MXPA99008169A - Absorbent article having a breathable backsheet - Google Patents

Abstract

A disposable absorbent article (20) having a breathable laminate backsheet (26). The absorbent article (20) has a front waist region (46), a rear waist region (44), a crotch region (48) positioned between the front waist region (46) and the rear waist region (44), a pair of opposed side edges (50), a first end edge (52) and a second end edge (52). The absorbent article (20) includes an absorbent core (28) having a pair of opposing longitudinal edges (50), a garment-facing side (70) and a body-facing side (72), and a breathable laminate backsheet (26) disposed adjacent to the garment-facing side (70) of the absorbent core (28). The breathable laminate backsheet (26) has an inner layer (90) and an outer layer (92) joined to one another. The inner layer (90) is positioned between the absorbent core (28) and the outer layer (92). The outer layer (92) is relatively vapor pervious. The inner layer (90) is substantially liquid impermeable and substantially vapor pervious. The inner layer (90) is longitudinally coterminous with the absorbent article (20) and of a smaller transverse width than the front waist region (46), the rear waist region (44), and the crotch region (48) so as to form a breathable zone (82) which is longitudinally coterminous with the absorbent article (20) and adjacent to each of the side edges.

Description

ABSORBING ITEMS THAT HAVE A RESPIRABLE REAR LEAF FIELD OF THE INVENTION The present invention relates generally to absorbent articles such as disposable diapers and, more particularly, to disposable absorbent articles having a breathable laminated backsheet.

BACKGROUND OF THE INVENTION Babies and others who incontinent individuals use disposable absorbent articles such as diapers to receive and contain urine and other exudates from the body. The absorbent articles function both to contain the discharged materials and to isolate these materials from the wearer's body and from the wearer's clothing and bedding. Absorbent articles having many different basic designs are known in the art. It is also known that the exterior of the disposable diapers can be covered with a flexible sheet, impervious to liquid and vapor, to prevent any liquid absorbed from passing through the diapers and staining adjacent articles such as clothing, sheets and the like. . These external covers, generally referred to as backsheets, are often constructed of fluid impervious films such as polyethylene. Even though these posterior sheets prevent the liquid from passing through the diaper, these can also form the warm sensation of the diaper and the discomfort of use because of its waterproof capacity. The backsheets that are vapor permeable are generally known as breathable backsheets and have been described in the art. In general, these posterior sheets are intended to allow the flow of vapor through them while slowing the passage of liquid. For example, U.S. Patent No. 3,156,242 issued to Crowe, Jr., on November 10, 1964 teaches the use of a microporous film as a breathable backsheet. U.S. Patent No. 3,881, 489 issued to Hartwell on May 6, 1975, will teach a breathable back sheet comprising two layers in combination, the first of which is a perforated hollow-volume thermoplastic film and the second of which is a porous, high-volume, hydrophobic tissue. That US Pat. No. 3,989,867 issued to Sisson on November 2, 1976 teaches a breathable back sheet provided with recessed, tapered protuberances, which prevent the passage of liquids while permitting the passage of vapors easily therethrough. Although these backsheets provide improvements over the waterproof backsheets, prior art, comfort, dryness, and vapor exchange (breathability) remain key design considerations. Accordingly, devices have been sought that provide retention and absorption of liquids that while providing the most efficient vapor passage. Therefore, it is an object of the present invention to provide a disposable absorbent article having a breathable back sheet to ensure comfort for the wearer. It is still another object of the present invention to provide a disposable absorbent article having a backsheet comprising areas of breathability, wherein the backsheet further comprises a vapor permeable and / or liquid permeable nonwoven web, which provides the surface that gives towards the garment of the back sheet with a sensation similar to the fabric.

It is still another object of the present invention to provide a disposable absorbent article having good containment and breathability characteristics that is economical and easy to manufacture at high speeds.

BRIEF DESCRIPTION OF THE INVENTION A disposable absorbent article having a front waist region having a transverse width, a back waist region having a transverse width, a region of between leg having a transverse width located between the front waist region and the rear waist region, a pair of opposite side edges, a first end edge located in the front waist region and a second end edge located in the rear waist region. The absorbent article comprising an absorbent core having a pair of opposed longitudinal edges, a side facing the garment and a side facing the body, and a breathable laminate disposed adjacent the garment-facing side of said absorbent core. . The breathable laminate comprises an inner layer and an outer layer bonded to one another. The inner layer is placed between the absorbent core and the outer layer. The outer layer is relatively vapor permeable, and the inner layer is substantially impermeable to liquid and substantially vapor permeable. The inner layer is longitudinally coextensive with the absorbent article and of a transverse width smaller than the transverse width of said front waist region, said back waist region, and said crotch region to form a breathable zone which is longitudinally coextensive with the absorbent article and adjacent to each of the lateral edges.

BRIEF DESCRIPTION OF THE DRAWINGS Although the description concludes with the claims pointing out in a particular way and claiming differently the matter that is considered as formant of the present invention, it is believed that the invention will be better understood from the following description which is taken in combination with the accompanying drawings, in which like designations are used to designate substantially identical elements, and in which: Figure 1 is a plan view of a disposable diaper embodiments of the present invention having cut-away portions to reveal the structure underlying, the inner surface of the diaper being facing the observer; Figure 2 is a plan view of a laminated backsheet suitable for use in the diaper of the present invention with the side facing the body of the backsheet facing towards the observer; Figure 3 is an enlarged cross-sectional view of the laminated backsheet of Figure 2; and Figure 4 is an enlarged, cross-sectional view of one embodiment of a disposable absorbent article comprising the backsheet shown in Figures 2 and 3.

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "absorbent article" refers to the devices that absorb and contain body exudates, and, more specifically, refers to devices that are placed against or close to the user's body to absorb. and contain the various exudates discharged from the body.

The term "disposable" is used herein to describe absorbent articles that are not intended to be washed or reused in any other way than as an absorbent article (ie, they are intended to be discarded after a single use and, preferably, to be recycled, composted or otherwise disposed in a manner that is environmentally compatible). A "unitary" absorbent article refers to absorbent articles that are formed of separate parts joined together to form a coordinated entity in such a way that separate manipulated parts such as a separate fastener and liner are not required. A preferred embodiment of an absorbent article of the present invention is the unitary disposable absorbent article, diaper 20, shown in Figure 1. As used herein, e! The term "diaper" refers to an absorbent article generally worn by infants and incontinent persons that is worn around the wearer's lower torso. However, it should be understood that the present invention is also applicable to other absorbent articles such as incontinence trunks, incontinence undergarments, diaper liners and fasteners, feminine hygiene garments, training pants, and the like. Figure 1 is a plan view of the diaper 20 of the present invention in its flattened non-contracted state (i.e., with the contraction induced by the elastic pulled outward) with parts of the structure that are trimmed to more clearly show the construction of the diaper 20 and with the part of the diaper 20 that faces the user, the inner surface 40, facing towards the observer. As shown in Figure 1, diaper 20 preferably comprises a containment assembly 22 comprising a liquid-permeable topsheet 24, a laminated backsheet 26 attached to the topsheet; and an absorbent core 28 located between the topsheet 24 and the backsheet sheet 26. The absorbent core 28 has a pair of opposite longitudinal edges 60, a side facing the body 62 and a side facing the garment 64. diaper preferably further comprises side panels 30; Elastic leg cuffs 32; elasticated waistbands 34; and a fastening system 36 preferably comprising a pair of securing members 37 and a tie member 38. The diaper 20 is shown in Figure 1 to have an inner surface 40 (facing the viewer in Figure 1), an outer surface 42 opposite the inner surface 40, a rear waist region 44, a front waist region 46 opposite the rear waist region 44, a crotch region 48 positioned between the rear waist region 44 and the region of front waist 46, and a periphery that is defined by the perimeter or outer edges of the diaper 20 in which the longitudinal edges or sides are designated 50 and the end edges are designated 52. The inner surface 40 of the cloth! comprises that part of the diaper 20 which is placed adjacent to the wearer's body during use (i.e., the inner surface 40 is generally formed by at least a portion of the topsheet 24 and other components attached to the topsheet 24). The outer surface 42 comprises that part of the diaper 20 that is positioned away from the wearer's body (i.e., the outer surface 42 is generally formed by at least a portion of the laminated back sheet 26 and other components attached to the laminated back sheet 26) . As used herein, the term "attached" encompasses configurations by means of which one element is directly secured to the other element by fixing the element directly to the other element, and configurations by which the element is indirectly secured to the other element. another element for fixing the element to a member or intermediate members, which in turn are fixed to the other element. The rear waist region 44 and the front waist region 46 extend from the end edges 52 of the periphery to the crotch region 48. The diaper 20 also has two centerlines, a longitudinal center line 100 transverse centerline 110. "longitudinal" term, as used herein, refers to a line, axis, or direction in the plane of the diaper 20 that is generally aligned with (eg, approximately parallel to) a vertical plane that divides a standing user in left and right body halves when the diaper 20 is used. The terms "transverse" and "lateral", as used herein, are interchangeable and refer to a line, axis or direction that is located within the plane of the diaper 20 which is generally perpendicular to the longitudinal direction (which divides the user into front and rear body halves). That the containment assembly 22 of the diaper 20 is shown in Figure 1 as comprising the main body (chassis) of the diaper 20. The containment assembly 22 preferably comprises a top sheet 24, a laminated back sheet 26 and an absorbent core 28 that they have a pair of opposite longitudinal edges SO, a ladc facing the body 62, and a side facing towards the garment 64. The side facing the body 62 generally faces towards the wearer's body while the side facing towards the body 62 faces towards the body of the wearer. the garment 64 generally gives away from the wearer's body. When the absorbent article comprises a separate fastener and liner, the containment assembly 22 generally comprises the fastener and the liner (i.e., the containment assembly 22 comprises one or more layers of material to define the fastener, while the liner comprises an absorbent composite such as a topsheet, a laminated backsheet, and an absorbent core). For the unitary absorbent articles, the containment assembly 22 preferably comprises the topsheet 24, the backsheet 26 and the absorbent core 28 of the diaper with other additional features to form the diaper composite structure. Figure 1 shows a preferred embodiment of the containment assembly 22 in which the topsheet 24 and the laminated backsheet 26 have length and width dimensions generally greater than those of the absorbent core 28. The topsheet 24 and the laminated backsheet 26 they extend beyond the edges of the absorbent core 28 to thereby form the periphery of the diaper 20. Although the topsheet 24, the laminated backsheet 26, and the absorbent core 28 can be assembled in a variety of well-known configurations, they are described generally the exemplary configurations of the containment assembly in U.S. Patent No. 3,800,003 entitled "shrinkable side portions for disposable diaper" which was issued to Kenneth B. Buell on January 14, 1975; and U.S. Patent No. 5,151,092 entitled "Absorbent Article with Dynamic Characteristics of Elastic Waist Having a Pre-Disposed Resilient Flex Articulation" which was issued to Kenneth B. Buel et al. on September 29, 1992.; each of which is incorporated herein by reference. The absorbent core 28 can be any absorbent member that is generally compressible, conformable, non-irritating to the wearer's skin, and capable of absorbing and retaining liquids such as urine and other certain exudates from the body. As shown in Figure 1, the absorbent core 28 has a garment-facing side 64, a side facing the body 62, a pair of side edges 60, and a pair of waist edges. The absorbent core 28 can be manufactured in a wide variety of sizes and shapes (eg, rectangular, hourglass, "T.", asymmetric, etc.) and from a wide variety of liquid absorbent materials used in disposable diapers and other absorbent articles such as crushed wood pulp, which is generally referred to as air felt. Examples of other suitable absorbent materials include accreted cellulose wadding, meltblown polymers including coform; chemically hardened, modified or cross-linked cellulosic fibers; tissue including tissue wraps and tissue laminates; absorbent foams; absorbent sponges; superabsorbent polymers; gelling absorbent materials; and any equivalent material or combinations of materials.

The configuration and construction of the absorbent core 28 may vary (eg, the absorbent core may have varying gauge zones, a hydrophilic gradient, a superabsorbent gradient, or lower average weight basis acquisition areas and lower average density, or may comprise one or more layers or structures). In addition, the size and absorbent capacity of the absorbent core 28 can also be varied to suit users ranging from babies to adults. However, the total absorbent capacity of the absorbent core 28 must be compatible with the design load and intended use of the diaper 20. One embodiment of the diaper 20 has an absorbent core 28 with a modified, asymmetric T-shape, having ears in the region. of front waist, but a generally rectangular shape in the posterior waist region. Exemplary absorbent structures for use as the absorbent core 28 of the present invention which have achieved wide acceptance and commercial success are described in U.S. Patent No. 4,610,678 entitled "High Density Absorbing Structures" issued to Wesiman et al. September 1986; United States Patent No. 4,673,402 entitled "Absorbent articles with cores in double layers" issued to Weisman et al. On June 16, 1987; United States Patent No. 4,888,231 entitled "Absorbent core is having a dust cover" issued to Angstadt on December 19, 1989; and U.S. Patent No. 4,834,735 entitled "high density absorbent members having lower basis weight and lower density acquisition zones", issued to Alemany et al. on May 30, 1989. The absorbent core may further comprise the dual core system containing a core of acquisition / distribution of chemically hardened fibers placed on an absorbent storage core as detailed in U.S. Patent No. 5,234,423 entitled "absorbent article with elastic waist characteristics and increased absorbency" issued to Alemany et al. on August 10, 1993; and in US Pat. No. 5,147,345 entitled "high efficiency absorbent articles for incontinence management" issued to Young, LaVon and Taylor on September 15, 1992. All of these patents are incorporated herein by reference. The topsheet 24 is preferably positioned adjacent the side facing the body 62 of the absorbent core 28 and is preferably attached to it and to the laminated backsheet 26 by attachment means (not shown) such as those well known in the art. Suitable attachment means are described with respect to the attachment of the laminated backsheet 26 to the absorbent core 28. In a preferred embodiment of the invention, the topsheet 24 and the laminated backsheet 26 are directly bonded together at the periphery of the diaper and they are joined indirectly together by joining them directly to the absorbent core 28 by any suitable joining means. The topsheet 24 is preferably docile, gentle in feel, and non-irritating to the wearer's skin. In addition, the topsheet is preferably permeable to the liquid allowing liquids (eg, urine) to easily penetrate through its thickness. A suitable top sheet 24 can be manufactured from a wide range of materials such as woven and nonwoven materials; polymeric materials such as thermoplastic films formed with openings, plastic films with openings, and hydroformed thermoplastic films; porous foams; cross-linked foams; crosslinked thermoplastic films; and thermoplastic canvases. Suitable woven and nonwoven materials may be composed of natural fibers (for example, wood or cotton fibers), synthetic fibers (for example, polymer fibers such as polyester, polypropylene, or polyethylene fibers) or a combination thereof. of natural and synthetic fibers. The topsheet 24 is preferably made of a hydrophobic material to isolate the wearer's skin from the liquids that have passed through the topsheet 24 and which are contained within the absorbent core 28 (i.e., to avoid rewetting). If the upper sheet 24 is made of a hydrophobic material, at least the upper surface of the upper sheet 24 is treated so that it is hydrophilic in such a way that liquids will transfer more rapidly through the upper sheet. This decreases the likelihood that the body exudates will flow out of the topsheet 24 instead of being drawn through the topsheet 24 and absorbed by the absorbent core 28. The topsheet 24 can be made hydrophilic by treating it with a surfactant. . Suitable methods for treating the topsheet 24 with a surfactant include spraying the top sheet material 24 with the surfactant and immersing the material within the surfactant. A more detailed discussion of this treatment and hydrophilic capacity is contained in US Pat. Nos. 4,988,344 entitled "Absorbent articles with multilayer absorbent layers" issued to Reising et al. On January 29, 1991 and the patent of US-A-4,988,345 entitled "Absorbent articles with fast-absorbing absorbent cores" issued to Reising on January 29, 1991, each of which is incorporated by reference herein. A preferred alternate top sheet comprises a film formed with openings. Films formed with openings are preferred for the topsheet because they are permeable to body exudates and not yet absorbent and have a reduced tendency to allow liquids to pass back through and rewet the user's skin. This way, the surface of the formed film that is in contact with the body remains dry, thus reducing the staining of the body and creating a more comfortable feeling for the user. Suitable formed films are described in U.S. Patent No. 3,929,135 entitled "Absorption structures having tapered capillaries", which was issued to Thompson on December 30, 1975; U.S. Patent No. 4,324,246 entitled "Disposable Absorbent Article Having a Stain Resistant Topsheet", which was issued to Mullane et al. on April 13, 1982; U.S. Patent No. 4,342,314 entitled "resilient plastic web exhibiting fiber-like properties", which was issued to Radel et al. on August 3, 1982; U.S. Patent No. 4,463,045 entitled "macroscopically expanded three-dimensional plastic weft exhibiting a non-glossy visible surface and a fabric-like fingerprint," which was issued to Ahr et al. on July 31, 1984; and that the all-bound patent No. 5,006,394"multi-layer polymer films" issued to Baird on April 9, 1991. Each of these patents is hereby incorporated by reference. The laminated backsheet 26 of the present invention is that part of the diaper 20 that is generally placed away from the foot! of the user and what! it prevents the exudates absorbed and contained in the absorbent core 28 from wetting the articles that are in contact with the diaper 20 such as sheets and undergarments. The laminated backsheet 26 is preferably positioned adjacent the garment facing side 64 of the absorbent core 28 and is preferably attached to it by any suitable joining means known in the art. For example, the laminated backsheet 26 can be secured to the absorbent core 28 by one capable of uniform, continuous adhesive, a patterned adhesive layer, or an array of separate lines, coils, or spots of adhesives. The adhesives that have been found to be satisfactory are manufactured by HB Fuller Company of St. Paul, Minnesota, and marketed as HL-1258.1 Example of a suitable bonding medium comprising an open-pattern network of adhesive filaments is disclosed in US Pat. U.S. Patent No. 4,573,986 entitled "Disposable Garbage Containment Garment", which was issued to Minetola et al. on March 4, 1986. Another suitable joining means comprising several lines of adhesive filaments twisted in a pattern. spiral is illustrated by the apparatus and methods shown in U.S. Patent No. 3,911, a 73 issued to Sprague, Jr., on October 7, 1975; U.S. Patent No. 4,785,996 issued to Ziecker et al. on November 22, 1978; and in U.S. Patent No. 4,842,666 issued to Werenicz on June 27, 1989. Each of these patents is incorporated herein by reference. Alternatively, the joining means may comprise heat bonds, pressure joints, ultrasonic joints, mechanical dynamic joints, or any other suitable joining means or combinations of these joining means as are known in the art. Also contemplated are embodiments of the present invention wherein the absorbent core 28 is not attached to the laminated backsheet 26, and / or the topsheet 24 so as to provide greater extension capacity especially in the front waist region 46 and the region back waist 44. The laminated backsheet 26 of the present invention, as shown in Figures 2 and 3, comprising an inner layer 90 and an outer layer 92 joined together. The means by which the inner layer and the outer layer 92 are joined to each other, includes any of the means known in the art such as adhesive bonds, heat bonds, pressure joints, extrusion bonds, and ultrasonic bonds. . The laminated backsheet 26 has a side facing body 72, a garment facing side 70, a central region 74 and two outer regions 76. In addition, the laminated backsheet 26 comprises at least three distinct zones, one first breathable zone 82, and two opposite breathable secondary zones 80. The first breathable zone 82 preferably comprises the central region 74 of the laminated backsheet 26 and is juxtaposed with at least a portion of the garment-facing side 64 of the absorbent core 28 The first breathable zone 82 provides a structure substantially impermeable to liquid containing liquids that have passed into containment assembly 22. In a preferred embodiment, first breathable zone 82 covers the entire garment-facing side 64 of the absorbent core. 28. (As used herein, the term "covers" means that a member is generally, either directly or indirectly in a relationship face to face with the other member). In a particularly preferred embodiment, the first breathable zone 82 not only covers the garment-facing side 64 of the absorbent core 28, but also extends laterally outwardly to at least any location in which any of the barrier folds (described below) that can be attached to the diaper 20, such as the proximal edge 33 of the barrier folds 32. (As used herein, the term "laterally outward" refers to a direction away from the center line longitudinal 100.) This ensures that any liquid absorbed by the absorbent core 28 or otherwise deposited within the containment assembly 22 of the diaper 20 will not coalesce through the second respirable areas 80 of the laminated backsheet 26. The outer layer 92 preferably comprises a nonwoven web. However, embodiments are contemplated wherein the outer layer 92 comprises materials such as woven wefts, foams, canvases, films, or any other material or combinations of materials known in the art that would give the diaper an appearance and / or feel similar to that of the diaper. fabric and is at a minimum permeable to air. The outer layer 92 covers that the entirety is of the laminated backsheet 26 thereby forming the periphery of the diaper 20. In addition, the nonwoven web of the outer layer 92 provides the diaper with a look and feel similar to the fabric. In addition, the outer layer 92 can provide the diaper with a low-cost lanyard capable of attaching to the hook-and-loop type fasteners. This mooring area can be used as a part of a primary fastening system or as a means to discard a dirty diaper. The non-woven web of the outer layer 92 is permeable to liquid and air to allow free passage of the vapor in the second respirable areas 80. The non-woven web may comprise natural fibers (e.g., wood or cotton fibers), or may comprise polyethylene, polypropylene, polyester fibers, or any combination of these fibers. In addition, the non-woven web may be carded, spun in the molten state, blown in the molten state, or bonded by continuous air which, or have any other characteristic or be manufactured in any manner known in the art. Preferably, the non-woven web is composed of sufficient thermoplastic material to allow thermal bonding of the non-woven web to other diaper components. An especially preferred nonwoven web is a non-woven, carded web made of 100% polypropylene fibers such as FPN 290 manufactured by FiberWeb North America of Simpsonville, S.C. however, it may be desirable to provide an outer layer 92 that acts to change the permeability (either vapor or liquid) in certain regions of the second respirable zones 80. This is the case in the designs of disposable articles wherein the second zones breathable 80 is located or is otherwise in contact with any part of the article that can absorb liquids. In these cases, it may be desirable to use a hydrophobic nonwoven web to help prevent any leakage or runoff of the article liquids. Interposed between the absorbent core 28 and the outer layer 92 is the layer - internal 90. The inner layer 90 prevents the fluids retained by the absorbent core 28 from penetrating into the diaper 20 and staining the adjacent garments. Therefore, the inner layer 90 should be at least substantially impermeable to the fluid and preferably, completely impermeable to the fluid. Suitable materials are well known in the art, including woven or non-woven fabrics which have been treated to make liquid repellents. The breathable or vapor permeable liquid resistant materials, and those materials described in U.S. Patent No. 3,881, 489 issued to Hartwell on May 6, 1975 and U.S. Patent No. 3,989,867 issued to Sisson on 2 November 1976, can also be used. These patents are incorporated herein by reference.

The size of the inner layer 90 is a key factor in the formation of the first breathable zone 82 and the second breathable zones 80. The size and shape of the inner layer 90 generally determines the size, shape, and location of the first breathable zone. 82 and the second breathable areas 80. Although the inner layer 90 is longitudinally coextensive with (i.e., the same length as) the diaper 20, the inner layer 90 has a transverse width smaller than the transverse width of the diaper 20 in the front waist region 46, back waist region 44 and crotch region 48 such that a second breathable zone 80 is formed in diaper 20, which is longitudinally coextensive with diaper 20. Therefore, the layer internal 90 may generally be of any shape and size conforming to the above description to allow the laminated backsheet 26 to have two opposite breathable secondary zones 80, which are length inally coextensive with the diaper 20. Although the inner layer 90 is longitudinally coextensive with the outer layer 92, the inner layer 90 has a smaller transverse width than that of the outer layer 92 in all regions of the diaper, i.e., the waist region front 46, the rear waist region 44, and the crotch region 48 such that a second breathable zone 80 is formed in the backsheet 26, which is iongitudinally coextensive with the backsheet 26. A preferred shape of the layer internal 90 is shown in Figure 2. The inner layer 90 has a uniform transverse width. Furthermore, the inner layer has a uniform transverse width which is smaller than the narrowest portion of the crotch region 48 of the diaper 20. With this configuration two opposite breathable secondary zones 80 are formed which are longitudinally coextensive with the diaper 20. For disposable absorbent articles, and particularly for garments such as diapers which are in a tight fit such as those disclosed herein, the breathability exhibited by the backsheet has been found to be critical to the operation of the absorbent article especially in heat and humidity conditions. When the absorbent article is placed on a wearer, the skin is obstructed by the materials forming the absorbent article. This obstruction of the skin, especially in conditions of heat and humidity, which prevents evaporation and the resulting cooling of the occluded area. The resulting perspiration raises the relative humidity of the air within the absorbent article, resulting in less comfort for the wearer and negative benefits perceived by the person placing the diaper. In addition, incidents of heat rash and other relative macerations in the skin may be increased if the absorbent article does not have sufficient capacity to move the water vapor created by the body out of the absorbent article. Conventional diapers have tried to use breathable materials to reduce moisture inside the diaper. However, these materials have not provided sufficient moisture vapor transmission coefficients to reduce the moisture inside the product to a point that provides comfort to the user when exposed to hot and humid conditions. It has been found that the wet vapor transmission coefficient of the second respirable zone 80 of the backsheet 26 in combination with the total steam transmission coefficient of the rest of the backsheet, it is important to reduce the occurrences of heat rash and other skin problems associated with high heat and humidity conditions. In order to reduce the formation of moisture and heat within the absorbent article, it was found that the second respirable zones 80 of the backsheet 26 must have a mass vapor transmission coefficient of at least about 2500 g / m2 / 24 hr. ., more preferably at least about 3000 g / m2 / 24 hr.

The central region 74 comprising the first breathable zone 80 is substantially liquid impermeable to contain the liquids absorbed by the absorbent core 28. Since the central region 74 comprising the first breathable zone 82 must contain the liquids absorbed by the absorbent core, it is typically having a lower mass vapor transmission coefficient than that of the second respirable zones 80 which are not suitable for containing any of the absorbed liquids. Accordingly, it was found that the first breathable zone 82 is the main limiting factor in providing a total absorbent article with a high average mass vapor transmission coefficient. However, it was found that the first breathing zone 82 must have a mass vapor transmission coefficient of at least about 1500 g / m2 / 24 hr., More preferably at least about 2000 g / m2 / 24 hr. . The first breathable zone 82 and thus the total absorbent article, given the materials, which would give a mass vapor transmission coefficient in a range of at least about 1500 g / m2 / 24 hr to about 8000 g // m2 / 24 hr, more preferably approximately 2000 g // m2 / 24 hr. at approximately 7000 g // m2 / 24 hr. In this way, it is preferred that each zone of the backsheet 26 should have a mass vapor transmission coefficient of at least about 1500 g / m2 / 24 hr. As can be seen, because the first breathable zone 82 comprises both of the inner layer 90 and the outer layer 92, it has an effective mass vapor transmission coefficient which is less than that of the second breathable areas. which comprise only the outer layer 92. This is expected since the first breathable zone 82 is responsible for retaining the liquids absorbed by the absorbent core 28 from passing through the laminated backsheet 26 while the second breathable areas 80 of the laminated backsheet 26 does not need to assist in the containment of liquids within the disposable diaper 20.

The transmission coefficient of the humid steam is measured by the method established below. A known amount of CaCl2 is placed inside a flanged cup. A sample is placed on top of the cup and is held securely by a retainer ring and a gasket. The assembly is then weighed and recorded as the initial weight. The assembly is placed inside a chamber at constant temperature (40 degrees Celsius) and humidity (75% RH) for five hours. The assembly is then removed from the chamber and allowed to equilibrate for -30 minutes at the temperature of the room where the balance was located. The assembly is then weighed and recorded as the final weight. It is calculated that the mass vapor transmission coefficient (MVTR) y is expressed in g // m2 / 24 hr using the following formula: MVTR = (final weight - initial weight) x 24.0. Sample area in meters x 5.0 (camera time) In the embodiments of the present invention comprising leg cuffs 32, as described below, the second breathable zones 80 may be disposed laterally inwardly or outwardly of the leg cuffs 32. In addition, the second respirable zones 80 may form a part of the leg cuffs 32. However, in a preferred embodiment, the second breathable zones 80 extend laterally outwardly from the proximal edge 33 of the leg cuffs. 32. In another preferred embodiment of the present invention, the second breathable zones 80 extend laterally outwardly from a location that is laterally outside of the proximal edge 33 of the leg cuffs 32, and laterally within the crease fold 63. This configuration proportional diaper 20 with a liquid impermeable gasket seal around the user's legs to prevent liquids escaping from the retainer assembly 22 of the diaper 20. In yet another embodiment, the second breathable areas 80 extend laterally outwardly from a location laterally outside the packing fold 63. It may also be desirable to provide the disposable article of the present invention with expandability or elasticity in all or part of the side panels 30. (as used herein, the term "extensible" refers to materials that are capable of extending in at least one direction to a certain degree without undue rupture.The terms "elasticity" and "elastically extensible" It refers to the extensible materials that have the ability to be returned to approximately their original dimensions after the force extending material is removed.As used herein, any material or element described as "extensible" can also be elastically elastic. extendable unless otherwise provided.) Extendable side panels 30 provide a Greater comfort and contour adjustment initially conveniently adjust the diaper to the wearer and hold this adjustment throughout the time of use even after when the diaper has been loaded with exudates, since the side panels allow the diaper sides expand and contract. The side panels extensions 30 furthermore provide for greater effective application of the diaper 20 since even if the person placing the diaper pulls one side panel 30 farther than the other during the application (asymmetrically), the diaper 20 will "auto adjust" during the use. Although extensible side panels 30 can be constructed in a number of configurations, examples of diapers with extensible side panels are disclosed in U.S. Patent No. 4,857,067 entitled "Disposable diaper having gathered ears" issued to Wood et al. August 1989; U.S. Patent No. 4,381,781 issued to Sciaraffa et al. on May 3, 1983; U.S. Patent No. 4,938,753 issued to Van Gompel et al. on July 3, 1990; and that United States Patent No. 5,151,092 issued to Buell et al. on September 29, 1992; each of which is incorporated herein by reference. Extending side panels 30, or any other diaper elements 20 in which stretch or stretch capacity such as waistbands 34 are desirable, may comprise materials that have been "preformed", or mechanically preformed (i.e. a degree of mechanical stretching of a localized pattern to permanently lengthen the material), or frames in the form of structural elastic (SELF), as described below. The materials can be preformed using deep enhancement techniques as are known in the art. Alternatively, the materials can be preformed by directing the material through an incremental mechanical stretching system as described in U.S. Patent No. 5,330,458 entitled "absorbent article with elastic characteristic having a mechanically preformed portion" issued to Buell et al. On July 19, 1994. Materials are then allowed to return to their substantially unstressed condition, thereby forming a zero tension stretching material that is extensible, at least up to the initial stretch point. Examples of zero stress materials are disclosed in United States Patent No. 2,075,189 issued to Galligan on March 30, 1937; U.S. Patent No. 3,025,199 issued to Harwood on March 13, 1962; U.S. Patent Nos. 4,107,364 and 4,209,563 issued to Sisson on August 15, 1978 and June 24, 1980, respectively; U.S. Patent No. 4,834,741 issued to Sabee on May 30, 1989; and in U.S. Patent No. 5,151,092 issued to Buell et al. on September 29, 1992. All of the above-referenced patents are hereby incorporated by reference. Alternatively, the extendable side panels 30 or any part of the side panels 30 or the materials included in the side panels or any other element of the diaper 20 in which extension capacity is desirable, may comprise a weft of shaped film. of structural elastic (SELF). A film web in structural elastic form is a material exhibits a behavior in the form of elastic in the direction of elongation without the use of additional elastic materials. The SELF frame includes a deformable network that has at least two contiguous, distinct and non-similar regions. One of the regions that is configured in such a way that it will exhibit resistance forces in response to an axial elongation applied in a direction parallel to the previously determined axis before a substantial portion of the other region develops significant resistance forces to the applied elongation. At least one of the regions has a surface path length that is greater than that of the other region as measured substantially parallel to the predetermined axis, while the material is in an unstressed condition. The region exhibiting the greater surface path length includes one or more deformations that extend beyond the plane of the other region. The SELF screen exhibits at least two significantly different stages on the controlled resistance force to the elongation, along at least one predetermined axis when some elongation applied in a direction parallel to the predetermined axis is subjected. The SELF screen exhibits first applied elongation resistance forces until the elongation of the weft is sufficient to cause a substantial part of the region having the largest surface path length, between the plane of the applied elongation, after which the SELF frame exhibits second strengths of additional elongation. The total resistance forces to the elongation are greater than the first elongation resistance forces provided by the first region. The SELF frames suitable for the present invention and the method for making these frames are described more fully in the commonly assigned US patent.

United States No. 5,518,801 entitled "web materials exhibiting behavior in the form of elastic" issued to Chappell et al. On May 21, 1996, which is incorporated herein by reference. The diaper 20 in preferably further comprises elasticized leg cuffs 32 to provide improved containment of liquids and other exudates from the body. Each elasticized leg fold 32 may comprise several different embodiments to reduce leakage of body exudates in the leg regions. (The leg fold can be and is sometimes also referred to as leg bands, side flaps, barrier folds, or elastic folds). U.S. Patent No. 3,860,003 discloses a disposable diaper that provides a collapsible leg opening having a side flap and one or more elastic members to provide an elasticized leg fold (packing fold). U.S. Patent No. 4,909,803 entitled "Disposable Absorbent Article Having Elasticized Fins" issued to Aziz et al. On March 20, 1990, discloses a disposable diaper having "upright" elasticated fins (barrier folds) to improve containment of the leg regions. U.S. Patent No. 4,695,278 entitled "Absorbent Article Having Double Folds" issued to Lawson on September 21, 1987; and the all-attached patent No. 4,795,454 entitled "Absorbent article having double leak-resistant folds" issued to Dragoo on January 3, 1989, describes in disposable diapers having double folds that include a gusset fold and a fold of glue. barrier. U.S. Patent No. 4,704,115, entitled "Disposable Waist Containment Garment" issued to Buell on November 3, 1987, discloses a disposable diaper or incontinence garment having leakage channels on the lateral bank configured for Contain free liquids inside the garment. (Each of these patents is incorporated herein by reference.) Although each elasticized leg fold 32 can be configured to be similar to any of the leg bands, barrier folds, side flaps, or elastic folds described above, it is preferred that each elasticized leg fold 32 comprises at least one internal barrier fold comprising a barrier fin and a separation element as described in the aforementioned US Patent No. 4,909,803. In a preferred embodiment, the elasticized leg fold 32 further comprises an elastic packing gusset 63 with one or more elastic threads 65, placed outside the barrier fold as described in the aforementioned US Patent No. 4,695,278 . In addition, as Figure 4 is used, the elasticized leg fold 32 preferably has a proximal edge 33 and a distal edge 35. The distal edge 35 of the elasticized leg fold 32 is that part of the elasticized leg fold 32 that is spaced apart. of the diaper chassis 22 when the diaper 20 is being used. The proximal edge 33 is that portion of the elasticized leg fold 32 that is attached to the chassis 22 of the diaper 20. The proximal edge 33 is generally located laterally inside the periphery of the diaper 20. A portion of the elasticized leg 32, however, may extend laterally outward from the proximal edge 33 such that the material covers at least a portion of the outer region 76 of the backsheet 26 (FIG. not shown). An example of an elasticized fold 32 having a side extending laterally outward over most or all of the outer region 76 of the backsheet 26 which is described in the above-referenced United States Patent No. 4,795,454 issued to Dragoo, which is incorporated by reference here. The diaper 20 preferably further comprises an elasticated waistband 34 which provides improved fit and containment. The elasticated waistband 34 is tpart or area of the diaper 20 which is intended to expand and contract elastically to dynamically adjust the wearer's waist. The elasticized waistband 34 preferably extends longitudinally outwardly from at least one of the waist edges of the absorbent core 28 and generally forms at least a portion of the end edge of the diaper 20. Disposable diapers are generally constructed to have two elasticated waistbands, one placed in the posterior waist region and one placed in the frontal waist region, although diapers can be constructed with an individual elasticized waistband. Further, while the elasticized waistband 34 or any of its constituent elements may comprise a separate element secured to the diaper 20, the elasticized waistband 34 may be constructed as an extension of other diaper elements such as the backsheet 26 or the upper sheet 24 , preferably both of the backsheet 26 and the upper sheet 24 Elasticated waistband 34 may be constructed in a number of different configurations including those described in U.S. Patent No. 4,515,595 entitled "Disposable diapers with elastically shrinkable waistbands" issued to Kievit et al. On May 7, 1985 and the aforementioned United States Patent No. 5,151,092 issued to Buell; each of these references being incorporated herein by reference. The diaper 20 also comprises a fastening system 36, which forms a lateral closure which maintains the rear waist region 44 and the front waist region 46 in an overlapping configuration, such that lateral stresses are maintained around the circumference of the diaper to keep the diaper on the wearer. Exemplary fastening systems are described in the all-attached patent No. 3,848,594 issued to Buell on November 19, 1974; U.S. Patent No. 4,662,875 issued to Hirotsu and Robertson on May 5, 1987; U.S. Patent No. 4,869,724 issued to Scripps on September 26, 1989; U.S. Patent No. 4,846,815 issued to Scripps on July 11, 1989; patent all attached No. 4,894,060 issued to Nestegard on January 16, 1990; U.S. Patent No. 4,946,527 issued to Battrell on August 7, 1990; and in U.S. Patent No. 5,326,612 entitled "Non-woven female component for restrainable fastening device and method for making the same" issued to David JK Goulait on July 5, 1994. Each of these patents is incorporated herein by reference. reference. Although particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, attempts are made to protect all these changes and modifications within the scope of the present invention in the appended claims.

Claims (7)

1. A disposable absorbent article having a front waist region having a transverse width, a back waist region having a transverse width, a leg region having a transverse width positioned between the front waist region and the rear waist region , a pair of opposite side edges, a first end edge located in the front waist region and a second end edge located in the rear waist region, the absorbent article comprising an absorbent core having a pair of opposite longitudinal edges, one side that gives towards the garment and a side that gives towards the body; characterized to! absorbent article by a breathable laminate disposed adjacent to the garment facing the absorbent core, said breathable laminate comprising an inner layer and an outer layer bonded together, the capital being placed between the absorbent core and the outer layer, the layer being externally relatively vapor permeable, said inner layer being substantially impermeable to liquid and substantially vapor permeable, said inner layer being longitudinally coextensive with the absorbent article and of a transverse width less than the transverse width of the frontal waist region, said region of rear waist, and said region between the leg to form a breathable zone that is longitudinally coextensive with the absorbent article and adjacent to each of the lateral edges.

2. A disposable absorbent article having a front waist region, a back waist region, a leg region located between the front waist region and the rear waist region, a pair of opposite side edges, a first end edge located in the front waist region and a second end edge located in the rear waist region, the absorbent article comprising an absorbent core having a pair of opposite longitudinal edges, a side facing the garment and a side facing the body; characterized the article by a breathable laminate disposed adjacent the garment-facing side of said absorbent core, the breathable laminate comprising an inner layer and an outer layer joined together, the inner layer being placed between the absorbent core and the outer layer said outer layer comprising a non-woven web relatively permeable to vapor, said inner layer comprising a liquid-resistant, breathable polymeric material, said breathable laminate having a side facing the garment, a side that faces the body, a central region, and two outer regions, the central region juxtaposed to the garment side of the absorbent core, said outer regions extending laterally continuously outwardly from the central region beyond the longitudinal edges of the absorbent core and so that it longitudinally continues from the extreme edge located in the front end region such through the region of between the leg towards the second end edge located in the rear waist region, the central region comprising said inner layer and said outer layer, said outer region comprising said outer layer, the central region having a first coefficient of steam transmission in mass, said external regions having a second vapor transmission coefficient in mass greater than that of said central region.

3. Disposable absorbent article according to any of claim 1 or 2, wherein the outer layer is a nonwoven web.

4. The disposable absorbent article according to claim 3, wherein the nonwoven web is permeable to liquid.

The disposable absorbent article according to any of the preceding claims, wherein the inner layer has a uniform transverse width.

6. The disposable absorbent article according to any of the preceding claims, wherein the absorbent article further comprises a liquid permeable top sheet disposed adjacent the side facing the absorbent core body. The disposable absorbent article according to any of the preceding claims, wherein said external region has a mass vapor transmission coefficient of at least 2500 g / m2 / 24hr.