MXPA97004830A

MXPA97004830A - Elastomer absorbent structure

Info

Publication number: MXPA97004830A
Application number: MXPA/A/1997/004830A
Authority: MX
Inventors: John Wisneski Anthony; Padmanabhan Anjur Sriram; Narendra Shah Ketan
Original assignee: Kimberlyclark Worldwide Inc
Priority date: 1994-12-29
Filing date: 1997-06-26
Publication date: 1998-07-03

Abstract

An elastomeric absorbent structure containing wet mountable short fiber and thermoplastic elastomeric fiber is described. The elastomeric absorbent structure exhibits improved elastic properties compared to an otherwise essentially identical absorbent structure without any thermoplastic elastomeric fiber. Also disclosed is a disposable absorbent product containing such an elastomeric absorbent structure.

Description

ELASTOMERIC ABSORBENT STRUCTURE The present invention relates to an elastomeric absorbent structure suitable for use in absorbent products. More particularly, the present invention relates to an elastomeric absorbent structure comprising a wettable short fiber and a thermoplastic elastomeric fiber.

Disposable absorbent products currently enjoy wide use in a wide variety of applications. Disposable absorbent products include those such as diapers, adult incontinence products, and bed pads, catamenial devices, such as sanitary napkins and tampons, and other products such as cleansers, bibs, wound dressings, and coats or layers. surgical drapes. Such disposable absorbent products are generally suitable for absorbing many liquids, such as water, salt water and synthetic urine, and body fluids such as urine, menstrual fluids and blood.

The purpose of disposable absorbent products is typically the management of body waste. In order to handle the waste of the liquid body, the disposable absorbent products typically include an absorbent structure which must generally be able to first take the liquid into the absorbent structure, then distribute the liquid inside the absorbent structure, and then retain the liquid inside the absorbent structure.

Typically, the absorbent structure and the disposable absorbent product are made of materials that do not stretch easily, particularly when they are under the forces typically encountered in use by the absorbent structure and the disposable absorbent product. One problem resulting from the lack of ability of the absorbent structure and the disposable absorbent product to stretch easily is that such a structure or product does not conform well to the wearer's body using the disposable absorbent product. This is a particular problem when the user of the disposable absorbent product is active and moves. Such lack of conformity to the user's body generally results in a disposable absorbent product that is not comfortable to the user as desired. In addition, a lack of conformity to the user's body generally results in a disposable absorbent product that is not efficient in taking, distributing and retaining a liquid as the disposable absorbent product was designed to handle. Another problem resulting from the lack of ability of the absorbent structure to easily stretch is that if a lot of tension is placed on the absorbent structure during use, the absorbent structure can break into pockets or piles of material causing discomfort to the user and reducing the efficiency of the absorbent structure.

The present invention seeks to overcome these problems. The object is solved by the absorbent structure according to the independent clause 1 and the absorbent product of the independent clause 22.

The additional advantages, features, aspects and details of the invention are evident from the dependent clauses, the description and the accompanying drawings. The claims are intended to be understood as a first non-limiting approach to defining the invention in general terms.

It is desirable to produce an absorbent structure capable of filling or exceeding the performance characteristics of known absorbent structures. In particular, it is desired to produce an absorbent structure which is capable of stretching and conforming to a user's body and whose absorbent structure is still capable of rapidly absorbing a liquid discharged under the pressures typically encountered during use and to have the liquid absorbed. for pressures typically encountered during use. These and other related objects are achieved by an elastomeric absorbent structure comprising a wettable short fiber and a thermoplastic elastomeric fiber, wherein the absorbent structure exhibits improved stretchability as compared to another essentially identical absorbent structure which does not comprise the thermoplastic elastomeric fiber.

In one embodiment of the present invention, an absorbent structure comprises from about 20 to about 80 percent by weight of wettable short fiber and from more than 20 to about 80 percent by weight of thermoplastic elastomeric fiber, wherein All percents by weight are based on the total weight of the wettable short fiber and the thermoplastic elastomeric fiber in the elastomeric absorbent structure. The elastomeric absorbent structure exhibits a specific saturated liquid retention capacity value of at least about 5 grams of liquid absorbed to one gram of absorbent structure base, a Maximum Stretch value in a dry condition that is greater than about of 60 percent, a Maximum Stretch value in a saturated condition of 100 percent liquid that is greater than about 150 percent, a Stretch Recovery value in a dry condition that is greater than about 70 percent, and a Stretch Recovery value in a 100 percent liquid saturated condition that is greater than about 75 percent.

In another aspect, it is desirable to provide a disposable absorbent product, such as an infant diaper, which product includes an elastomeric absorbent structure.

In one embodiment, this objective is achieved in an absorbent garment comprising a liquid pervious topsheet, a backsheet and an elastomeric absorbent structure positioned between the topsheet and the backsheet, wherein the elastomeric absorbent structure comprises a fiber. humid cut and a thermoplastic elastomeric fiber.

The invention will be better understood with reference to the following description of the embodiments of the invention taken in conjunction with the accompanying drawings wherein: Figure 1 is a perspective view of one embodiment of the disposable absorbent product as claimed in the present invention; Figure 2 is an illustration of the equipment used to determine the retention capacity of the saturated liquid of a material.

In one aspect, the present invention relates to a useful absorbent structure in a disposable absorbent product possessing desirable and improved elastic characteristics that can be achieved by the careful selection and use of a wettable short fiber and a thermoplastic elastomeric fiber used in forming such structures absorbents and disposable absorbent products.

As used herein, the term "short fiber" is meant to refer to natural fibers or a section cut from, for example, a manufactured filament. Such staple fibers are intended to act in the absorbent structure of the present invention as a temporary reservoir for the liquid and also as a conduit for the distribution of the liquid.

Suitably, the short fibers used in the absorbent structures herein should vary in length from about 0.1 to about 15 cm, and more suitably from about 0.2 to about 7 cm. Short fibers of these size characteristics help to impart desirable volume characteristics, liquid acquisition, liquid distribution and strength and / or desirable flexibility and elastic properties to the absorbent structures of this invention.

A wide variety of short fiber materials can be used in the structures given here. The short fibers useful in the present invention may be formed of natural and synthetic materials and may include cellulosic fibers such as wood pulp fibers and modified cellulose fibers, textile fibers such as cotton or rayon, and essentially non-absorbent synthetic polymer fibers. .

For reasons of availability and cost, cellulosic fibers will often be preferred to be used as the short fiber component of the absorbent structures of the invention. Wood pulp fibers are more preferred. However, other cellulosic fibers, such as cotton fibers can also be used as short fiber.

Another preferred type of the short fiber useful herein comprises crimped synthetic fibers, essentially non-absorbent. The individual fibers of this type are in themselves essentially non-absorbent. Therefore, such fibers must be prepared from a synthetic polymer material which does not essentially swell or gel the presence of liquids, such as urine or menstrual fluids, typically found in disposable absorbent products. Suitable polymeric materials which can be used to prepare the desired short fibers include polyesters, polyolefins, polyacrylates, polyamides and polystyrenes. Suitable short fibers are made of polyethylene, polypropylene or polyethylene terephthalate.

The short fibers used herein can also be crimped so that the resulting absorbent structure has a desired elasticity and bulking resistance during use in the absorbent products. Curled short fibers are those which have a wavy, curved or nicked character along their length. Fiber curling of this kind is more fully described in U.S. Patent No. 4,118, 531, incorporated herein by reference.

As used herein, the term "fiber" or "fibrous" is intended to refer to a particulate material in which the proportion of length or diameter of such particulate material is greater than about 10. Conversely, the "non-fiber" material "or" non-fibrous "is meant to refer to a particulate material wherein the ratio of length or diameter of such particulate material is about 10 or less.

As used herein, the term "wettable" is meant to refer to a fiber which exhibits a liquid, such as water, synthetic urine, or a 0.9 percent by weight aqueous solution of water, at an angle of air contact of less than 90 °. As used herein, the contact angle can be determined, for example, as established by Robert J. Good and Robert J. Stromberg, Ed., In the work "Surface Science and Colloid - Experimental Methods", volume 11, ( Plenum Press, 1979). Suitably, a wettable fiber refers to a fiber which exhibits an aqueous solution water solution of 0.9 percent by weight at an air contact angle of less than 90 ° at a temperature of between about 0 ° C and around lOOoC and suitably to environmental conditions, such as around 23 c.

Suitable wettable fibers can be formed of intrinsically wettable fibers or can be formed of intrinsically hydrophobic fibers having a surface treatment thereon which makes the fiber hydrophilic. When treated surface fibers are used, the surface treatment is desirably non-fugitive. That is, the surface treatment desirably does not wash away from the surface of the fiber with the first insult or liquid contact. For the purposes of this application, a surface treatment on a generally hydrophobic polymer will be considered non-fugitive when a majority of the fibers demonstrate a contact angle of a liquid in air of less than 90 ° for three consecutive contact angle measurements. , with drying between each measurement. That is, the same fiber is subjected to three separate contact angle determinations and, if all three contact angle determinations indicate a liquid contact angle in air of less than 90o, the surface treatment on the fiber will be considered Not a fugitive. If the surface treatment is fugitive, the surface treatment will tend to wash away from the fiber during the first contact angle measurement, thus exposing the hydrophobic surface of the underlying fiber and will demonstrate subsequent contact angle measurements greater than 90o.

The wettable short fibers should be present in an elastomeric absorbent structure of the present invention in an amount effective to result in the desired absorbent and elastic properties described herein.

As such, the wettable short fiber must be present in the absorbent structure in less than an excessive amount so that the absorbent structure exhibits the desired elastic properties. In addition, the wettable short fiber must be present in the absorbent structure in more than a minimal amount so that the absorbent structure exhibits the desired absorbent properties.

The wettable short fiber is therefore desirably present in an elastomeric absorbent structure of the present invention in an amount of from about 20 to about 80 percent by weight, suitably from about 25 to about 75 percent by weight, and more suitably from about 30 to about 70 percent by weight of wettable short fiber, with all percentages by weight based on the total weight of the wettable short fiber and the thermoplastic elastomeric fiber in the absorbent structure.

It has been found that by including a thermoplastic elastomeric fiber in an absorbent structure, the elastic properties of the absorbent structure can be substantially improved, particularly in comparison to an otherwise essentially identical absorbent structure not comprising a thermoplastic elastomeric fiber.

In particular, the absorbent structures of the present invention have been found to exhibit very high elastic stretchability and very high elastic recovery of the stretch, compared to an otherwise essentially identical absorbent structure that does not comprise a thermoplastic elastomeric fiber.

As used herein, the term "an otherwise essentially identical absorbent structure without any thermoplastic elastomeric fiber", and other similar terms, is intended to refer to a control absorbent structure that was prepared using essentially identical materials and a process essentially identical in comparison to an elastomeric absorbent structure of the present invention, except that the control absorbent structure did not comprise or was not prepared with the thermoplastic elastomeric fiber described herein but, instead, comprised an amount of an additional wettable short fiber. essentially identical to the amount of the thermoplastic elastomeric fiber used in the elastomeric absorbent structure of the present invention. As such, the otherwise essentially identical absorbent structure without any thermoplastic elastomeric fiber or the elastomeric absorbent structure of the present invention will generally have essentially identical base weights. As a result of not understanding the thermoplastic elastomeric fiber, the otherwise essentially identical absorbent structure will not generally exhibit the desired elastic properties described herein as compared to an elastomeric absorbent structure of the present invention.

As used herein, the term "thermoplastic" is intended to describe a material that softens when exposed to heat and which essentially returns to its original condition when cooled to room temperature.

As used herein, the terms "elastic" and "elastomeric" are used interchangeably to mean a material that is generally capable of recovering its shape after deformation when the deforming force is removed. Specifically, as used herein, elastic or elastomeric is intended to be that property of any material, which, with the application of a pressing force, allows the material to stretch to a pressed and stretched length which is at least of about 125 percent, this is about 1.25 times its length not pressed and relaxed, and it will cause the material to recover at least 40 percent of its elongation with the ease of the stretching and stretching force . A hypothetical example which satisfies this definition of an elastomeric material will be a sample of 25.4 mm (one (1) inch) a material which can be lengthened to at least 31.75 mm (1.25 inches) and which, having been lengthened to 31.75 mm (1.25 inches) and released it will recover to a length of no more than about 29.29 mm (1.15 inches). Many elastic materials can stretch for much more than 25 percent of their relaxed length, and many of these will recover to essentially their relaxed original length with the ease of stretching and stretching force. This last class of materials is generally beneficial for the purposes of the present invention.

The term "recovery" refers to a contraction of a stretched material upon the termination of a pressing force after the stretching of the material by the application of the pressing force. For example, if a material having an unpressed and relaxed length of 25.4 mm (one (1) inch) was 50 percent elongated by stretching it to a length of 38.1 mm (1.5 inches) the material had been lengthened by 50 percent and it would have a stretched length that is 150 percent of its relaxed length. If this example stretched material were to contract, that is, it would recover to a length of 27.94 mm (1.1 inches) after the release of the pressing and stretching force, the material would have recovered 80 percent (10.16 mm (0.4 inches) ) of its lengthening.

Suitable materials for use in the preparation of the thermoplastic elastomeric fiber herein include elastomeric diblock, triblock or multiblock copolymers, such as olefinic copolymers, such as styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene / butylene- styrene, or styrene-ethylene / propylene-styrene, such as those available from the Shell Chemical Company, under the trade designation Kraton elastomeric resin; polyurethanes, such as those available from E. I. Du Pont de Nemours Co., under the trade name Polyurethane Lycra; polyamides, such as polyester block amides available from Ato Chemical Company, under the trade name of polyester block amide Pebax; or polyesters, such as those available from E. I. D? Pont de Nemours Co., under the trade name Hytrel polyester.

A number of block copolymers can be used to prepare the thermoplastic elastomeric fibers useful in this invention. Such block copolymers generally comprise an elastomeric middle block portion and a thermoplastic end block portion. The block copolymers used in this invention generally have a three-dimensional physical cross-linking structure below the glass transition temperature (Tg) of the end block portion and are elastomeric. Block copolymers are also thermoplastic in the sense that they can melt above the Tg of the end block, form and resolidify several times with little or no change in physical properties (assuming a minimum of oxidative degradation).

One way to synthesize such block copolymers is to polymerize the thermoplastic end block portions separately from the elastomeric middle block portions. Once the middle block and block end parts have been formed separately, they can be linked. Typically, the middle block parts can be obtained by polymerizing unsaturated C4-C10 di- and tri-hydrocarbons, such as, for example, dienes such as butadiene, isoprene and the like, and thionars such as 1,3,5-heptatriene and the like. . When an end block part A is joined to an intermediate block part B a block copolymer unit AB is formed, which unit can be coupled by various techniques or with several coupling agents C to provide a structure such as ABA which it is believed that they comprise two AB blocks, joined together in a tail-to-tail arrangement ABCBA. By a similar technique, a radial block copolymer having the formula (AB) nC can be formed, wherein C is the hub or center polyfunctional coupling agent and n is a number greater than 2. Using the coupling agent technique, the functionality of C determines the number of branches AB.

The end block portion A generally comprises a poly (vinylarene) such as polystyrene, having an average molecular weight of between 1,000 and 60,000. The middle block part B generally comprises an essentially amorphous polyolefin such as polyisoprene, ethylene / propylene polymers, ethylene / butylene polymers, polybutadiene and the like or mixtures thereof having an average molecular weight of between about 5,000 and about 450,000. The molecular weight of the block copolymer is suitably from about 10,000 to about 500,000 and more suitably from about 200,000 to about 300,000. Any residual unsaturation in the middle block portion of the block copolymer can selectively be hydrogenated so that the content of the olefinic double bonds in the block copolymers can be reduced to a residual part of less than 5 percent and suitably less than about 2 percent. Such hydrogenation tends to reduce the sensitivity to oxidative degradation and may have beneficial effects on the elastomeric properties.

Suitable block copolymers used in this invention comprise at least two essentially polystyrene end block parts and at least one middle ethylene / butylene block part essentially. As an example, ethylene / butylene typically can comprise the major amount of the repeating units in such a block copolymer and can constitute, for example, 70 percent by weight or more of the block copolymer. The block copolymer, if it is radial, can have three or more arms, and good results can be obtained with, for example, four, five or six arms. The middle block portion can be hydrogenated if desired.

Linear block copolymers, such as A-B-A, A-B-A-B-A, or the like are suitably selected on the basis of the end block content, the large end blocks being preferred. For polystyrene-ethylene-butylene-polystyrene block copolymers, an excess styrene content of about 10 percent by weight is suitable, such as from about 12 to about 30 percent by weight. With the upper styrene fabric, the polystyrene end block portions generally have a relatively high molecular weight. A commercially available example of such a linear block copolymer is a styrene-ethylene / butylene-styrene block copolymer which contains about 13 weight percent of styrene units, and essentially the remainder being ethylene-butylene units, commercially available from Shell Chemical Company, under the trade designation of KRATON G1657 elastomer resin. Typical properties of the KRATON G1657 elastomeric resin are reported to include a tensile strength of 2 x 106 kilograms per square meter, (3400 pounds per square inch) a 300 percent modulus of 1.4 x 105 kilograms per square meter ( 350 pounds per square inch), a 750 percent elongation at break, a Shore A hardness of 65, and a Brockfield viscosity, when it is a 25 percent by weight concentration, in toluene solution of about 4.2 Paßs (4200 centipoise) at room temperature.

The thermoplastic elastomeric fiber can generally be formed of any thermoplastic elastomeric composition capable of being extruded into fibers. A thermoplastic elastomeric fiber suitable for the present invention comprises fibers formed by melt blowing. Such meltblown fibers are typically very fine fibers prepared by extruding liquefied, or melted, fiber-forming copolymers through holes in a matrix into a high velocity gas stream. The fibers are attenuated by the gas stream and subsequently solidified. The resulting stream of the solidified thermoplastic elastomeric fibers can be collected, as for example, on a grid placed in the gas stream, as a tangled coherent fibrous mass. Such a tangled fibrous mass is characterized by an extreme entanglement of the fibers. This entanglement provides coherence and resistance to the resulting fabric structure. Such entanglement also adapts the fabric structure to constrict or trap the wettable short fiber within the structure after the wet mop fiber has been incorporated into the fabric structure, either during or after the formation of the fabric structure. . The thermoplastic elastomeric fibers are generally sufficiently entangled so that it is generally impossible to remove a complete fiber from the fiber mass or to draw a fiber from the beginning to the end.

As used herein, the constriction or entrapment of the wettable short fiber within the structure of the fabric is intended to represent that the wettable short fiber is substantially immobilized, so that the wettable short fiber is not free to move essentially or migrate in or out. outside the woven structure. Such constraint or entrapment, for example, can be done by means of adhesive or by entangling the thermoplastic elastomeric fibers of the fabric structure.

The thermoplastic elastomeric fiber used herein may be circular, but may also have other geometries in cross section such as elliptical, rectangular, triangular or multi-lobal.

The thermoplastic elastomeric fiber is suitably wettable. The thermoplastic elastomeric fiber can be made wettable by first preparing the thermoplastic elastomeric fiber and subsequently subsequently applying a hydrophilizing surface treatment to the fiber.

Alternatively, the thermoplastic elastomeric fiber was prepared comprising a polymeric hydrophilizing component. In general, any polymer component capable of being polymerized with the thermoplastic elastomer component, capable of hydrophilizing the resulting copolymer material to make it moistenable according to the definition of the present invention, wherein the hydrophilizing component does not essentially affect the elastic properties of the fiber prepared, is suitable for use in the present invention. Polymeric hydrophilizing components suitable for use in the present invention include polyethylene oxide or polyvinyl alcohol.

The thermoplastic elastomeric fiber should be present in the absorbent structure of the present invention in an amount effective to result in the desired absorbent and elastic properties described herein. In particular, the thermoplastic elastomeric fiber must be present in the absorbent structure of the present invention in more than a minimum effective amount to substantially increase the elasticity of the elastomeric absorbent structure. At the same time, the thermoplastic elastomeric fiber should be present in the elastomeric absorbent structure of the present invention in less than an excessive amount so that the liquid absorbent properties of the elastomeric absorbent structure are not substantially adversely affected.

The thermoplastic elastomeric fiber is desirably present therefore in an elastomeric absorbent structure of the present invention in an amount of from about 20 to about 80 weight percent, suitably from about 25 to about 75 weight percent, and more suitably from about 30 to about 70 percent by weight, with all percents by weight based on the total weight of the wettable short fiber and the thermoplastic elastomeric fiber in the absorbent structure.

Although the main components of the elastomeric absorbent structure of the present invention have been described above, such an elastomeric absorbent structure is not limited thereto and may include other components that do not adversely affect the desired absorbent and elastic properties of the elastomeric absorbent structure. . Exemplary materials which may be used as additional components may include, without limitation, pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, particulates, binder fibers, and aggregate materials to improve the processability of the components.

For example, in order to improve the absorbent capacity of an absorbent structure it is known to incorporate a polymeric hydrogel-forming material into the absorbent structure. The introduction of the hydrogel-forming polymeric material into such an absorbent structure generally allows the use of a shorter, less wettable fiber, since the hydrogel-forming polymer material generally has a higher absorption capacity on a gram basis per gram than that of short wettable fiber. In addition, such a hydrogel-forming polymeric material is generally less sensitive to pressure than the wettable short fiber. Thus, the use of the hydrogel-forming polymer material generally allows the production and use of a thinner and smaller disposable absorbent product. As such, the absorbent structure of the present invention can also optionally include a hydrogel-forming polymeric material.

As used herein, "the hydrogel-forming polymeric material" is meant to mean a high-absorbency material commonly referred to as a superabsorbent material. Such high-absorbency materials can generally be capable of absorbing a quantity of liquid, such as synthetic urine, an aqueous salt water solution of 0.9 percent by weight or body fluids such as menstrual fluids, urine, or blood. , at least about 10, suitably about 20, and up to about 100 times the weight of the superabsorbent material at the conditions under which the superabsorbent material is being used. Typical conditions include, for example, a temperature between about 0o to about 100oc and suitably at ambient conditions, such as about 23 oC and about 30 to about 60 percent relative humidity. As the liquid is absorbed, the superabsorbent material typically swells and forms a hydrogel.

The hydrogel-forming polymeric material can be formed of an organic hydrogel material which can include natural materials, such as agar, pectin and guar gum, as well as synthetic materials, such as synthetic hydrogel polymers. Synthetic hydrogel polymers include, for example, carboxymethyl cellulose, alkali metal salts of polyacrylic acid, polyacrylamides, polyvinyl alcohol, ethylene maleic anhydride copolymers, polyvinyl ethers, hydroxypropyl cellulose, polyvinyl morpholinone. , vinyl sulfonic acid polymers and copolymers, polyacrylates, polyacrylamides, and polyvinyl pyridines. Other suitable hydrogel polymers include the hydrolyzed acrylonitrile grafted starch, the acrylic acid grafted starch, and the isobutylene maleic anhydride copolymers and mixtures thereof. The hydrogel polymers are preferably only slightly degraded to render the material essentially insoluble in water but swellable in water. The gradient can, for example, be made by irradiation or covalent, ionic, Van der Waals or hydrogen bonding. Suitable superabsorbent materials are typically available from various commercial vendors, such as from The Dow Chemical Company, Hoechst Celanese, Allied Colloids Limited or Stockhausen, Inc.

The hydrogel-forming polymeric material, used in the absorbent structures or in the products of the present invention, must suitably be capable of absorbing a liquid under an applied load. For the purposes of this application, the ability to form a hydrogel-forming polymeric material to absorb a liquid under an applied load and therefore perform the work is quantified as the Absorbency Under Load (AUL) value. The absorbency value under load was expressed as the amount (in grams) of a sodium chloride solution of 0.9 percent by aqueous weight which can absorb the polymeric hydrogel-forming material in about 60 minutes per gram of polymeric forming material of hydrogel under a load of about 2.0 kilopascals (approximately 0.3 pounds per square inch) while restricting swelling in the normal plane to the applied load. The hydrogel-forming polymer material employed in the absorbent structures of the present invention suitably exhibits an absorbency value under load of at least about 15, more suitably at least about 20 and up to about 50 grams of the liquid per gram of hydrogel-forming polymeric material. The method by which the absorbency value under load can be determined, for example, is set forth in detail in U.S. Pat. Nos. 5,149,335 or A-5,247,072 incorporated herein by reference.

Suitably, the polymeric hydrogel-forming material is in the form of particles which, in the non-swollen state they have maximum cross-sectional diameters within the range of from about 50 μm to about 1000 μm, preferably within the range of from about 100 μm to about 800 μm as determined by screening screen analysis. according to the American Society for Testing and Materials (ASTM) test method D-1921. It is understood that the particles of the hydrogel-forming polymer material falling within the ranges described above may comprise solid particles, porous particles, or they may be agglomerated particles comprising many smaller particles agglomerated into particles falling within the described size ranges. The hydrogel-forming polymeric material is typically present in an absorbent structure or in a disposable absorbent product of the present invention in an amount effective to result in the absorbent structure or the product being capable of absorbing a desired amount of liquid. The hydrogel-forming polymeric material is beneficially present in an absorbent structure in an amount of from about 15 to about 60 percent by weight, suitably in an amount of from about 20 to about 50 percent by weight, and more suitably from about 25 to about 40 percent by weight, based on the total weight of the hydrogel-forming polymeric material, of wettable short fiber and of the thermoplastic elastomeric fiber in the absorbent structure.

Because the hydrogel-forming polymer material present in the elastomeric absorbent structure of the present invention can be present at high concentrations, the absorbent and elastomeric structures of the present invention can be relatively thin and light in weight, have a relatively small volume, and still work in a desirable way.

The elastomeric absorbent structure of the present invention suitably comprises a fibrous matrix comprising the thermoplastic elastomeric fiber wherein the fibrous matrix restrains or traps the wettable short fiber and, optionally, a polymeric hydrogel-forming material.

The fibrous matrix can be formed by fibers placed by air, through a meltblown or meltblowing process, a carding process, a wet-laying process, or essentially through any other means known to those skilled in the art. in art to form a fibrous matrix.

Methods for incorporating the wettable short fiber and optionally, a hydrogel-forming polymeric material into the fibrous matrix are known to those skilled in the art. Suitable methods include incorporating the wettable short fiber and optionally, a hydrogel-forming polymeric material into the fiber matrix during matrix formation, such as by air placement of the fibrous matrix and fiber fibers. wetting and / or the hydrogel-forming polymer material at the same time or by wet-laying the fibers of the fibrous matrix and the wettable short fiber and / or the hydrogel-forming polymer material at the same time. Alternatively, it is possible to apply the wettable short fiber and / or a hydrogel-forming polymeric material to the fibrous matrix after formation of the fibrous matrix. Other methods include sandwiching the hydrogel-forming polymeric material between two sheets of material, at least one of which is impermeable to liquid and fibrous. The hydrogel-forming polymeric material may be generally located between the two sheets of material or may be located in discrete bags formed by the two sheets. It is preferred that the wettable short fiber is generally evenly distributed within the fibrous matrix. However, the wettable short fiber may be distributed non-uniformly as long as the liquid absorbing properties and the desired elastic properties of the elastomeric absorbent structure are still achieved.

The fibrous matrix may be in the form of an integrally formed and single layer or a composite comprising multiple layers. If the fibrous matrix comprises multiple capable, the layers are preferably in fluid communication with one another, so that a liquid present in a fibrous layer can flow or be transported to the other fibrous layer. For example, the fibrous layers can be separated by cellulosic tissue wrapping sheets known to those skilled in the art.

The hydrogel-forming polymeric material may be distributed in the individual layers in a generally uniform manner or may be present in the fibrous layers as a layer or other non-uniform distribution.

The elastomeric absorbent structure of the present invention can generally be of any size or dimension provided that the elastomeric absorbent structure exhibits the desired absorbent and elastic characteristics as described herein. Typically, the elastomeric absorbent structure will have a volume of at least about 18 cubic centimeters, such as with a width of about 6 centimeters, a length of about 6 centimeters, and a depth of about 0.5 centimeters. Suitably, the elastomeric absorbent structure will have a volume of at least about 60 cubic centimeters such as with a width of about 10 centimeters, a length of 6 centimeters and a depth of about 1 centimeter.

The elastomeric absorbent structure of the present invention suitably has a basis weight of about 100 grams per square meter (g / sm) to about 1000 g / sm, more suitably from about 200 g / sm to about 800 g / sm , and more suitably from about 300 g / sm to about 700 g / sm.

The elastomeric absorbent structure of the present invention suitably has a density of about 0.03 grams per cubic centimeter (g / cc) to about 0.5 g / cc, more suitably from about 0.05 g / cc to about 0.45 g / cc, and more suitably from about 0.08 g / cc to about 0.4 g / cc.

The elastomeric absorbent structure of the present invention can also be used or combined with other absorbent structures, with the elastomeric absorbent structure of the present invention being used as a separate layer or as a single zone or area within a larger composite absorbent structure. The elastomeric absorbent structure of the present invention can be combined with other absorbent structures by methods well known to those skilled in the art, such as by using adhesives or simply by layered the different structures together and holding together the composite structures with, for example, a tissue wrapping sheet.

The elastomeric absorbent structure according to the present invention is suitable for absorbing many liquids such as water, salt water, and synthetic urine, and body fluids, such as urine, menstrual fluids and blood, and is suitable for use in disposable absorbent products such as diapers, incontinence products for adults, and bed pads; in catamenial devices such as sanitary napkins and tampons; and in other disposable absorbent products such as cleansers, bibs, wound dressings and surgical drapes or drapes. Therefore, in another aspect, the present invention relates to a disposable absorbent product comprising an elastomeric absorbent structure as described herein.

The use of the described elastomeric absorbent structure in a disposable absorbent product allows the formation of a disposable absorbent product which is capable of rapidly receiving an unloaded liquid, which is a thin disposable absorbent product and whose disposable absorbent product has desired elastic properties .

In one embodiment of the present invention, there is provided a disposable absorbent product, which disposable absorbent product comprises a liquid-permeable top sheet, a backsheet attached to the topsheet, and an elastomeric absorbent structure positioned between the top sheet and the sheet. backup.

While one embodiment of the invention has been described in terms of the use of an elastomeric absorbent structure in a diaper for infement, it should be understood that the elastomeric absorbent structure is equally suitable for use in other disposable absorbent products known to those skilled in the art.

Turning now to the drawings, Figure 1 illustrates a disposable diaper 11 according to one embodiment of the present invention. The disposable diaper 11 includes a backsheet 12, an upper sheet 14, and an elastomeric absorbent structure 16, located between the backsheet 12 and the top sheet 14. The elastomeric absorbent structure 16 is an absorbent structure according to the present invention. invention.

Those skilled in the art will recognize suitable materials to be used as the top sheet and the backing sheet. Exemplary materials suitable for use as the topsheet and liquid permeable materials such as polypropylene and spunbonded polyethylene having a basis weight of from about 15 to about 25 grams per square meter. Exemplary materials suitable for use as the backing sheet are liquid impervious materials, such as polyolefin films, as well as vapor permeable materials, such as microporous polyolefin films.

Absorbent products and structures according to all aspects of the present invention are generally subjected, during use, to multiple insults of a body fluid. Thus, absorbent products and structures are desirably capable of absorbing multiple insults of body fluids in amounts to which the products and absorbent structures will be exposed during use. Insults are usually separated from each other for a period of time.

It is desirable that the elastomeric absorbent structure of the present invention exhibit both desirable elastic properties and desirable liquid absorbent properties.

The desirable liquid absorbent properties of the elastomeric absorbent structure of the present invention include exhibiting an effective specific saturated liquid retention capacity.

As used herein, the "effective liquid saturated retention capacity" of an absorbent structure is intended to represent the amount of liquid that the absorbent structure can hold, on one gram of liquid per gram of base of absorbent structure, when gives a sufficient amount of time to reach a 100 percent saturation with an aqueous salt water solution of 0.9 percent by weight at room temperature and when externally applied pressure at around 3.45 kPa (0.5 psi) is applied to the saturated structure. The specific liquid saturated retention capacity of an absorbent structure can be determined according to the procedure described in the Test Methods section given herein.

The elastomeric absorbent structure of the present invention suitably has a value of Saturated Retention Capacity of Specific Liquid, on one gram of liquid absorbed to one gram of base of absorbent structure (g / g) of at least about 5 g / g, suitably at least about 7 g / g, more suitably at least about 9 g / g, more suitably at least 11 g / g and up to about 50 g / g.

An absorbent structure in the form of a disposable absorbent product will generally be used on a wearer in both a dried and liquid condition. As such, it is generally desired that the absorbent structure exhibits effective elastic properties in both a dry and saturated liquid condition at 100 percent. Therefore, the desired elastic properties of the elastomeric absorbent structure of the present invention include exhibiting a maximum stretch in both a dry condition as well as a. a 100 percent saturated liquid condition and an effective stretch recovery in both a dry condition as well as in a 100 percent saturated liquid condition.

The "maximum stretch" of a material is meant to represent the amount of stretch or extension a material can exhibit before the material breaks or, in other words, cohesively fails. As used herein, all stretch or extensions are expressed as one percent of the undrawn or relaxed length of a material. Therefore, 100 percent stretch or extension means that the unstressed material has stretched to twice its relaxed length, or not stressed. The maximum stretch of a material can be determined according to the test methods described herein.

A material will often exhibit a different maximum stretch value when it is in the dry condition compared to when the material is in a 100 percent liquid saturated condition. This is because the liquid that saturates the material will frequently interact with the material and will affect the elastic properties of the material. As will be recognized by one skilled in the art, such a difference in the maximum stretch values of a material when it is in a dry condition as compared to when the material is in a 100% liquid saturated condition, will depend on the composition and the structure of the material.

As will be appreciated by one skilled in the art, a material such as an absorbent structure will trap a relatively minor amount of the liquid, such as water, within the material before use. For example, the liquid can be absorbed by the absorbent structure of moisture in the air. Such an absorbent structure is still intended to be considered in a dry condition for the purposes of the present invention. Therefore, as used herein, the "dry condition" of a material is meant to represent that material comprising an amount of liquid that is suitably less than about 5 percent by weight, more suitably less than about 3 percent. by weight, and more suitably from about 1 percent by weight, based on the total weight of the material.

As used herein, the term "100 percent liquid saturated condition" of a material is intended to show that the material comprises an amount of the liquid that is about 100 percent of the saturated liquid absolute retention capacity of the material. material.

It is desired that the elastomeric absorbent structure of the present invention does not exhibit a maximum stretch value, in either a dry condition or a 100% saturated liquid condition that is too low since it will indicate that the elastomeric absorbent structure is not sufficiently elastic.

Thus, the elastomeric absorbent structure of the present invention will exhibit a maximum stretch value in a dry condition that is greater than about 60 percent, beneficially greater than about 80 percent, adequately greater than about 100 percent, more adequately more than about 120 percent and more adequately more than about 140 percent.

The elastomeric absorbent structure of the present invention also exhibits a maximum stretch value in a 100 percent liquid saturated condition that is greater than about 150 percent, suitably greater than about 200 percent, more adequately greater than about 250 percent, and more appropriately greater than about 300 percent.

In one embodiment of the present invention, the elastomeric absorbent structure exhibits a maximum stretch value in a 100 percent liquid saturated condition that is greater than the maximum stretch value exhibited by the elastomeric absorbent structure in a dry condition. This is believed to occur because the liquid saturating the elastomeric absorbent structure helps to break up any hydrogen bond that occurs between the wettable short fibers, thereby improving the elastic properties of the elastomeric absorbent structure.

The "stretch recovery" of a material is intended to represent the amount of recovery exhibited by a material upon the termination of a pressing force after stretching of the material by the application of the pressing force. As used herein, all stretch recovery values are expressed as the percent of an elongated part of the length at which the material recovers after being allowed to relax. As used herein, all stretch recovery values are intended to be determined when a material is stretched by about 20 percent to about 20 minutes and then allowed to relax. For example, if a material having an unpressed and relaxed length of 25.4 mm (one (1) inch) would be lengthened by 20 percent by stretching to a length of 30.48 mm (1.2 inches), the material would have been lengthened by 20 percent. and it would have a stretched length that. It is 120 percent of your relaxed length. If this example stretched material were to contract, this would recover to a length of 26.42 mm (1.04 inches) after the release of the pressing and stretching force, the material would have a stretch recovery of 80 percent, having recovered 80 percent (4.04 mm (0.16 inches)) of its elongation. Stretch recovery of a material can be determined according to the test methods described herein.

The elastomeric absorbent structure of the present invention exhibits a stretch recovery value in a dry condition that is greater than about 70 percent, suitably greater than about 75 percent, more adequately greater than about 80 percent, and more appropriately more than about 90 percent.

The elastomeric absorbent structure of the present invention also exhibits a stretch recovery value in a 100 percent liquid saturated condition that is greater than about 75 percent, suitably greater than about 80 percent, more adequately greater than about of 85 percent and more appropriately greater of around 90 percent.

TEST METHODS Saturated Liquid Retention Capacity The saturated liquid retention capacity was determined as follows. The material to be tested, having a moisture content of less than about 7 percent by weight, was weighed and immersed in an excess amount of an aqueous salt water solution of 0.9 percent by weight at temperature environment (around 23oC). The material to be tested was allowed to remain submerged for around 20 minutes. After 20 minutes of immersion, the material 31 was removed, and referring to Figure 2, it was placed on a TEFLON "3 ^ 3 coated fiberglass grating having 0.6 cm (0.25 inch) openings (commercially available from Taconic Plastics, Inc., of Petersburg, New York) which in turn was placed on a vacuum box 30 and covered with a flexible rubber dam material 32. A vacuum of about 3.5 kilopascals (about 0.5 pounds per square inch) was pulled over the vacuum box for a period of about 5 minutes with the use of, for example, a vacuum gauge 36 and a vacuum pump 38. The material being tested is then removed from the grid The amount of liquid retained by the material being tested was determined by subtracting the dry weight of the material from the wet weight of the material (after the application of the vacuum) and was reported as the saturated retention capacity of the material. absolute liquid in grams of the liquid retained. If desired, the weight of the retained liquid can be converted to liquid volume by using the test liquid density and reported as the saturated reagent capacity of absolute liquid in millimeters of retained liquid. For relative comparisons, this absolute liquid saturated retention capacity value can be divided by the weight of the material 31 to give the specific liquid saturated retention capacity in grams of liquid retained per grams of tested material. This is reported as the Saturated Fluid Retention Capacity value. If a material, such as hydrogel-forming polymeric material or fiber, is pulled through the fiberglass grid while it is on the vacuum box, a grid should be used having smaller openings. Alternatively, a piece of tea bag or similar material may be placed between the material and the grid and the final value adjusted for the liquid required by the tea bag or similar material.

Maximum Stretching The maximum stretch of a material was evaluated by using a voltage tester, such as an Instron Model 4201 with Microcon II from Instron Corporation, of Canton, Massachusetts. The machine was calibrated by placing a weight of 100 grams in the center of an upper jaw, perpendicular to the jaw and hung without obstruction. The voltage cell used is an electrically calibrated 5 kilogram calibrated load cell. The weight is then displayed on the Microcon display benefit. The process was carried out at a temperature with an atmosphere at the standard condition, such as around the temperature of about 23 ° C and a relative humidity of about 20 percent.

A rectangular sample with a width of about 25.4 mm (1 inch), a length of about 76.2 mm (3 inches), a thickness of about 2.54 mm (0.1 inches), and a basis weight of between about 300 to about 700 grams per square meter was weighed and the pressure was applied to the sample to reach a desired density. The sample was then placed in the pneumatic action jaws with rubber coated gripping faces of 25.4 by 76.2 mm (1 inch by 3 inches). The calibrate length (the length of the sample currently being stretched) is around 50.8 mm (2 inches) and the crosshead speed is around 304.8 cm / min (120 inches per minute). Cross-head velocity is the rate at which the upper jaw moves upward pulling the sample to failure. The maximum displacement of the jaw is around 355.6 mm (14 inches). The maximum stretch is the stretched length of the material to the fault, recorded as one percent of the original length (50.8 mm (2 inches)) of the unstressed sample. The maximum stretch was evaluated for the material in both a dry condition and a 100 percent liquid saturated condition. The maximum stretch for the material in a 100 percent liquid saturated condition is done by placing a dry sample on the jaws of the tester and then moistening the sample with a desired amount of a 0.9% saltwater solution, as shown. determined by the saturated retention capacity of absolute liquid of the material.

A time of 10 minutes was left for the sample to equilibrate.

Stretch Recovery Stretch recovery of a material was evaluated by using a voltage tester such as an Instron Model 4201 with Microcon II from Instron Corporation, of Canton, Massachusetts. The machine was calibrated by placing a weight of 100 grams in the center of the upper jaw, perpendicular to the jaw and hanging without obstruction. The voltage cell used is an electrically calibrated self-identifying load cell. The weight is then displayed on the Microcon display benefit. The procedure was carried out in a room with an atmosphere at the standard condition such as around a temperature of about 23 ° C and a relative humidity of about 50 percent.

A rectangular sample with a width of about 25.4 mm (1 inch) and a length of about 76.2 mm (3 inches) was weighed and pressure applied to the sample to achieve a desired density. The sample is then placed in the pneumatic action jaws with rubber coated gripping faces of 25.4 by 76.2 mm (1 inch by 3 inches). The length of calibration (the length of the sample that is currently being stretched) is around 50.8 mm (2 inches) and the crosshead speed is around 300 millimeters per minute. Cross-head velocity is the rate at which the upper jaw moves upward pulling the sample to failure. The sample was stretched for about 20 percent or about 10.16 mm (0.4 inches), at a stretched measuring length of about 60.96 mm (2.4 inches). The sample was held at this stretched length for about 20 minutes and then allowed to relax by removing the sample from the jaws. The stretch recovery value is the final relaxed length without the original length (50.8 mm (2 inches)) divided by the original length (50.8 mm (2 inches)), and multiplying by 100 percent. Stretch recovery was evaluated for the material in both a dry condition and a 100 percent liquid saturated condition. Stretch recovery for material in a 100 percent liquid saturated condition is done by placing a dry sample on the jaws of the tester and then moistening the sample with a desired amount of a 0.9 percent saltwater solution as was determined by the saturated retention capacity of absolute liquid of the material. A time of 10 minutes was left for the sample to equilibrate.

Example Samples 1-3 are absorbent structures prepared comprising a wettable short fiber and a thermoplastic elastomeric fiber. For the wettable short fiber, a cellulose wood pulp was used, prepared from about 80 percent soft wood from the south and around percent hardwood.

For the thermoplastic elastomeric fiber, a block copolymer was prepared comprising about 75 weight percent of a styrene-ethylene / butylene-styrene block copolymer which contains about 13 weight percent of styrene units, essentially the rest being ethylene-butylene units commercially available from Shell Chemical Company, under the trade designation Elastomeric resin KRATON G1657, at about 25 weight percent of a processing aid which was a polyethylene wax, commercially available from Quantum Chemical Company , under the trade designation NA 601 and having a melt flow rate of around 2000 grams per 10 minutes. These materials were mixed together before being extruded to a fiber with an average diameter of around 5 to about μm.

The thermoplastic elastomeric fiber was formed by meltblowing into a composite fabric entangled with the hydrogel-forming polymeric material fed into the meltblown stream and the short fiber fed into the composite fabric structure with a pick-up roller. After the formation of the thermoplastic elastomeric fibers, a wetting agent was applied to the fibers. The wetting agent was a nonionic surfactant octylphenoxypolyethoxyethanol, available from Rohm & Haas Company, under the designation of Triton X-102 surfactant trade.

Sample 4 was a control sample comprising a hydrogel-forming polymeric material and a wettable short fiber. For the hydrogel-forming polymeric material a high-absorbency poly (acrylic acid) material available from Stockhausen, Inc., under the trade designation Favor SAB 870, was used. For the humid short fiber, the same cellulose wood pulp was used that was used in sample 1-3. Sample 4 was prepared by an air-forming process where the wettable short fibers and the hydrogel-forming polymeric material were mixed by an air stream and then placed by air inside a fabric on top of a box of air. empty. The composite fabric formed was then wrapped with a light weight base tissue paper to allow for handling and sample testing.

The relative and absolute basis weight amounts used in the different materials for the various samples are indicated in Table 1. Base weight amounts are given in grams per square meter (g / sm) of the absorbent structure formed. The initial dry density of each sample material was around 0.17 grams per cubic centimeter.

Samples were evaluated for maximum stretch and stretch recovery according to the procedures described here. The results are described in Table 2. For some of the samples, exact measurements could not be made of the maximum stretch and stretch recovery values even when the values were set to be greater than or less than the specific values.

Although the invention has been described in detail with respect to the specific embodiments thereof, it will be appreciated by those skilled in the art to achieve an understanding of the foregoing, which can easily be conceived, alterations, variations and equivalents of these modalities. Therefore, the scope of the present invention should be established as that of the appended claims and any equivalents therein.

TABLE 1 Fiber Agglutinante Hidrogel Fiber Short Sample Weight Base Weight Base Weight Base Base Tot; No. (cr / sm) _% _. cr / sm)% (cr / sml 1% (cr / sm) 1 181 31 0 0 404 69 585 2 269 46 0 0 316 54 585 3 357 61 0 0 228 39 585 4 * 0 0 315 35 585 65 900 * It is not an example of the present invention.

TABLE 2 Sample Stretching Maximum Stretch Recovery No. Dry Saturated Dry Saturated 1 30 90 > 80 > 90 2 160 > 300 > 80 > 90 3 175 > 300 > 80 > 90 4 * < 5 < 5 0 > 90 * It is not an example of the present invention

Claims

R E I V I N D I C A C I O N S

1. An elastomeric absorbent structure comprising: a) from about 20 to about 80 percent by weight, preferably from about 25 to 75 percent by weight of wettable short fiber; I b) from more than 20 to about 80 percent by weight, preferably from about 25 to 75 percent by weight of thermoplastic elastomeric fiber; wherein all percents by weight are based on the total weight of the wettable short fiber and the thermoplastic elastomeric fiber in the elastomeric absorbent structure.

2. The elastomeric absorbent as claimed in clause 1, characterized in that the elastomeric absorbent structure has a value of Saturated Retention Capacity of Specific Liquid of at least about 5 grams, preferably about 7 grams of liquid absorbed at one gram of absorbent structure base.

3. The elastomeric absorbent as claimed in at least one of the preceding clauses, characterized in that the elastomeric absorbent structure has a Maximum Stretch value at a dry condition that is greater than about 60 percent, preferably about 100 percent. hundred.

4. The elastomeric absorbent as claimed in at least one of the preceding clauses, characterized in that the elastomeric absorbent structure has a Maximum Stretch value at a 100% liquid saturated condition that is greater than about 150 percent, preferably about 200 percent.

5. The elastomeric absorbent as claimed in at least one of the preceding clauses, characterized in that the elastomeric absorbent structure has a Stretch Recovery value in a dry condition that is greater than about 70 percent, preferably about 75 percent. percent.

6. The elastomeric absorbent as claimed in at least one of the preceding clauses, characterized in that the elastomeric absorbent structure has a Stretch Recovery value in a 100% liquid saturated condition that is greater than about 75 percent , preferably about 80 percent.

7. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the wettable short fiber has a fiber length of from about 0.1 to about 15 centimeters.

8. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the wettable short fiber is selected from the group consisting of cellulosic fibers, textile fibers and synthetic polymer fibers.

9. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the wettable short fiber is a wood pulp fiber.

10. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the thermoplastic elastomeric fiber is a melt-blown fiber comprising a block copolymer.

11. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the thermoplastic elastomeric fiber is wettable.

12. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the elastomeric absorbent structure exhibits a value of Saturated Retention Capacity of Specific Liquid of at least about 7 grams of liquid absorbed to one gram of absorbent structure base.

13. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the elastomeric absorbent structure exhibits a Maximum Stretch value in a dry condition that is greater than about 100 percent.

14. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the elastomeric absorbent structure exhibits a Maximum Stretch value in a 100 percent liquid saturated condition that is greater than about 200 percent.

15. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the elastomeric absorbent structure exhibits a Stretch Recovery value in a dry condition that is greater than about 75 percent.

16. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the elastomeric absorbent structure exhibits a Stretch Recovery value in a 100 percent liquid saturated condition that is greater than about 80 percent .

17. The elastomeric absorbent structure as claimed in at least one of the preceding clauses further characterized in that it comprises a polymeric hydrogel-forming material.

18. The elastomeric absorbent structure as claimed in at least one of the preceding clauses further characterized in that it comprises from about 15 to about 60 weight percent of a polymeric hydrogel-forming material, based on the total weight of the material hydrophilic short fiber hydrogel forming material, and thermoplastic elastomeric fiber in the elastomeric absorbent structure.

19. The elastomeric absorbent structure as claimed in at least one of clauses 17 to 18, characterized in that the hydrogel-forming polymeric material is a polyacrylate material.

20. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the elastomeric absorbent structure comprises a fibrous material comprising the thermoplastic elastomeric fiber, wherein the fibrous matrix constrains the wettable short fiber and the forming polymeric material of hydrogel.

21. The elastomeric absorbent structure as claimed in at least one of the preceding clauses characterized in that the thermoplastic elastomeric fiber is a blow molded thermoplastic elastomeric melt fiber comprising a polyolefin.

22. A disposable absorbent product comprising a liquid pervious top sheet, a backsheet and an elastomeric absorbent structure positioned between the top sheet and the backsheet, wherein an elastomeric absorbent structure is enclosed according to at least one of the preceding clauses. SUMMARY An elastomeric absorbent structure containing moist mountable short fiber and thermoplastic elastomeric fiber is described. The elastomeric absorbent structure exhibits improved elastic properties compared to an otherwise essentially identical absorbent structure without any thermoplastic elastomeric fiber. Also disclosed is a disposable absorbent product containing such an elastomeric absorbent structure.