.0g of each slurry strip in a small beaker. After treatment, the pulp strips were dried in an oven with hot air at 80 ℃ for 2 minutes.

Stripe particle example 6: diaper core assembly and soil test with CTZ treated indicator tape

One gram of CTZ treated tape of the above-described size (containing a total of 2.0mg CTZ per gram) was sprinkled onto the rear surface of the diaper core containing the luciferase-treated fluff pulp (at a concentration of about 0.56mg luciferase per gram fluff, or about 5.6mg luciferase per diaper core). The diaper core assembly is then sandwiched between a liquid impermeable polyester backsheet and a liquid impermeable topsheet, with the CTZ treated strips disposed adjacent the backsheet.

60ml of soil of pH 7.5PBS was added to the diaper core. Chemiluminescence was observed and imaged, and also visible through the negative in the dark room and also under low light.

Negative example 1: CTZ formulation for backsheet application

Solvent solutions containing coelenterazine ("CTZ") were prepared with various binders, such as ethylcellulose (E-C4 cP, from Sigma) and polyurethane (Versamid PUR 1120, from BASF). The binder was diluted in ethanol and CTZ was then added. After dissolution, corn starch was added. The mixture was vortexed. Sample formulations are shown in the table below.

Table 9: exemplary formulations for treating a backsheet

Component (A)	wt.％
		Ethanol	47.10
E-C 4cP	1.49
		PUR	＜1.0
CTZ	＜0.50
		Corn starch	50.67

Corn starch does not exhibit agglomeration in ethanol and similar formulations up to 52 weight percent starch were found to remain flowable.

Negative example 2: applying and promoting wicking drying

The formulation from example 1 was flow coated IN a six inch line onto a polyester backsheet (XP-1943 SX polyester film, berry Global Co., evansville, in) using a small syringe (1 m 1) such that 64mg of formulation per inch of backsheet (about 0.05 to 0.30mg CTZ per inch) was applied.

Immediately after application, a diaper core made of luciferase-treated fluff pulp and SAP (at a concentration of less than 1.0 weight percent) was laid over the flow-coated line on the backsheet.

The fluff core wicks solvent (in this case ethanol) faster than air dries.

Negative example 3: chemiluminescent test

The sample of (1) the treated backsheet and diaper core, and (2) only the diaper core, was contaminated with PBS pH 7.5. Samples of the treated backsheet and diaper core assembly exhibited strong bioluminescence. Samples of diaper cores also exhibited only some bioluminescence, indicating that some CTZ had diffused into the diaper core when used to wick solvent.

Negative example 4: relative Light Unit (RLU) analysis

Will have an Acquisition Distribution Layer (ADL)A standard diaper topsheet was applied to the bare side of the diaper core of the assembly of example 3 to sandwich the diaper core between the topsheet/ADL and the treated backsheet. Six discs of 1 inch diameter were punched from the assembly to produce six "mini-diaper" assemblies. These were placed in a six sample test cartridge designed for use inBioluminescence testing was performed in a Discover System photometer (Promega, madison, wis.). Each mini-diaper was soiled with a 0.84ml dose of pH7.5PBS buffer solution, which was proportional to 60ml soil delivered to the mini-diaper. Continuous contamination was performed at 1.5 hour intervals. The RLET plot for analysis as shown in fig. 13 shows the chemiluminescent levels at and after each soil. The results show that the luminescence intensity (RLET) increases after the first contamination (at t=0) and then gradually decreases. Each successive insult will be followed by a spike and then a gradual decrease. The results indicate that in this application the more liquid is present the higher the light intensity.

In addition, chemiluminescence after fourth contamination was observed in the darkroom, although the treated area was small (one inch line in each mini-diaper) relative to the fully treated infant diaper core.

SAP content examples: the amount of variation in superabsorbent polymer affects water utilization in aqueous systems

Diaper cores are made of varying amounts of superabsorbent polymers (SAP): the weight percentages based on the total cellulosic fibers (fluff) in the core are 0, 6, 12, 18, 24 and 36. The cellulose fibers are treated with luciferase (GLuc). The tissue was flow coated to give a formulation with a concentration of pure coelenterazine ("CTZ") of less than 1.0mg, CTZ in ethanol (purity about 50%), ethylcellulose (EC 4 cP) 0.88wt%, polyurethane (PUR) 0.33wt% and cornstarch 0.40wt%.

Diaper cores having luciferase (GLuc) -containing cellulosic fibers and varying SAP content were modified to include tissues treated with CTZ formulations. In each case, the treated tissue is between the diaper core and the diaper backsheet.The modified diapers were cut with a 1 inch diameter die to produce mini-diapers that were continuously four contaminated at 2 hour intervals with 0.63ml doses of pH 7.5PBS, which corresponds to 45ml of pH 7.5PBS in full diaper soil doses. At the position of Bioluminescence Relative Light Units (RLU) were measured in a discover System photometer (Promega, madison, wis.). The RLU graph is shown in fig. 14A for SAP content of 0, 6 and 12 weight percent and in fig. 14B for SAP content of 18, 24 and 36 weight percent.

Mineral salt application example

The PB S buffer was used as a carrier solution for the aluminium chloride treatment slurry strips. Each slurry strip was treated with its weight of aluminum chloride containing PBS buffer. For example, if it is desired to have a slurry treated with 1% aluminum chloride, a PBS buffer containing 1% aluminum chloride is used. If it is desired to have a slurry treated with 2% aluminum chloride, PBS buffer containing 2% aluminum chloride is used, and so on.

After treatment, the pulp strips were dried and then fiberized in a Kamas hammer mill.

The mat was formed by mixing 7.4g of fibers with 4.2g BASF T9400 SAP in a 6 "mat-forming machine. The pad was then pressurized at 50psi for 20 seconds.

It was found that the addition of mineral salts of aluminium and magnesium inhibits the reaction conditions after early contamination due to a reduced (unfavorable) pH. More fouling leads to buffering or increasing the pH, which then favors the reaction conditions, leading to higher luminescence peaks after several contaminations (see fig. 16).

For example, the addition of other mineral salts that do not lower the pH will counteract the effects of SAP by increasing the osmotic pressure in the fluff pulp. Thus, more free water is available for the aqueous system to initiate the chemiluminescent system reaction.

Conclusion and illustrative examples

The various illustrative ranges provided for the components and materials discussed herein are intended to encompass the exemplary upper and/or lower limits of the given ranges, as well as any and all subranges within the given ranges, without explicitly referring to such subranges. Likewise, various illustrative combinations of the above-described components, steps, processes, materials, concepts and principles, for example, in various treated materials, absorbent articles, formulations, treatment methods, manufacturing methods, etc., are intended to be inclusive of all combinations thereof that will be apparent to one of ordinary skill in the art given this disclosure without such combinations being explicitly recited. Thus, 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 disclosure.

As used herein, the word "about" with respect to an amount refers to a number that is within a slight variation above or below the reference number. For example, "about" may refer to a number within a range of 10%,9%,8%,7%,6%,5%,4%,3%,2%, or 1% above or below the indicated reference number. In some embodiments, "about" refers to a number within 5% above or below the indicated reference number. In some embodiments, "about" refers to a number within 10% above or below the indicated reference number. In some embodiments, "about" refers to a number within 1% above or below the indicated reference number.

Illustrative, non-exclusive examples of inventive subject matter in accordance with the present disclosure are described in the paragraphs enumerated below:

1. a treated tissue composition comprising:

a liquid permeable tissue sheet comprising cellulosic fibers and having two opposed surfaces;

wherein at least one surface is treated with at least one component of a chemiluminescent system, wherein the chemiluminescent system is 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; and is also provided with

Wherein the at least one component is retained on the at least one surface.

1.1. The treated tissue composition of paragraph 1 wherein the at least one component is luciferin.

1.1.1. The treated tissue composition of paragraph 1.1 wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

1.1.2. The treated tissue composition of paragraph 1.1 wherein the luciferin is coelenterazine.

1.1.2.1. The treated tissue composition of paragraph 1.1.1 comprising from 0.00002 to 20 weight percent coelenterazine.

1.1.2.1.1. The treated tissue composition of paragraph 1.1.2.1 comprising from 0.00002 to 0.01 weight percent coelenterazine.

1.1.2.1.2. The treated tissue composition of paragraph 1.1.2.1 comprising 0.01 to 2 weight percent coelenterazine.

1.1.2.1.3. The treated tissue composition of paragraph 1.1.2.1 comprising 2 to 10 weight percent coelenterazine.

1.1.2.1.3.1. The treated tissue composition of paragraph 1.1.2.1.3 comprising from 1 to 6 weight percent coelenterazine.

1.1.2.1.4. The treated tissue composition of paragraph 1.1.2.1 comprising 10 to 20 weight percent coelenterazine.

1.1.2.2. The treated tissue composition of paragraph 1.1.1 wherein the tissue sheet is 0.1-235mm wide and comprises 0.01mg-25g coelenterazine per 12 inch length, the weight of coelenterazine per 12 inch length being less than or equal to the weight of an untreated tissue sheet of 12 inch length.

1.1.2.3. The treated tissue composition of paragraph 1.1.1 wherein the tissue sheet is 0.1-235mm wide and comprises 0.1-100mg of coelenterazine per 12 inch length, the weight of coelenterazine per 12 inch length being less than or equal to the weight of an untreated tissue sheet of 12 inch length.

1.2. The treated tissue composition of any of paragraphs 1-1.1.2.2, wherein the at least one component is retained on the at least one surface by an adhesive.

1.2.1. The treated tissue composition of paragraph 1.2 wherein the binder comprises one or more binders selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose, and polyurethane.

1.3. The treated tissue composition of any one of paragraphs 1-1.2, wherein the tissue sheet has a basis weight of from 10 to 1500g/m ² 。

1.4. The treated tissue composition of any of paragraphs 1-1.3, wherein the tissue sheet further comprises synthetic fibers.

1.5. The treated tissue composition of any of paragraphs 1-1.4, wherein the area of the at least one surface treated with the component has a width less than or equal to the width of the sheet of tissue.

1.5.1. The treated tissue composition of paragraph 1.5 wherein the treated region is in the form of a longitudinal strip.

1.5.1.1. The treated tissue composition of paragraph 1.5.1 wherein the longitudinal strips are continuous.

1.5.1.2. The treated tissue composition of paragraph 1.5.1 wherein the longitudinal strips are discontinuous.

1.5.1.2.1. The treated tissue composition of paragraph 1.5.1.2 wherein the longitudinal strips are one or more of dotted and/or dashed lines.

1.5.1.3. The treated tissue composition of any one of paragraphs 1.5.1-1.5.1.2.1, wherein the longitudinal strips are straight.

1.5.1.4. The treated tissue composition of any one of paragraphs 1.5.1-1.5.1.2.1, wherein the longitudinal strips comprise one or more curved portions.

1.5.1.5. The treated tissue composition of any one of paragraphs 1.5.1-1.5.1.2.1, wherein the longitudinal strips comprise one or more straight portions.

1.5.2. The treated tissue composition of paragraph 1.5 wherein the treated region is in the form of one or more shapes.

1.5.3. The treated tissue composition of paragraph 1.5 wherein the total treated area is from 0.003 to 100% of the area of the tissue sheet.

1.6. The treated tissue composition of paragraph 1 wherein the at least one component is a luciferase enzyme.

1.6.1. The treated tissue composition of paragraph 1.6 wherein the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase and firefly luciferase.

1.7. The treated tissue composition of any of paragraphs 1-1.6, wherein the at least one component is luciferin and luciferase.

1.7.1. The treated tissue composition of paragraph 1.7 wherein the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furanazine, and/or wherein the luciferases are selected from Gaussia luciferases, renilla luciferases, metridia luciferases, oplophorus luciferases, dinoflagellate luciferases, copepodiums luciferases and firefly luciferases.

1.7.2. The treated tissue composition of paragraph 1.7 or 1.7.1 wherein the luciferin is coelenterazine and the luciferase is one or more of Gaussia luciferase, renilla luciferase and Metridia luciferase.

1.8. The treated tissue composition of any of paragraphs 1-1.7.2, further comprising a release agent adapted to facilitate release of the at least one component from the at least one surface in the presence of an aqueous system.

1.9. The treated tissue composition of any of paragraphs 1-1.8 comprising at least two liquid permeable layers, one of which is the tissue sheet.

1.9.1. The treated tissue composition of paragraph 1.9 comprising first and second liquid permeable tissue sheets wherein at least one surface of each tissue sheet is treated with a different component of the chemiluminescent system.

1.9.2. The treated tissue composition of paragraph 1.9 or 1.9.1 wherein the tissue sheet is sandwiched between two liquid permeable layers.

1.10. An absorbent core for an absorbent article comprising the treated tissue composition of any one of paragraphs 1-1.9.2.

1.10.1. The absorbent core of paragraph 1.10 comprising an absorbent structure at least partially surrounded by the treated tissue composition of any of paragraphs 1-1.9.2.

1.10.2. An absorbent article comprising the absorbent core of paragraph 1.10 or 1.10.1.

1.11. An absorbent core for an absorbent article comprising an absorbent structure at least partially surrounded by the treated tissue composition of any of paragraphs 1-1.1.2.2, wherein the treated tissue composition comprises luciferin, and wherein the absorbent structure comprises luciferase.

2. An indicator particle comprising hydrogen-bonded cellulose pulp fibers and at least one component of a chemiluminescent system, wherein the chemiluminescent system is adapted to react in the presence of an aqueous system to produce light;

Wherein the at least one component is retained on the cellulose pulp fibers.

2.1. The indicator particle of paragraph 2, wherein the at least one component is disposed on the cellulose fibers of at least one surface of the particle.

2.2. The indicator particle of paragraph 2, wherein the at least one component is disposed on the cellulose pulp fibers throughout the particle.

2.3. The indicator particle of paragraph 2, wherein the at least one component is luciferin.

2.3.1. The indicator particle of paragraph 2.3 wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

2.4. The indicator particle of paragraph 2, wherein the at least one component is a luciferase.

2.4.1. The indicator particle of paragraph 2.4 wherein the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase and firefly luciferase.

2.4.2. The indicator particle of paragraph 2.4 wherein the luciferase is one or more of Gaussia luciferase, renilla luciferase and Metridia luciferase.

2.5. An indicator particle according to paragraph 2 comprising both luciferin and luciferase,

wherein the luciferin is selected from coelenterazine, a coelenterazine analog, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine; and is also provided with

Wherein the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepodia luciferase and firefly luciferase.

2.5.1. The indicator particle of paragraph 2.5, wherein the luciferin is coelenterazine, and wherein the luciferase is one or more of Gaussia luciferase, renilla luciferase, and Metridia luciferase.

2.5.1.1. The indicator particle of paragraph 2.5.1 wherein the particle comprises 0.00002-20.0 weight percent coelenterazine.

2.5.1.1.1. The indicator particle of paragraph 2.5.1.1 wherein the particle comprises 0.00002-0.01 weight percent coelenterazine.

2.5.1.1.2. The indicator particle of paragraph 2.5.1.1 wherein the particle comprises 0.01-0.20 weight percent coelenterazine.

2.5.1.1.2. The indicator particle of paragraph 2.5.1.1 wherein the particle comprises 0.2-5.0 weight percent coelenterazine.

2.5.1.1.3. The indicator particle of paragraph 2.5.1.1 wherein the particle comprises 5.0-20.0 weight percent coelenterazine.

2.5.1.2. The indicator particle of any one of paragraphs 2.5.1-2.5.1.1.3, wherein the particle comprises 0.0003-10.0 weight percent luciferase.

2.5.1.2.1. The indicator particle of paragraph 2.5.1.2 wherein the particle comprises 0.001 to 0.10 weight percent luciferase.

2.5.1.2.2. The indicator particle of paragraph 2.5.1.2 wherein the particle comprises 0.001 to 0.10 weight percent luciferase.

2.5.1.2.3. The indicator particle of paragraph 2.5.1.2 wherein the particle comprises 0.10-2.0 weight percent luciferase.

2.5.1.2.4. The indicator particle of paragraph 2.5.1.2 wherein the particle comprises 2.0-10 weight percent luciferase.

2.5.1.3. An indicator particle according to paragraph 2.5.1, wherein the particle comprises 0.00002 to 20.0 weight percent coelenterazine and 0.0003 to 10.0 weight percent Gaussia luciferase, renilla luciferase and/or Metridia luciferase.

2.6. The indicator particle of any one of paragraphs 2-2.5.1.3 having a length, width and thickness;

wherein the length is greater than or equal to the width; and is also provided with

Wherein the width is greater than or equal to the thickness.

2.6.1. The indicator particle of paragraph 2.6 wherein the ratio of the length to the width is less than 1.5.

2.6.1.1. The indicator particle of paragraph 2.6.1 wherein the product of the length and the width is between 0.1 and 300mm ² Between them.

2.6.1.2. The indicator particle of paragraph 2.6.1 wherein the product of the length and the width is between 8-30mm ² Between them.

2.6.2. The indicator particle of paragraph 2.6, wherein the ratio of the length to the width is greater than or equal to 1.5.

2.6.2.1. The indicator particle of paragraph 2.6.2 wherein the indicator particle has a cross-sectional area of 0.01-200mm ² 。

2.6.2.2. An indicator particle according to paragraph 2.6.2 or 2.6.2.1 having a length of 1-800 mm.

2.6.2.3. An indicator particle according to paragraph 2.6.2 or 2.6.2.1 having a length of 1-350 mm.

2.6.2.4. The indicator particle of any one of paragraphs 2.6.2-2.6.2.3 having a width of 0.5-2.5mm and a thickness of 0.05-2.0 mm.

2.7. The indicator particle of any one of paragraphs 2-2.6.2.4, further comprising a synthetic fiber.

2.7.1. The indicator particle of paragraph 2.7 wherein the synthetic fibers have a fiber diameter of 1-100 microns.

2.8. The indicator particle of any one of paragraphs 2-2.7.1 having a particle size of 10-850g/m ² Is based on the weight of the substrate.

2.9. The indicator particle of any one of paragraphs 2-2.8, further comprising a binder, wherein the binder retains the at least one component on the cellulose pulp fibers.

2.9.1. The indicator particle of paragraph 2.9, wherein the binder comprises one or more binders selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose, and polyurethane.

2.9.1.1. The indicator particle of paragraph 2.9.1 wherein the at least one component is luciferin.

2.10. The indicator particle of any one of paragraphs 2-2.9.1.1, further comprising a porous transfer agent adapted to facilitate transfer of the at least one component and/or the aqueous system relative to the indicator particle upon contact of the indicator particle with the aqueous system.

2.10.1. The indicator particle of paragraph 2.10 wherein the porous transfer agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

2.11. The indicator particle of any one of paragraphs 2-2.10.1, further comprising a release agent adapted to facilitate release of the at least one component from the cellulose pulp fibers in the presence of an aqueous system.

2.12. An absorbent article comprising a plurality of indicator particles according to any one of paragraphs 2-2.11.

2.12.1. The absorbent article of paragraph 2.12, further comprising a liquid permeable topsheet, a liquid impermeable backsheet, and an absorbent material disposed between the topsheet and the backsheet;

wherein the indicator particles are disposed between the topsheet and the backsheet.

2.12.2. The absorbent article of paragraphs 2.12 or 2.12.1, wherein the indicator particles are disposed between the absorbent material and the backsheet.

2.12.3. The absorbent article of any one of paragraphs 2.12-2.12.2, wherein each of the plurality of indicator particles comprises both luciferin and luciferase.

2.12.3.1. An absorbent article as defined in paragraph 2.12.3,

2.12.3.1.1. An absorbent article as defined in paragraph 2.12.3.1, wherein the luciferin is coelenterazine and the luciferase is one or more of Gaussia luciferase, renilla luciferase and Metridia luciferase; and is also provided with

Wherein the plurality of indicator particles collectively comprise from 0.0001 to 20.0mg coelenterazine and from 0.00003 to 20.0mg of total luciferase.

3. An article of manufacture, comprising:

synthetic fibers; and

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.

3.1. The article of paragraph 3, wherein the synthetic fibers form an absorbent matrix.

3.2. The article of paragraph 3.1 wherein the absorbent matrix comprises synthetic fibers.

3.3. The article of any one of paragraphs 3-3.2, wherein the at least one component is luciferin.

3.3.1. The article of manufacture of paragraph 3.3 wherein the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

3.4. The article of any one of paragraphs 3-3.2, wherein the at least one component is a luciferase.

3.4.1. The article of manufacture of paragraph 3.4 wherein the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, rhizopus luciferases and firefly luciferases.

3.4.1.1. The article of manufacture of paragraph 3.4.1 wherein the luciferase is a Gaussia luciferase.

3.4.1.2. The article of manufacture of paragraph 3.4.1 wherein the luciferase is Renilla luciferase.

3.4.1.3. The article of manufacture of paragraph 3.4.1 wherein the luciferase is a Metridia luciferase.

3.4.1.4. The article of manufacture of paragraph 3.4.1 wherein the luciferase is two or more of Gaussia luciferase, renilla luciferase and Metridia luciferase.

3.5. The article of any one of paragraphs 3-3.2, comprising both luciferin and luciferase,

3.5.1. The article of manufacture of paragraph 3.5.1 wherein the luciferase is one or more of Gaussia luciferase, renilla luciferase and Metridia luciferase.

3.6. The article of any of paragraphs 3-3.5.1, wherein the article is configured as an absorbent core for use in an absorbent article.

3.6.1. The article of paragraph 3.6, wherein the synthetic fibers are at least partially surrounded by a liquid permeable material.

3.6.1.1. The article of paragraph 3.6.1 wherein the liquid permeable material is a tissue sheet.

3.7. The article of any one of paragraphs 3-3.6.1.1, wherein the at least one component is retained on the synthetic fibers.

3.7.1. The article of paragraph 3.7, further comprising a binder, wherein the binder retains the at least one component on the synthetic fibers.

3.7.1.1. The article of paragraph 3.7.1, wherein the binder comprises one or more binders selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose, and polyurethane.

3.8. The article of any one of paragraphs 3.7-3.7.1.1, further comprising a release agent adapted to facilitate release of the at least one component from the synthetic fibers in the presence of an aqueous system.

3.9. An absorbent article incorporating the article of any one of paragraphs 3-3.8.

4. An absorbent article, comprising:

a liquid permeable topsheet;

a liquid impermeable backsheet;

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; and

a chemiluminescent system adapted to react in the presence of an aqueous system to produce light;

wherein components of the chemiluminescent system are independently disposed in or on two or more of the absorbent material, the topsheet and the at least one structural element in a configuration in which a first component is transferred to a second component by the aqueous system moving through the absorbent article.

4.1. The absorbent article of paragraph 4, wherein a first of the components is disposed within the absorbent material.

4.1.1. The absorbent article of paragraph 4.1, further comprising a liquid permeable tissue sheet at least partially surrounding the absorbent material, wherein a second of the components is disposed on at least one surface of the tissue sheet.

4.1.1.1. An absorbent article according to paragraph 4.1.1,

wherein the chemiluminescent system comprises luciferin and luciferase,

wherein the luciferase is disposed within the absorbent material and

wherein the luciferin is disposed on the sheet of tissue.

4.1.1.1.1. An absorbent article according to paragraph 4.1.1.1,

4.1.1.1.2. The absorbent article of paragraphs 4.1.1.1 or 4.1.1.1.1, wherein the luciferin is coelenterazine and the luciferase is one or more of Gaussia luciferase, renilla luciferase and Metridia luciferase.

4.1.2. The absorbent article of paragraph 4.1 wherein the absorbent material comprises fibers treated with the component.

4.1.2.1. The absorbent article of paragraph 4.1.2 wherein the treated fibers comprise cellulosic fibers.

5. An absorbent article, comprising:

a liquid permeable topsheet;

a liquid impermeable backsheet;

a fibrous absorbent material comprising fibers treated with a luciferase; and

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.

5.1. The absorbent article of paragraph 5, wherein the tissue sheet at least partially encloses the absorbent material to form an absorbent core.

5.2. An absorbent article according to paragraph 5 or 5.1,

5.3. The absorbent article of any one of paragraphs 5-5.2, wherein the luciferase is one or more of Gaussia luciferase, renilla luciferase, metridia luciferase, and wherein the luciferin is coelenterazine.

5.3.1. The absorbent article of paragraph 5.3 comprising 0.00001 to 100.0mg coelenterazine and 0.00001 to 100.0mg total luciferase.

5.3.2. An absorbent article as in paragraph 5.3 comprising 0.0001-20.0mg coelenterazine and 0.00003-20.0mg total luciferase.

5.3.3. An absorbent article as in paragraph 5.3 comprising 0.01 to 100.0mg coelenterazine and 0.2 to 40mg total luciferase.

6. A formulation, comprising:

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; and

a liquid carrier.

6.1. The formulation of paragraph 6 wherein the at least one component is luciferin.

6.1.1. A formulation according to paragraph 6.1,

wherein the liquid carrier comprises a solvent in which luciferin is dissolved; and is also provided with

Wherein the formulation comprises 40-99 weight percent solvent and 0.01-20 weight percent luciferin.

6.1.1.1. The formulation of paragraph 6.1.1 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.

6.1.1.2. The formulation of paragraph 6.1.1 or 6.1.1.1 wherein the solvent comprises ethanol.

6.1.2. The formulation of paragraphs 6.1 or 6.1.1 wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

6.1.2.1. The formulation of any one of paragraphs 6.1-6.1.2, wherein the luciferin is coelenterazine.

6.1.2.1.1. The formulation of paragraph 6.1.2.1, wherein the formulation comprises 0.1-0.3 weight percent coelenterazine.

6.1.2.1.2. The formulation of paragraph 6.1.2.1, wherein the formulation comprises 0.2 to 0.5 weight percent coelenterazine.

6.1.2.1.3. The formulation of paragraph 6.1.2.1, wherein the formulation comprises 0.5-0.9 weight percent coelenterazine.

6.1.2.1.4. The formulation of paragraph 6.1.2.1, wherein the formulation comprises 0.9-2.0 weight percent coelenterazine.

6.1.2.1.5. The formulation of paragraph 6.1.2.1, wherein the formulation comprises 2.0-10 weight percent coelenterazine.

6.1.2.1.6. The formulation of paragraph 6.1.2.1, wherein the formulation comprises 10-20 weight percent coelenterazine.

6.1.3. The formulation of any one of paragraphs 6.1-6.1.2.1, wherein the liquid carrier is non-aqueous, and wherein the formulation further comprises 0.01-20 weight percent luciferase.

6.2. The formulation of any one of paragraphs 6-6.1.3, further comprising a binder adapted to retain the at least one component on a matrix material to which the formulation is applied.

6.2.1. The formulation of paragraph 6.2 wherein the formulation comprises 0.1-30 weight percent of the binder.

6.2.2. The formulation of paragraph 6.2 or 6.2.1 wherein the binder is selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose and polyurethane.

6.3. The formulation of any one of paragraphs 6-6.1.3, further comprising a viscosity modifier in an amount sufficient to impart a desired viscosity to the formulation.

6.3.1. The formulation of paragraph 6.3 wherein the formulation comprises 0.1-15 weight percent of the viscosity modifier.

6.3.1.1. The formulation of paragraph 6.3 or 6.3.1 wherein the desired viscosity is a viscosity suitable for application of the formulation by flow coating.

6.3.1.2. The formulation of paragraph 6.3 or 6.3.1 wherein the desired viscosity is a viscosity suitable for application of the formulation by printing.

6.3.1.3. The formulation of paragraph 6.3 or 6.3.1 wherein the viscosity is suitable for application of the formulation by coating.

6.3.2. The formulation of any one of paragraphs 6.3-6.3.1.3, wherein the viscosity modifier is selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose, and polyurethane.

6.4. The formulation of any one of paragraphs 6.1-6.3.2, further comprising a porous transfer agent adapted to facilitate transfer of the component and/or the aqueous system relative to the matrix material when the matrix material treated with the formulation is contacted with the aqueous system.

6.4.1. The formulation of paragraph 6.4 comprising 0.01 to 52 weight percent porous transfer agent.

6.4.2. The formulation of paragraph 6.4 or 6.4.1 wherein the porous transfer agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers and synthetic polymer fibers.

6.5. The formulation of paragraph 6, comprising both luciferin and luciferase.

6.5.1. The formulation of paragraph 6.5 wherein the liquid carrier comprises a solvent in which luciferin is dissolved, and wherein the luciferase is dispersed in the liquid carrier.

6.5.1.1. The formulation of paragraph 6.5.1 wherein the formulation comprises 40-99 weight percent solvent, 0.01-20 weight percent luciferin and 0.01-20 weight percent luciferase.

6.5.1.1.1. The formulation of paragraph 6.5.1.1, wherein the luciferin comprises coelenterazine and the luciferase comprises Gaussia luciferase, renilla luciferase and/or Metridia luciferase.

6.5.1.1.1.1. The formulation of paragraph 6.5.1.1.1, comprising 0.05 to 0.2 total weight percent luciferase.

6.5.1.1.1.2. The formulation of paragraph 6.5.1.1.1, comprising 0.2 to 0.6 total weight percent luciferase.

6.5.1.1.1.3. The formulation of paragraph 6.5.1.1.1, comprising 0.1 to 1.0 total weight percent luciferase.

6.5.1.1.1.4. The formulation of paragraph 6.5.1.1.1, comprising 1.0 to 10 total weight percent luciferase.

6.5.1.1.1.5. The formulation of paragraph 6.5.1.1.1, comprising 10 to 20 total weight percent luciferase.

6.5.2. The formulation of paragraphs 6.5 or 6.5.1 wherein the luciferin comprises coelenterazine, the luciferase comprises Gaussia luciferase, reni1la luciferase and/or Metridia luciferase, and the solvent comprises ethanol; and is also provided with

Wherein the formulation comprises:

50-99 weight percent ethanol;

0.1-5.0 weight percent coelenterazine;

0.1-5.0 total weight percent luciferase;

optionally, 0.01-30 total weight percent of one or more of the following:

a binder adapted to hold the at least one component on a matrix material to which the formulation is applied; and

a viscosity modifier; and

optionally, 0.1 to 10 weight percent of a porous transfer agent.

6.5.3. The formulation of any one of paragraphs 6.5-6.5.2, further comprising a binder, and wherein the binder is selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose, and polyurethane.

6.5.4. The formulation of any one of paragraphs 6.5-6.5.3, further comprising a viscosity modifier, and wherein the viscosity modifier is selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose, and polyurethane.

6.5.5. The formulation of any one of paragraphs 6.5-6.5.4, further comprising a porous transfer agent, and wherein the porous transfer agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

6.6. The formulation of paragraph 6, wherein the component is luciferin, wherein the luciferin comprises coelenterazine, and wherein the liquid carrier comprises a solvent having coelenterazine dissolved therein and comprising ethanol; and is also provided with

Wherein the formulation comprises:

40-90 weight percent ethanol;

0.1-5.0 weight percent coelenterazine;

0.01-15 weight percent of a binder; and

9-52 weight percent of porous transfer agent.

6.6.1. The formulation of paragraph 6.6 further comprising a luciferase.

6.6.2. The formulation of paragraphs 6.6 or 6.6.1 wherein the binder is selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose and polyurethane.

6.6.3. The formulation of any one of paragraphs 6.6-6.6.2, wherein the porous transfer agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

7. A partially aqueous formulation for applying luciferin to a matrix material, the formulation comprising luciferin, a solvent to dissolve the luciferin, the solvent comprising 40-99 weight percent water and 1-60 weight percent of an excipient suitable for promoting the solubility of the luciferin in water, and optionally a binder suitable for binding the luciferin to the matrix material.

7.1. The formulation of paragraph 7, wherein the excipient comprises a polar protic solvent other than water.

7.2. The formulation of paragraph 7 or 7.1 wherein the excipient is selected from the group consisting of hydroxypropyl-P-cyclodextrin, ethanol, butanol, propanol, isopropanol, pentanone, and combinations thereof.

7.3. The formulation of any one of paragraphs 7-7.2, further comprising a binder, wherein the binder is selected from the group consisting of ethylcellulose, methylcellulose and polyurethane, and wherein the formulation comprises up to 15 weight percent of the binder.

7.3.1. The formulation of paragraph 7.3 comprising 0.01 to 1.2 weight percent of the binder.

7.3.2. The formulation of paragraph 7.3 comprising 8.0 to 12.5 weight percent of the binder.

7.4. The formulation of any one of paragraphs 7-7.3, further comprising a porous transfer agent.

7.4.1. The formulation of paragraph 7.4 wherein the porous transfer agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

7.5. The formulation of any one of paragraphs 7-7.4.1, wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, and furazine.

7.5.1. The formulation of paragraph 7.5 wherein the luciferin is coelenterazine.

7.5.1.1. The formulation of paragraph 7.5.1 wherein the excipient comprises hydroxypropyl-beta-cyclodextrin at a concentration of 45-50mM, and wherein the formulation comprises luciferin at a concentration of up to 3.7 mM.

7.5.1.2. The formulation of paragraph 7 comprising up to 11 weight percent coelenterazine in solution.

8. A method of enabling application of a luciferase to a matrix material capable of maintaining up to a moisture threshold content after removal of any free water, the method comprising:

applying a formulation comprising a luciferase dispersed in an aqueous liquid to the surface of the matrix material such that the concentration of luciferase of the matrix is between 0.01 and 20mg per gram of matrix material;

wherein the applying step does not increase the moisture content of the matrix material above a moisture threshold content.

8.1. The method of paragraph 8, wherein the matrix material is fluff pulp sheet having a moisture threshold content of at least 15 weight percent.

8.1.1. The method of paragraph 8.1, wherein the luciferase formulation is applied to the surface at a rate that increases the moisture content of the fluff pulp sheet by less than 10 weight percent.

8.2. The method of paragraph 8, wherein the matrix material has a moisture threshold content of up to 25 weight percent.

8.3. The method of any one of paragraphs 8-8.2, wherein the luciferase formulation has a luciferase concentration of 5.0-30 weight percent.

8.4. The method of any one of paragraphs 8-8.3, wherein the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, rhizopodia luciferase, and firefly luciferase.

8.4.1. The method of paragraph 8.4 wherein the luciferase is one or more of Gaussia luciferase, renilla luciferase and Metridia luciferase.

9. A method of applying a chemiluminescent system to a matrix material that reacts in the presence of free water to produce light, the matrix material being capable of remaining up to a moisture threshold content after removal of any free water, the method comprising:

a luciferase treatment step in which a region on the surface of the substrate is treated with a luciferase preparation including a luciferase in an aqueous liquid;

a luciferin treatment step wherein the region 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 matrix material above a moisture threshold content.

9.1. The method of paragraph 9, wherein the substrate is fluff pulp sheet having a moisture threshold content of at least 15 weight percent.

9.1.1. The method of paragraph 9.1, wherein the luciferase formulation is applied to the surface at a rate that increases the moisture content of the fluff pulp sheet by less than 10 weight percent.

9.2. The method of paragraph 9, wherein the matrix material has a moisture threshold content of up to 25 weight percent.

9.3. The method of any one of paragraphs 9-9.2, wherein the luciferase formulation has a luciferase concentration of 5.0-30 weight percent.

9.4. The method according to any one of paragraphs 9-9.3,

10. A method of producing a treated tissue composition for incorporation into an absorbent article, the method comprising:

applying a formulation to a surface of a liquid permeable tissue sheet, wherein the formulation comprises luciferin and a solvent in which the luciferin is dissolved, and wherein the luciferin remains on the tissue sheet when the formulation is applied; and

the solvent is then removed from the tissue sheet.

10.1. The method of paragraph 10, wherein applying comprises flow coating the formulation to the surface.

10.1.1. A method according to paragraph 10.1,

wherein the formulation is flow coated by a flow coating device, and

wherein applying further comprises moving the tissue sheet relative to the flow coating device.

10.1.1.1. The method of paragraph 10.1.1, wherein the flow coating device comprises one or more nozzles through which the formulation is flow coated, the one or more nozzles positioned in contact with the moving surface.

10.1.1.2. The method of paragraph 10.1.1 or 10.1.1.1 wherein the surface of the tissue sheet to which the formulation is flow coated is suspended between two fixed points.

10.2. The method of any of paragraphs 10-10.1.2, wherein the tissue sheet is continuous.

10.3. The method of any of paragraphs 10-10.2, wherein removing the solvent comprises heat treating a surface of the tissue sheet treated with the formulation.

10.4. The method of any of paragraphs 10-10.3, wherein the tissue sheet comprises cellulosic fibers, and wherein the formulation further comprises a binder adapted to retain the luciferin on the cellulosic fibers.

10.4.1. The method of paragraph 10.4, wherein the tissue sheet further comprises synthetic fibers.

10.5. The method of any one of paragraphs 10-10.4.1, wherein the formulation comprises 40-99 weight percent solvent and 0.01-20 weight percent luciferin.

10.5.1. The method of paragraph 10.5 wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

10.5.1.1. A method according to paragraph 10.5.1, wherein the luciferin is coelenterazine, and wherein the formulation is applied at a rate to produce a treated tissue composition having a coelenterazine concentration of 0.00002 to 20 weight percent.

10.5.2. The method of paragraph 10.5 or 10.5.1, wherein the formulation is applied at a rate to produce a treated tissue composition having a luciferin concentration of 0.001 to 10 weight percent.

10.5.3. The method of any one of paragraphs 10.5 to 10.5.2, wherein the solvent comprises ethanol.

10.5.4. The method of any one of paragraphs 10.5-10.5.3, wherein the solvent comprises 40-99 weight percent water and 1-60 weight percent excipient configured to promote solubility of the luciferin in water.

10.5.5. The method of any one of paragraphs 10.5-10.5.4, wherein the formulation further comprises 0.01-30 weight percent of a binder adapted to retain the luciferin on the cellulose fibers.

10.5.5.1. The method of paragraph 10.5.5 wherein the amount of binder is selected to impart a desired viscosity to the formulation.

10.6. The method of any of paragraphs 10-10.5.4.1, wherein the formulation is applied to the surface in the form of a longitudinal strip having a width less than or equal to the width of the sheet of tissue.

10.6.1. The method of paragraph 10.6, wherein the longitudinal strips are continuous.

10.6.2. The method of paragraph 10.6, wherein the longitudinal strips are discontinuous.

10.6.2.1. The method of paragraph 10.6.2, wherein the longitudinal strips are one or more of dotted and dashed lines.

10.6.3. The method of any one of paragraphs 10.6-10.6.2.1, wherein the longitudinal strips are straight.

10.6.4. The method of any of paragraphs 10.6-10.6.2.1, wherein the longitudinal strip comprises one or more curved portions.

10.6.5. The method of any of paragraphs 10.6-10.6.2.1, wherein the longitudinal strip comprises one or more straight portions.

10.7. The method of any one of paragraphs 10-10.5.4.1, wherein the formulation is applied to the surface in the form of one or more shapes.

10.8. The method of any one of paragraphs 10-10.7, wherein the formulation further comprises a luciferase.

10.9. The method of any of paragraphs 10-10.8, wherein the method is performed at least in part on a tissue printer.

10.10. The method of any of paragraphs 10-10.9, wherein the luciferin is coelenterazine, and wherein the formulation is applied at a rate to produce a treated tissue composition having 0.01mg-25g of coelenterazine per 12 inch length of tissue sheet.

10.10.1. The method of paragraph 10.10 wherein the formulation is applied at a rate to produce a treated tissue composition having 0.01 to 100mg coelenterazine per 12 inch length of tissue sheet.

10.10.2. The method of paragraph 10.10 wherein the formulation is applied at a rate to produce a treated tissue composition having 0.01 to 1.0g coelenterazine per 12 inch length of tissue sheet.

10.10.3. The method of any of paragraphs 10.10-10.10.2, wherein the tissue sheet to which the formulation is applied is continuous, and wherein the method further comprises dividing the tissue sheet into discrete lengths after applying the formulation.

10.11. A method of producing an absorbent core for incorporation into an absorbent article, the method comprising:

producing a treated tissue composition according to the method of any one of paragraphs 10-10.10;

the absorbent material is at least partially surrounded by the treated composition.

11. A method of producing a liquid impermeable backsheet structure for incorporation into an absorbent article, the liquid impermeable backsheet structure being 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 surface of a liquid impermeable backsheet, wherein the formulation comprises:

the at least one component, wherein the at least one component is selected from luciferin and luciferase; a liquid carrier; and

a binder adapted to hold the component to the backsheet; and

at least some of the liquid carrier is then removed from the backsheet.

11.1. The method of paragraph 11, wherein the component is luciferin, and wherein the liquid carrier comprises a solvent having luciferin dissolved therein and comprising ethanol; and is also provided with

Wherein the formulation comprises:

40-90 weight percent ethanol;

0.1-5.0 weight percent luciferin;

0.01-15 weight percent of a binder; and

9-52 weight percent of porous transfer agent.

11.2. The method of paragraph 11 or 11.1 wherein the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

11.2.1. The method of paragraph 11.2 wherein the luciferin comprises coelenterazine.

11.3. The method of any of paragraphs 11-11.2, wherein the binder is selected from the group consisting of ethylcellulose, methylcellulose, nitrocellulose, and polyurethane.

11.4. The method of any of paragraphs 11-11.3, wherein the porous transfer agent is selected from the group consisting of starch, amorphous silica, clay minerals, cellulose pulp fibers, cotton fibers, and synthetic polymer fibers.

11.5. The method of any of paragraphs 11-11.4, wherein the amount of one or more of the binder and the porous transfer agent is selected to impart a desired viscosity to the formulation.

11.6. The method of any of paragraphs 11-11.5, wherein applying comprises flow-coating the formulation to the surface.

11.7. The method of any of paragraphs 11-11.6, further comprising applying a coating on the surface of the backsheet treated with the formulation, wherein the coating is one or more of water-soluble or water-permeable.

11.8. The method of any of paragraphs 11-11.7, wherein removing the liquid carrier comprises heat treating a surface of the backsheet treated with the formulation.

11.9. The method of any of paragraphs 11-11.8, wherein removing the liquid carrier comprises contacting a surface of the backsheet treated with the formulation with an absorbent material adapted to wick the liquid carrier from the surface of the backsheet.

11.9.1. The method of paragraph 11.9, wherein the at least one component in the formulation is luciferin, and wherein the absorbent material is treated with luciferase.

11.9.1.1. The method of paragraph 11.9.1, wherein the absorbent material is in the form of an absorbent core comprising one or more of absorbent fibers and superabsorbent polymers.

12. A composition, comprising:

an encapsulating material consisting of particles, the particles comprising a first component of a chemiluminescent system, wherein the particles each have a coating covering the entire surface of the particles, wherein the coating comprises a material that is one or more of water permeable and water soluble, wherein the particles comprise a predetermined amount of the component; and

a predetermined amount of a second component of the chemiluminescent system;

wherein the predetermined amount of the respective component is an amount sufficient to produce light of the desired intensity in the presence of the aqueous system.

12.1. An absorbent article, comprising:

a liquid permeable topsheet;

a liquid impermeable backsheet;

an absorbent material disposed between the topsheet and the backsheet; and

the composition of paragraph 12.

13. A method of producing an absorbent article for detecting aqueous soil, the method comprising:

producing an encapsulating material consisting of particles comprising one of two reactive components of a chemiluminescent system configured to generate light upon contact with an aqueous system from a material that is one or more of water permeable and water soluble;

producing an absorbent article comprising

Disposing the wrapper between a liquid permeable topsheet and a liquid impermeable backsheet, an

Another reactive component of the chemiluminescent system is disposed in a structural element of the absorbent article.

14. A method of producing fluff pulp treated with a chemiluminescent system, the method comprising independently applying a non-aqueous solution comprising luciferin and an aqueous solution comprising luciferase to portions of fluff pulp sheets.

14.1. The method of paragraph 14 wherein the luciferin and the respective portion to which the luciferase is applied are non-overlapping.

14.2. The method of paragraph 14 or 14.1, wherein the portions are on opposite surfaces of the fluff pulp sheet.

14.3. The method of paragraph 14 or 14.1, wherein the portions are on the same surface of the fluff pulp sheet.

15. A method of producing a fluff pulp composition comprising:

fiberizing the sheet of fluff pulp fibers to produce a dispersion of individualized fluff pulp fibers in air; and

spraying into the dispersion a formulation of at least one component of a chemiluminescent system adapted to react in the presence of an aqueous system to produce light;

wherein the concentration of the at least one component retained on the individualized fluff pulp fibers is from 0.0003 to 10.0 weight percent of the individualized fluff pulp fibers.

15.1. A method according to paragraph 15,

wherein the fiberizing is performed in a chamber of a hammer mill, and

wherein the formulation is sprayed into a chamber of the hammer mill.

15.2. A method according to paragraph 15,

wherein the fiberizing is performed in a chamber of a hammer mill,

wherein the dispersion is air delivered from the chamber, and

wherein the formulation is sprayed into the dispersion after air delivery from the chamber.

16. A kit, comprising

An absorbent article comprising a liquid permeable topsheet, a liquid impermeable backsheet, an absorbent material disposed between the topsheet and the backsheet, and a first component of a chemiluminescent system disposed between the topsheet and the backsheet, wherein the first component is one of luciferin and luciferase; and

A measured amount of a second component of the chemiluminescent system, wherein the amount is adapted to react with the first component in the presence of an aqueous system to produce light of a predetermined duration and/or intensity.

16.1. The kit of paragraph 16, wherein the second component is in the form of a liquid formulation, gel, or powder.

16.2. The kit of paragraphs 16 or 16.1, wherein at least a portion of the absorbent article is configured to allow the second component to be applied thereto.

16.2.1. The kit of paragraph 16.2, wherein one or more of the topsheet and the backsheet are selectively openable and resealable.

17. A structural element for incorporation into an absorbent article, the structural element comprising:

a first surface having a treatment zone treated with at least one component of a chemiluminescent system adapted to react in the presence of an aqueous system to produce light;

Wherein the total treatment area is smaller than the area of said first surface.

17.1. A structural element according to paragraph 17,

wherein the first surface comprises a target area corresponding to an area where one or more fluid insults are expected during use of the absorbent article into which the structural element is incorporated; and is also provided with

Wherein the treatment region at least partially overlaps the target region.

17.1.1. A structural element according to paragraph 17.1,

wherein the target region comprises two or more regions corresponding to regions where respective sequences of fluid insults are expected during use of the absorbent article; and is also provided with

Wherein the treatment region comprises two or more discrete portions that at least partially overlap the two or more corresponding regions, respectively.

17.1.1.1. A structural element according to paragraph 17.1.1, wherein a first portion of the treated region is configured to produce visible light that differs from a second portion in at least one visual aspect.

17.1.1.1.1. A structural element according to paragraph 17.1.1.1, wherein a first portion of the treated region is configured to provide visible light having a different intensity relative to a second portion.

17.1.1.1.2. A structural element according to paragraph 17.1.1.1, wherein a first portion of the treated region is configured to provide visible light of a different color than a second portion.

17.1.1.1.3. A structural element according to paragraph 17.1.1.1, wherein a first portion of the treatment region is configured to provide visible light having a different duration relative to a second portion.

17.1.1.2. The structural element of any one of paragraphs 17.1.1-17.1.1.1.3, wherein each of the two or more discrete portions of the treatment area overlap only a respective corresponding area.

17.1.1.3. The structural element of any one of paragraphs 17.1.1-17.1.1.2, wherein the first and second portions of the treatment area overlap respective corresponding portions to different extents.

17.1.1.4. The structural element of any one of paragraphs 17.1.1-17.1.1.3, wherein at least two of the corresponding regions are substantially concentric.

17.1.2. The structural element of paragraph 17.1, wherein the target region comprises two or more regions corresponding to regions where respective sequences of fluid insults are expected during use of the absorbent article; and is also provided with

Wherein the treatment region at least partially overlaps one but not the other of the two or more corresponding regions.

17.2. The structural element of any one of paragraphs 17-17.1.1.4, wherein the treated region is in the form of a continuous shape.

17.2.1. The structural element of paragraph 17.2, wherein the treatment area is in the form of a longitudinal strip.

17.2.1.1. The structural element of paragraph 17.2 or 17.2.1, wherein the first surface has a length, and wherein the length of the longitudinal strip is less than the length of the first surface.

17.3. The structural element of any one of paragraphs 17-17.1.1.4, wherein the treated region is in the form of a pattern comprising two or more discrete portions.

17.3.1. A structural element according to paragraph 17.3, wherein the pattern is in the form of discontinuous longitudinal strips.

17.3.1.1. The structural element of paragraph 17.3 or 17.3.1, wherein the first surface has a length, and wherein the length of the longitudinal strip is less than the length of the first surface.

17.3.2. The structural element of paragraph 17.3, wherein the pattern is in the form of a shape arrangement.

17.3.3. The structural element of paragraph 17.3 or 17.3.2, wherein the pattern extends over an area that is less than an area of the first surface.

17.4. The structural element of any one of paragraphs 17-17.3.1.1, wherein the at least one component is luciferin.

17.4.1. A structural element according to paragraph 17.4, wherein the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

17.5. The structural element of any one of paragraphs 17-17.3.1.1, wherein the at least one component is a luciferase.

17.5.1. The structural element of paragraph 17.5 wherein the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, rhizopus luciferases and firefly luciferase.

17.6. The structural element of any one of paragraphs 17-17.3.1.1, wherein the at least one component is luciferin and luciferase.

17.6.1. The structural element of paragraph 17.6, wherein the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furanazine, and/or wherein the luciferases are selected from Gaussia luciferases, renilla luciferases, metridia luciferases, oplophorms luciferases, dinoflagellate luciferases, copepodiums luciferases and firefly luciferases.

17.6.2. The structural element of paragraph 17.6 or 17.6.1, wherein the treated region comprises separate regions treated with luciferin and luciferase, respectively.

17.6.2.1. A structural element according to paragraph 17.6.2, wherein at least two independent regions are adjacent to each other.

17.7. The structural element of any one of paragraphs 17-17.6.2.1, wherein the treated region is a first treated region, and wherein the first surface further comprises a second treated region treated with a non-chemiluminescent wetness indicator.

17.7.1. The structural element of paragraph 17.7, wherein the first treated region and the second treated region are non-overlapping.

17.8. The structural element of any one of paragraphs 17-17.7.1, wherein the treated area is 1-99% of the area of the surface, or any range therein.

17.9. The structural element of any one of paragraphs 17-17.8, wherein the structural element is in a form selected from the group consisting of an absorbent core, a layer of material used in an absorbent core, a liquid permeable sheet, a liquid impermeable sheet, a tissue sheet, and a backsheet.

17.10. An absorbent article incorporating the structural element of any of paragraphs 17-17.9, wherein the absorbent article is in a form selected from the group consisting of infant diapers, wearable adult incontinence products, feminine hygiene products, pet pads, and mattresses.

17.11. A method of producing the structural element of any one of paragraphs 17-17.9, the method comprising applying a formulation to a first surface of the structural element to form a treatment region, wherein the formulation comprises at least one component of a chemiluminescent system.

17.11.1. The method of paragraph 17.11, wherein the formulation is an ink formulation, and wherein applying the formulation comprises applying the ink formulation by printing.

17.11.1.1. The method of paragraph 17.11.1, wherein the printing comprises inkjet printing.

17.11.1.1.1. The method of paragraph 17.11.1.1, wherein the inkjet printing comprises continuous inkjet printing.

18. A method of producing a structural element for incorporation into an absorbent article, the structural element being 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 the first surface of the structural element, wherein the formulation comprises the at least one component, and wherein the at least one component is selected from luciferin and luciferase.

18.1. The method of paragraph 18, wherein the predetermined region at least partially overlaps with a region where one or more fluid insults are expected during use of the absorbent article in which the structural element is incorporated.

18.2. The method of paragraph 18 or 18.1, wherein the predetermined area is in the form of a continuous shape.

18.3. The method of any of paragraphs 18-18.2, wherein the predetermined area comprises two or more discrete portions.

18.3.1. A method according to paragraph 18.3, wherein the predetermined area is in the form of a pattern comprising two or more discrete portions.

18.4. The method of any one of paragraphs 18-18.3.1, wherein the at least one component is luciferin.

18.4.1. The method of paragraph 18.4 wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

18.5. The method of any one of paragraphs 18-18.3.1, wherein the at least one component is a luciferase.

18.5.1. The method of paragraph 18.5 wherein the luciferase is selected from the group consisting of Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, rhizopus luciferases and firefly luciferase.

18.6. The method of any one of paragraphs 18-18.3.1, wherein the at least one component is luciferin and a luciferase.

18.6.1. The method of paragraph 18.6 wherein the luciferin is selected from coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine, and/or wherein the luciferases are selected from Gaussia luciferases, renilla luciferases, metridia luciferases, oplophorus luciferases, dinoflagellate luciferases, copepodiums luciferases and firefly luciferases.

18.6.2. The method of paragraph 18.6, wherein applying a formulation comprises applying at least two formulations, wherein one of the at least two formulations comprises the luciferin, and wherein another of the at least two formulations comprises the luciferase.

18.6.2.1. The method of paragraph 18.6.2, wherein applying the formulation comprises independently applying the at least two formulations.

18.6.2.2. The method of paragraphs 18.6.2 or 18.6.2.1, wherein at least two agents are applied to non-overlapping portions of the predetermined area, respectively.

18.7. The method of any one of paragraphs 18-18.6.2.2, wherein the formulation is an ink formulation, and wherein applying the formulation comprises applying the ink formulation by printing.

18.7.1. The method of paragraph 18.7, wherein the printing comprises inkjet printing.

18.7.1.1. The method of paragraph 18.7.1, wherein the inkjet printing comprises continuous inkjet printing.

18.8. The method of any one of paragraphs 18-18.7.1.1, further comprising applying a non-chemiluminescent wetness indicator to the first surface.

18.8.1. The method of paragraph 18.8, wherein the non-chemiluminescent wetness indicator is applied to at least partially overlap the predetermined area.

18.8.2. The method of paragraph 18.8, wherein the non-chemiluminescent wetness indicator is applied so as not to overlap the predetermined area.

Claims

1. A structural element for incorporation into an absorbent article, the structural element comprising:

wherein the at least one component is selected from luciferin and luciferase;

wherein the treatment area is smaller than the area of the first surface;

wherein the first surface comprises a target area corresponding to an area where one or more fluid insults are expected during use of the absorbent article into which the structural element is incorporated;

Wherein the treatment region at least partially overlaps the target region;

wherein the target region comprises two or more regions corresponding to regions where respective sequences of fluid insults are expected during use of the absorbent article;

wherein the treatment region comprises two or more discrete portions that at least partially overlap the two or more regions, respectively; and is also provided with

Wherein each of the discrete portions is shaped to have a surface area that increases with the expected wicking distance of the fluid front from the plurality of insults, which thus creates an increasingly larger light emitting area as the absorbent article receives successive insults.

2. The structural element of claim 1, wherein each of the two or more portions of the treatment region overlap only respective corresponding ones of the two or more regions.

3. The structural element of claim 1, wherein a first portion and a second portion of the two or more discrete portions overlap respective corresponding regions to different extents.

4. A structural element according to any one of claims 1-3, wherein at least two of the two or more regions are substantially concentric.

5. A structural element according to any one of claims 1-3, wherein the treatment region is in the form of a continuous shape.

6. A structural element according to any one of claims 1-3, wherein the treatment area is in the form of a pattern comprising two or more discrete portions, wherein the pattern is in the form of a shape arrangement, wherein the pattern extends over an area that is smaller than the total area of the first surface.

7. A structural element according to any one of claims 1 to 3, wherein the at least one component is luciferin.

8. The structural element of claim 7, wherein said luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin and furazine.

9. A structural element according to any one of claims 1-3, wherein the at least one component is a luciferase.

10. The structural element of claim 9, wherein the luciferase is selected from Gaussia luciferase, renilla luciferase, metridia luciferase, oplophorus luciferase, dinoflagellate luciferase, copepoda luciferase and firefly luciferase.

11. A structural element according to any one of claims 1 to 3, wherein the at least one component is luciferin and luciferase.

12. The structural element of claim 11, wherein the luciferin is selected from the group consisting of coelenterazine, coelenterazine analogs, dinoflagellate luciferin, bacterial luciferin, fungal luciferin, firefly luciferin, renilla luciferin, and furazine, and

13. The structural element of claim 11, wherein the treatment region comprises separate regions, wherein one region is treated with luciferin and the other region is treated with luciferase.

14. The structural element of claim 13, wherein the independent regions are adjacent to each other.

15. The structural element of claim 13, wherein the independent regions are overlapping.

16. A structural element according to any one of claims 1-3, wherein the treated region is a first treated region, and wherein the first surface further comprises a second treated region treated with a non-chemiluminescent wetness indicator.

17. The structural element of claim 16, wherein the first treated region and the second treated region are non-overlapping.

18. A structural element according to any one of claims 1-3, wherein the treated area is 1-99% of the area of the first surface.

19. A structural element according to any one of claims 1-3, wherein the structural element is in a form selected from the group consisting of an absorbent core, a layer of material used in an absorbent core, a liquid permeable sheet, a liquid impermeable sheet, a tissue sheet and a backsheet.

20. An absorbent article incorporating the structural element of any one of claims 1-19, wherein the absorbent article is in a form selected from the group consisting of infant diapers, wearable adult incontinence products, feminine hygiene products, pet pads, and mattresses.

21. A method of producing the structural element of any one of claims 1-19, the method comprising applying a formulation to a first surface of the structural element to form a treatment region, wherein the formulation comprises the at least one component of the chemiluminescent system.

22. The method of claim 21, wherein the formulation is an ink formulation, and wherein applying the formulation comprises applying the ink formulation by printing.

23. The method of claim 22, wherein the printing comprises inkjet printing.

24. The method of claim 23, wherein the inkjet printing comprises continuous inkjet printing.