CZ20003516A3 - An elastic component and a disposable garment with improved body fit throughout the wear - Google Patents

Abstract

An elastic member (70) comprising an elastomeric material (124) having a first surface (150) and a second surface (152) opposite thereto, and a first cover layer (122) attached to the first surface of the elastomeric material, wherein the elastomeric material has a retained retention force of at least about 15.75 g/cm after 12 hours at 50% stretch. A disposable garment comprising a containment assembly (41) having a front region (26), a back region (28) and a crotch region (30) between the front and back regions, at least one pair of side panels (46, 48) extending laterally outwardly from the containment assembly in the front or back region. At least one of the side panels comprises an elastomeric material extending laterally outwardly from the containment assembly; wherein said elastomeric material has a retained retention force of at least about 15.75 g/cm after 12 hours at 50% stretch. The containment assembly (41) includes a liquid pervious topsheet (24), a liquid impervious backsheet (22) bonded to the topsheet, and an absorbent core (25) disposed between the topsheet and backsheet.

Description

Technical field

The invention relates to elastic components and disposable clothing components. Examples of such disposable components include disposable underwear, disposable diapers including pull-on diapers and training pants, and disposable menstrual panties. The invention more particularly relates to elastic components and disposable clothing components that have improved fit to the skin or body throughout their use.

State of the art

Elastic components have been used in the past in a variety of disposable products, including sweatbands, bandages, and disposable underwear items including disposable diapers and incontinence products. As used herein, the term elastic component refers to an elastically extensible single layer material or materials of two or more layers, often referred to as an elastic laminate, comprising at least one elastically extensible single layer material. These products are generally expected to provide a good fit to the body and/or skin of the wearer throughout their entire period of use, by using suitable elastic components. Examples of such elastic laminates that have been used in the past include composite materials made of a gatherable material attached to an elastic material, composites made of mesh, tissue paper, and microfibers, as well as composite materials made of a central elastic layer, a breathable material, and a layer of adhesive. Examples of these laminates are described in U.S. Patent No. 4,552,863 (Kieck et al.) and U.S. Patent No. 4,977,011 (Smith).

Meanwhile, young children and other incontinent individuals wear disposable articles of clothing, such as diapers, to receive and contain urine and other body exudates. One type of such disposable article, often called the belt type, has a fastening system that holds the disposable article in the waist area of the wearer. The fastening system often uses either an adhesive tape system or a mechanical fastener system. Recently, elastically expandable side panels have been preferred in this type of disposable article because they provide a better fit to the waist area of the wearer by working together with the fastening system. Another type of absorbent article, often called the panty type or pull-on type, has fixed or fixed sides and has become popular for use with children who are able to walk and often those who are toilet trained. These pull-on products have side panels whose edges are sewn together to form two leg openings and a waist opening. In order for these stretchable members to contain body exudates, they need to fit snugly around the wearer's waist and legs, without sagging, sagging, or sliding down from their location on the wearer's lower torso. Examples of such stretchable members are disclosed, for example, in U.S. Patent No. 5,171,239 (Igaue et. al.), in U.S. Patent No. 4,610,681 • ·

(Strohbeen et al.), WO 93/17648, published September 16, 1993, U.S. Patent No. 4,940,464 (Van Gompel et al.), U.S. Patent No. 5,246,433 (Hasse et al.), and U.S. Patent No. 5,569,234 (Buell et al.).

Good performance characteristics of these stretchable side panels are important for these types of disposable products. More specifically, the stretch properties, which include the stretch forces, the return forces, the retention forces, and the usable stretch (extension) of the side panels - are important considerations when making arrangements for stretchable components. The stretch properties provide the wearer and wearer with the overall perceived stretchability during use. These properties also affect the wearer's ability to achieve the appropriate degree of applied stretch (i.e., for normal perceived stretching of the diaper during application or use, the overall amount of resulting stretch is what is desired to achieve/maintain a good fit). A side panel with a relatively high stretch force often facilitates the development of sores from application. A side panel with a relatively high recovery force often causes red marks on the wearer's skin, while a relatively low recovery force causes the product to sag/slip on the wearer. Another side panel, with very little stretch, may not achieve an appropriate level of body fit and may contribute to a diaper design that is uncomfortable for the wearer to wear and difficult to pull on. Still another side panel, with relatively low retention forces, may not stay in position on the wearer and tends to cause sag/slip on the wearer, leading to poor fit and retention.

The above-discussed stretch properties of the elastic components and/or side panels are important for good • · • · · · · * · ♦ • · « · ····· • ·

The essence of the invention

The invention relates to an elastic component comprising an elastomeric material having a first surface and a second surface opposite the first surface, and a first cover layer attached to the first surface of the elastomeric material, wherein the elastomeric material has a retained retention force (RFH12H) of at least about 15.75 g/cm after 12 hours at 50% elongation.

The present invention also relates to a disposable garment comprising a containment assembly (or main structural component, chassis) having a front region, a back region, and a crotch region between the front and back regions; at least one pair of side panels extending outwardly from the containment assembly in the front or back region; and at least one of the side panels comprising an elastomeric material extending laterally outwardly from the containment assembly; wherein the elastomeric material has a retained retention force (RFH12H) of at least about 15.75 g/cm after 12 hours, at 50% stretch. The containment assembly comprises a liquid pervious topsheet, a liquid impervious backsheet bonded to the topsheet, and an absorbent core disposed between the topsheet and the backsheet.

These and other features, aspects and advantages of the present invention will become apparent to one skilled in the art upon reading the present description.

Overview of images in drawings

Although the description concludes with claims specifically defining and distinctly claiming the invention, it is believed that the invention will be better understood from the following description of preferred embodiments thereof, taken in conjunction with the accompanying drawings, in which like numerals are used to designate substantially identical elements, and in which:

Fig. 1 - represents a cross-sectional view of an elastic member /70/ of a preferred embodiment of the present invention.

Fig. 2 - represents a partial enlarged side view of the elastic component /70/, shown in Fig. 1.

Fig. 3 - is a graph showing two cycles of the hysteresis curve of an elastomeric material in a preferred embodiment.

Fig. 4 - is a graph showing the change in retention force at 50% elongation over time, in a preferred embodiment.

Fig. 5 - represents a perspective view of a preferred embodiment of a disposable retractor of the present invention, in a typical user configuration.

Fig. 6 - represents a simplified plan view of the embodiment shown in Fig. 5, in its flat, uncompressed state, illustrating the various parts or zones of the component.

Fig. 7 - represents a sectional view of a preferred embodiment taken along section line 7-7 in Fig. 6.

• ······ • · ♦ · · · • · · ··· ·· · ·

Examples of embodiments of the invention

All cited references are incorporated herein by reference in their entirety. The citation of any reference is not an admission of any determination as to its applicability as prior art to the claimed invention.

As used herein, the term pull-on garment refers to wearable articles that have a defined waist opening and a pair of leg openings and that are pulled onto the body of a wearer by inserting the wearer's legs into the leg openings and pulling the article over the waist. The term disposable is used herein to describe products that are not intended to be washed or otherwise returned to their original condition or reused as such (i.e., are intended to be discarded after a single use and, preferably, recycled, composted, or otherwise disposed of in an environmentally compatible manner). A unitary pull-on member refers to pull-on articles formed from separate parts joined together to form a coordinated unit, but the side panels are not separate elements attached to a separate chassis in that the side panels are formed of at least one layer that also forms the center or chassis of the article (i.e., it does not require separate manipulative parts such as a separate chassis and separate side panels). The pull-on member is also preferably absorbent and absorbs and retains various body exudates excreted by the wearer's body. A preferred embodiment of the pull-on garment member of the present invention is a unitary, disposable absorbent pull-on member, a pull-on diaper 20, shown in Fig. 5. As used herein, the term pull-on diaper refers to pull-on products commonly worn by young children and other incontinent individuals to absorb and retain urine and feces. However, it should be understood that the present invention is also applicable to other pull-on products such as, for example, training pants, incontinence briefs, feminine hygiene items or panties, and the like. The term "portion" as used herein refers to any area or portion of a pull-on diaper. (Although a portion is typically a distinct area or portion, a portion may be somewhat coincident (functionally correspond) to an adjacent portion.) As used herein, the term "attached" includes arrangements where a portion is directly attached to another portion by attaching that portion directly to the other portion, and arrangements where a given portion is indirectly attached to the other portion by attaching that portion to an intermediate portion(s) which are in turn attached to the second portion.

Fig. 1 illustrates an elastic member 70 of the present invention that is elastically extensible in at least one direction. The elastic member 70 includes an elastomeric material 124 having a first surface 150 and a second surface 152 opposite the first surface 150, and a first cover layer 122 that is attached to the first surface 150 of the elastomeric material 124. In a preferred embodiment, the first cover layer 122 is attached to the first surface 150 of the elastomeric material 124 by an adhesive 160, as shown, for example, in Fig. 2. More preferably, the elastomeric member 70 further includes a second cover layer 126 that is attached to the second surface 152 of the elastomeric material 124 by an adhesive 164.

The elastomeric material 124 of the present invention can be formed into a wide variety of sizes, shapes, and forms. In a preferred embodiment, the elastomeric material 124 is in the form of a continuous planar layer. Preferred forms of a continuous planar layer include a mesh, a perforated (or perforated) film, an elastomeric woven or nonwoven material, and the like. In an alternative embodiment, the elastomeric material 124 is in the form of strips (or threads) that are not interconnected to form a continuous planar layer. The continuous planar layer can have any shape that can be conveniently secured in the side panels. Preferred forms of a continuous planar layer include four-sided shapes including a rectangle and a square, a trapezoid, and other polygons.

Elastomeric materials that have been found to be particularly suitable for elastomeric material 124 are styrene block copolymer (copolymer) based foam materials, apertured elastic films, preferably having a thickness of from about 0.05 mm to about 1.0 mm. Other suitable elastomeric materials for elastomeric material 124 include living synthetic or natural rubber, other synthetic or natural rubber materials, elastomeric films (including heat shrinkable elastomeric films), elastomeric woven or nonwoven structures, elastomeric blended materials, and the like.

It has been found that the stretch properties of the elastomeric material 124, such as the first cycle elongation force at 100% elongation (FCEF100%), the first cycle elongation force at 200% elongation (FCEF200%), and the second cycle recovery force at 50% elongation (SCRF50%), are important considerations in the performance of disposable devices. The elastomeric material 124 of the present invention has stretch properties within defined limits. FCEF100% and FCEF200% are measures of the overall perceived stretch during donning/doffing of disposable devices. These two properties also affect the ability of the wearer to achieve a suitable degree of donning stretch. An elastomeric material 124 with a relatively high FCEF100% and FCEF200% may cause difficulty in donning the disposable device on the wearer (i.e., ease of donning). On the other hand, elastomeric material 124 with a relatively low FCEF100% and FCEF 200% may not achieve ...

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appropriate level of fit/body conformability. SCRF50% is also closely related to the fit/body conformability of a disposable component for a given wearer. An elastomeric material 124 with a relatively high SCRF50% tends to cause red bumps on the wearer's skin and may be uncomfortable for the wearer during wear. An elastomeric material 124 with a relatively low SCRF50% may not provide enough elastic force to hold the diaper in place on the wearer and may not provide a good fit to the body.

The values of FCEF100%, FCEF200%, and SCRF50% can be measured using a tensile testing apparatus. The tensile tester includes an upper jaw and a lower jaw positioned below the upper jaw. The upper jaw is movable and connected to a means of measuring tensile force. The lower jaw is fixed to a table (or floor). A test sample (i.e., thermoplastic material to be measured) is prepared, which is about 2.54 cm wide and about 12.75 cm long, and clamped between the upper jaw and the lower jaw so that the effective length (L) of the sample (i.e., the gauge length) is about 5.08 cm. A tensile force is applied to the test sample by the upper jaw. If no tensile force is applied to the sample, it will be at its original length (i.e., 0% elongation). A tensile testing apparatus suitable for use herein is available from Instron Corporation (100 Royall Street, Canton, MA02021, USA), under the trademark Instron 5564.

Fig. 3 shows one preferred example of elongation and restoring force curves for two hysteresis cycles of elastomeric material 124. elongation in the first cycle, restoring force in the first cycle.

Curve E1 represents the force while curve R1 represents the force. Curve E2 (shown in dashed lines) represents the elongation force in the second cycle while curve R2 represents the recovery force in the second cycle. The elongation and recovery properties are measured as follows.

• 9 9 9 9

9 9 9 9 • 9

In the first cycle, the test sample is subjected to an initial stretching force at a crosshead movement of 50.8 cm/min, at approximately 23°C, and held for 30 seconds at 200% elongation. The test sample is then allowed to relax to its original state (i.e., 0°C elongation) by the same amount. The test sample is then left unrestrained for one minute before being subjected to a second stretching force (for the second cycle) at the same magnitude and conditions.

In preferred embodiments, the FCEF100% value of the elastomeric 124 material is at least about 39.4 grams/cm. More preferably, the FCEF100% is between about 47.2 grams/cm to about 86.6 grams/cm, most preferably between about 59.0 grams/cm and 74.84 grams/cm for best fit to the wearer. The FCEF200% is preferably between about 63.0 grams/cm and about 126.0 grams/cm, preferably between about 70.9 grams/cm and about 102.3 grams/cm, and even more preferably between about

78.7 grams/cm and about 94.5 grams/cm.

The SCRF50% value of the elastomeric material 124 is preferably between about 15.7 grams/cm and about 51.1 grams/cm, more preferably between about 25.6 grams/cm and about 41.3 grams/cm, and even more preferably between about 29.5 grams/cm and about 37.4 grams/cm.

It has also been found that the release force of the elastomeric material 124 can significantly affect the release force performance of disposable articles and/or garment components. As used herein, the term release force refers to the gradual reduction in the stretch/recovery forces caused when the material is stretched at a certain stretch force and then held at that stretch state for a certain period of time. In normal use, a disposable diaper is worn for a few hours, and sometimes for about 8 to 12 hours. It is important that the elastomeric material 124 used in disposable components maintain the majority of its stretch/recovery force throughout the wear period. Retention force, which is defined as the second cycle of the stretch force retained φφφ φφφ φφ φφ • φ φ φ φ φ φ φ · φ φ · φ φ φ · • Φ φφ after a certain retention time (e.g., 12 hours) at 50% elongation, is a measurement of the release force of elastomeric materials. For this measurement, the retention force retained after 12 hours at 50% elongation (RFH12H) is used. This RFH12H is defined as the elongation force (g/cm) of the elastomeric material after a force for 50% elongation is applied to the elastomeric material for 12 hours. An elastomeric material with a relatively low RFH12H (in other words, a large force release) cannot provide a permanent fit for disposable products and/or components during use. In particular, when a given disposable component is filled with body exudates and becomes heavy, an elastomeric material used therein with a relatively low RFH12H value tends to cause the component to sag or slide when placed on the lower torso of the wearer.

The RFH12H value is measured using the same tensile testing equipment as the FCEF100%, FCEF200% and SCRF50% values, except that the measurement is made in a constant temperature chamber. A constant temperature chamber suitable for use here is available from Instron Corporation, 100 Royall Street, Canton, MA 02021, USA, under the type code 3119-005. The measurement is made at 37°C with a 2.54 cm wide sample. The effective length of the sample (gauge length) is 5.08 cm. During the measurement, the test sample is subjected to an initial tensile force at a crosshead movement rate of 50.8 cm/min, at about 23°C, and after reaching 200% elongation, it is held at 200% elongation for 30 seconds. The test specimen is then allowed to relax to the original state (0°C elongation) by the same amount. The test specimen is left unrestrained for one minute before being subjected to a second elongation force (for the second cycle) to 50% elongation at the same crosshead speed and is held at 50% elongation for 12 hours.

φ φ φ ΦΦΦΦ φ φφφ ·· φ*

The elastomeric material 124 of the present invention has an RFH12H value of at least about 15.7 grams/cm, preferably at least about 19.7 grams/cm, and even more preferably at least about 23.6 grams/cm.

One preferred example of the change in retention force of an elastomeric material is shown in Fig. 4. In Fig. 4, the vertical axis represents retention force and the horizontal axis represents the time held at 50% elongation (from 0 hours to 12 hours).

In preferred embodiments where the elastomeric material 124 is provided in a zero-strain stretch laminate, such as, for example, the side panel 46 shown in Fig. 7, it is preferred that the elastomeric material 124 have sufficient strength or toughness to not be damaged by the mechanical stretching process. If the elastomeric material 124 is damaged even partially, the elastomeric material 124 tends to be easily crushed or torn by the stress (strain) that is continuously applied to the side panels and thus the elastomeric material 124 during the wearing of the disposable components. Elongation at break (EB) and tear/break resistance (TR) are two mechanical properties to indicate the strength or toughness of the elastomeric material 124 against the mechanical stretching process. Elastomeric materials with relatively low EB or relatively low TR tend to be easily crushed or torn during mechanical stretching procedures or during the use of disposable components.

In preferred embodiments, the elastomeric material 124 has an EB value of at least about 600%, preferably at least about 800%.

EB is measured by applying a continuously increasing force to a sample elastomeric material (i.e., specimen) at a rate

50.8 cm/min., at about 23 °C, and the force applied and the elongation length (EL) are recorded. The sample is about 2.54 cm wide and 9 • 9 • 9 ·· 99

9 9 9 • ·

99

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99 gauge is about 5.08 cm. The EB (%) value is defined by the following expression:

EB = (EL / OL) x 100 (%) (1) where

- EL is the elongation length when the sample is torn by applying excessive force, and

- OL is the original length (i.e. gauge length) of the sample before the force is applied.

The tensile testing apparatus for measuring the EB value herein is available from Instron Corporation (100 Royall Street, Canton, MA02021, USA), under the trademark Instron 5564.

The elastomeric material 124 has a tear resistance (TR) of at least about 16 hours, more preferably at least about 24 hours. To measure the TR value, a force is continuously applied to a sample elastomeric material (i.e., a sample) that causes 100% elongation. Accordingly, the sample is stretched to 100% elongation and maintained in a constant temperature water bath at 35°C. A constant temperature water bath suitable for use herein is available from Yamato Co., Tokyo, Japan, under the code designation BK 43. The sample size is about 3.60 cm wide and about 3.81 cm long. The TR value (hours) is defined as the time interval between the time the force is first applied to the sample and the time at least 30% of the width of the sample is torn.

It has also been found that the moisture vapor transmission rate (breathability or permeability) of the elastomeric material 124 is very important in reducing the incidence of vapor urticaria and other problems associated with high temperature and humidity conditions during the wearing of disposable products. The elastomeric material 124 has a direct impact on the moisture vapor transmission rate (i.e., breathability) of the disposable products. It is preferred that the elastomeric material 124 have a relatively high opening ratio (holes) that provides a high moisture vapor transmission rate or high breathability for the disposable products.

In a preferred embodiment, the elastomeric material 124 is in the form of a perforated (or apertured) film having an opening ratio (or aperture) of at least about 8%, preferably at least about 15%. The opening ratio OR (%) is defined by the following expression:

OR = (OA / TA) x 100 (%) --(2) where

- OA is the total area of open parts (or holes) in the perforated foil, and

TA is the total area of the perforated foil.

In an alternative preferred embodiment, the elastomeric material 124 is in the form of a mule having an opening ratio of at least about 30%, preferably at least about 40%, and even more preferably at least about 50%.

In the preferred embodiment shown in Fig. 1, the elastomeric mat 124 has a plurality of first strands 125 and a plurality of second strands 127. The plurality of first strands 125 intersect the plurality of second strands 127 at nodes 130 at a predetermined angle α (alpha), forming a web-like, open structure with a plurality of apertures 132. Each aperture 132 is defined by at least two adjacent strands and at least two adjacent second strands, such that the apertures 132 are substantially rectangular in shape. Other arrangements of apertures 132 may also be provided, such as parallelograms, squares, or circular arc segments. The first and second strands 125 and 127 are preferably substantially straight and

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Φ Φ are substantially parallel to each other. The first strands 125 preferably intersect the second strands 127 at nodes 130 such that the angle α is about 90 degrees. The first and second strands 125 and 127 are preferably connected or tied at nodes 90.

A preferred elastomeric mul 125 is manufactured by Conwed Plastics Company under the designation X02414. This material has about 12 elastic strands per inch (2.54 cm) in the B-pattern direction (i.e., first strands 125) and about 7 elastic strands per inch (2.54 cm) in the D-pattern direction (i.e., second strands 127). This elastomeric mul 124 has an OR of about 50% to about 60%. This elastomeric mul 124 also has an RFH12H of about 19.7 grams/cm to about 25.6 grams/cm, an FCEF100% of about 68.9 grams/cm, an FCEF200% of about 94.5 grams/cm, an SCRF50% of about 33.4 grams/cm, an EB of at least about 800%, and a TR of at least 24 hours.

In the embodiment shown in Fig. 1, the elastic member 70 includes first and second cover layers 122 and 126, and an elastomeric material 124 disposed in the first and second cover layers 122 and 126. The first cover layer 122 has an inner surface 142 and an outer surface 144. The inner surface 142 of the first cover layer 122 is the surface facing the elastomeric material 124. The second cover layer 126 also has an inner surface 146 and an outer surface 148. The inner surface 146 of the second cover layer 126 is the surface facing the elastomeric material 124. The elastomeric material 124 also has two planar surfaces, a first surface 150 and a second surface 152, each of which is substantially parallel to the planes of the first and second cover layers 122 and 126. The first surface 150 is that planar surface of the elastomeric material 124 that is most closely adjacent to the inner surface 142 of the first cover layer 122. The second surface 152 is that planar surface of the elastomeric material 124 that is most closely adjacent to the inner surface 146 of the second cover layer 126.

• · * · ·* •

• · φ • · φ · • · φ ·· «

Because the elastic member 70 will be subjected to mechanical stretching before and during use, the first and second cover layers 122 and 126 preferably have a relatively high elongation at break and are more preferably extensible or extensible, more preferably tensile (but not necessarily elastomeric), without undue and preferably without any tearing or tearing. Further, the first and second cover layers 122 and 126 are preferably conformable, soft-feeling, and non-irritating to the wearer's skin, and provide the product with the feel and comfort of a fabric member. Suitable materials for the first and second cover layers 122 and 126 can be made from a wide range of materials such as plastic films, apertured plastic films, woven or nonwoven structures of natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polyolefins, polyamides, polyester, polyethylene, or polypropylene fibers), or combinations of natural and/or synthetic fibers, or coated woven or nonwoven structures.

Preferably, each of the first and second cover layers 122 and 126 is an identical, reinforced nonwoven material. An exemplary nonwoven material is manufactured by FiberWeb Company under the designation Sofpan 200. This material has a basis weight of 25 g/m ² before reinforcement and a basis weight of 63 g/m ² after reinforcement. As used herein, basis weight is the weight of one square meter of a planar structure material. Alternatively, highly stretchable nonwoven materials may be used. Alternatively, the first and second cover layers 122 and 126 need not be the same materials as long as the desired performance requirements such as elastic performance, softness, flexibility, breathability and durability are met. As used herein, the term reinforced nonwoven material means a nonwoven material that has been gathered or constricted under mechanical tension in the D direction of the structure, such that « ·· ·· ·« · · · · » . » · · • » · · · · • · · « e *·· ·· ·· ·· ·Ι» > · · « using heat, alternative materials can elongate in the structural direction D under low forces.

Fig. 2 shows a partial enlarged side view in direction B of the laminate structure 120 (i.e., elastic member 70).

It has been found that when the laminate 120 is bonded or otherwise secured so as to form lateral secured zones A, such laminate 120 is both highly elastic and substantially free from delamination and creep, while providing very good performance characteristics in all required performance categories, without any compromise (or compromise) in any desired performance characteristic. The lateral securing is preferably accomplished by lateral bonding using adhesive droplets to secure the elastomeric material 124 between the cover layers 122 and 126 as part of the lamination process. The lateral securing may alternatively be accomplished by sewing, ultrasonically bonded closure, needling, gluing processes, or any other means known to one skilled in the art. Another alternative is to laterally secure the layers of the laminate structure after the lamination of their respective elastomeric and cover components.

Preferably, the laminate 120 can provide a very good, soft feel to the wearer and consumer. This is important because consumers value softness. In traditional laminates, attempts to eliminate creep have often required an unacceptable reduction in softness, often accompanied by a reduction in their actuation ability. This is because these previous attempts (which focused on the use of an additional, heat-blown adhesive, often in the overall surface finish pattern, in an attempt to strengthen the respective bonds) have failed to eliminate creep. This has resulted in an undesirable overall stiffening of the laminate overall. However, the laminates of preferred embodiments provide creep elimination without • ·

without losing the soft feel desired by the consumer and without reducing their activation ability.

Referring to Fig. 2 , a first adhesive 170 is applied to the inner surface 146 of the second cover layer 126 at locations corresponding to each of the outer edges 180 of the laminate structure 120. The first adhesive 170 may alternatively or additionally be applied to the inner surface 142 of the first cover layer 122. For ease of illustration, the description and figures relate only to application to the second cover layer 126.

This pattern creates lateral attachment zones A that substantially eliminate the delamination and creep associated with prior art laminates and that allow the laminate 120 to undergo greater stresses without creep or delamination. It has also been found that confining the first adhesive 170 to the edge surfaces 180 of the laminate structure 120 prevents the expansion of the laminate 120 from being restricted and also avoids cracking in the cover layers 122 and 126. Preferably, the first adhesive 170 is applied as a plurality of droplets 168, as shown in Fig. 2. The first adhesive 170 is preferably a flexible adhesive, with an amorphous and a crystallizable component. Such a preferred adhesive is manufactured by Findley Adhesive Company under the designation H9224.

The laminate 120 preferably includes a second adhesive 164. The second adhesive 164 is preferably applied to the second surface 152 of the elastomeric material 124, but could be applied to the first surface 150 of the material. The second adhesive 164 is preferably applied in a spiral pattern 166, thereby forming bond points 167b that are more spaced apart than if they were formed using linear spraying. Without being bound by theory, it is believed that the majority of the second adhesive 164 so sprayed aligns in the structural direction D. Accordingly, spiral spraying has been found to result in very good activation properties. As used herein, activation refers to the ability to stretch.

It has been found that spraying a layer of second adhesive 164 directly onto the second surface 152 of the elastomeric material 124 is preferable to applying the second adhesive 164 to the opposing (i.e., second) cover layer 126. This is because the second adhesive 164 tends to penetrate any residual processing agents or oils that may remain on the surface of the elastomeric material 124. Such residual materials, if left on the elastomeric material 124, can weaken the adhesive bond and the laminate structure 120 over time. For example, if the residual materials are left intact, the bonds used to form the laminate 120 may weaken over a period of time before a consumer purchases the product.

The adhesion values of the laminate 120 in the spiral adhesive areas are typically higher when the spirals 166 are applied directly to the elastomeric material 124 than to the opposing (i.e., second) cover layer 126. As used herein, the term peel strength value refers to the amount of force required to separate the two layers of cover material 122 and 126 from each other. High values here typically equate to less chance of delamination in use.

A third adhesive 160 may also be preferably applied to the inner surface 143 of the first cover layer 122. The third adhesive 160 is preferably an elastomeric adhesive. In a manner similar to that described with reference to the spiral application of the second adhesive 166, the adhesive 160 is preferably applied in a spiral spray pattern 162, thereby forming bond points 167a that are more widely spaced than if they were formed using a linear pattern.

• · · · • · ♦ · · • · · · • · · · spray. Without being bound by theory, it is believed that the majority of the adhesive 160 so sprayed aligns in the structural direction D.

The second and third adhesives 164 and 160 are preferably the same elastomeric adhesive. The preferred adhesive for use in the second and third spiral sprays of adhesive 166 and 162 is an adhesive manufactured by Findley Adhesive Company, under the designation H2120. Preferably, the addition level for each of the second and third spiral sprays, 166 and 162, is about 0.6 milligrams to about

1.8 milligrams per square centimeter, more preferably about 1.2 milligrams per square centimeter.

The elastomeric material 124 of the present invention is useful in a variety of disposable products, including sweatbands, bandages, and disposable undergarments including disposable diapers and incontinence devices. Although preferred embodiments of the present invention are described only for disposable items, including disposable pull-on diapers herein, it will be apparent to one skilled in the art that the use of the present invention is not limited to these embodiments.

Referring to Fig. 5 , the disposable component 20 of the present invention includes a (retention) assembly 41 having a front region 26; a back region 28; and a crotch region 30 between the front region 26 and the back region 28; and at least one pair of side panels 46 and 48 extending outwardly from the assembly 41 in the front region 26 or the back region 28. At least one of the side panels 46 or 48 includes an elastomeric material 124 (not shown in FIG. 5) extending laterally outwardly from the containment assembly 41. The assembly 41 includes a liquid pervious topsheet 24, a liquid impervious backsheet 22 associated with the topsheet 24, and an absorbent core 25 (not shown in FIG. 5) disposed between the topsheet 24 and the backsheet 22. The elastomeric material 124 has a retained retention force (RFH12H) of at least about 15.75 g/cm after 12 hours at 50% stretch, and may additionally have other preferred stretch properties of the elastomeric material 124 as previously described.

The at least one pair of side panels may be either a pair of front side panels 46 or a pair of back side panels 48. In a preferred embodiment, where the disposable component 20 is a pull-on disposable diaper, the at least one pair of side panels includes a pair of front side panels 46 provided in the front region 26 and a pair of back side panels 48 provided in the back region 28, and the disposable component 20 further includes seams 32, each connecting corresponding edges of the side panels 46 and 48, thereby forming two leg openings 34 and a waist opening 36.

In yet another preferred embodiment, where the disposable component 20 is a disposable strip-type diaper, at least one pair of side panels is a rear side panel 48.

Fig. 5 illustrates one preferred embodiment of a disposable component 20 of the present invention (i.e., a pull-on diaper 20). The pull-on diaper 20 includes a (retention or chassis) assembly 41 having a front region 26, a back region 28, and a crotch region 30 between the front region 26 and the back region 28. The assembly 41 includes a liquid pervious topsheet 24, a liquid impervious backsheet 22 associated with the topsheet 24, and an absorbent core 25 (not shown in FIG. 5, but shown in FIG. 6) disposed between the topsheet 24 and the backsheet 22. The pull-on diaper 20 further includes front side panels 46, each extending laterally outward from a corresponding side of the assembly 41 in the front region 26, and rear side panels 48, each extending laterally outward from a corresponding side of the assembly 41 in the back region 28. Preferably, at least one pair of the front and rear side panels 46 and 48 is elastically extensible in at least a lateral (toward side) direction. The pull-on diaper 20 further includes seam portions 66, each extending into the • · · · ·

I··· ···· sides outwardly from each of the front and rear side panels 46 and 48; and tear opening tabs 31, each extending laterally outwardly from the seam portions 66. Other preferred examples of the pull-on diaper 20 are described in U.S. Patent No. 5,569,234 (Buell et al.) issued October 29, 1996.

Preferably, at least one, more preferably both, pairs of front and rear side panels 46 and 48 are elastically extensible. As used herein, the term extensible refers to materials that can be stretched in at least one direction to some extent without undue rupture. The terms elasticity and elastically extensible refer to extensible materials that have the ability to return to approximately their original dimensions after the force that stretched the material is removed. As used herein, any material or part described as extensible may also be elastically extensible unless otherwise stated. The expandable side panels 46 and/or 48 provide a more comfortable and snug fit by initially conforming the diaper to the wearer and maintaining this fit throughout wear, long after the diaper has become filled with exudates, because the side panels 46 and/or 48 allow the sides of the diaper to expand and contract.

In a preferred embodiment, the front and rear side panels 46 and 48 are elastically expandable only in the lateral direction. In an alternative embodiment, the front and rear side panels 46 and 48 are elastically expandable in both the lateral and longitudinal directions.

The front and back side panels 46 and 48 form a continuous waistband 58 and a portion of the containment assembly 41 around the waist opening 36. In both the front region 26 and the back region 28, elasticized waistbands 50 are preferably provided. The pull-on diaper 20 additionally includes elasticized leg features 52.

• · · · · * Σ .·.··;.....

········ ··· ··· ··

The continuous belt 38 functions to dynamically generate seating forces in the pull-on diaper 20 when placed on the wearer, to maintain the pull-on diaper 20 on the wearer even when filled with body exudates and thus to maintain the absorbent core 25 in close proximity to the wearer, and to distribute forces dynamically generated during wear around the waist, thereby providing additional support for the absorbent core 25, without binding or bunching it.

The front and back side panels 46 and 48 may be formed from unitary portions of the pull-on diaper 20 (i.e., they are not separate engaging or manipulative elements attached to the pull-on diaper 20, but rather are formed from and are extensions of one or more different layers of the pull-on diaper). In a preferred embodiment, each of the front and back side panels 46 and 48 is an extended portion of the absorbent assembly 41 (shown more clearly in FIG. 6). The front and back side panels 46 and 48 preferably include at least one unitary portion or continuous sheet material (e.g., nonwoven material 23 in FIG. 7) that forms a portion of the assembly 41 and extends continuously into the front side panels 46 and the back side panels 48.

In preferred embodiments, each of the seam portions 66 is a continuum of the corresponding front side portions 46 and rear side portions 48, or at least one of the component parts used herein, or any combination thereof. Preferably, each of the tear-open tabs 31 is also a continuum of the corresponding seam portion 66, or at least one of the component parts used herein, or any combination thereof.

Alternatively, the front and rear side panels 46 and 48 may be separate parts (not shown in the figures) that do not have any unitary element that forms part of the retaining assembly 41. The front and rear side panels 46 and 48 are formed by • · • . · ; · · · · «··« ···· ··· ··* ·· *· joining these separate parts to the side edges of the assembly £1.

The pull-on diaper 20 further includes seams 32, each connecting corresponding edges of the front and back side panels 46 and 48, thereby forming two leg openings 34 and a waist opening 36. The front and back side panels 46 and 48 are joined by a seam, more preferably seam portions 66, in an overlapping manner and form an overlapping seam assembly. Alternatively, the front and back side panels 46 and 48 may be joined by a seam, but in a butt seam manner (not shown in the figures). The joining of the seams 32 may be accomplished by any suitable means known in the art, suitable for the particular materials used in the front and back side panels 46 and 48. Thus, suitable techniques may include ultrasonic bonding, heat bonding, pressure bonding, adhesive or cohesive bonding, sewing bonding, autogenous bonding, and the like. The seam portions 66 are joined by a predetermined pattern of heat/pressure or ultrasonic welds that will withstand the forces and stresses on the diaper 20 during wear.

Fig. 6 is a partially cutaway, plan view of the pull-on diaper 20 in its flattened, unstretched condition (i.e., with the elastic-induced contraction material pulled outward, except for the side panels 46 and 48, which are left in their relaxed condition), with the topsheet 24 facing the wearer, before the side panels 46 and 48 are joined together by seams 32. The pull-on diaper 20 has a front region 26, a back region 28 opposite the front region 26, and a crotch region 30 located between the front region 26 and the back region 28, and a perimeter defined by the outer perimeter or edges of the pull-on diaper 20, in which the side edges are designated 150 and the end edges or waist edges are designated 152. The topsheet 24 has a body-facing surface of the pull-on diaper 20 that is positioned when worn at The backsheet 26 has an outward facing surface of the pull-on diaper 20 that is positioned away from the wearer's body when worn. The pull-on diaper 20 includes a liquid-permeable topsheet 24, a liquid-impermeable backsheet 26 associated with the topsheet 24, and an absorbent core 25 disposed between the topsheet 24 and the backsheet 26. The pull-on diaper 20 further includes front and back side panels 46 and 48 extending laterally outwardly from the assembly 41, elasticized leg cuffs 52, and elasticized waist bands 50. The topsheet 24 and the backsheet 26 have overall length and width dimensions greater than those of the absorbent core 25. The topsheet and the backsheet 26 extend beyond the edges of the absorbent core 25 to form the perimeter of the diaper 20. The liquid-impermeable backsheet 26 preferably includes a liquid-impermeable plastic film 68 that is bonded to the nonwoven material 23 of the backsheet.

Although the topsheet 24, backsheet 26 and absorbent core may be assembled in a variety of configurations well known in the art, exemplary containment assembly configurations are generally described in U.S. Patent No. 3,860,003 (Kenneth B. Buell), entitled Pull-On Side Panels for Disposable Diapers, issued January 14, 1975; and in U.S. Patent No. 5,151,092 (Kenneth B. Buell), entitled Absorbent Article with Dynamic Elastic Waistband with Pre-arranged, Flexible Bending Hinge, issued September 29, 1992.

The pull-on diaper 20 also has two central axes, a longitudinal central axis 100 and a transverse central axis 110. The term longitudinal, as used herein, refers to a line, axis, or direction in the plane of the pull-on diaper 20 that is generally aligned with (i.e., approximately parallel to) a vertical plane bisecting a standing wearer into left and right halves of the body when the pull-on diaper 20 is worn. The terms transverse and lateral (sideways) as used herein are interchangeable and refer to • · · > ·

I · · · · · · • * * • * · • · · · » * · lines, axes, or directions that lie within the plane of a given pull-on diaper 20 that is generally perpendicular to the longitudinal direction (which divides the wearer into left and right halves of the body). The pull-on diaper 20 and its component materials also have a body-facing surface, facing the wearer's skin when worn, and an outward-facing surface, opposite the body-facing surface.

Fig. 7 is a cross-sectional view of a preferred embodiment taken along section line 7-7 of Fig. 6. The pull-on diaper 20 includes a containment assembly, or chassis, 41 that includes a liquid-permeable topsheet 24, a liquid-impermeable backsheet 22 associated with the topsheet 24, and an absorbent core 25 disposed between the topsheet 24 and the backsheet 22. The pull-on diaper 20 further includes front and rear side panels 46 and 48 extending laterally outwardly from the assembly 41, and elasticized leg cuffs 52.

The structure of the front side panel is similar to the assembly. File 41

Although Fig. 7 shows only 4-6, the rear side panels 48 preferably further include an acquisition/distribution layer 82 and/or an acquisition/distribution core 84 between the topsheet 24 and the absorbent core 25. Each of the front side panels 46 is formed by laminating the elongated portion 72 of the barrier flap 56, the elastic member 70, and the nonwoven material 74 of the backsheet.

The absorbent core 25 can be any absorbent portion that is generally compressible, conformable, non-irritating to the wearer's skin, and capable of absorbing and retaining fluids such as urine and certain other body exudates. The absorbent core 25 can be manufactured in a wide variety of sizes and shapes (e.g., rectangular, hourglass, T-shaped, asymmetrical, etc.) and from a wide variety of fluid-absorbing materials commonly used in disposable diapers and other absorbent articles, such as • · comminuted wood pulp, which is generally referred to as airlaid. Examples of other suitable absorbent materials include crepe cellulose wadding, meltblown polymers including coform, chemically stiffened, modified or crosslinked cellulose-based fibers, tissue-containing webs and laminates thereof, absorbent foams and absorbent sponges, superabsorbent polymers, absorbent gelling materials, or any other equivalent material or combination of these materials.

The arrangement and construction of the absorbent core 25 may vary (for example, the absorbent core may have zones of varying tangibility or thickness, a hydrophilic gradient, a superabsorbent gradient, or acquisition zones of lower average density and lower basis weight; or may include one or more layers or structures). However, the overall absorbent capacity of the absorbent core 25 should be compatible with the designed load and intended use of the diaper 20. Furthermore, the size and absorbent capacity of the absorbent core 25 may also vary to accommodate a range of wearers, from infants to adults.

The preferred embodiment of the diaper 20 has an asymmetrical, hourglass-shaped, modified absorbent core 25 with tabs in the front and back regions 26 and 28. Other exemplary absorbent structures that have achieved widespread acceptance and commercial success are described in U.S. Patent No. 6,610,678, entitled High Density Absorbent Structures, issued to Weisman and Goldman on September 9, 1986; U.S. Patent No. 4,673,402, entitled Absorbent Products with Double Layered Cores, issued to Weisman et al. on June 16, 1987; U.S. Patent No. 4,888,231, entitled Absorbent Core with Dust Layer, issued to Angstadt on December 19, 1989; and in U.S. Patent No. 4,834,735, entitled Absorbent Components with • · φ · • ·

φ · * ♦ •φ*» φ··· »·· high density, having lower density and lower basis weight receiving zones, granted to Alemany et al. on May 30, 1989.

The containment assembly, or chassis, 41 further includes a chemically stiffened fiber acquisition/distribution core 84 disposed over the absorbent core 25 to form a dual core system. Preferred dual core systems are described in U.S. Patent No. 5,234,423, entitled Absorbent Article with Elastic Waistband and Enhanced Absorbency, issued to Alemany et al. on August 10, 1993; and in U.S. Patent No. 5,147,345, entitled High Performance Absorbent Articles for Incontinence Control, issued to Young, LaVon and Taylor on September 15, 1992. In a preferred embodiment, the acquisition/distribution core 84 comprises a chemically treated, stiffened cellulosic fibrous material, available from Weyerhaeuser Co., USA, under the trade name CMC.

More preferably, the assembly 41 further includes an acquisition/distribution layer 82 between the topsheet 24 and the acquisition/distribution core 84, as shown in Fig. 7. The acquisition/distribution layer 82 is provided to help reduce the tendency for the surface of the topsheet 24 to become wet. The acquisition/distribution layer 82 preferably includes a carded, resin-bonded, highly lightweight nonwoven, such as that available under the designation FT-6860 from Polymer Group, Inc., North America (Landisiville, New Jersey, USA), which is made of 6 dtex polyethylene terephthalate fibers and has a basis weight of about 43 g/m ² .

The topsheet 24 is preferably conformable, soft-feeling, and non-irritating to the wearer's skin. Furthermore, the topsheet 24 is permeable to liquids (e.g., urine), allowing them to readily penetrate its thickness. Suitable topsheet 24 can be made from a wide variety of materials such as:

999 9 9999 ·· 99

9 9 * · · ’ ·· «

9· ·♦ woven and nonwoven materials, polymeric materials such as apertured, formed thermoplastic films, hydroformed thermoplastic apertured plastic films, films, porous foams, reticulated (net-like) foams, reticulated thermoplastic films, thermoplastic scrims. Suitable woven nonwoven materials may be composed of natural fibers (e.g., wood or cotton (e.g., polymer fibers), synthetic fibers such as polyester, polypropylene, or polyethylene fibers) or combinations of natural and synthetic fibers. Preferably, the topsheet 24 is made of a hydrophobic (water-repellent) material to isolate the wearer's skin from liquids that have passed through the topsheet 24 and are retained in the absorbent core 25 (i.e., to prevent rewetting). If the topsheet 24 is made of a hydrophobic material, at least its upper surface is treated to be hydrophilic so that fluids will pass through the topsheet more quickly. This reduces the likelihood that body fluids will run off the topsheet 24 rather than being drawn into and absorbed by the absorbent core 25. The topsheet 24 can be made hydrophilic by treating it with a surfactant. Suitable methods for treating the topsheet 24 with this surfactant include spraying the material with the surfactant and dipping the material into it. This treatment and hydrophilicity are discussed in more detail in U.S. Patent No. 4,988,344, entitled

Absorbent Articles with Multiple Absorbent Layers, issued to Reising et al. on January 29, 1991; and U.S. Patent No. 4,988,345, entitled Absorbent Articles with Rapidly Acquiring Absorbent Cores, issued to Reising on January 29, 1991.

In preferred embodiments, the topsheet 24 is a nonwoven structure that can provide a reduced tendency for surface moisture and subsequently facilitate, upon wetting, • · φ φ ·

ΦΦΦ * • · φφφφ φφφφ keeping urine absorbed by the core 25 away from the wearer's skin. One preferred topsheet material is a thermally bonded carded structure available under the designation P-8 from Fiberweb North America, Inc. (Simpsonville, South Carolina, USA). Another preferred topsheet material is available under the designation S-2355 from Havix Co., Japan. This material is a double-layer composite material made from two types of synthetic, surfactant-treated, bicomponent fibers using carding and air flow techniques. Yet another preferred topsheet material is a thermally bonded carded structure available under the designation Profleece Style 040018007 from Amoco Fabrics, Inc. (Gronau, Germany).

Yet another preferred topsheet 24 comprises an apertured formed sheet. Aperture formed sheets are preferred for the topsheet 24 because they are permeable to body exudates and yet nonabsorbent and have a reduced tendency to allow fluids to pass back through and rewet the wearer's skin. Thus, the body-contacting surface of the formed sheet remains dry, thereby reducing body soiling and creating a more comfortable feel for the wearer. Suitable formed sheets are described in U.S. Patent No. 3,929,135, issued to Thompson on December 30, 1975; entitled Absorbent Structures Having Narrowed Capillaries; in U.S. Patent No. 4,324,246, issued to Mullane et al. on April 13, 1982, entitled Disposable Absorbent Article Having a Spill-Resistant Topsheet; in U.S. Patent No. 4,342,314, issued to Radel et al. on August 3, 1982, entitled Flexible Plastic Structure Exhibiting Fiber-Like Properties; in U.S. Patent No. 4,463,045, issued to Ahr et al. on July 31, 1984, entitled Macroscopically Expanded, Three-Dimensional Plastic Structure Exhibiting a Non-Gloss Visible Surface and a Cloth-Like Tactile Feel; and in U.S. Patent No. 5,006,394, issued to Baird on April 9, 1991, entitled Multiple Polymeric Sheet.

In preferred embodiments, the backsheet 22 includes a liquid impervious sheet 68, as shown in, for example, Fig. 7. The liquid impervious sheet 68 has a body-facing surface and an outward-facing surface. The liquid impervious sheet 68 is preferably impervious to liquids (e.g., urine) and is preferably made of a thin plastic film. However, more preferably, the plastic film allows vapor to escape from the diaper 20. In a preferred embodiment, a microporous polyethylene film is used for the plastic film 68. A suitable microporous polyethylene film is manufactured by Mitsui Toatsu Chemicals, Inc., Nagoya, Japan, and is sold under the trade name Espoir No.

In a preferred embodiment, the liquid-impermeable sheet (i.e., plastic sheet 68 in FIG. 6) extends into the front, back, and crotch regions 26, 28, and 30. The plastic sheet 68 preferably has a non-uniform width, such that it forms a first portion 94 in at least a portion of the crotch region 30, and a second portion 96 in at least a portion of the front or back regions 26 and 28. The second portion 96 has a width dimension less than the width dimension of the first portion 94, such that the plastic sheet 68 does not extend into the front side panels 46 or the back side panels 48. In a preferred embodiment, the lateral (sideways) width LW of the plastic sheet 68 gradually decreases toward the waist edges 152, as shown in FIG. 6.

A suitable material for the plastic film 68 is a thermoplastic film, preferably comprising polyethylene or polypropylene, with a thickness of from about 0.012 mm to about 0.051 mm. Preferably, this plastic film has a basis weight of from about 5 grams/m ² to about 35 grams/m ² . However, it should be noted that other flexible, fluid-permeable materials may be used herein.

φφφ · impermeable materials. As used in this material, the term flexible refers to materials that are pliable and easily conform to the overall shape and contours of the human body.

The backsheet 22 further includes a nonwoven structure 23 that is bonded to the outwardly facing surface of the plastic sheet 68 to form a laminate (i.e., the backsheet 22). The nonwoven structure 23 (or backsheet nonwoven material) is disposed in the outermost portion of the diaper 20 and covers at least a portion of the outermost portion of the diaper 20. In a preferred embodiment, the nonwoven structure 23 covers substantially the entire surface of the outermost portion of the diaper 20, and the nonwoven structure may be attached to the plastic sheet 68 by any attachment means known in the art. For example, the nonwoven structure 23 may be attached to the plastic sheet 68 by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an arrangement of discrete lines, spirals, or dots of adhesive. Suitable adhesives include hot melt adhesives available from Nitta Findley Co., Ltd., Osaka, Japan, as H-2128, and hot melt adhesive available from H.B. Fuller Japan Co., Ltd., Osaka, Japan, as JM-6064.

In a preferred embodiment, the nonwoven structure 23 is a carded nonwoven structure, available, for example, from Havix Co., Ltd., Gifu, Japan, as E-2341. The nonwoven structure 23 is made of bicomponent fibers of polyethylene (PE) and polyethylene terephthalate (PET). The PE/PET material ratio is about 40/60. The PE/PET bicomponent fiber has dimensions of 2d x 51 mm. Another preferred carded nonwoven structure is available from Chisso Corp., Osaka, Japan. The nonwoven outer cover 23 is also made of bicomponent fibers of polyethylene (PE) and polyethylene terephthalate (PET). The PE/PET material ratio is about 30/70.

• ·*· ·>♦· • ·

In yet another preferred embodiment, the nonwoven structure is a nonwoven, multi-drawn structure, for example, available from Mitsui Petrochemical Industries, Ltd., Tokyo, Japan. This nonwoven structure is made of bicomponent fibers of polyethylene (PE) and polypropylene (PP). The ratio of PE/PP material is about 80/20. The bicomponent PE/PP fiber has a thickness of about 2.3d.

The backsheet 22 is preferably positioned adjacent a suitable exterior facing surface of the absorbent core 25 and is preferably attached by any attachment means known in the art. For example, the backsheet 22 may be attached to the absorbent core 25 by a uniform, continuous layer of adhesive, a patterned layer of adhesive, or an arrangement of discrete lines, spirals, or dots of adhesive. Adhesives that have been found to be satisfactory are manufactured by H. B. Fuller Company of St. Paul, Minnesota, USA, commercially available as HL-1358J. An example of a suitable attachment means comprising an open pattern of filaments of adhesive is described in U.S. Patent No. 4,573,986, entitled Disposable Undergarment Component for Containing Body Exudates, issued to Minetolo et al. on

March 4, 1986. Another suitable fastening means, multiple lines of adhesive fibers twisted into a pattern, is illustrated by the apparatus and methods shown in U.S. Patent No. 3,911,173, 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 U.S. Patent No. 4,842,666, issued to Werenicz on June 27, 1989. Alternatively, such fastening means may include heat bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other suitable means known in the art.

including spiral

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In an alternative embodiment, the absorbent core 25 is not attached to the backsheet 22 and/or the topsheet 24 to provide greater extensibility in the front waist region 26 and the back waist region 28.

The pull-on diaper 20 preferably further includes stretchable leg cuffs 52 to provide improved containment of fluids and other body exudates. The elasticized leg cuffs 52 may include several different configurations to limit leakage of body exudates in the leg regions (the leg cuff may be and is sometimes referred to as leg bands, side flaps, barrier cuffs, or elastic cuffs). U.S. Patent No. 3,860,003 describes a disposable diaper that provides a leg opening having a side flap and one or more elastic members to secure an elasticized leg cuff (sealing cuff). U.S. Patent No. 4,909,803, entitled Disposable Absorbent Article Having Elasticized Flaps, issued to Aziz et al. on March 20, 1990, describes a disposable diaper having stand-up elasticized flaps (barrier cuffs) to improve containment in the leg areas. U.S. Patent No. 4,695,278, entitled Absorbent Article with Double Cuffs, issued to Lawson on September 22, 1987, and U.S. Patent No. 4,795,454, entitled Absorbent Article Having Leakage-Resistant Double Cuffs, issued to Dragoo on January 3, 1989, describe disposable diapers having double cuffs, including a sealing cuff and a barrier cuff. U.S. Patent No. 4,704,115, entitled Disposable, Waist-Waist, Exudate Containment Garment, issued to Buell on November 3, 1987, describes a disposable diaper or incontinence garment having leak-proof, side edge drainage channels arranged to contain free fluids within the garment.

• 9 ·« *·

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9 9

9 ·*·· 9999 9

Although each elasticized leg cuff 52 may be configured to be similar to any of the leg bands, side flaps, barrier cuffs or elastic cuffs described above, it is preferred that each elasticized leg cuff 52 include inner barrier cuffs 54, each including a barrier flap 56 and a spacer 58 (as shown in FIGS. 5 and 6), as described in the aforementioned U.S. Patent No. 4,909,803. In a preferred embodiment, the elasticized leg cuff 52 additionally includes an elastic sealing cuff 62 with one or more elastic strands 64 (as shown in FIG. 6), disposed outwardly of the barrier cuff 54, as described in the aforementioned U.S. Patent Nos. 4,695,278 and 4,795,454.

The pull-on diaper 20 further preferably includes an elasticized waist feature 50 that provides improved fit and containment. The elasticized band 50 is that portion or zone of the pull-on diaper 20 that is intended to elastically expand and contract to dynamically fit the waist of the wearer. The elasticized band 50 preferably extends longitudinally outwardly from at least one of the waist edges of the absorbent core 25 and generally forms at least a portion of the trailing edge of the pull-on diaper 20. Disposable diapers preferably have two elasticized waist features 50, one located in the back region 28 and one located in the front region 26, although other pull-on diapers may be constructed with a single elasticized waist. The elasticized waistband strip 50 can be assembled in a number of different configurations, including those described in U.S. Patent No. 4,515, entitled Disposable Diapers with Elastically Retractable Waistbands, issued to Kievit et al. on May 7, 1985, and the above-referenced U.S. Patent No. 5,151,092, issued to Buell.

• »4 ·* • · >

• · » 4 4 ( » · · « •« 44

The web 50 may include materials that have been "pre-stretched" or "mechanically pre-stretched" (i.e., subjected to some degree of localized mechanical stretching pattern, in order to permanently stretch the material). These materials may be pre-stretched using deep drawing techniques known in the art. Alternatively, these materials may be pre-stretched by directing them through a system of incremental (i.e., gradual, increments) mechanical stretching, as described in U.S. Patent No. 5,330,458, entitled Absorbent Article with Elasticity Having a Mechanically Pre-Stretched Portion, issued to Buell et al. on July 19, 1994. These materials are then allowed to return to their substantially unstretched state, thus forming a zero-tension extensible material that is extensible to at least the point of initial stretch. Examples of zero-tension materials are described in U.S. 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 U.S. Patent No. 5,151,092, issued to Buell et al. on September 29, 1992.

Referring to Fig. 7, at least one of the front and rear side panels (i.e., in this embodiment, the front side panels 46) includes an elastic member 70 of the present invention. The elastic member 70 includes an elastomeric material 124 that preferably extends laterally outwardly from the assembly 41 to provide a good fit by generating an optimal retention (or retention) force in the waist region of the wearer. The elastomeric material 124 is extensible in at least one direction, preferably in a direction having a vector component in the lateral direction, to generate a retention (or retention) force that is optimal for preventing the pull-on diaper 20 from sagging, sagging, or sliding down from its location on the lower torso without causing red marks on the wearer's skin. In preferred embodiments, both the front and rear side panels 46 and 48 include the elastomeric material 124.

An elastic member 70, comprising an elastomeric material 124 (not shown in FIG. 7 ), is operably connected to at least one of the nonwoven structures 72 and 74 in the front and rear side panels 46 and 48, and allows the elastic member 70 to be extensible in at least a lateral direction. In a preferred embodiment, the elastic member 70 is operably connected to the nonwoven structures 72 and 74, attaching them to at least one, preferably both, of the nonwoven structures 72 and 74 while they are in a substantially unstretched (zero tension) state.

The elastic member 70 may be operatively connected to the nonwoven structures 72 and 74 using either an intermittent connection arrangement or a substantially continuous connection arrangement. As used herein, the term intermittently connected laminate structure means a laminate in which the layers are initially connected to each other at discrete points spaced apart, or a laminate structure in which the layers are substantially unconnected to each other at laterally spaced apart areas. Accordingly, a substantially continuous connected laminate structure means a laminate structure in which the layers are initially connected to each other substantially continuously at their interface areas. Since it is preferred that the stretchable laminate be connected across all or a significant portion of the stretchable laminate such that the non-elastic structures (i.e., the nonwoven structures 72 and 74) are stretched or pulled without causing cracking, the layers of the stretchable laminate are preferably connected in an arrangement,

Φ· ·· • · · « • # • φ φ · φφφφ ·*·* φφ »· • * · · φ · φ * φ φ φ · • φ φ · «φ ·* which maintains, after the operation of progressive mechanical stretching, all the layers of this stretchable laminate in relatively close adhesion to each other; the components of the elastic member and the other layers of the stretchable laminate are substantially continuously bonded together by the use of an adhesive. In a particularly preferred embodiment, the selected adhesive is applied in a spiral pattern (such as that shown in U.S. Patent No. 3,911,173 (Sprague Jr.) and in U.S. Patent No. 4,842,555 (Werenicz), at a basis weight of about 0.00116 g/cm ² . The spirals have a width of about

1.9 cm and are either placed next to each other or slightly overlapped (less than 2 mm). The adhesive is preferably an adhesive such as that available from Findley Adhesives, under the designation H2120. Alternatively, the elastic member portion and any other components of the stretch laminates may be joined intermittently or continuously to each other, using thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other method known in the art.

After the elastic member 70 is operably attached to at least one of the nonwoven structures 72 and 74, at least a portion of the resulting, composite, stretchable laminate is then subjected to mechanical stretching sufficient to permanently stretch the inelastic components, which are, for example, the nonwoven structures 72 and 74. The composite stretchable laminate is then allowed to return to its substantially unstretched state. At least one pair, preferably both the front and rear side panels, 46 and 48, are thus formed into zero-tension stretchable laminates (alternatively, the elastic member 70 could be operably attached in a tensioned state and then subjected to mechanical stretching, although this is not preferred as a zero-tension stretchable laminate). As used herein, the term

AA AA « · A · • A And » · And · «*·· AAA* • · ·· **A AA ·· A A A · • A «Α«· A A A · · A A and A « A A A AAA AAA AA AA 39 Zero-stretch expandable laminates regards laminates

composed of at least two layers of material that are attached to each other along at least a portion of their co-extending surfaces while in a substantially unstretched (zero-stress) state; one of the layers comprises a material that is extensible and elastomeric (i.e., will return substantially to its unstretched dimensions upon release of the applied force), and a second layer that is extensible (but not necessarily elastomeric) such that upon extension it will be, at least to some degree, permanently stretched such that upon release of the applied tensile force it will not fully return to its original, undeformed configuration. The resulting extensible laminate is thereby rendered elastically extensible, at least to the point of initial extension, in the direction of initial extension. Particularly preferred methods and apparatus used for making extensible laminates employ interlocking corrugated rollers to mechanically extend the components. In particular, preferred apparatus and methods are described in U.S. Patent No. 5,167,897, issued to Weber et al. on December 1, 1992; U.S. Patent No. 5,156,793, issued to Buell et al. on October 20, 1990; and U.S. Patent No. 5,143,679, issued to Weber et al. on September 1, 1992. It should be noted that Japanese applications equivalent to these U.S. patents have been published in Japanese under Nos. H6-505681, H6-505408, and H6-505446, respectively.

The elastic member 70 is preferably attached to, more preferably directly, respective edges 78 of the liquid-impermeable film (i.e., the plastic film 68) by means of an adhesive 76, as shown in Fig. 7. The adhesive 76 is preferably applied as a reinforced bead. In preferred embodiments, the adhesive 76 is a flexible adhesive with an amorphous and a crystallizable component. Such a preferred adhesive is manufactured by Findley Adhesive Company under the designation H9224.

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Alternatively, the elastic member 70 may be attached to the respective edges 78 of the plastic sheet 68 by any other attachment means known in the art, including thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or combinations of these attachment means.

In a preferred embodiment, for example, shown in Fig. 6, the elastic member 70 is attached to a second portion 96 that has a width dimension less than the width dimension of the first portion 94. Preferably, the elastic member 70 is attached to respective edges 78 of the plastic film 68 at the outwardly facing surface 77, as shown in Fig. 7. In an alternative embodiment, the elastic member 70 may be attached to respective edges 78 of the plastic film 68 at the body-facing surface 79 (not shown in the figures).

It is understood that the examples and embodiments described herein are for illustrative purposes only, and that a person skilled in the art will suggest various modifications or changes without departing from the scope of the present invention.

Claims (20)

PATENT CLAIMS An elastic member (70) elastically extensible in at least one direction, comprising: an elastomeric material (124) having a first surface (150) and a second surface (152) opposite to the first surface, and a first cover layer (122) that is attached to the first surface of the elastomeric material; characterized in that the elastomeric material has a retention force of at least about 15.75 g / cm 2 after 12 hours at 50% elongation. 2. The elastic member of claim 1, further comprising a second cover layer (126) attached to the second surface of the elastomeric material. 3. The elastic member of claim 1, wherein the elastomeric material is in the form of a scrim, apertured film or strand. 4. The elastic member of claim 1, wherein the elastomeric material has a second cycle recovery force at 50% elongation of from about 15.75 g / cm to about 51.1 g / cm. 5. The elastic member of claim 1, wherein the elastomeric material has a first cycle elongation strength at 100% elongation of at least about 39.4 g / cm and a first cycle elongation strength at 200% elongation between about 63.0 g / cm and about 126.0 g / cm. 6. The elastic member of claim 1, wherein the first cover layer is a nonwoven web. 7. A disposable item of laundry comprising: a containment assembly (41) having a front region (26), a back region (28) and a crotch region (30) between said front and back regions, the assembly comprising a liquid pervious topsheet (24), a liquid impervious backsheet (22) associated with a topsheet, and an absorbent core (25) disposed between the topsheet and the backsheet, at least one pair of side panels (46, 48) extending outwardly from the containment assembly in the front or rear region, and at least one of the side panels comprises an elastomeric material extending laterally outward from the containment assembly; characterized in that the elastomeric material has a retention force of at least about 15.75 g / cm 2 after 12 hours at 50% elongation. 8. The disposable component of claim 7, wherein the at least one pair of side panels is a pair of front side panels secured in the front region, or is a pair of rear side panels secured in the rear region. 9. The elastic member of claim 7, wherein at least one of the side panels is formed from a zero-tension extensible laminate. The disposable component of claim 7, wherein the at least one pair of side panels includes a pair of front side panels secured in the front region and a pair of rear side panels secured in the rear region, and the disposable component further includes seams that each seam each. «·» »· · · φ · ·· join the corresponding edges of the side panels to form two leg openings and a waist opening. 11. The disposable component of claim 7, wherein the elastomeric material has a second cycle recovery force at 50% elongation of from about 15.75 g / cm to about 15.75 g / cm. 51.1 g / cm. 12. The disposable component of claim 7, wherein the elastomeric material has a first cycle elongation strength at 100% elongation, of at least about 39.4 g / cm, and a first cycle elongation strength at 200% elongation. between 63.0 g / cm and about 126.0 g / cm. 13. The disposable component of claim 7, wherein the elastomeric material has an elongation at break of at least about 600%. 14. The disposable component of claim 7, wherein the elastomeric material is an elastomeric scrim. 15. The disposable component of claim 7, wherein the elastomeric material is a perforated film. 16. The disposable component of claim 7, wherein the elastomeric scrim has a tear resistance of at least about 16 hours. 17. The disposable component of claim 7, wherein at least one of the front and rear side panels comprises a continuous sheet material that extends continuously from the containment assembly. The disposable component of claim 17, wherein the continuous sheet material is a nonwoven backsheet material. 19. The disposable component of claim 7, wherein the elastomeric material is attached to an edge of the containment assembly. The disposable component of claim 10, wherein the corresponding front and rear side panels are stitched in an overlapping manner to form a structure with an overlapping seam.