MXPA06007119A - Treated nonwoven material - Google Patents

Abstract

A nonwoven material adapted for use as a surge layer or a transfer layer that includes a layer that includes fibers that have been treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide is provided.

Description

NON-TISSUE MATERIAL TREATED CROSS REFERENCE TO RELATED REQUESTS Tapplication relates to the commonly assigned United States of America patent application serial number 10 / 743,893, entitled "Porous Substrates Having a Treated Side to a Higher Concentration and Methods for Treating Porous Substrates", filed by the Express Courier procedure EL 439721061 on December 22, 2003.

FIELD OF THE INVENTION The present invention relates to non-woven materials.

BACKGROUND OF THE INVENTION The conventional emergence material is a material used in absorbent articles such as diapers to provide fluid intake and some temporary storage before the fluid is absorbed by an absorbent material or super absorbent material. Many high-absorbency materials are unable to efficiently absorb a liquid at the rate at which the liquid is applied to the absorbent compounds during use. Consequently, a relatively high concentration of fibrous sprouting material is desirable to temporarily hold the liquid until the high absorbency material can absorb it. The conventional emergence material is also used to distribute or space the fluid over more surface area of the absorbent material thereby increasing the absorption efficiency and the efficiency of material utilization.

By providing a temporary storage of fluids the emergence material keeps the fluid from returning, referred to as reflux, through the lining from the side to the body of the diaper, or from another article, and contacting the skin. The emergence material increases the absorption efficiency and decreases the reflux caused by the slower absorption of the absorbent material. Examples of particular emergence materials can be found in U.S. Patent No. 5,490,846 issued to Ellis et al. And in U.S. Patent No. 5,364,382 issued to Latimer et al.

There is a need for an emergence material with improved picking properties that can also reduce reflux and leakage of urine, or other fluid, from the absorbent article to the wearer's skin. In addition, there is a need for an emergence material that improves dryness in absorbent articles for personal care such as diapers. Improved dryness can be measured by the TransEpidermal Water Loss also referred to by the acronym TEWL. There is also a need for the use of less surfactants or surface active agents to treat emergence materials in such a way that the design of the absorbency characteristics of the super absorbent material is not adversely affected. There is also a need to treat the emergence material with compounds that have high affinity for tightly absorbing water-based fluids and moisture in an environment enclosed in a diaper.

SYNTHESIS OF THE INVENTION Personal care items such as diapers, training pants, incontinence garments, sanitary napkins, bandages, etc., are often required to accept rapid and large discharges of body exudates that are beyond the absorption capacity of the body. short term of the product. As a result, it has been found advantageous to use emergence layers within such absorbent articles for personal care. Absorbent personal care articles have a fluid-permeable body-side liner, also referred to as a topsheet, and a liquid-impermeable backing layer with an absorbent core disposed in the middle. In a desirable embodiment, the present invention provides a nonwoven fibrous fabric that is particularly suitable for use as an emergence layer or a transfer layer and is disposed between the body-side liner and the absorbent core. Furthermore, it is useful if the emergence layer of the present invention is coupled to the liner and the absorbent core promotes the transfer of the liquid.

In one embodiment, the present invention provides a nonwoven material adapted to be used as an emergence layer or a transfer layer that includes fibers that have been treated with a treatment composition comprising a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide, wherein the treatment composition over the emergence layer reduces the surface tension of an aqueous fluid for less than about 20 dynes per centimeter as measured by the American Society's Test Method for Testing and Materials' D-1590-60. The non-woven material may also further include second fibers that have not been treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide. Desirably, at least a portion of the fibers are treated with a modified polysaccharide. In one embodiment, the non-woven fibers are included in a bonded and knitted fabric having a basis weight in the range from about 20 grams per square meter to about 150 grams per square meter and comprises greater than about 20 percent by weight. weight of the first fibers and greater than about 10 percent by weight of the second fibers. In other embodiments, the non-woven fibers include greater than about 30 percent by weight of the first fibers and greater than about 20 percent by weight of the second fibers; greater than about 40 percent by weight of the first treated fibers and greater than about 30 percent by weight of the second fibers and even greater than about 50 percent by weight of the first fibers and greater than about 40 percent by weight percent by weight of the second fibers. In exemplary embodiments, the non-woven fiber layer consists essentially of about 30 weight percent to about 80 weight percent of the first fibers and greater than about 20 weight percent to about 60 weight percent. weight of the second fibers. The fibers can also be treated with a lubricant and / or an antistatic agent to facilitate the carding process. The fibers can be polyolefin fibers, polyester fibers, polyamide fibers, or poly (lactic acid) fibers or lactic acid copolymer fibers. In incorporating specimens, the first fibers are bico-polyolefin fibers that include a polypropylene core and a polyethylene sheath or a polyethylene terephthalate core and a polyethylene sheath. Suggested polysaccharides, modified polysaccharides, derivatives of a polysaccharide and modified polysaccharide derivatives include cellulose, cellulose derivatives, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose, methyl hydroxypropyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, derivatives of starch, pectin derivatives, carboxymethyl starch, aldehyde starch, pectates, animal products derivatives, carboxymethyl chitin and carboxymethyl chitosan.

The present invention also provides articles for personal care, for example a diaper, which includes a nonwoven material that includes fibers that have been treated with a treatment composition comprising a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derived from a modified polysaccharide, wherein the composition of the treatment over the emergence layer reduces the surface tension of aqueous fluid for less than about 20 dynes per centimeter as measured by Test Method D 1590-60 of the American Society for Testing and Materials (ASTM) as an emergence layer or as a transfer layer. In certain embodiments, the present invention provides a diaper that includes an emergence layer or a transfer layer comprising fibers treated with a polysaccharide, a modified polysaccharide., a derivative of a polysaccharide or a derivative of a modified polysaccharide wherein the treated emergence layer or the transfer layer modifies the surface tension of distilled water to about 56 dynes per centimeter or greater as measured by the Test Method D 1590-60 from the American Society for Testing and Materials (ASTM) and treating the fibers of the emergence layer or a transfer layer reduces the surface tension of distilled water for less than about 20 dynes as measured by Test Method D 1590-60 of the American Society for Testing and Materials (ASTM). In certain embodiments, the treated emergence layer or the transfer layer can modify the surface tension of distilled water to about 58 dynes per centimeter or greater as measured by Test Method D 1590-60 of the American Society for Testing and Materials (ASTM). In other embodiments, the treated emergence layer or the transfer layer can modify the surface tension of distilled water to about 60 dynes per centimeter or greater as measured by Test Method D 1590-60 of the American Society for Testing. and Materials' (ASTM). Desirably, the diaper can have a transepidermal water loss value (TEWL) of less than about 37 grams per square meter per hour. More desirably, the diaper can have a transepidermal water loss reduction (TEWL) of at least about 3 grams per square meter per hour compared to a diaper of the same construction but with the emergence layer that includes fibers not treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide. The outer cover of the diaper can have a water vapor transmission rate (WVTR) of less than 20,000 grams per square meter per 24 hours.

The present invention also provides a method of forming a layer of nonwoven fibers including: providing a plurality of first fibers that treat the plurality of first fibers with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide; provides a plurality of second fibers; combines the first fibers with the second fibers to form a mixture comprising the first fibers and the second fibers; and forming a nonwoven fabric of a mixture including the first fibers and the second fibers. The method of forming a non-woven fabric can include carding and bonding the first fibers and the second fibers to form a fabric.

In yet another embodiment, the present invention provides absorbent articles, such as diapers, that include a top sheet or other body contact surface and an optional emergence administration layer that reduces the surface tension of distilled water. of about 20 dynes as measured by Test Method D 1590-60 of the American Society for Testing and Materials (ASTM). In certain embodiments, the diaper includes an emergence layer or a transfer layer that includes fibers that have been treated with a treatment composition comprising a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide. In yet another embodiment, the present invention provides an absorbent article that includes: a porous treated substrate comprising a first surface comprising a first quantity of a surfactant or mixture of surfactants and a second surface comprising a second quantity of the surfactant or the mixture of surfactants in which the second quantity of the surfactant or the mixture of surfactants is less than the first quantity of the surfactant or the mixture of surfactants; and a layer of nonwoven fibers comprising fibers treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide. In certain embodiments, the first surface of the porous treated substrate is oriented toward or adjacent to the layer of the nonwoven fibers treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide. The porous treated substrate may also include a skin health agent. In certain embodiments, the non-woven fibers are included in a spunbonded fabric including nonwoven fibers treated with hydroxyethyl ethyl cellulose, hydroxypropyl cellulose or a mixture thereof. In certain embodiments, the second surface of the porous treated substrate comprises essentially no surfactant. In certain embodiments, the porous treated substrate is a single layer. Desirably, the transepidermal water loss (TEWL) of the combination is less than the transepidermal water loss (TEWL) of the porous treated substrate and the nonwoven fiber layer.

In still another embodiment, the present invention provides a bonded and carded fabric adapted for use as an emergence layer or a transfer layer having a basis weight of from about 50 to about 200 grams per square meter and comprising bicomponent fibers of polyethylene sheath fibers and propylene core which have been treated with a treatment composition comprising a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide, wherein the treatment composition on the bicomponent fibers reduces the surface tension of distilled water for less than about 20 dynes per centimeter as measured by Test Method D 1590-60 of the American Society for Testing and Materials (ASTM). In consecuense, the present invention also provides a diaper comprising an emergence layer which is a bonded and knitted fabric having a basis weight from about 50 to about 200 grams per square meter where the carded and bonded fabric comprises fibers that have been treated with a treatment composition comprising a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide, or a derivative of a modified polysaccharide, wherein the treatment composition on the fibers reduces the surface tension of distilled water by less than about of 20 dynes per centimeter as measured by Test Method D 1590-60 of the American Society for Testing and Materials (ASTM).

Other features and aspects of the present invention are described in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS A complete and authoritative description of the present invention, including the best mode thereof addressed to one skilled in the art, is pointed out more particularly in the remainder of the specification, including reference to the accompanying figures in which: Figure 1 representatively shows a top plane view, partially sectioned, of an absorbent article in accordance with an embodiment of the invention; Y Figure 2 representatively shows a sectional view of the absorbent article of figure 1 taken along line 2-2.

The repeated use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DEFINITIONS "Carded and bonded fabric or fabric" refers to fiber fabrics made of basic fibers which are sent through a combing or carding unit, which "separates" and partially aligns the basic fibers in the direction of the machine to form A fibrous nonwoven fabric generally oriented in the machine direction Such fibers are generally purchased in bales which are placed in an opening and mixing system which separates and mixes the fibers before the carding unit. The fabric is formed, is then joined by one or more of several joining methods, one such bonding method is the bonding by powder, where a powder adhesive is distributed through the cloth and then activated, usually by warming the fabric and the adhesive with hot air Another suitable method of joining is pattern bonding, where heated calendering rolls or ultrasonic bonding equipment are used to join the fibers. ntas, usually in a localized bonding pattern, even when the fabric can be bonded across its entire surface if desired. Another suitable and well-known method of joining, particularly when using bicomponent basic fibers is the bonding through air.

As used herein, the term "air binding" or " " means a bonding process of a nonwoven fiber fabric in which air having a temperature above the melting point of at least one of the polymers of the fabric is forced through the fabric. The air speed can be between 100 and 500 feet per minute and the dwell time can be as long as 10 seconds. Melting and re-solidifying the polymer provide the bond. Air binding has relatively restricted variability and since air binding requires melting of at least one of the components to achieve bonding, it is generally restricted to fabrics with two components of the conjugate fiber type or those which include an adhesive. The binder through the air, the air having a temperature above the melting temperature of one of the components and below the melting temperature of another component is directly from a surrounding hood, through the fabric, and in a perforated roller that supports the fabric. Alternatively, the binder through air may be a flat arrangement wherein air is directed vertically downward toward the tissue. The operating conditions of the two configurations are similar, the primary difference being the geometry of the fabric during joining. The hot air melts the lower melted polymer component and thus forms the bonds between the filaments to integrate the fabric.

As used herein, the term "thermal spot bonding" involves passing a fabric or fabric of fibers to be joined between a heated calender roll and an anvil roll. The calendering roll is usually, though not always, stamped in some way so that the entire fabric does not join across its entire surface, and the anvil roll is usually flat. As a result, several patterns for calendering rollers have been developed for functional as well as aesthetic reasons. An example of a pattern has points and pattern Hansen Pennings or "H &P "with about 30% union area with about 100 joints per square inch as taught in U.S. Patent No. 3,855,046 issued to Hansen &Pennings, incorporated herein by reference in its entirety. The H &P pattern has joint areas in a square or bolt point where each bolt has a dimension of 0.038 inches. (0.965 millimeters), a spacing of 0.070 inches (1,778 millimeters) between the bolts, and a bond depth of 0.023 inches (0.584 millimeters). The resulting pattern has a bound area of about 29.5%. Another typical point-of-attachment pattern is the Hansen Pennings expanded bonding pattern or "EHP" that produces a 15% bond area with a square bolt that has a side dimension of 0.037 inches (0.94 millimeters), a bolt spacing of 0.097 inches (2,464 millimeters) and a depth of 0.039 inches (0.991 millimeters). Another typical designated junctional pattern "714" has square bolt joint areas where each bolt has a side dimension of 0.023 inches, a spacing of 0.062 inches (1,575 mm) between bolts, and a joint depth of 0.033 inches (0.838 mm). The resulting pattern has a bound area of about 15%.

Yet another common pattern is the Star C pattern, which has a bond area of about 16.9%. The star pattern in C has a crossed direction bar or "corduroy" design interrupted by the falling stars. Other common patterns include the diamond pattern with repeated and slightly offset diamonds with about 16% area of bond and a wire-frame pattern that looks like the name suggests, for example, as a window-grid pattern with a Union area of 19%. Typically, the percentage of the bonding area varies from about 10% to about 30% of the area of the fabric of the fabric laminate. As is well known in the art, knit bonding holds the laminate layers together as well as imparting integrity to each individual layer by joining the filaments and / or fibers within each layer.

As used herein, the term "joining window" means the range of temperature of the mechanism, for example, calendering rollers, used to join together the non-woven fabric, upon which such bonding is successful. For bonding with polypropylene yarn, this bond window is typically from about 270 degrees Fahrenheit to around 310 degrees Fahrenheit (132 degrees Celsius to 154 degrees Celsius). Below about 270 degrees Fahrenheit the polypropylene is not hot enough to melt and bond and above about 310 degrees Fahrenheit the polypropylene will melt excessively and can stick to the calendering rollers. The polyethylene has an even narrower connecting window.

As used herein, the term "surfactant" is a substance that acts by modifying the surface or boundary between two phases and is also referred to as an "active surface agent". These substances are compounds that reduce the surface tension when they are present, in a very small amount (= O.Ol molar) in water or water solutions, or that reduces the interfacial tension between two liquids, or between a liquid and- solid. A wide variety of substances that can be surface active in aqueous media have common characteristics. For example, its molecular structures are composed of at least two different functional parts, namely one being hydrophilic (a polar head soluble in water) and the other being lipophilic (an apolar tail soluble in oil). The lipophilic part is usually a long hydrocarbon chain of about 6 carbons or more. These molecules are surface active because when they dissolve in water they have a tendency to break or adsorb interfaces of a liquid / air, liquid / liquid, or solid / liquid. There is a wide variety of surfactants that can be broadly classified into 5 categories: 1) Anionic: these are ionized salts where the anion (eg, carboxylate, sulfate, sulfonate, etc.) is coupled to a long alkyl chain; 2) Cationic: these are surfactants carrying a positive charged group (eg, ammonium group) coupled to a long alkyl chain; 3) Non-ionic: these are polyether derivatives made from ethoxylate reactions (eg, ethoxylated hydrogenated castor oil); 4) Amphoteric: these are surfactants that can be either cationic or anionic depending on the pH (eg, botnet, dimethyl N-dodecyl-N: N); 5) Polymeric: these can consist of any of the previous categories, but they are larger molecular weights, for example higher than around 1200.

As used herein, the term "wetting agent" is a product that acts by modifying the wetting characteristics of a solid surface and includes any compound that promotes the wettability of • water of a solid material. Generally, there are two means for promoting water wettability: 1) increasing the surface energy of a solid substrate to a level that at least equals the surface tension of the water; and 2) reducing the surface tension of the water to at least equal to the surface energy of the solid substrate. The latter means promoting wettability, reducing the surface tension of water by at least about 20 dynes per centimeter is achieved by surfactants. Increasing the surface energy of the solid substrates can be achieved by various means including wet chemistry using surface coating with water soluble high molecular weight polymers, copolymerization of radiation induced grafts of hydrophilic monomers on solid surfaces, or dry processes, such as flame treatment, incandescent corona discharge and incandescent plasma discharge.

TEST METHODS Skin Hydration Test The hydration values of the skin are determined by measuring the TransEpidermal Water Loss (TEWL) and can be determined by using the following test procedure. The test is conducted in adults on the forearms. Any medication should be checked to ensure that it has no effect on the test results and the forearms of the subjects should be free of any skin conditions such as irritations or abrasions. Subjects should relax in the test environment which should be around 72 degrees Fahrenheit (22 degrees Celsius) with a humidity of around 40 percent, for about 15 minutes before the test and the movement should be maintained at a minimum during the test. Subjects should wear short sleeve shirts, not bathe or wash for about 2 hours prior to the test, and should not apply any perfume, lotion, powder, etc., on the forearm.

The measurements are taken with an evaporimeter, such as a DERMALAB® instrument distributed by Cortex Technology, Textilvaenget 1 9560, from Hadsund, Denmark.

A reading of the baseline should be taken on the forearm in the middle of the subject's hand and should be less than 10 grams per square meter per hour. Each test measurement is taken for a period of two minutes with the values of TransEpidermal Water Loss (TEWL) taken once per second (a total of 120 TransEpidermal Water Loss values (TEWL)).

The end of an assortment tube is placed on the middle of the forearm to perform the test. The tube eye must face the target positioning area. A product to be tested is placed on the forearm of the subject directly on the end of the tube. The product may vary depending on the type of material to be tested or the availability of the material, so care must be taken to ensure that the test results are comparable. A network capable of stretching such as that which is available from Sturgilast Elastic Dressing Retainer Western Medical. It should be placed on the product to help hold it in place.

Three equal loads of 70 milliliters of 0.9 per • One hundred by weight of an aqueous solution of sodium chloride, available from WWR Scientific Products at about 95 degrees Fahrenheit +/- 5 degrees Fahrenheit (35 degrees Celsius) are supplied to the product at an interval of 45 seconds at a rate of 300 mils per minute for a pump such as a MASTERFLEX LS® pump. After 60 minutes, the product is removed from the forearm of the subject and the Evaporimeter readings taken immediately on the skin in the forearm in the middle of the subjects where the product has been. The values of the TransEpidermal Water Loss (TEWL) are reported as the difference between the values at one hour and the baseline in grams per square meter per hour.

Test of the Water Vapor Transmission Rate An adequate technique to determine the value of the water vapor transmission rate (WVTR) of a material is the standard test procedure by the Association of the Non-Woven Fabrics Industry (INDA), IST number 70.4 (99), entitled "STANDARD METHOD OF TEST FOR THE TRANSMISSION RATE OF WATER STEAM THROUGH A NON-WOVEN AND A PLASTIC FILM USING A GUARD FILM AND A VAPOR PRESSURE SENSOR", which is incorporated by reference herein. The procedure of the Association of the Non-Woven Fabrics Industry (INDA) provides the determination of the water vapor transmission rate (WVTR), the permeability of the film to water vapor and, for homogeneous materials, the coefficient of water vapor permeability.

The test method of the Association of The Non Woven Fabrics Industry (INDA) is well known and will not be pointed out in detail here. However, the test procedure is synthesized as follows. A dry chamber is separated from a wet chamber of known temperature and humidity by a permanent guard film and the sample material to be tested. The purpose of the guard film is to define a defined air opening and to quiet or stop the air in the air opening while the air opening is characterized. The dry chamber, the guard film, and the humid chamber make a diffusion cell in which the test film is sealed. The sample holder is known as the Permatran-W model 100K, manufactured by Mocon / Modern Controls, Inc., of Minneapolis, Minnesota. A first test is made of the water vapor transmission rate (WVTR) of the guard film and the air gap between an evaporator assembly that generates 100 percent relative humidity. The water vapor diffuses through the air opening and the guard film and is then mixed with a flow of dry gas that is proportional to the concentration of water vapor. The electrical signal is routed to a computer for processing. The computer calculates the transmission rate of the air opening and the guard film and stores the value for further use.

The transmission rate of the guard film and the air opening is stored in the computer as CalC. The sample material is then sealed in the test cell. Again, water vapor diffuses through the air opening to the guard film and the test material and is then mixed with a flow of dry gas sweeping the test material. Also, again, this mixture is taken to the vapor sensor. The computer then calculates the transmission rate of the combination of the air opening, the guard film, and the test material. This information is then used to calculate the rate of transmission in units of grams per square meter per 24 hours in which moisture is transmitted through the test material.

DETAILED DESCRIPTION Reference will now be made in detail to the embodiments of the invention, one or more examples of which are indicated below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. For example, the features illustrated or described as part of an embodiment may be used over another embodiment to produce still further incorporation. Therefore, it is intended that the present invention cover such modifications and variations, as come within the scope of the appended claims and their equivalents.

The present invention relates to a non-woven material adapted to be used as an emergence layer or a transfer layer including fibers at least a portion of which have been treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide, or a derivative of a modified polysaccharide or of a combination or mixture thereof. In an exemplary embodiment, the present invention provides a fibrous non-woven emergence layer treated for an absorbent article for personal care that has improved wettability while minimizing the use of surfactants and the chemistry of the surfactant, for example, reducing stress of the surface of the discharged liquid. Unexpectedly, the treated fibrous nonwoven emergence layer also reduces skin hydration as measured by the TransEpidermal Water Loss (TEWL) test. The use of wet chemistries is preferable in this application. A combination of water soluble polymer with a small amount of surfactant is suggested while the surface tension of an aqueous discharge is reduced by no more than 20 dynes per centimeter.

Examples of absorbent articles for personal care include, but are not limited to, diapers, training pants, incontinence garments, sanitary napkins, absorbent pads, surgical covers, bandages, etc. Absorbent personal care articles typically include a liquid-permeable body-side liner and a liquid-impermeable backing layer or cushion with an absorbent core disposed in the middle. As described in the background, a common problem with many of these products and their designs is the fact that they do not accept rapid and / or multiple discharges of body fluids or exudates such as menstrual flow and urine in a sufficient period of time short without filtration. This is particularly true as the designs of these products attempt to be thinner to present a discreet appearance. In an attempt to overcome this problem, many product designs have included something like an additional layer between the side-to-body liner and the absorbent core to act as a splashing-type bowl to temporarily absorb, hold and then discharge the particular exudate. of the body taken in the lining. An additional problem with many of these products and their designs is the fact that they have the tendency to cause the user's skin to overhydrate possibly contributing to skin health problems. The hydration of the skin may be due to excessive flow of fluid back from the absorbent core towards the wearer's skin or excess moisture in the diaper environment. The reflux of the fluid may be due to the excessive amount of surfactant which decreases the surface tension of the discharge fluid such that the fluid flows back easily, under minimal pressure, from the absorbent core to the outer layers of view to the skin of the diaper user. Less surfactant is also desired because less surfactant will minimize or eliminate any negative effects on the swelling behavior of the superabsorbent particles present in the absorbent core. For example, if a super absorbent material is used in or as the second layer of the substrate, rapid or substantially intermediate degradation will limit the amount of gel blockage that occurs because the non-degraded surfactant will allow the fluid to be absorbed into the super absorbent particles. faster than that of a fluid that does not contain surfactant. In addition, as the superabsorbent particle swells it forms a gel that tends to block the flow of fluid in and around the particle. Therefore, if the particle has swollen the capacity and the gel of the particle has been formed in such a way that the fluid does not pass in or around the particle, then the fluid will often be flooded above the area that is blocked by the particle. gel. Further still, where the gel block has occurred, the material whose fluid would otherwise enter through the gel part of the material will have to find an alternative route to that material or it will not be used. In any event, the efficiency of the absorption of the material has been reduced. Thus, desirable embodiments of the present invention minimize hydration of the skin and thus promote skin health without compromising the main fluid handling functions of a personal care product such as a diaper.

The present invention provides a fibrous non-woven emergence layer that provides effective means for temporarily storing and then distributing body exudates when incorporated into the absorbent article or personal care product. A fibrous non-woven emergence layer of the present invention includes a layer of non-woven fibers that includes fibers that have been treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide, or a derivative of a modified polysaccharide. In certain desirable embodiments, the body-facing surface of the top layer of the non-woven fibers is free of surfactant and does not include fibers that have been treated with a surfactant. Personal care articles typically include and are made of synthetic materials that are not inherently wettable, such as polyethylene, polypropylene or polyester resins. These non-wettable materials are often treated with surfactants to improve the wetting of the materials. The present invention provides a wettable treatment for inherently non-wettable materials, such as polyolefins, which eliminate, or at least reduce, the use of surfactants in personal care articles and other absorbent articles. It has been alleged that many conventional surfactants can irritate or sensitize human skin for at least a percentage of the population. Examples of such irritant or sensitive surfactants include, but are not limited to, ionic and cationic surfactants such as alkyl sulfate, ammonium alkyl salts, and the like. It may be particularly desirable to eliminate the inclusion of such surfactants in components of such articles that will contact or be close to the skin.

Generally, surfactants modify the surface or boundary between two phases and can reduce surface tension when dissolved in water or in water solutions. The surfactants have a lipophilic tail of six carbon atoms or more and a hydrophilic head. The hydrophilic head and lipophilic tail of the surfactant molecule are attracted to hydrophilic and hydrophobic species, respectively, and act to reduce surface tension at a limit of hydrophilic species and hydrophobic species, eg, urine and a non-woven substrate of polyolefin. Excessive levels of surfactants can contribute to skin health problems because the surfactants can penetrate the natural barrier provided by the stratum corneum and thus provide a pathway for irritation of viable skin cells under the stratum corneum. In addition, the surfactants can have effects of diminishing the functions of the superabsorbent material present in the absorbent core. The surfactants can also promote the reflux of the fluid under pressure and therefore can negatively impact the dryness of the skin.

The present invention provides an emergence layer that is treated with a water soluble polymer such that the surface tension of the aqueous contact fluid, eg, urine, is reduced by no more than 20 dynes per centimeter. Example of such surfaced treated material exhibits improved dryness. An example of such an emergence layer includes fibers that are treated with a polysaccharide, a modified polysaccharide, a polysaccharide derivative, or a derivative of a modified polysaccharide and a part of fibers that are not treated with a polysaccharide, a modified polysaccharide, a polysaccharide derivative, or a derivative of a modified polysaccharide. It is believed that the polysaccharide, a modified polysaccharide, a polysaccharide derivative, or a derivative of a modified polysaccharide act as a moisture and / or water trap to promote dryness as measured by an unexpected decrease in transepidermal water loss. (TEWL). Optionally a suitable crosslinking agent can be added to the formula containing the modified polysaccharide prior to application to the fibers in order to control the solubility of the polysaccharide polymer at the desired level and obtain greater control over the extent of the reduction limit in the the surface tension of the aqueous liquid or urine.

Generally, a polysaccharide is a natural polymer that has glucose as repeating units. The polysaccharide can have a plurality of hydrophobic groups and a plurality of hydrophilic groups. "The hydrophobic groups can be groups = CH- and -CH2- on the polysaccharide column.The hydrophobic groups can be adapted to provide an affinity to the polysaccharide for the hydrophobic polymer of which the porous substrate is composed and the hydrophilic groups can be adapted for Modifying the chemical and / or physical properties of the polysaccharide Examples of polysaccharides include, but are not limited to, natural gums, such as agar, agarose, carrageenan, furcellene, alginates, locust bean gum, gum arabic, guar gum, gum konjac, and karaya gum; microbial fermentation products, such as gelan gum, xanthan gum, and dextrin gum; cellulose, such as microcrystalline cellulose and high molecular weight water soluble cellulose, and high weight water soluble cellulose derivatives molecular, and animal products, such as hyaluronic acid, heparin, chitin, chitosan, etc. Examples of polysaccharide derivatives include, but are not limited to, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, etc. Natural polymers such as the polysaccharides listed above and derivatives of polysaccharides differ from surfactants because these derivatives of natural polymers do not have the molecular structural characteristics of a conventional surfactant and significantly do not reduce the surface tension of water as do conventional surfactants . further, polysaccharides have the tendency to strongly adsorb on synthetic fibers and therefore they do not readily migrate to the aqueous phase with exposure to an aqueous fluid, unlike most other surfactants. Polysaccharides also have a tendency to strongly bind water molecules and therefore act as dehydrating agents, especially in a diaper occlusive environment. The tendency to agglutinate water can also be optimized by using suitable crosslinking agents for the polysaccharide. The crosslinking agents can already be synthetic or natural based materials capable of interacting with the polysaccharide and render it cross-linked.

The polysaccharide treatment of the present invention can be or include a modified polysaccharide. A modified polysaccharide can have a plurality of hydrophobic groups and a plurality of hydrophilic groups. The hydrophobic groups can be = CH- and -CH2- groups on the polysaccharide column or pendant groups. The hydrophilic groups can also be pendant groups. The term "slope" used herein with respect to hydrophobic groups or other groups means that such groups are coupled to the column of the polymer but are not part of it. Therefore, the removal of the pending groups will not alter the chemical structure of the column. Again, the hydrophobic groups can be adapted to provide an affinity of the polysaccharide to the hydrophobic polymer from which the porous substrate is compounded and the hydrophilic groups can be adapted to yield the hydrophilic polysaccharide. By way of illustration only, examples of modified polysaccharides include, but are not limited to, modified celluloses or cellulose derivatives, such as hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose, methyl hydroxypropyl cellulose, ethyl hydroxyethyl cellulose, and carboxymethyl. cellulose; starch and pectin derivatives, such as carboxymethyl starch, aldehyde starch, and pectates; and animal product derivatives, such as carboxymethyl chitin and carboxymethyl chitosan, etc.

Particularly useful types of polysaccharides and modified polysaccharides include, by way of illustration, agar, alginates; and modified celluloses, such as ethyl hydroxyethyl cellulose (EHEC), hydroxy propyl cellulose (HPC), etc. In certain embodiments, a portion of the fibers are treated with hydroxyethyl cellulose (EHEC) or hydroxypropyl cellulose (HPC) or hydroxyethyl cellulose (EHEC) or hydroxypropyl cel.ulose (HPC) derivatives or any combination thereof. In modified polysaccharides, particularly in the useful type of modified polysaccharides noted above, the hydrophobic groups may be pendent monovalent alkyl groups. For example, such hydrophobic groups can be methyl or ethyl groups. As another example, the hydrophilic groups can be pendant monovalent hydroxyalkyl groups. Yet another example, such hydrophilic groups can be hydroxyethyl groups. Particularly suggested polysaccharides include ethyl hydroxyethyl celluloses sold by Akzo Nobel, of Stratford, Connecticut, under the brand name of. BERMOCOLL EBS E481 FQ and BERMOCOLL E230 FQ. BERMOCOLL EBS E481 FQ is a derivative of high molecular weight hydroxyethyl ethyl cellulose. A general chemical formula for BERMOCOLL cellulose derivatives is: Which has an average degree of polymerization (N) in the range from 300 to 2600 (n ranges from around 300 to around 2600). The BERMOCOLL E230 FQ has an average degree of polymerization (n) of around 300. The BERMOCOLL EBS E481 FQ has an average degree of polymerization (n) of 2600. Other ethyl hydroxyethyl cellulose derivatives produced by Akzo Nobel, include BERMOCOLL EHM 100 and BERMOCOLL EHM 200, which are both cellulose derivatives analogous to BERMOCOLL E230 FQ that have alkyl chains of more than two carbons. Other cellulose derivatives and suggested examples include, but are not limited to, hydroxypropyl cellulose available from Hercules of Wilmington, Delaware under the brand name of Klucel® HPC and is a cellulose derivative analogous to BERMOCOLL E230 FQ having alkyl chains of more than of two coals.

The fibers treated with a polysaccharide, a modified polysaccharide, a polysaccharide derivative or a modified polysaccharide derivative or a combination thereof can be treated using known fiber treatment methods. Desirably, the fibers are treated before they are incorporated into a fabric or combined with other fibers in a fabric. Suggested methods of treating the fibers with a polysaccharide, a modified polysaccharide, a polysaccharide derivative or a modified polysaccharide derivative include, but are not limited to, saturation, spraying, groove, matrix, printing, foaming, and combinations and modifications of the same.

The fibers can be treated with the polysaccharide, a modified polysaccharide, a polysaccharide derivative or a modified polysaccharide derivative or a combination thereof using any known process for treating the surface of the fibers including, but not limited to, a saturation process . In a saturation process, bundles of fiber bundles are not immersed in a bath containing the treatment solution. The fibers are impregnated with treatment solution and the excess solution can optionally be removed by pressure point between two pressure point rollers. Alternatively, the treatment solution is sprayed onto the tow tow followed by drying. The fiber tows can be treated once or several times in consecutive steps if desired. Also a combination of processes can also be used in such a way that for example, a saturation step followed by a spray of the same or a different chemical.

As previously noted, a non-woven fibrous fabric of the present invention can be used as an emergence layer or as a transfer layer disposed between the body-side liner and the absorbent core of an absorbent article, for example a diaper. An emergence layer is more typically placed between and in contact with the side-to-body lining and the absorbent core even though other additional layers may be incorporated throughout the product design if desired. For another improvement in fluid transfer, it is desirable that the emergence layer of the nonwoven fibrous tissue be coupled to the layers directly above and below its outer surfaces. To this end, suitable coupling means include, but are not limited to, adhesives (water-based, solvent-based and thermally-activated adhesives), thermal bonding, ultrasonic bonding, stitching and pin drilling as well as combinations of the above or other appropriate coupling means. A transfer layer is also more typically placed between and in contact with the absorbent core of an absorbent article and transfers the fluid between the two layers, but typically has lower capacity or emergence volume as compared to the emergence material. A transfer layer is configured to increase the rate of liquid adsorption by the article and reduce the backflow of absorbed liquid "against the user's skin." Transfer layers are described in detail in the United States of America patent number 5,192,606 which is incorporated herein by reference herein.

The following description will be made in the context of a disposable diaper article that is adapted for use by children around the lower torso. It is readily apparent, however, that the absorbent article of the present invention may also be suitable for use as other types of absorbent articles, for example: underpants, absorbent underwear, products and devices for incontinence, hygiene products female, absorbent pads, mortuary products, veterinary products, wound dressings and bandages, hygiene products, etc.

Examples of suitable constructions of absorbent articles for use in the present invention are described below and representatively illustrated in Figures 1 and 2. Figure 1 is a representative plan view of an integral absorbent article of garment, such as a disposable diaper 10 , of the present invention in its uncompacted, flat state (for example, with all the folding and contraction inducing elastics removed). Parts of the structure are partially cut to more clearly show the interior construction of the diaper 10, and the surface of the diaper that contacts the wearer facing the observer. Figure 2 representatively shows a sectional view of the absorbent article of Figure 1 taken along line 2-2. With reference to figures 1 and 2, the disposable diaper 10 generally defines a front waist section 12, a rear waist section 14, and an intermediate section 16 interconnecting the front and rear waist sections. The front and rear waist sections include the general parts of the article that are constructed to extend substantially over the user's front and back abdominal regions, respectively, during use. The middle section of the article includes the general part of the article that is constructed to extend through the user's crotch region between the legs.

The absorbent article may include a vapor permeable lower sheet 20, a liquid permeable upper sheet 22 placed in facing relation with the lower sheet 20, and an absorbent body 24, such as an absorbent pad, which is located between the lower sheet 20 and the upper sheet 22. The lower sheet 20, also referred to as an outer cover, defines a length and width which, in the illustrated embodiment, matches the length and width of the diaper 1Q. The absorbent body 24 generally defines a length and a width that are less than the length and width of the lower sheet 20, respectively. Thus, the marginal portions of the diaper 10, such as the marginal sections of the lower sheet 20, can extend past the end edges of the absorbent body 24. In the illustrated embodiments, for example, the lower sheet 20 extends outwardly further. beyond the terminal marginal edges of the absorbent body 24 to form the side margins and end margins of the diaper 10. The topsheet 22 is generally coextensive with the bottom sheet 20 but may optionally cover an area that is greater or less than the area of the lower sheet 20, as desired. The lower sheet 20 and the upper sheet 22 are intended to face the garment and the wearer's body, respectively, while in use. The permeability of the lower sheet is configured to highlight the ability of the absorbent article to breathe to reduce the hydration of the user's skin during use without allowing excessive condensation of vapor, such as urine, on the surface of the garment view. of the lower sheet 20 which can undesirably wet the user's clothes.

To provide an improved fit and to help reduce leakage of diaper body exudates 10, the diaper side margins and end margins can be elastified with suitable elastic members, such as single or multiple elastic yarns as is known. The elastic threads may be composed of natural or synthetic rubber and may optionally be heated to shrink or heat-stretch. For example, as representatively illustrated in Figures 1 and 2, the diaper 10 may include a matched pair of leg elastics 26 that are constructed to operably fold and purse the side margins of the diaper 10 to provide elastified leg bands that can closely Adjust around the user's legs to reduce filtration and provide improved comfort and appearance. Similarly, the waist elastics 28 can be used to elasticize the end margins of the diaper 10 to provide elasticized waists. The front and rear waist elastics are configured to operably fold and purse the waist sections to provide a close, flexible, comfortable fit around the wearer's waist. In the illustrated embodiments, the elastic members are illustrated in their unstressed condition, stretched for clarity purposes.

The fastening means, such as hook and loop fasteners 30, are employed to secure the diaper to a wearer. Alternatively, other fastening means, such as buttons, bolts, snap snaps, adhesive tape fasteners, cohesives, mushroom and curl fasteners, or the like, may be employed. The diaper 10 may further include other layers between the absorbent body 24 and the topsheet 22 or the bottom sheet 20. For example, as representatively illustrated in Figures 1 and 2, the diaper 10 may include a ventilation or spacing layer 32 located between the absorbent body 24 and the lower sheet 20 for insulating the lower sheet 20 of the absorbent body 24 to improve air circulation and effectively reduce the moisture of the surface facing the garment of the lower sheet 20. The ventilation layer 32 can also assist in distributing fluid exudates to absorbent body parts 24 that do not directly receive the discharge. The diaper 10 may also include an emergence delivery layer 34 located between the topsheet 22 and the absorbent body 24 to prevent puddling of the fluid exudates and further improve air exchange and distribution of the fluid exudates within the diaper 10. .

The diaper 10 can be in various suitable shapes. For example, the diaper may have a total rectangular shape, a T-shape or a shape of about an hourglass. In the embodiment shown, the diaper 10 has a generally I-shape. The diaper 10 further defines a longitudinal direction 36 and a lateral direction 38. Other suitable diaper components that may be incorporated within the absorbent articles of the present invention include fins. of containment, waist flaps, elastomeric side panels, and the like, which are generally known to those skilled in the art. Examples of diaper configurations suitable for use in connection with immediate application which may include other diaper components suitable for use in diapers are described in U.S. Patent No. 4,798,603, issued January 17, 1989 to Meyer and others; U.S. Patent No. 5,176,668, issued January 5, 1993 to Bernardin; U.S. Patent No. 5,176,672, issued January 5, 1993 to Bruemmer et al .; U.S. Patent No. 5,192,606, issued March 9, 1993 to Proxmire et al .; and U.S. Patent No. 5,509,915, issued April 23, 1996 to Hanson et al., the descriptions of which are hereby incorporated by reference in their entirety.

The various components of the diaper 10 can be integrally assembled together using various types of suitable coupling means, such as adhesive, sonic bonds, thermal bonding, or combinations thereof. In the embodiment shown, for example, the upper sheet 22 and the lower sheet 20 are assembled together and the absorbent body 24 with lines or. swirls of adhesive, such as a hot-melt, pressure-sensitive adhesive. Similarly, other components of the diaper, such as the elastic members 26 and 28, the fastening members 30, and the ventilation and emergence layers 32 and 34 can be assembled in the diaper article by the use of the coupling mechanisms previously identified.

The lower sheet 20 of the diaper 10, as representatively illustrated in Figures 1 and 2, is typically composed of a substantially vapor permeable material. The lower sheet 20 can be operably constructed to be permeable to at least water vapor and can have a water vapor transmission rate of at least about 800 grams per square meter per 24 hours, desirably at least about 1500 grams per square meter per. 24 hours, more desirably at least about 3000 grams per square meter per 24 hours, and even more desirably at least about 6000 grams per square meter per 24 hours. For example, the lower sheet 20 can define a water vapor transmission rate from about 800 to about 15,000 grams per square meter per 24 hours. Materials that have a water vapor transmission rate of less than those above usually. they do not allow a sufficient amount of air exchange and may undesirably result in increased levels of skin hydration if no other means of reducing moisture within the diaper is available. The lower sheet 20 is also desirably substantially impervious to liquid to minimize bumping through liquids, such as urine, during use.

The lower sheet 20 can be composed of any suitable materials that either directly provide liquid impermeability and air permeability with the above desired levels or, in an alternative, materials that can be modified or treated in some way to provide such levels. The lower sheet 20 can be a fibrous nonwoven fabric constructed to provide liquid impermeability, for example, a nonwoven fabric composed of polymer fibers spunbonded or meltblown can be selectively treated with a water repellent coating or laminated with a vapor permeable polymer film, impervious to liquid to provide the bottom sheet 20. Particularly, bottom sheet 20 may comprise a non-woven fabric composed of a plurality of randomly deposited hydrophobic thermoplastic meltblown fibers that are sufficiently bonded or otherwise connected to each other to provide a substantially liquid impermeable and substantially permeable fabric steamed. The lower sheet 20 may also comprise a vapor permeable nonwoven layer that has been partially coated or otherwise configured to provide liquid impermeability in selected areas.

Examples of suitable materials for the lower sheet 20 are also disclosed in U.S. Patent No. 5,482,765, issued January 9, 1996, in the name of Bradley et al., And entitled "Non Woven Fabric Laminated With Improved Properties of Barrier"; U.S. Patent No. 5,879,341 issued March 9, 1999 in the name of Odorzynski and entitled "Absorbent Article Having a Gradient Capable of Breathing"; U.S. Patent No. 5,843,056 issued December 1, 1998 in the name of Good et al. and entitled "Absorbing Article Having a Bottom Sheet Capable of Compound Breathing"; and U.S. Patent No. 6,309,736 issued October 30, 2001, in the name of McCormack et al., and entitled "Low Caliber Films and Film / Non-Woven Laminates", the descriptions of which are incorporated herein. by reference in its entirety.

In a particular embodiment of a diaper, the lower sheet 20 is provided by a laminate highly capable of breathing and more particularly by a microporous film / nonwoven laminate, comprising a material bonded with nonwoven yarn laminated to a microporous film. The spunbond nonwoven comprises filaments of about 1.8 denier extruded polypropylene and which defines a basis weight from about 17 to about 25 grams per square meter. The film comprises a co-extruded molded film having a linear low polyethylene microporous core filled with calcium carbonate and ethylene vinyl acetate and a Catalloy ™ polypropylene (Catalloy ™ 357P), available from Basell (having offices in Wilmington, Delaware), mixed in the skin layer that has a basis weight of about 58 grams per square meter before stretching. The film is previously heated, stretched and tempered to form the micropores and then laminated to a spunbonded fabric. The resulting nonwoven laminate / microporous film base material has a basis weight from about 30 to about 60 grams per square meter and a water vapor transmission rate from about 800 to about 15,000 grams per square meter per 24 hours. Examples of such film / non-woven laminate materials are described in greater detail in U.S. Patent No. 6,309,736 issued October 30, 2001, in the name of McCormack et al., And entitled "Low-Caliber Film and Film / Non-Woven Laminates ", the description of which was incorporated by reference above.

The topsheet 22, as representatively illustrated in Figures 1 and 2, suitably presents a body-side surface that is docile, soft to the touch, and non-irritating to the user's skin. In addition, the topsheet 22 may be less hydrophilic than the absorbent body 22, to present a relatively dry surface to the wearer, and may be sufficiently porous to be permeable to the liquid, allowing the liquid to readily penetrate through its thickness. A suitable top sheet 22 can be made from a wide selection of fabric materials, such as porous foams, cross-linked foams, perforated plastic films, natural fibers (e.g., • wood or cotton fibers), synthetic fibers (e.g. polyester or polypropylene fibers), or a combination of natural and synthetic fibers. The topsheet 22 is suitably employed to help isolate the user's skin from liquids held in the absorbent body 24.

Various woven and non-woven fabrics can be used for the topsheet 22. For example, the topsheet can be composed of a meltblown fabric or bonded with polyolefin fiber yarn. The top sheet can also be a carded and bonded fabric composed of natural and / or synthetic fibers. The topsheet may be composed of a substantially hydrophobic material, and the hydrophobic material, optionally, treated with a surfactant or otherwise processed to impart a desired level of wettability and hydrophilicity. In a particular embodiment of the present invention, the topsheet 22 comprises a non-woven fabric bonded with polypropylene composed from about 2. 2 to about 2.8 denier fiber formed into a fabric having a basis weight of about 17 grams per square meter and a density of about 0.11 grams per cubic centimeter. Such top sheet 22 can be treated on the surface with an effective amount of a surfactant such as about 0.3 weight percent of a commercially available surfactant from Uniqema, under the trademark designation of AHCOVEL BASE N-62. In a suggested embodiment, the top sheet is treated on a surface, the surface facing the emergence layer and inside of the diaper, with a 3: 1 mixture of AHCOVEL BASE N-62 surfactant and GLUCOPON 220 UP surfactant in such a way that no or a minimum amount of surfactant is on the surface that contacts the body of the top sheet. Details of a material treated on one side and of a single-sided foam treatment method are described in commonly assigned United States Patent Application Serial No. 10 / 743,893 entitled "Porous Substrate which It has a treated side to a Higher Concentration and Methods of Treating Porous Substrates ", presented by express mail procedure EL 439721061 US and which is incorporated here by reference to it. The top sheet may be untreated. Desirably, the sheet - top is a 0.5 oz nonwoven fabric per square yard of 2.7 denier polypropylene fibers treated on one side with a high viscosity foam consisting of about 18 percent by weight of AHCOVEL BASE N-62 surfactant and surfactant GLUCOPON 220 UP at a ratio of 3 to 1 in water. A foam can be generated from the surfactant solution at 3: 1 of AHCOVEL BASE N-62 / GLUCOPON 220 UP by mixing the surfactant and the high-speed water solution until a uniform, small-cell foam is produced from the components of the solution.

In another desirable embodiment, the topsheet 22 is treated with a non-surfactant chemistry that does not depress water by at least about 20 dynes per centimeter at a concentration of 0.01 molar and with a minimal amount of surfactants or surfactant chemistry. Accordingly, in one embodiment, no surfactant is added to or incorporated into the topsheet of the present invention. However, in an alternative embodiment, the liner or upper sheet 22 of the diaper 10 can also be treated with a surfactant to promote the wettability of the liner, thereby promoting the transmission of moisture away from the user's skin surface and improved conditions. of skin health. Additionally, one or more skin health agents may be included in the diaper, for example, on top sheet 22 or emergence delivery material 34. Skin health agents include any compound, composition, or formula that is or includes a compound that is or can be used to protect, repair, moisten or otherwise provide relief to damaged or undamaged skin. Such skin health agents include but are not limited to polydimethyl siloxane compounds, alkyl silicones, phenyl silicones, amino functional silicones, silicon gums, silicon resins, silicon elastomers, dimethicones, dimethicone copolyols, and lipids and derivatives of the same and botanical extracts, emollients, clay particles, talc particles, boron nitride particles, corn starch, zeolites, zinc oxide, glycerin, and related polyols, hyaluronic acid, chitosan and chemically modified sulphated chitosan.

As noted above, in an alternative embodiment incorporating a surfactant, the upper sheet fabric 22 can be surface treated with about 0.3 percent by weight of a surfactant mixture containing a surfactant mixture of AHCOVEL BASE N -62 and GLUCOPON 220 UP in a ratio of 3: 1 based on a total weight of the surfactant mixture. Other possible cases of surfactants include the surfactant MASIL SF 19 and DC 193. The AHCOVEL BASE N-62 is acquired from Uniqema (a division and ICI, which has offices in New Castle, Delaware), and includes a mixture of hydrogenated ethoxylated castor oil and sorbitan monooleate. GLUCOPON 220 UP is purchased from Cognis Corporation, and includes an alkyl polyglycoside. MASIL SF 19 surfactant and DC 193 are purchased from BASF of Mount Olive, New Jersey, and Dow Corning, of Midland, Michigan, respectively. The surfactant MASIL SF 19 and DC 193 are examples of typical ethoxylated polyalkyl siloxanes. The surfactant can be applied by any conventional means, such as saturation, spraying, printing, roller transfer, slot coating, brush coating, internal melt addition, or the like. The surfactant may be applied to the entire topsheet 22 or may be selectively applied to particular sections of the topsheet 22, such as the midsection along the longitudinal center line of the diaper, to provide for greater wettability of such sections.

The absorbent body 24 of the diaper 10, as representatively illustrated in Figures 1 and 2, may suitably comprise a matrix of hydrophilic fibers, such as a cellulose fluff fabric mixed with particles of a high-absorbency material commonly known as a material. super absorbent. In a particular embodiment, the absorbent body 24 comprises a cellulose fluff matrix, such as wood pulp fluff, and super absorbent hydrogel formation particles. The wood pulp fluff can be interchanged with synthetic, polymeric, melt blown or a combination of meltblown and natural fiber fibers. The super absorbent particles can be substantially homogeneously mixed with the hydrophilic fibers or they can be mixed non-uniformly. Alternatively, the absorbent body 24 may comprise a laminate of fibrous fabrics and super absorbent material or other suitable means of maintaining a super absorbent material in a localized area.

The absorbent body 24 can have any number of shapes. For example, the absorbent core may be rectangular, I-shaped, or T-shaped. It is generally desired that the absorbent body 24 be narrower in the middle section than in the front or back waist sections of the diaper 10. Absorbent body 24 may be provided by a single layer or, alternatively, may be provided by multiple layers, all of which do not need to extend the full length and width of absorbent body 24. In the illustrated embodiment, absorbent body 24 is generally in the form of T with the laterally extended transverse bar of the T generally corresponding to the front waist section 12 of the absorbent article for improved performance, especially for children. In the typical illustrated embodiments of a diaper that will fit a baby weighing from about 22 to 37 pounds, for example, the absorbent body 24 through the front waist section 12 of the article has a width in the transverse direction of about 16 centimeters, the narrowest part of the intermediate section 16 has a width of about 9 centimeters and in the rear waist section 14 it has a width of about 11 centimeters.

The size and absorbent capacity of the absorbent body 24 must be compatible with the intended user's size and the liquid load imparted by the intended use of the absorbent article. In addition, the size and absorbent capacity of the absorbent body 24 can be varied to accommodate users in the range from infants to adults. Furthermore, it has been found that with the present invention, the densities and / or base weights of the absorbent body 24 can be varied. In a particular aspect of the invention, the absorbent body 24 has an absorbent capacity of at least about 300 grams of physiological saline. Suggested absorbent bodies include a combination of hydrophilic fibers and high-absorbency particles, hydrophilic fibers and high-absorbency particles can form a basis weight in the main discharge area of the product for the absorbent body 24 which is within the range of around from 600 to around 1300 grams per square meter. Suggested basis weights of the fiber / particle composite in the main discharge area of the product of such absorbent body 24 are within the range of about 600 to about 1200 grams per square meter, and desirably are within the range of about 800 to about of 1150 grams per square meter to provide the desired performance.

In order to provide the desired dimension of thinness to the various configurations of the absorbent article of the invention, the absorbent body 24 can be configured with a volume of thickness that is not more than about 0.8 centimeters. Desirably, the volume thickness is no more than about 0.6 centimeters, and more desirably is no more than about 0.5 centimeters to provide improved benefits. The volume thickness is determined under a restricted pressure of 0.2 pounds per square inch (psi) (1.38 kilopascals). The high-absorbency or super-absorbent material can be selected from polymers and natural, synthetic, and modified natural materials. The high-absorbency materials may be inorganic materials, such as silicon gels, or organic compounds, such as crosslinked polymers. Examples of high-absorbency, synthetic, polymeric materials include, but are not limited to, alkali metal and ammonium salts of poly (acrylic acid) and de-poly (methacrylic acid), poly (archylamides), poly (vinyl ether) , maleic anhydride copolymers with vinyl ether and alpha olefins, poly (vinyl pyrrolidone), poly (vinyl morpholinone), poly (vinyl alcohol), and mixtures and copolymers thereof. Other polymers suitable for use in the absorbent core include natural and modified natural polymers, such as hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, methylcellulose, carboxymethyl cellulose, hydroxypropyl cellulose, and natural gums, such as alginates, xanthan gum, gum of carob, and the like. Blends of natural and fully or partially synthetic absorbent polymers may also be useful in the present invention.

The high absorbency material can be in any of a wide variety of physical forms. As a general rule, it is desired that the high-absorbency material be in the form of discrete particles. However, the high absorbency material may also be in the form of fibers, flakes, rods, spheres, needles, or the like. In general, high-absorbency material is present in the absorbent body in an amount from about 5 to about 90 percent by weight, desirably in an amount of at least about 30 percent by weight, and even more desirably in an amount of at least about 40 percent by weight based on the total weight of the absorbent body 24. For example, the absorbent body 24 may comprise a laminate that includes at least in part, and desirably at least about 40 per cent. percent by weight and more desirably of at least about 70 percent by weight of high-absorbency material overcoated by a fibrous fabric or other suitable means of maintaining the high-absorbency material in a localized area. An example of the high-absorbency material suitable for use in the present invention is a HYSORB® 8800 polymer available from BASF of Mount Olive, New Jersey. Other suitable super absorbers may include, but are not limited to, DRYTECH® 2035M, available from Dow Chemical Co., located in Midland, Michigan, or from FAVOR SXM 9543 polymer, obtained from Stockhausen, a business with offices in Greensboro, NC. North.

Optionally, a tissue or synthetic nonwoven wrapping sheet (not illustrated) can be used to help maintain the integrity of the structure of the absorbent body 24. The tissue wrapping sheet or barrier layer is typically placed around or over the body absorbent and may be composed of a cellulose absorbent material, such as a creped filler or a high wet strength tissue. In an aspect of the invention, the barrier layer or tissue wrap can be configured to provide a transmission layer that helps to rapidly distribute the liquid over the mass of absorbent fibers comprising the absorbent body.

In addition, the absorbent body 24 may additionally include a plurality of high air permeability zones (not shown) that allow air and vapors to readily pass through the absorbent body 24 and through the vapor permeable bottom sheet 20 outside the body. diaper 10 to the ambient air. A more detailed description and explanation of unit component examples can be found in U.S. Patent No. 6,152,906, issued November 28, 2000 to Faulks et al .; U.S. Patent No. 6,238,379, issued May 28, 2001 to Keuhn et al .; and U.S. Patent No. 6,287,286, issued September 11, 2001 to Akin et al., the descriptions of which are incorporated by reference in their entirety.

As in conventional absorbent articles, due to the thinness of the absorbent body 24 and the presence of high-absorbency material within the absorbent body 24, the liquid intake rates of the absorbent body 24, by themselves, may be very low, or may not be adequately supported on multiple discharges of liquid in the absorbent body 24. To improve the total liquid intake and air exchange, a diaper of the present invention may include the aforementioned additional porous layer, permeable to the liquid of emergence administration 34, as representatively illustrated in Figures 1 and 2. The emergence delivery layer 34 is typically less hydrophilic than the absorbent body 24, and has an operable level of density and basis weight for quickly collecting and temporarily sustaining liquid discharges, to transport the liquid from its initial point of entry and to substantially Completely releasing the liquid to other parts of the absorbent body 24. This configuration can help to prevent the liquid from pooling and collecting on the part of the absorbent garment placed against the wearer's skin, thereby reducing the user's sensation of moisture. . The structure of the emergence administration layer 34 also generally improves the exchange of air within the diaper 10.

Various woven and non-woven fabrics can be used to construct the emergence administration layer 34. For example, the emergence administration layer 34 can be a bonded and carded fabric or an air-laid fabric composed of natural and synthetic fibers. The carded and bonded fabric can, for example, be a thermally bonded fabric that is bonded using low melt binder fibers. Powder or adhesive The fabrics may optionally include a mixture of different fibers. Alternatively, the emergence administration layer 34 may be a composite layer of a meltblown or spunbonded fabric of synthetic fibers, such as polyolefin fibers. The emergence administration layer 34 may be comprised of a substantially hydrophobic material, and the hydrophobic material may optionally be treated with a surfactant or otherwise processed to impart a desired level of wettability and hydrophilicity. In certain embodiments, the emergence administration layer 34 includes a non-woven, hydrophobic material having a basis weight from about 20 to about 150 grams per square meter which is treated to reduce the hydrophobicity of the non-woven material.

For example, in a particular embodiment, the emergence administration layer 34 may comprise a carded and bonded fabric, a nonwoven fabric that includes bicomponent fibers and which defines a total basis weight of about 76 grams per square meter. The emergence administration layer 34 in such a configuration can be a homogeneous mixture composed of about 60 percent by weight polyethylene / polyester sheath-core bicomponent fibers.

(PE / PET) or polyethylene / polypropylene (PE / PP) that have a fiber denier from about 1 denier to about 3 denier and about 40 percent by weight of single-component polyester fibers that have a fiber denier of around 6 denier and having fiber lengths from about 3.8 to about 5.1 centimeters. Examples of such bicomponent basic fibers include 1.5 denier fibers T-258 from KoSa Fibers, Salisbury, North Carolina, and 1.7 denier fibers T-215A from Fibervisions of Athens, Georgia. The bicomponent fibers are desirably coated with a coating that includes from about 0.05 to about 0.25 percent by weight added of BERMOCOL E230FQ or DE BERMOCOL EBS 481 FQ, about 0.10 percent by weight of an antistatic agent and about 0.1 percent by weight of a lubricant such as a combination of sorbitan monooleate and ethoxylated hydrogenated castor oil. Examples of such polyester fibers include 6. 0 denier T-295 fibers from KoSa Fibers. The polyester fibers are desirably coated with a combination of fatty ester including sorbitan monooleate; ethoxylated hydrogenated castor oil and polyethylene glycol-400 monolaurate.

In the illustrated embodiments, the emergence administration layer 34 is desirably arranged in a direct manner, in contact with liquid communication with the absorbent body 24. The emergence delivery layer 34 can be operably connected to the topsheet 22 with a pattern conventional adhesive, such as an adhesive swirl pattern. In addition, the emergence administration layer 34 can be operably connected to the absorbent body 24 with any other adhesive pattern. The amount of adhesive added must be sufficient to provide the desired binding levels, but it must be sufficiently low to avoid excessively restricting the movement of the liquid from the topsheet 22, through the emergence delivery layer 34 and into the absorbent body. 24 The absorbent body 24 is desirably placed in liquid communication with the emergence delivery layer 34 to receive the liquids released from the emergence delivery layer, and to hold and store the liquid. The emergence administration layer 34 serves to promptly collect and temporarily hold the discharged liquids, to transport such liquids from the initial point of contact and distribute the liquid to other parts of the emergence administration layer 34, and then substantially completely release such liquids. in the layer or layers comprising the absorbent body 24.

The emergence administration layer 34 can be of any desired shape. Suitable shapes include, for example, circular, rectangular, triangular, trapezoidal, oblong, bone-shaped, hourglass-shaped, or oval. In certain embodiments, for example, the emergence administration layer may be generally rectangular in shape. In the illustrated embodiments, the emergence delivery layer 34 exceeds a portion of the absorbent body 24 and is centered around the longitudinal centerline 36 of the absorbent body 24. The emergence delivery layer 34 is placed towards the front waist section 12 of the diaper 10 and extends beyond the intermediate section 16 of the diaper 10. Alternatively, the emergence administration layer 34 may be selectively placed on either side along the absorbent body 24 or may be coextensive with the absorbent body 24. .

Additional suitable materials for the emergence administration layer 34 are set forth in U.S. Patent No. 5,486,166, issued January 23, 1996 to Ellis et al., And entitled "Non-Woven Fiber Weave Emergence Layer Absorbent Articles for Personal Care and the like "; U.S. Patent No. 5,490,846, issued February 13, 1996, in the name of Ellis et al., and entitled "Improved Woven Fabric of Nonwoven Fibrous Emergence for Absorbent Personal Care and Similar Items"; and U.S. Patent No. 5,364,382, issued November 15, 1994, in the name of Latimer et al., and entitled "Absorbent Structure Having Improved Fluid Emergence Management and the Product Incorporating Same," the descriptions of which are here incorporated by reference in their entirety. These additional exemplary materials may include fibers, all or a portion of which, have been treated with a treatment composition that includes a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide, or a derivative of a modified polysaccharide, wherein the Treatment composition over the emergence layer reduces the surface tension of an aqueous fluid for less than about 20 dynes per centimeter as measured by test method D-1590-60 from the American Society for Testing and Materials (ASTM) .

The non-woven materials of the present invention that are suggested for use as an emergence material include, but are not limited to, carded and knitted fabrics that have a basis weight that is in the range from about 20 to about 150 grams per square meter. An exemplary carded and bonded fabric of the present invention includes, but is not limited to, a carded and air-bonded fabric of a single layer of a homogeneous mixture of: (1) 60 percent by weight of a bicomponent fiber of 1.5 denier including a polyethylene sheath and a surface-treated polypropylene core with 0.10 percent by weight of hydroxyethyl cellulose ethyl BERMOCOLL E "# = FQ solution and (2) 40 percent by weight of basic polyester fibers of 6 untreated denier Both fibers can be obtained from KoSa of Salisbury, North Carolina Other suggested fabric materials of the present invention include blends of: (1) 60 weight percent ESC 233A HR6 3.0 denier bicomponent fiber including a sheath polypropylene core and polypropylene core, commercially available from ES Fibervisions, of Athens, Georgia, or 3.0 denier bicomponent fiber Type 256 including polyethylene sheath and polyester core, commercially available available from KoSa, Salisbury, North Carolina, both of which are surface treated with a polysaccharide, a modified polysaccharide, a polysaccharide derivative, a derivative of a modified polysaccharide; and (2) 40 percent by weight of a basic 6-denier polyester fiber Type 295-6, commercially available from KoSa. Another suitable emergence material has a basis weight of from about 20 to about 150 grams per square meter, and comprises a carded and bonded fabric through homogenous mixture air of: (1) 60 percent by weight of bicomponent fiber of 1.5 denier ESC 215A HR6, including a polyethylene sheath and polypropylene core, commercially available from ES Fibervision or 2.0 denier bi-component fiber Type 256, including a polyethylene sheath and polyester core, commercially available from KoSa, both of which are surface treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide, or a derivative of a modified polysaccharide; and (2) 40 percent by weight of a basic 3.0 denier polyester fiber, commercially available from KoSa. The treated fibers and the untreated fibers may be of the same type and composition or may differ in composition or in another parameter such as denier or length. The treatment may also include processing aids such as lubricating or antistatic agents to facilitate the carding process.

Suggested fibers include most synthetic basic fibers that are typically used to make fibrous fabrics into disposable personal care articles, including but not limited to, most synthetic base fibers, thermoplastic fibers, polyolefin fibers, natural fibers etc. The cross sections of the fiber can be either circular or non-circular, including, for example, bilobal, trilobal, and X-shaped cross sections. The fibers can be solid or hollow. In addition, they may be made of a single-fiber polymer, or of multiple polymers such as are commonly found in bicomponent and bicomponent or multi-component fibers. When bicomponent fibers are used, the cross sections of the fiber may include, for example, sheath and core cross sections, side by side, and islands in the sea. The resulting non-woven fibrous fabric will be a homogeneous uniformly blended uniform layer blend of any type of chosen fiber or fibers. In addition, a part of all the fibers can be curled. The ripple can be imparted both mechanically and chemically thus forming zig-zag or sawtooth curled fibers, and helical curls or spirals.

The processes used to form the nonwoven fibrous tissue include those that will result in a material that, as described below, has a defined range of physical properties. Suitable processes may include, but are not limited to, the formation of air-laid tissue, joined with spinning, carded and bonded and coformming processes. The non-woven spunbonded fabrics are made of fibers that are extruded from a molten thermoplastic material as filaments through a plurality of fine spinner capillaries having a circular or other shape, with the diameter of the extruded filaments being rapidly reduced as, for example, by extrudate from eductive and non-eductive fluid, and by other well known spin-bonding mechanisms. The production of non-woven spunbonded fabrics is illustrated in U.S. Patent Nos. 4,340,563 issued to Appel et al., And U.S. Patent No. 3,692,618 issued to Dorschner et al. United States of America numbers 3,338,992 and 3,341,394 granted to Kinney, the United States of America patent number 3,276,944 granted to Levy; U.S. Patent No. 3,502,538 issued to Peterson; U.S. Patent No. 3,502,763 issued to Hartman, U.S. Patent 3,542,615 issued to Dobo et al .; Canadian Patent No. 803,714 issued to Harmon, all of which are hereby incorporated by reference in their entirety.

Carded and knitted fabrics are made of basic fibers that are usually purchased in bales. The basic fibers are taken from one or more of these bales and sent through open and mixing equipment and then through one or more carding units, where the basic fibers are also separated and partially aligned in the machine direction . The resultant carding fabric can be combined with one or more additional cardinal fabrics or it can be placed in a folded pattern and supplied through one or more additional cardings to form a single direction fabric. Once the tissue is formed, it is then joined by one or more of various joining methods. One such joining method is the powder binding, wherein an adhesive powder is distributed through the fabric and then activated, usually by heating the fabric and the adhesive with hot air. Another suitable bonding method is pattern bonding, where heated calendering rolls or ultrasonic bonding equipment are used to join the fibers together, usually in a localized bonding pattern., even when the fabric can be joined through its total surface if desired. Another suitable and well known joining method, particularly when using basic bicomponent fibers, is the bonding through air. One of the advantages of the union through air is the ability to control the level of compression or collapse of the structure during the formation process. In the union through air, heated air is forced through the fabric to melt and join the fibers together at their crossing points. Typically the unbonded fabric is supported on a forming wire or drum. In addition a vacuum can be pulled through the tissue if it is desired to further contain the fibrous tissue during the bonding process.

Air placement is another well-known process by which fibrous non-woven fabrics according to the present invention can be made. In the air-laying process, bales of small fibers usually have lengths in the range of between about 6 and about 19 millimeters are separated and entrained in an air supply and then deposited on a formation grid, sometimes with the assistance of a vacuum supply. The randomly deposited fibers are then bonded together using, for example, a sprayed or hot air adhesive. A part of the fibers that make up the fabric can be made of polymers that are capable of bonding by heat. The ability to bind by heat means that the randomly deposited fibers that make up the non-woven fabric can be subjected to heat or ultrasonic energy of a sufficient degree that the fibers will adhere to each other at the cross-points of the fiber due to melting. or partial softening of the polymer that makes up the fibers capable of joining by heat. Suitable polymers for forming such fibers capable of being bonded by heat are permanently fusible and are typically referred to as being thermoplastic. Examples of suitable thermoplastic polymers include, but are not limited to, polyolefins, polyesters, polyamides, orlon, acetates and polyvinyl alcohol, as well as homopolymers, copolymers and blends. Optionally, the wetting agents and / or surfactants can be added either internally, such as with siloxane during the fiber spinning process, or externally as a further treatment to either the fibers and / or the resulting fabric, as with surfactants of low ionic or nonionic level including ethoxylated hydrocarbons, siloxanes and fluorocarbons in such a way that the surface tension of a discharge is not reduced by more than 20 dynes per centimeter. Such wetting agents / surfactants as well as their use are well known and need not be described in detail here.

The fibers formed of the aforementioned polymers may be staple length-length fibers, such as are used in the air-laid and carding and bonded processes, or uncut, more continuous fibers as they are formed in, for example, the process of joined with yarn.

Typical lengths of staple basic fiber will be in the range of between about 38 and about 51 millimeters, even though lengths outside this range can also be used. For example, air placement typically involves using fibers with cut lengths in the range of about 6 to about 19 millimeters. The fiber diameters will be in the range of between about 1.0 and about 16 denier with the target range being between about 1.5 and about 6 denier.

To facilitate the air binding process, it has been found advantageous to use bicomponent fibers having both components of high melting points and lower melting points such as side-by-side, sheath / core, or island configurations in the sea. The lower melting point component or polymer of the bicomponent fibers provides efficient means for joining the fibers together while the higher melting point component helps in maintaining the structure rigidly and the opening of the material both in the dry and wet states . Suitable bicomponent fibers, for example, be basic fiber or the form of more continuous spinning, polyethylene / polypropylene and polyethylene / polyester fibers. The fibrous nonwoven fabric according to the present invention can be made completely from bicomponent fibers or it can be made from a mixture of bicomponent fibers and other fibers such as single component fibers including polyester, nylon, rayon, and polyolefins such as polypropylene. They can also be made exclusively from single-component fibers. Generally, the fibrous non-woven fabric according to this embodiment of the present invention will include at least 50 percent by weight of bicomponent fibers, based on the total weight of the fabric. Such bicomponent fibers will typically have an average denier equal to or greater than 1.5 denier.

In order to demonstrate the properties of the present invention, a series of materials were formed and then tested. In addition, samples of these materials were then placed inside the diaper constructions and tested for transepidermal water loss properties (TEWL) and depression of surface tension. The test procedures, materials and test results are indicated below.

EXAMPLES All of the following examples were prepared using conventional carding equipment and were subsequently bonded through air at temperatures and times sufficient to cause the lowest melting point component of the bicomponent fibers to at least partially melt and bond to each other in their criss-crossing points.

Control example The control example was a Size 4 HUGGIES Ultratrim diaper that includes an emergence layer consisting of a bonded and carded fabric having a basis weight of about 101 grams per square meter formed of a uniform blend of 60 weight percent by weight. 1.5 denier basic fibers including polyethylene sheath and polypropylene core and 40 percent by weight of 6-denier poly (ethylene terephthalate) basic fibers. Both fibers were obtained from KoSa of Salisbury, North Carolina. The poly (ethylene terephthalate) fibers were pretreated with a 9.55 weight percent solution of a mixture of hydrogenated ethoxylated castor oil and sorbitan monooleate (referred to as a L-1 finish). The treatment may also include other processing aids such as a commonly available lubricant and antistatic agents to facilitate the carding process.

Example 1 A single layer bonded and carded fabric having a basis weight of approximately 101 grams per square meter was formed from a uniform blend of 60 percent by weight of 1.5 denier bicomponent fibers previously treated with a 0.10 percent by weight solution. of BERMOCOLL EBS E481 FQ ethyl hydroxyethyl cellulose (EHEC) and 40 percent basic fibers of poly (ethylene terephthalate) at 6 denier. The bicomponent fibers consisted of 45 percent by weight of polyethylene sheath and 55 percent by weight of a polypropylene core that were previously treated with a solution of 0.55 percent by weight of a mixture of ethoxylated, hydrogenated castor oil and sorbitan monooleate. Both sets of fibers were obtained from KoSa, from Salisbury, North Carolina.

The carded and bonded fabric was then inserted between the side-to-body lining and the absorbent core of a size 4 HUGGIES Ultratrim diaper for evaluation. The materials were then tested on human subjects for TransEpidermal Water Loss using the described test procedure and using three overcoats that have the ability to breathe from the water vapor transmission rate (WVTR) as measured in units of grams per square meter per 24 hours. The first diaper and the least able to breathe includes an outer cover with a breathing capacity of the water vapor transmission rate (WVTR) of 885 grams per square meter per 24 hours. The second diaper most capable of breathing includes an outer cover with a breathing capacity of the water vapor transmission rate (WVTR) of 9055 grams per square meter per 24 hours. And, the third and most breathable diaper includes an outer shell with a breathing capacity of the water vapor transmission rate (WVTR) of 14,460 grams per square meter per 24 hours. Twenty test subjects participated in the bracelet study on the transepidermal water loss arm (TEWL). The diapers were applied to the arm and three discharges of 70 milliliters of saline at a rate of 300 milliliters per minute were applied every 45 seconds. The test subjects used the bracelets for 60 minutes and the baseline and final loss of transepidermal water loss (TEWL) readings were completed using the Dermalab Evaporimeter. The averages of the test results are given in Table 1 below.

Table 1 Value of Skin Hydration as Measured by Trans-Epidermal Water Loss (TEWL) of Diaper Constructions Against Control Examples Diapers that include an emergence layer in which the fibers have been treated with BERMOCOLL EBS E481 FA ethyl hydroxyethyl cellulose (EHEC) showed significantly decreased skin hydration as measured by improved transepidermal water loss (TEWL) ) against diapers that include conventionally treated emergence layers. The amount of liquid that evaporates from the skin decreases by 4 grams per square meter per hour in the diaper example of low capacity to breathe and decreases by 7 • * grams per square meter per hour in the diaper example with high capacity of breathe.

Diapers that include an emergence layer containing the EHEC-treated fibers, showed improved skin dryness as exhibited by the consistent reduction in transepidermal water loss (TEWL), compared to diapers that contain a similar emergence layer. carded and united that was treated with a conventional surfactant system.

Example 2 Additionally, another example was prepared which includes a single layer bonded and carded fabric having a basis weight of about 76 grams per square meter formed of a uniform blend of 60 percent by weight of bicomponent fibers at 1.5 denier with an 0.10 percent by weight of BERMOCOLL EBS E481 FQ ethyl hydroxyethyl cellulose (EHEC) and 40 percent by weight of 6-denier poly (ethylene terephthalate) basic fibers previously treated with a 0.55 percent by weight solution of an oil blend of hydrogenated ethoxylated castor and sorbitan monooleate. The bicomponent fibers consist of 45 percent by weight of a polyethylene sheath and 55 percent by weight of a polypropylene core. Both fibers were obtained from KoSa, from Salisbury, North Carolina.

Using a size 4 HUGGIES Ultratrim diaper with an outer water vapor transmission rate (WVTR) cover of approximately 1500 grams per square meter per 24 hours, the bonded and carded fabric was inserted between the absorbent body and an upper sheet that has a surfactant treatment on only one side that faces the emergence management layer. To produce the one-sided top sheet, a surface treatment solution capable of foaming was prepared. The treatment solution consists of about 18 percent by weight aqueous solution of a 3: 1 mixture of surfactant AHCOVEL Base N-62 obtained from Uniqema, a division of ICI having offices in New Castle, Delaware, and surfactant GLUCOPON 220 UP available from Cognis Corporation, of Ambler, Pennsylvania. The solution was subjected to high-cut mixing using the GASTON Systems CFS equipment from Gaston Systems, Inc., of Stanley, North Carolina, with a built-in mixer set at 600 revolutions per minute for about 30 minutes to generate a foam of small and uniform cell size of the components of the solution. The foam was then immediately smeared via a parabolic applicator having a 1/8 inch slot opening on one side of a sample of spinning lining material. The added level of the treatment composition can be controlled by varying the concentration of the bath, the flow rate of the treatment composition through the applicator on the material to be treated and / or the on-line speed of the material to be treated, among other variables. . The added level was around 0.25 percent by weight.

The liner was subsequently dried in a hot air dryer by directing the heated air to both surfaces of the liner but by directing more air towards the surface of the liner that was not treated such that the flow of heated air was greater on the non-treated side. treat the liner, therefore, minimizing rinsing through the treatment composition to the untreated side of the liner. The base material for the top sheet was a 0.5 oz. Per square yard spunbonded liner made from Exxon PP 3155 polypropylene resin obtainable from Kimberly-Clark Corporation.

In an additional code, only the side-to-body lining was replaced with the one-sided treated liner. These material combinations and the control code were tested on human subjects for Transepidermal Water Loss (TEWL) using the described test procedure. Data on Transepidermal Water Loss (TEWL) are presented in Table 2 below.

Table 2 The results indicate the treatment of the upper leaf on one side to reduce skin hydration as measured by the TransEpidermal Water Loss (TEWL) by 5.9 grams per square meter per hour. The experimental emergence administration layer reduces TransEpidermal Water Loss (TEWL) by an additional 3.0 grams per square meter per hour for a total additive of 8.9 grams per square meter per hour. Both the upper leaf treatment and the emergence administration treatment provide improved skin hydration performance.

Other incorporations may include a combination of basic fibers that are treated with EHEC along with a small amount of a surfactant system in such a way that the surface tension of incoming aqueous discharges is not reduced by more than 20 dynes per centimeter as illustrated in Table 3, below. The examples in Table 3 that include a derivatized polysaccharide, BERMOCOLL EBS E481 FQ or BERMOCOLL E230 FQ and an antistatic include the polysaccharide derivative and the antistatic at a ratio of 3: 1, that is three parts by weight of the polysaccharide derivative and one part by weight of the antistatic. The added added is the total addition on both components. The antistats were applied to the fibers by the fiber supplier.

Table 3 Water Surface Tension Following Exposure to Various Processed Emerging Materials Example Description Surface Tension (dynes / cm) Control sample 40% T-295/60% T-258 54 40% T-295/60% TL836A -E481 without antistatic 58 40% T-295/60% TL836A -E481 with anti-static 1 to 0.10% added 61 40% T-295/60% TL836HM-E230 with anti-static 1 to 0.10% added 56 40% T-295/60% TL836KM-E230 with antistatic 2 to 0.10% added 58 40% T-295/60% TL836GM-E230 with anti-static 1 to 0.06% added 60 40% T-295/60% TL836I-E230 with anti-static 1 to 0.15% added 61 40% T-295/60% TL836J-E230 with anti-static 1 to 0.20% added 59 Test Method: The surface tension (ST) of water exposed to the materials identified in Table 2, was determined by cutting 1.0 grams of nonwoven in approximately 1-inch squares and placing them in a 250 milliliter beaker and add 100 milliliters of de-ionized water at room temperature (around 25 degrees Celsius). The sample was shaken lightly by hand with a glass stirrer for one minute and the liquid was decanted into a suitable vessel to measure surface tension in accordance with the Test Method of the American Society for Testing and Materials (ASTM) using a Fisher Tensometer (from Fisher Scientific Company, of Pittsburg, Pennsylvania). As a reference, the surface tension of water before coming into contact with the treated materials is around 71 dynes per centimeter. These results demonstrate that the surface tension of a typical aqueous discharge fluid is not significantly diminished by contacting a treated emergence material. Minimizing the reduction in surface tension is important because minimizing surface tension can negatively minimize the surfactant on: (1) the super absorbent material in the absorbent core of a diaper, (2) the fluid reflows under pressure as in a situation where the baby sits while the diaper is wet, and (3) the capillarity and movement of the fluid in the porous structures.

Although several embodiments of the invention have been described above using specific terms, devices, and methods, such description is for illustration purposes only. The words used are words of description rather than limitation. It should be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit and scope of the present invention, which is pointed out in the following claims. In addition, it should be understood that aspects of the various incorporations can be exchanged both in whole and in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.

Claims (20)

RE I V I N D I C A C I O N S

1. A non-woven material adapted to be used as an emergence layer or a transfer layer comprising at least a first part of first fibers that have been treated with a treatment composition comprising a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide, wherein the treatment composition on the emergence layer or the transfer layer fibers reduces the surface tension of the distilled water for less than about 20 dynes / centimeter as measured by the method of test ASTM D 1590-60.

2. The nonwoven material as claimed in clause 1, characterized in that the nonwoven material further comprises a second part of second fibers that have not been treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of modified polysaccharide.

3. The non-woven material as claimed in clauses 1 or 2, characterized in that the layer of non-woven fibers is a bonded and knitted fabric having a basis weight in the range of from about 20 grams per square meter to about 150 grams per square meter and comprises more than about 20% by weight of the first fibers and more than about 10% by weight of the second fibers.

4. The non-woven material as claimed in clauses 1 or 2, characterized in that the layer of non-woven fibers comprises more than about 30% by weight of the first fibers and more than about 20% by weight of the second fibers .

5. The nonwoven material as claimed in clauses 1 or 2, characterized in that the layer of non-woven fibers comprises more than about 40% by weight of the first fibers and more than about 30% by weight of the second fibers .

6. The nonwoven material as claimed in clauses 1 or 2, characterized in that the layer of non-woven fibers comprises more than about 50% by weight of the first fibers and more than about 30% by weight of the second fibers .

7. The nonwoven material as claimed in clauses 1 or 2, characterized in that the layer of non-woven fibers consists essentially of from about 30% by weight to about 80% by weight of the first fibers and from about 20% by weight at about 70% or by weight of the second fibers.

8. The nonwoven material as claimed in clauses 1 or 2, characterized in that the first fibers are treated with a lubricant or an antistatic agent.

9. The nonwoven material as claimed in clauses 1 or 2, characterized in that the first fibers and the second fibers are treated with a lubricant or antistatic agent.

10. The nonwoven material as claimed in clauses 1 or 2, characterized in that the polysaccharide, the modified polysaccharide, the derivative of a polysaccharide or the derivative of a modified polysaccharide is selected from the group consisting of modified celluloses, cellulose derivatives , hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose ethyl cellulose, methyl hydroxypropyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, starch derivatives, pectin derivatives, carboxymethyl starch, starch aldehyde, pectates, animal product derivatives, carboxymethyl chitin and carboxymethyl chitosan.

11. An absorbent article comprising the nonwoven material as claimed in clauses 1 or 2.

12. A method for forming a layer of non-woven fibers comprising: to. provide a plurality of first fibers; b. treating the plurality of first fibers with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide; provide a plurality of second fibers; d. combining the first fibers with the second fibers to form a mixture comprising the first fibers and the second fibers; and. forming a non-woven fabric of the mixture comprising the first fibers and the second fibers.

13. The method as claimed in clause 12, characterized in that the formation of the non-woven fabric of the mixture comprising the first fibers and the second fibers comprises carding and joining the first fibers and the second fibers to form a fabric.

14. An absorbent article comprising: to. a porous treated surface comprising a first surface comprising a first quantity of a surfactant or a mixture of surfactants and a second surface comprising a second quantity of the surfactant or the mixture of surfactants wherein the second quantity of the surfactant or the mixture of surfactants is less than the first quantity of the surfactant or the mixture of surfactants; Y b. a layer of non-woven fibers comprising fibers treated with a polysaccharide, a modified polysaccharide, or a derivative of a polysaccharide or a derivative of a modified polysaccharide.

15. The absorbent article as claimed in clause 14, characterized in that the first surface of the porous treated substrate is oriented towards or adjacent to the layer of non-woven fibers treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derived from a modified polysaccharide.

16. The non-woven material as claimed in clause 14, characterized in that the layer of non-woven fibers comprising the fibers treated with a polysaccharide, a modified polysaccharide, a polysaccharide derivative or a derivative of a modified polysaccharide is a woven fabric with spinning or a carded and bonded fabric of fibers treated with hydroxyethyl cellulose, hydroxypropyl cellulose, or a mixture thereof.

17. The nonwoven material as claimed in clauses 14, 15 or 16, characterized in that the second surface of the porous treated substrate does not contain essentially surfactant.

18. The nonwoven material as claimed in clauses 14, 15 or 16, characterized in that the porous treated substrate is a single layer.

19. The non-woven material as claimed in clauses 14, 15 or 16, characterized in that the TEWL of the absorbent article includes the combination of the porous treated substrate and the treated non-woven fiber layer is less than TEWL of an absorbent article including only one of the porous treated substrate or the treated nonwoven fiber layer.

20. The nonwoven material as claimed in clauses 14, 15 or 16, characterized in that the TEWL of the absorbent article is reduced by at least about 3 g / square meter / hour compared to a diaper of the same construction but with the emergence layer not including the fibers treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide. R E S U E N A nonwoven material adapted to be used as an emergence layer or a transfer layer including a layer including fibers that have been treated with a polysaccharide, a modified polysaccharide, a derivative of a polysaccharide or a derivative of a modified polysaccharide is provided .